Calibration standards for major greenhouse gases and carbon monoxide: status and challenges.

NASA Astrophysics Data System (ADS)

Zellweger, Christoph; Mohn, Joachim; Wyss, Simon A.; Brewer, Paul; Mace, Tatiana; Nieuwenkamp, Gerard; Pearce-Hill, Ruth; Tarhan, Tanil; Walden, Jari; Emmenegger, Lukas

2017-04-01

Human influence on increasing greenhouse gas mole fractions in the atmosphere and effects on positive radiative forcing as well as observed global warming and sea level rise are well accepted [1]. For interpretation of global or continental scale greenhouse gas data, obtained from different laboratories, measurement results have to coincide within compatibility goals set by the World Meteorological Organization (WMO) [2]. Despite significant advances in measurement techniques [3], WMO compatibility goals are regularly missed, shown by round-robin experiments of standard gases and comparisons of field samples or parallel measurements. Therefore, precise and accurate calibration using standards with good long-term stability is needed to reduce uncertainties of atmospheric measurements. This is addressed by the WMO Global Atmosphere Watch Programme (GAW), where Central Calibration Laboratories (CCLs) maintain calibration scales to ensure consistency of measurements within the network to primary reference materials. Furthermore, participating GAW laboratories are supported by World Calibration Centres (WCCs) performing audits and organizing round-robin comparisons. The CCL participates regularly in comparisons with independent primary scales to assure traceability of established primary reference materials to fundamental quantities (SI) [e.g. 4]. Within the European Metrology Research Programme (EMRP) ENV52 project "Metrology for high-impact greenhouse gases" (HIGHGAS), static and dynamic primary reference gas mixtures for ambient levels of CO2, CH4, N2O and CO in air were prepared by different National Metrology Institutes (NMIs). In order to progress beyond the state of the art, research focused on improving passivation chemistry, quantification of target impurities in the air matrix, and determining the isotopic composition. These primary reference gas mixtures were compared in a round robin experiment against standards calibrated against reference gases currently used by the GAW community. We will show results of the comparison of the HIGHGAS and the WMO reference standards, and put this into the context of the WMO/GAW quality management framework. [1] IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp. [2] WMO: 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques (GGMT-2015), La Jolla, CA, USA, 13-17 September 2015, GAW Report No. 229, World Meteorological Organization, Geneva, Switzerland, 2016. [3] Zellweger, C., Emmenegger, L., Firdaus, M., Hatakka, J., Heimann, M., Kozlova, E., Spain, T. G., Steinbacher, M., van der Schoot, M. V., and Buchmann, B.: Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations, Atmos. Meas. Tech., 9, 4737-4757, 2016. [4] Flores, E., Viallon, J., Choteau, T., Moussay, P., Wielgosz, R., Kang, N., Kim, B. M., Zalewska, E., van der Veen, A., Konopelko, L., Wu, H., Han, Q., Rhoderick, G., Guenther, F. R., Watanabe, T., Shimosaka, T., Kato, K., Hall, B., and Brewer, P.: International comparison CCQM-K82: methane in air at ambient level (1800 to 2200) nmol/mol, Metrologia, 52, 08001, 2015.

Age of the granitic magmatism and the W-Mo mineralization in skarns of the Seridó belt (NE Brazil) based on zircon U-Pb (SHRIMP) and molybdenite Re-Os dating

NASA Astrophysics Data System (ADS)

Hollanda, Maria Helena B. M. de; Souza Neto, João A.; Archanjo, Carlos J.; Stein, Holly; Maia, Ana C. S.

2017-11-01

Over five hundred W-Mo skarns have been reported in the Neoproterozoic Seridó belt in the northeastern Brazil. The origin of these mineralizations has been attributed to metasomatic reactions occuring after the infiltration of hydrothermal fluids that are mostly derived from the plutonic magmatic activity that ranged between approximately 600 and 525 Ma. Here we date molybdenite using N-TIMS on Re-Os analysis of three major scheelite deposits (Brejuí, Bonfim and Bodó) hosted in the skarn horizons of the metasedimentary sequence. Molybdenite is an integral part of the mineralizations that include scheelite in skarns and, in the Bonfim deposit, gold concentrate in late brittle faults. The Re-Os ages are 554 ± 2 Ma (Brejuí), 524 ± 2 Ma (Bonfim) and 510 ± 2 Ma (Bodó). The age of the Brejuí molybdenite, however, appears to be anomalous based on the local geology of the deposit, which is located next to the contact of a batholith dated ca. 575 Ma. In turn, the Bonfim molybdenite yields similar ages in replicated samples with variable high Re contents. New U-Pb SHRIMP ages of four biotite (leuco)granite plutons vary from 577 ± 5 Ma to 526 ± 8 Ma, which overlap with molybdenite crystallization. These results indicate a close connection between the W-Mo mineralizations and the plutonic activity that intruded the belt after the peak HT/LP metamorphism. The latest pulses of felsic magmatism, which were contemporaneous with the emplacement of Be-Ta-Nb-Li pegmatites, therefore constitute a potential guide in the Seridó belt for prospective W-Mo deposits.

Toward seamless weather-climate and environmental prediction

NASA Astrophysics Data System (ADS)

Brunet, Gilbert

2016-04-01

Over the last decade or so, predicting the weather, climate and atmospheric composition has emerged as one of the most important areas of scientific endeavor. This is partly because the remarkable increase in skill of current weather forecasts has made society more and more dependent on them day to day for a whole range of decision making. And it is partly because climate change is now widely accepted and the realization is growing rapidly that it will affect every person in the world profoundly, either directly or indirectly. One of the important endeavors of our societies is to remain at the cutting-edge of modelling and predicting the evolution of the fully coupled environmental system: atmosphere (weather and composition), oceans, land surface (physical and biological), and cryosphere. This effort will provide an increasingly accurate and reliable service across all the socio-economic sectors that are vulnerable to the effects of adverse weather and climatic conditions, whether now or in the future. This emerging challenge was at the center of the World Weather Open Science Conference (Montreal, 2014).The outcomes of the conference are described in the World Meteorological Organization (WMO) book: Seamless Prediction of the Earth System: from Minutes to Months, (G. Brunet, S. Jones, P. Ruti Eds., WMO-No. 1156, 2015). It is freely available on line at the WMO website. We will discuss some of the outcomes of the conference for the WMO World Weather Research Programme (WWRP) and Global Atmospheric Watch (GAW) long term goals and provide examples of seamless modelling and prediction across a range of timescales at convective and sub-kilometer scales for regional coupled forecasting applications at Environment and Climate Change Canada (ECCC).

Is Ozone Going Up Now?

NASA Astrophysics Data System (ADS)

Steinbrecht, W.; Froidevaux, L.; Davis, S. M.; Degenstein, D. A.; Wild, J.; Roth, C.; Kaempfer, N.; Leblanc, T.; Godin-Beekmann, S.; Vigouroux, C.; Swart, D. P. J.; Querel, R.; Harris, N.; Nedoluha, G. E.

2016-12-01

The last WMO ozone assessment (WMO, 2014) concluded that observations show significant ozone increase, 3% per decade (±2% per decade, 2σ), in the upper stratosphere since 2000. At other levels, or for total ozone, increases were not found or not significant. Overall, this is consistent with expectations from model simulations, (e.g. CCMVal2, Eyring et al., 2010). These simulations indicate that declining chlorine levels and stratospheric cooling due to CO2 increase should contribute roughly equal parts to ozone increase in the upper stratosphere. Shortly after the assessment, results from the SI2N initiative (Harris et al., 2015) confirmed increasing ozone in the upper stratosphere. However, the SI2N results indicated smaller increases (+1.5% per decade) than the WMO assessment, and substantially larger uncertainties (±5% per decade, 2σ). Differences can be attributed to time period, 1998 to 2012, compared to 2000 to 2013/14 for the assessment, and to larger assumed instrumental drift uncertainties, 6% per decade, (only 1 to 2% per decade in WMO 2014, see also Hubert et al., 2016). Here, we explore how additional ground-based and satellite data since 2013, as well as new and improved records, affect ozone trends and uncertainties. The focus will be on ozone in the upper stratosphere, because this is the region where the earliest signs of beginning ozone recovery are expected. ReferencesEyring, V., et al.: Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models, Atmos. Chem. Phys., 10, 9451-9472, doi:10.5194/acp-10-9451-2010, 2010. Harris, N. R. P., et al.: Past changes in the vertical distribution of ozone - Part 3: Analysis and interpretation of trends, Atmos. Chem. Phys., 15, 9965-9982, doi:10.5194/acp-15-9965-2015, 2015. Hubert, D., et al.: Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records, Atmos. Meas. Tech., 9, 2497-2534, doi:10.5194/amt-9-2497-2016, 2016. WMO 2014: Pawson, S., Steinbrecht, W. et al.: Update on global ozone: Past, present, and future, Chapter 2 in: Scientific Assessment of Ozone Depletion: 2014, Global Ozone Research and Monitoring Project - Report No. 55, World Meteorological Organization, Geneva, Switzerland, 2014.

Megacities and Large Urban Complexes - WMO Role in Addressing Challenges and Opportunities

NASA Astrophysics Data System (ADS)

Terblanche, Deon; Jalkanen, Liisa

2013-04-01

Megacities and Large Urban Complexes - WMO Role in Addressing Challenges and Opportunities Deon E. Terblanche and Liisa Jalkanen dterblanche@wmo.int ljalkanen@wmo.int World Meteorological Organization, Geneva, Switzerland The 21st Century could amongst others, become known as the century in which our species has evolved from Homo sapiens to Homo urbanus. By now the urban population has surpassed the rural population and the rate of urbanization will continue at such a pace that by 2050 urban dwellers could outnumber their rural counterpart by more than two to one. Most of this growth in urban population will occur in developing countries and along coastal areas. Urbanization is to a large extent the outcome of humans seeking a better life through improved opportunities presented by high-density communities. Megacities and large urban complexes provide more job opportunities and social structures, better transport and communication links and a relative abundance of physical goods and services when compared to most rural areas. Unfortunately these urban complexes also present numerous social and environmental challenges. Urban areas differ from their surroundings by morphology, population density, and with high concentration of industrial activities, energy consumption and transport. They also pose unique challenges to atmospheric modelling and monitoring and create a multi-disciplinary spectrum of potential threats, including air pollution, which need to be addressed in an integrated way. These areas are also vulnerable to the changing climate and its implications to sea-level and extreme events, air quality and related health impacts. Many urban activities are significantly impacted by weather events that would not be considered to be of high impact in less densely populated areas. For instance, moderate precipitation events can cause flooding and landslides as modified urban catchments generally have higher run-off to rainfall ratios than their more pristine rural counterparts. The urban environment also provides numerous opportunities. One example being the better use of weather and environmental predictions to proactively optimize the functioning of the urban environment in terms of the use of energy, goods and services. Another is the providing of air quality forecasting services to benefit the health of the population. To address the challenges and opportunities facing megacities and large urban complexes, WMO has established the Global Atmosphere Watch (GAW) Urban Research Meteorology and Environment (GURME). Air pollution questions in urban areas, in particular megacities, is the main focus, building observational and modelling capabilities in developing countries through pilot projects and transfer of scientific expertise. GURME contributes to improving capabilities to handle meteorological and related features of air pollution by addressing end-to-end aspects of air quality, linking observational capabilities with the needs of chemical weather prediction, with the goal of providing high quality air quality services. Using examples from around the world but with specific reference to Africa, the unique challenges and opportunities related to megacities and large urban complexes, as perceived by the World Meteorological Organization (WMO) are highlighted.

WMO Conference averts a “data war”

NASA Astrophysics Data System (ADS)

Wakefield, Julie

Negotiations at the World Meteorological Organization (WMO) Conference in Geneva during the past few weeks appear to have averted an all-out “data war” over the exchange of international weather data—at least for now.Last week, policymakers were moving toward a compromise position, consistent with the U.S. position going into the conference. The compromise position would continue to support a policy of free and open exchange of data and would render unnecessary the European proposal to set up a two-tier system for the exchange of weather data. In addition, the compromise position would recognize the right of any country to place restrictions on its data through licensing and copyright agreements.

WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS): Research Implementation Status

NASA Astrophysics Data System (ADS)

Nickovic, Slobodan; Barrie, Leonard

2010-05-01

Strong winds cause lifting of large amounts of sand and dust from bare, dry soils into the atmosphere. For countries in and downwind of arid regions, airborne sand and dust presents serious risks to the environment, property and human health. Impacts on health include respiratory and cardio-vascular problems, eye infections and in some regions, diseases such as meningitis and valley fever. Dust can efficiently carry irritating spores, bacteria, viruses and persistent organic pollutants. It can also efficiently transport nutrients to parts of the world oceans and affect marine biomass production. Other impacts include negative effects on the ground transport, aviation, agriculture and visibility. The Inter-governmental Panel on Climate Change (IPCC) recognizes dust as a major component of the atmospheric aerosol that is an essential climate variable. Dust aerosol has important effects on weather through feedback on atmospheric dynamics, clouds and precipitation formation. Approximately 15 centres around the world provide sand and dust research operational forecasts. Many are operated by national meteorological services of the World Meteorological Organization (WMO). Sand and dust storm models can substantially reduce risk by providing dust concentration predictions for several days in advance. Numerical weather prediction systems that drive these models use complex parameterizations and assimilation of satellite, and surface-based observations to predict winds, clouds, precipitation and dust mobilization, transport, and removal from the atmosphere. Sand and dust forecast products contribute to the mitigation and reduction of risk through research based advances in understanding and forecasting products. Observations of sand and dust are made by many agencies and some of them are being coordinated globally through the WMO Global Atmosphere Watch (GAW) programme. In 2006, WMO and partners initiated the implementation of the Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS) in order to improve the capabilities of countries affected by dust to reduce risks associated with airborne sand and dust. This project is in response to the desire of more than 40 WMO member countries to improve capabilities for more reliable sand and dust storm forecasts. The project has strong crosscutting features: it relies on real-time delivery of products; it integrates research communities (modelling, observation groups, and effects) and communities of practice (e.g. medical, aeronautical, agricultural users). There are two already established SDS-WAS nodes (Asian and North-Africa-Europe-Middle East) that coordinate implementation of the project objectives at regional levels. This presentation will review current status and future steps in the project implementation.

International comparison CCQM-K84—carbon monoxide in synthetic air at ambient level

NASA Astrophysics Data System (ADS)

Lee, Jeongsoon; Moon, Dongmin; Lee, Jinbok; Lim, Jeongsik; Hall, Brad; Novelli, Paul; Brewer, Paul J.; Miller, Michael; Murugun, Arul; Doval Minarro, Marta; Qiao, Han; Shuguo, Hu; Konopelko, L. A.; Kustikov, Y. A.; Kolobova, A. V.; Pankratov, V. V.; Wasserman, I. I.; Zav'yalov, S. V.; Efremova, O. V.; Pavlov, M. V.; Mitchell, Gerald; Guenther, Frank; Walden, Jari; Aoki, Nobuyuki; Shimosaka, Takuya; Tatiana, Mace; Lagler, F.; Borowiak, Annette

2017-01-01

Carbon monoxide (CO) is reported to mainly be emitted from industries, transportation, and burnings for various usages. Its atmospheric lifetime varies from weeks to months, depending on the mixing ratio of the highly reactive hydroxyl radical. Even though the ambient level of CO varies as a function of regional sources, the mixing ratio ranges from 30 nmol/mol to 300 nmol/mol at the marine boundary layers and from 100 nmol/mol to more than 500 nmol/mol in urban areas(1). In order to study temporal trends and regional variations of the level of CO, the National Oceanic & Atmospheric Administration/Earth System Research Laboratory-Global Monitoring Division (NOAA/ESRL-GMD(2)) has played a key role as the designated Central Calibration Laboratory (CCL) within the frame of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) program. NOAA/ESRL-GMD provides natural air standards, analyzed for CO, to WMO GAW participants. Since the structure of WMO traceability chain appears hierarchical and explicit all over the world, WMO intends to improve the CO measurement compatibility to up to 2 ppb (in case of extensive compatibility goal: 5 ppb, GAW report No. 213(3)) in order to ensure compatibility through the GAW network. Nevertheless, accurate measurement of CO at an ambient level has proven to be difficult due to the lack of stability in cylinders. For these reasons, it is necessary that measured results are compared among the values assigned by various NMIs. This key comparison was initially proposed to be aimed at a CO/N2 standard in the 2010 CCQM meeting by KRISS. With participation of FMI, NOAA, and Empa, a modified scheme of CO/air standards was developed for the purpose of atmospheric observations and co-operative support to WMO/GAW activities. Therefore, the purpose of the comparison is to support the measurement capability of CO at an ambient level of 350 nmol/mol. Further, this key comparison is expected to contribute to the establishment of traceability to a single scale of CO between NMIs by means of harmonizing the results from different national standards. The Empa result lies in a different report. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The Pan-American Center for the WMO Sand and Dust Storm Warning Advisory and Assessment System

NASA Astrophysics Data System (ADS)

Sprigg, W. A.

2013-05-01

A World Meteorological Organization system has been established to coordinate knowledge, data, and information concerning airborne dust, the environmental conditions and storms that generate it, the consequences of it, and the means to mitigate and cope with it. Three nodes, or foci, of collaboration cover the globe: for Asia, administered from the China Meteorological Administration in Beijing; for Africa, Europe and the Middle East, administered from the Barcelona Supercomputing Center; and for Pan-America, administered from Chapman University in Orange, California. Pan-American Center priorities include understanding the sources of windblown dust and particulates, simulating and predicting dust events, and serving the health, safety and environmental communities that may benefit from the WMO system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gröbner, Julian; Reda, Ibrahim; Wacker, Stefan

Atmospheric longwave irradiance is currently not metrologically traceable. Traceability requires formal comparisons in the framwork of the CIPM MRA. A task team on Radiation has been created by the WMO to address these issues.

The state of greenhouse gases in the atmosphere using global observations through 2014

NASA Astrophysics Data System (ADS)

Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Ed

2016-04-01

We present results from the eleventh annual Greenhouse Gas Bulletin (http://www.wmo.int/pages/prog/arep/gaw/ghg/GHGbulletin.html) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (www.wmo.int/gaw). The Bulletin presents results of global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG). Bulletins are prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in collaboration with WDCGG. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of CO2, CH4 and N2O derived from this network reached new highs in 2014, at 397.7±0.1 ppm, 1833±1 ppb and 327.1±0.1 ppb respectively. These values constitute 143%, 254% and 121% of pre-industrial (before 1750) levels. The atmospheric increase of CO2 from 2013 to 2014 was 1.9 ppm, which is smaller than the increase from 2012 to 2013 and the average growth rate for the past decade (˜2.06 ppm per year), but larger than the average growth rate for the 1990s (˜1.5 ppm per year). Smaller growth in 2014 compared with other recent years is most likely related to a relatively small net change in large fluxes between the atmosphere and terrestrial biosphere. The rise of atmospheric CO2 has been only about a half of what is expected if all excess CO2 from burning fossil-fuels stayed in the air. The other half has been absorbed by the land biosphere and the oceans, leading to ocean acidification. For both CH4 and N2O the increases from 2013 to 2014 were larger than those observed from 2012 to 2013 and the mean rates over the past 10 years. The National Oceanic and Atmospheric Administration (NOAA) Annual Greenhouse Gas Index shows that from 1990 to 2014 radiative forcing by long-lived greenhouse gases increased by 36%, with CO2 accounting for about 80% of this increase. The radiative forcing by all long-lived greenhouse gases in 2013 corresponded to a CO2-equivalent mole fraction of 481 ppm (http://www.esrl.noaa.gov/gmd/aggi). The Bulletin cover story explains the role of the water vapor in the greenhouse effect. In spite of water vapor being a strong greenhouse gas, it is the non-condensable greenhouse gases affected by human activities that serve as climate forcing agents; water vapor and clouds act as fast feedbacks. The strong water vapor feedback means that for a doubling of CO2 abundance from preindustrial conditions (from about 280 to 560 ppm), water vapor and clouds lead to a global increase in surface thermal energy that is about three times that of long-lived (non-condensable) greenhouse gases.

Report of the international workshop on quality control of monthly climate data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-12-31

The National Climatic Data Center (NCDC), the US Department of Energy`s Carbon Dioxide Information Analysis Center, and the World Meteorological Organization (WMO) cosponsored an international quality control workshop for monthly climate data, October 5--6, 1993, at NCDC. About 40 scientists from around the world participated. The purpose of the meeting was to discuss and compare various quality control methods and to draft recommendations concerning the most successful systems. The near-term goal to improve quality control of CLIMAT messages for the NCDC/WMO publication Monthly Climatic Data for the World was sucessfully met. An electronic bulletin board was established to post errorsmore » and corrections. Improved communications among Global Telecommunication System hubs will be implemented. Advanced quality control algorithms were discussed and improvements were suggested. Further data exchanges were arranged.« less

WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS): Regional Cooperation Initiative for Americas

NASA Astrophysics Data System (ADS)

Nickovic, S.; Sprigg, W. A.

2011-12-01

For countries in and downwind of arid regions, airborne sand and dust present serious risks to the environment, property and human health. The World Meteorological Organization (WMO) has taken the lead on an international scale to develop and implement SDS-WAS - a system of dust-related research, observations, numerical dust prediction and services. Partnership in SDS-WAS is based on a federated 'open-club' principle. SDS-WAS realizes its goals by networking research institutions, operational centers and users organized through regional nodes assisted by associated regional centers. Growing interest and the needs of communities in the Americas call for establishing a Pan-American SDS-WAS node to serve as an information clearinghouse and to facilitate collaboration that will lead to greater economy of effort and speedier transition of research to applications.

The Onsala Twin Telescope Project

NASA Astrophysics Data System (ADS)

Haas, R.

2013-08-01

This paper described the Onsala Twin Telescope project. The project aims at the construction of two new radio telescopes at the Onsala Space Observatory, following the VLBI2010 concept. The project starts in 2013 and is expected to be finalized within 4 years. Z% O. Rydbeck. Chalmers Tekniska Högskola, Göteborg, ISBN 91-7032-621-5, 407-823, 1991. B. Petrachenko, A. Niell, D. Behrend, B. Corey, J. Böhm, P. Charlot, A. Collioud, J. Gipson, R. Haas, Th. Hobiger, Y. Koyama, D. MacMillan, Z. Malkin, T. Nilsson, A. Pany, G. Tuccari, A. Whitney, and J. Wresnik. Design Aspects of the VLBI2010 System. NASA/TM-2009-214180, 58 pp., 2009. R. Haas, G. Elgered, J. Löfgren, T. Ning, and H.-G. Scherneck. Onsala Space Observatory - IVS Network Station. In K. D. Baver and D. Behrend, editors, International VLBI Service for Geodesy and Astrometry 2011 Annual Report, NASA/TP-2012-217505, 88-91, 2012. H.-G. Scherneck, G. Elgered, J. M. Johansson, and B. O. Rönnäng. Phys. Chem. Earth, Vol. 23, No. 7-8, 811-823, 1998. A. R. Whitney. Ph.D. thesis, Dept. of Electrical engineering, MIT Cambridge, MA., 1974. B. A. Harper, J. D. Kepert, and J. D. Ginger. Guidelines for converting between various wind averaging periods in tropical cyclone conditions. WMO/TD-No. 1555, 64 pp., 2010 (available at \\url{http://www.wmo.int/pages/prog/www/tcp/documents/WMO_TD_1555_en.pdf})

Atmospheric CO2 Concentrations--The Canadian Background Air Pollution Monitoring Network (1993) (NDP-034)

DOE Data Explorer

Trivett, N. B. A. [Environment Canada, Atmospheric Environment Service, Downsview, Ontario, Canada; Hudec, V. C. [Environment Canada, Atmospheric Environment Service, Downsview, Ontario, Canada; Wong, C. S. [Marine Carbon Research Centre, Institute of Ocean Sciences, Sidney, British Columbia, Canada

1993-01-01

Flask air samples collected at roughly weekly intervals at three Canadian sites [Alert, Northwest Territories (July 1975 through July 1992); Sable Island, Nova Scotia (March 1975 through July 1992); and Cape St. James, British Columbia (May 1979 through July 1992)] were analyzed for CO2 concentration with the measurements directly traceable to the WMO primary CO2 standards. Each record includes the date, atmospheric CO2 concentration, and flask classification code. They provide an accurate record of CO2 concentration levels in Canada during the past two decades. Because these data are directly traceable to WMO standards, this record may be compared with records from other Background Air Pollution Monitoring Network (BAPMoN) stations. The data are in three files (one for each of the monitoring stations) ranging in size from 9.4 to 20.1 kB.

Impact of Satellite Atmospheric Motion Vectors In the GMAO GEOS-5 Global Data Assimilation System

NASA Technical Reports Server (NTRS)

Gelaro, Ronald; Merkova, Dagmar

2012-01-01

The WMO and THORPEX co-sponsored fifth Workshop on the Impact of Various Observing Systems on Numerical Weather Prediction will be organized by the Expert Team on the Evolution of the Global Observing System in Sedona, Arizona, United States, from 22 to 25 May 2012. Participants are expected to come from all the major NWP centres which are active in the area of impact studies. The workshop will be conducted in English. As for the first four workshops it is planned to produce a workshop report to be published as a WMO Technical Report that will include the papers submitted by the participants. The previous four workshops in this series took place in Geneva {April 1997), Toulouse (March 2000), Alpbach (March 2004) and Geneva (May 2008). Results from Observing System Experiments (OSEs), both with global and regional aspects were presented and conclusions were drawn concerning the contributions of the various components of the observing system to the large scale forecast skill at short and medium range (Workshop Proceedings were published as WMO World Weather Watch Technical Reports TD No. 868, 1034, 1228 and 1450). Since then, some significant changes and developments have affected the global observing system and more efforts have been devoted to meso-scale observing and assimilation systems. There has also been a trend toward using techniques other than OSEs to document data impact, such as adjoint-based sensitivity to observations or ensemble-based sensitivity. Field experiments have been carried out, in particular through the THORPEX project, and the use of targeted data has been assessed.

The Dust Storm Index (DSI): A method for monitoring broadscale wind erosion using meteorological records

NASA Astrophysics Data System (ADS)

O'Loingsigh, T.; McTainsh, G. H.; Tews, E. K.; Strong, C. L.; Leys, J. F.; Shinkfield, P.; Tapper, N. J.

2014-03-01

Wind erosion of soils is a natural process that has shaped the semi-arid and arid landscapes for millennia. This paper describes the Dust Storm Index (DSI); a methodology for monitoring wind erosion using Australian Bureau of Meteorology (ABM) meteorological observational data since the mid-1960s (long-term), at continental scale. While the 46 year length of the DSI record is its greatest strength from a wind erosion monitoring perspective, there are a number of technical challenges to its use because when the World Meteorological Organisation (WMO) recording protocols were established the use of the data for wind erosion monitoring was never intended. Data recording and storage protocols are examined, including the effects of changes to the definition of how observers should interpret and record dust events. A method is described for selecting the 180 long-term ABM stations used in this study and the limitations of variable observation frequencies between stations are in part resolved. The rationale behind the DSI equation is explained and the examples of temporal and spatial data visualisation products presented include; a long term national wind erosion record (1965-2011), continental DSI maps, and maps of the erosion event types that are factored into the DSI equation. The DSI is tested against dust concentration data and found to provide an accurate representation of wind erosion activity. As the ABM observational records used here were collected according to WMO protocols, the DSI methodology could be used in all countries with WMO-compatible meteorological observation and recording systems.

The state of greenhouse gases in the atmosphere using global observations through 2013

NASA Astrophysics Data System (ADS)

Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Ed; Montzka, Stephen A.; Keeling, Ralph; Tanhua, Toste; Lorenzoni, Laura

2015-04-01

We present results from the tenth annual Greenhouse Gas Bulletin (http://www.wmo.int/pages/prog/arep/gaw/ ghg/GHGbulletin.html) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (www.wmo.int/gaw). The Bulletin presents results of global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG), and for the first time, it includes a summary of ocean acidification. Bulletins are prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in collaboration with WDCGG. The summary of ocean acidification and trends in ocean pCO2 was jointly produced by the International Ocean Carbon Coordination Project (IOCCP) of the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO), the Scientific Committee on Oceanic Research (SCOR), and the Ocean Acidification International Coordination Centre (OA-ICC) of the International Atomic Energy Agency (IAEA). The tenth Bulletin included a special edition published prior to the United Nations Climate Summit in September 2014. The scope of this edition was to demonstrate the level of emission reduction necessary to stabilize radiative forcing by long-lived greenhouse gases. It shows in particular that a reduction in radiative forcing from its current level (2.92 W m-2 in 2013) requires significant reductions in anthropogenic emissions of all major greenhouse gases. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide, methane and nitrous oxide derived from this network reached new highs in 2013, with CO2 at 396.0 ± 0.1 ppm, CH4 at 1824 ± 2 ppb and N2O at 325.9 ± 0.1 ppb. These values constitute 142%, 253% and 121% of pre-industrial (before 1750) levels, respectively. The atmospheric increase of CO2 from 2012 to 2013 was 2.9 ppm, which is the largest year to year change from 1984 to 2013. The rise of CO2 concentration has been only about a half of what is expected if all the excess CO2 from the burning of fossil-fuel stayed in the air. The other half has been absorbed by the land biosphere and the oceans, but the split between land and oceans is not easily resolved from CO2 data alone. As described in the Bulletin, O2 measurements have been used to estimate the magnitude of the terrestrial biosphere sink. For N2O the increase from 2012 to 2013 is smaller than the one observed from 2011 to 2012 but comparable to the average growth rate over the past 10 years. Atmospheric CH4 continued to increase at a rate similar to the mean rate over the past 5 years. The National Oceanic and Atmospheric Administration (NOAA) Annual Greenhouse Gas Index shows that from 1990 to 2013 radiative forcing by long-lived greenhouse gases increased by 34%, with CO2 accounting for about 80% of this increase. The radiative forcing by all long-lived greenhouse gases in 2013 corresponded to a CO2-equivalent mole fraction of 479 ppm (http://www.esrl.noaa.gov/gmd/aggi). Uptake of anthropogenic CO2 by the ocean results in increased CO2 concentrations and increased acidity levels in sea-water. During the last two decades ocean water pH decreased by 0.0011 - 0.0024 per year, and the amount of CO2 dissolved in see water (pCO2) increased by 1.2 - 2.8 μatm per year for time-series from several featured ocean stations.

The state of greenhouse gases in the atmosphere using global observations through 2015

NASA Astrophysics Data System (ADS)

Tarasova, Oksana; Vermeulen, Alex; Ueno, Mikio

2017-04-01

We present results from the twelfth annual Greenhouse Gas Bulletin (http://www.wmo.int/pages/prog/arep/gaw/ghg/GHGbulletin.html) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (www.wmo.int/gaw). The Bulletin presents results of global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG). Bulletins are prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in collaboration with WDCGG. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide, methane and nitrous oxide derived from this network reached new highs in 2015, with CO2 at 400.0±0.1 ppm, CH4 at 1845±2 ppb and N2O at 328.0±0.1 ppb. These values constitute 144%, 256% and 121% of pre-industrial (before 1750) levels, respectively. It is predicted that 2016 will be the first year in which CO2 at the Mauna Loa Observatory remains above 400 ppm all year, and hence for many generations ( Betts et al., 2016). The atmospheric increase of CO2 from 2014 to 2015 was 2.3 ppm, which is larger than the increase from 2013 to 2014 and the average growth rate for the past decade (˜2.08 ppm per year), despite evidence that global anthropogenic emissions remained essentially static between 2014 and 2015. The higher growth rate in 2015 compared with the previous years is due to increased natural emissions of CO2 related to the most recent El Niño event. According to the most recent data, increased growth rates have persisted far into 2016, consistent with the expected lag between CO2 growth and the ENSO index. The average increase in atmospheric CO2 from 2005 to 2014 corresponds to ˜44% of the CO2 emitted by human activity with the remaining ˜56% removed by the oceans and the terrestrial biosphere (La Quéré et al., 2015). For CH4 the increase from 2014 to 2015 was larger than that observed from 2013 to 2014 and the mean growth rate over the past 10 years. The annual increase of N2O globally averaged mole fraction from 2014 to 2015 was similar to that observed from 2013 to 2014 and greater than the average growth rate over the past 10 years. The National Oceanic and Atmospheric Administration (NOAA) Annual Greenhouse Gas Index shows that from 1990 to 2015 radiative forcing by long-lived greenhouse gases increased by 37%, with CO2 accounting for about 80% of this increase. The radiative forcing by all long-lived greenhouse gases in 2015 corresponded to a CO2-equivalent mole fraction of 485 ppm (http://www.esrl.noaa.gov/gmd/aggi). Bulletin cover story explains the connection between CO2 growth rates and El Niño phenomena. Bulletin contains brief introduction of the Integrated Global Greenhouse Gas Information System, which will be presented separately at the other session. References Betts, R.A. et al, 2016: El Niño and a record CO2 rise. Nature Climate Change, 6(9):806-810, doi:10.1038/nclimate3063. Le Quéré, C. et al. 2015: Global carbon budget 2015. Earth System Science Data, 7(2):349-396, doi:10.5194/essd-7-349-2015.

31 CFR Appendix A to Part 500 - Qualifying International Institutions

Code of Federal Regulations, 2010 CFR

2010-07-01

... Organization (UNIDO) UN International Drug Control Program (UNIDCP) UN Population Fund (UNPF) World Health Organization (WHO) World Meteorological Organization (WMO) [58 FR 68532, Dec. 28, 1993] ... (IBRD, the “World Bank”) International Civil Aviation Organization (ICAO) International Development...

Deposition and separation of W and Mo from aqueous solutions with simultaneous hydrogen production in stacked bioelectrochemical systems (BESs): Impact of heavy metals W(VI)/Mo(VI) molar ratio, initial pH and electrode material.

PubMed

Huang, Liping; Li, Ming; Pan, Yuzhen; Quan, Xie; Yang, Jinhui; Puma, Gianluca Li

2018-04-16

The deposition and separation of W and Mo from aqueous solutions with simultaneous hydrogen production was investigated in stacked bioelectrochemical systems (BESs) composed of microbial electrolysis cell (1#) serially connected with parallel connected microbial fuel cell (2#). The impact of W/Mo molar ratio (in the range 0.01 mM : 1 mM and vice-versa), initial pH (1.5 to 4.0) and cathode material (stainless steel mesh (SSM), carbon rod (CR) and titanium sheet (TS)) on the BES performance was systematically investigated. The concentration of Mo(VI) was more influential than W(VI) in determining the rate of deposition of both metals and the rate of hydrogen production. Complete metal recovery was achieved at equimolar W/Mo ratio of 0.05 mM : 0.05 mM. The rates of metal deposition and hydrogen production increased at acidic pH, with the fastest rates at pH 1.5. The morphology of the metal deposits and the valence of the Mo were correlated with W/Mo ratio and pH. CR cathodes (2#) coupled with SSM cathodes (1#) achieved a significant rate of hydrogen production (0.82 ± 0.04 m 3 /m 3 /d) with W and Mo deposition (0.049 ± 0.003 mmol/L/h and 0.140 ± 0.004 mmol/L/h (1#); 0.025 ± 0.001 mmol/L/h and 0.090 ± 0.006 mmol/L/h (2#)). Copyright © 2018 Elsevier B.V. All rights reserved.

On the development of a methodology for extensive in-situ and continuous atmospheric CO2 monitoring

NASA Astrophysics Data System (ADS)

Wang, K.; Chang, S.; Jhang, T.

2010-12-01

Carbon dioxide is recognized as the dominating greenhouse gas contributing to anthropogenic global warming. Stringent controls on carbon dioxide emissions are viewed as necessary steps in controlling atmospheric carbon dioxide concentrations. From the view point of policy making, regulation of carbon dioxide emissions and its monitoring are keys to the success of stringent controls on carbon dioxide emissions. Especially, extensive atmospheric CO2 monitoring is a crucial step to ensure that CO2 emission control strategies are closely followed. In this work we develop a methodology that enables reliable and accurate in-situ and continuous atmospheric CO2 monitoring for policy making. The methodology comprises the use of gas filter correlation (GFC) instrument for in-situ CO2 monitoring, the use of CO2 working standards accompanying the continuous measurements, and the use of NOAA WMO CO2 standard gases for calibrating the working standards. The use of GFC instruments enables 1-second data sampling frequency with the interference of water vapor removed from added dryer. The CO2 measurements are conducted in the following timed and cycled manner: zero CO2 measurement, two standard CO2 gases measurements, and ambient air measurements. The standard CO2 gases are calibrated again NOAA WMO CO2 standards. The methodology is used in indoor CO2 measurements in a commercial office (about 120 people working inside), ambient CO2 measurements, and installed in a fleet of in-service commercial cargo ships for monitoring CO2 over global marine boundary layer. These measurements demonstrate our method is reliable, accurate, and traceable to NOAA WMO CO2 standards. The portability of the instrument and the working standards make the method readily applied for large-scale and extensive CO2 measurements.

Characteristics of multiple tropopauses in the tropics

NASA Astrophysics Data System (ADS)

Mehta, Sanjay Kumar; Ratnam Madineni, Venkat; Krishna Murthy, B. V.

The characteristics of multiple tropopauses (MTs) in the tropics are studied using radiosonde data from 5 stations (Truk,Rochambeau, Singapore, Seychelles and Darwin) in the tropical belt during 1999 to 2008 and COSMIC GPS RO data during 2006-2008. In this study we emphasized the limitations of the WMO criteria for identifying the MTs and evolved an alternative criterion to effectively delineate MTs over tropical region. The current method is based on cold point tropopause (CPT) and points of inflections in the temperature profile rather than lapse rate as in WMO criteria. The points of inflection can occur both below and above the CPT. The one which occurs below the CPT is designated as the lower tropopause (LT) and those occurring above the CPT as second tropopause (ST) and third tropopause (TT) according to their heights of occurrence with CPT as the first tropopause. The percentage occurrences (25-50) of MTs are observed to be higher using the current method than by the WMO criteria (10-30). There is significant seasonal variation in the LT, CPT and ST temperatures (heights) with lower (higher) values occurring in the Northern Hemisphere winter. While the CPT temperatures are lowest at the equator the CPT heights are not highest at the equator. The occurrences of MTs are higher over equator and decrease away towards higher latitudes in the tropics. Longitudinal variation of the MTs is observed with relatively high occurrences during NH summer season over placeIndian Ocean. The equatorial minimum in the CPT temperature is broader and colder in the eastern hemisphere than the western hemisphere It is found that MTs can either occur on consecutive days in groups or on isolated days. The plausible causative mechanisms will be presented in the conference.

Accuracy of tretyakov precipitation gauge: Result of wmo intercomparison

USGS Publications Warehouse

Yang, Daqing; Goodison, Barry E.; Metcalfe, John R.; Golubev, Valentin S.; Elomaa, Esko; Gunther, Thilo; Bates, Roy; Pangburn, Timothy; Hanson, Clayton L.; Emerson, Douglas G.; Copaciu, Voilete; Milkovic, Janja

1995-01-01

The Tretyakov non-recording precipitation gauge has been used historically as the official precipitation measurement instrument in the Russian (formerly the USSR) climatic and hydrological station network and in a number of other European countries. From 1986 to 1993, the accuracy and performance of this gauge were evaluated during the WMO Solid Precipitation Measurement Intercomparison at 11 stations in Canada, the USA, Russia, Germany, Finland, Romania and Croatia. The double fence intercomparison reference (DFIR) was the reference standard used at all the Intercomparison stations in the Intercomparison. The Intercomparison data collected at the different sites are compatible with respect to the catch ratio (measured/DFIR) for the same gauge, when compared using mean wind speed at the height of the gauge orifice during the observation period.The Intercomparison data for the Tretyakov gauge were compiled from measurements made at these WMO intercomparison sites. These data represent a variety of climates, terrains and exposures. The effects of environmental factors, such as wind speed, wind direction, type of precipitation and temperature, on gauge catch ratios were investigated. Wind speed was found to be the most important factor determining the gauge catch and air temperature had a secondary effect when precipitation was classified into snow, mixed and rain. The results of the analysis of gauge catch ratio versus wind speed and temperature on a daily time step are presented for various types of precipitation. Independent checks of the correction equations against the DFIR have been conducted at those Intercomparison stations and a good agreement (difference less than 10%) has been obtained. The use of such adjustment procedures should significantly improve the accuracy and homogeneity of gauge-measured precipitation data over large regions of the former USSR and central Europe.

Study of atmospheric CH4 mole fractions at three WMO/GAW stations in China

NASA Astrophysics Data System (ADS)

Fang, Shuang-Xi; Zhou, Ling-Xi; Masarie, Kenneth A.; Xu, Lin; Rella, Chris W.

2013-05-01

CH4 mole fractions were continuously measured from 2009 to 2011 at three WMO/GAW stations in China (Lin'an, LAN; Longfengshan, LFS; and Waliguan, WLG) using three Cavity Ring Down Spectroscopy instruments. LAN and LFS are GAW regional measurement stations. LAN is located in China's most economically developed region, and LFS is in a rice production area (planting area > 40,000 km2). WLG is a global measurement station in remote northwest China. At LAN, high methane mole fractions are observed in all seasons. Surface winds from the northeast enhance CH4 values, with a maximum increase of 32 ± 15 ppb in summer. The peak to peak amplitude of the seasonal cycle is 77 ± 35 ppb. At LFS, the diurnal cycle amplitude is approximately constant throughout the year except summer, when a value of 196 ± 65 ppb is observed. CH4 values at LFS reach their peak in July, which is different from seasonal variations typically observed in the northern hemisphere. CH4 mole fractions at WLG show both the smallest values and the lowest variability. Maximum values occur during summer, which is different from other northern hemisphere WMO/GAW global stations. The seasonal cycle amplitude is 17 ± 11 ppb. The linear growth rates at LAN, LFS, and WLG are 8.0 ± 1.2, 7.9 ± 0.9, and 9.4 ± 0.2 ppb yr-1, respectively, which are all larger than the global mean over the same 3 year period. Results from this study attempt to improve our basic understanding of observed atmospheric CH4 in China.

Development of a Northern Continental Air Standard Reference Material.

PubMed

Rhoderick, George C; Kitzis, Duane R; Kelley, Michael E; Miller, Walter R; Hall, Bradley D; Dlugokencky, Edward J; Tans, Pieter P; Possolo, Antonio; Carney, Jennifer

2016-03-15

The National Institute of Standards and Technology (NIST) recently began to develop standard mixtures of greenhouse gases as part of a broad program mandated by the 2009 United States Congress to support research in climate change. To this end, NIST developed suites of gravimetrically assigned primary standard mixtures (PSMs) comprising carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-natural air balance at ambient mole fraction levels. In parallel, the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, charged 30 aluminum gas cylinders with northern hemisphere air at Niwot Ridge, Colorado. These mixtures, which constitute NIST Standard Reference Material (SRM) 1720 Northern Continental Air, were certified by NIST for ambient mole fractions of CO2, CH4, and N2O relative to NIST PSMs. NOAA-assigned values are also provided as information in support of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Program for CO2, CH4, and N2O, since NOAA serves as the WMO Central Calibration Laboratory (CCL) for CO2, CH4, and N2O. Relative expanded uncertainties at the 95% confidence interval are <±0.06% of the certified values for CO2 and N2O and <0.2% for CH4, which represents the smallest relative uncertainties specified to date for a gaseous SRM produced by NIST. Agreement between the NOAA (WMO/GAW) and NIST values based on their respective calibration standards suites is within 0.05%, 0.13%, and 0.06% for CO2, CH4, and N2O, respectively. This collaborative development effort also represents the first of its kind for a gaseous SRM developed by NIST.

Toward a Global Water Quality Observing and Forecasting System

EPA Science Inventory

The Group on Earth Observations (GEO) Coastal and Inland Water Quality Working Group held a Water Quality Summit at the World Meteorological Organization (WMO) in Geneva, Switzerland April 20 to 22, 2015. The goal was to define specific water quality component requirements and de...

Thermo-mechanical properties of W/Mo markers coatings deposited on bulk W

NASA Astrophysics Data System (ADS)

Grigore, E.; Ruset, C.; Gherendi, M.; Chioibasu, D.; Hakola, A.; contributors, JET

2016-02-01

In the present paper marker structures consisting of W/Mo layers were deposited on bulk W samples by using a modified CMSII method. This technology, compared to standard CMSII, prevents the formation of nano-pore structures at interfaces. The thicknesses of the markers were in the range 20-35 μm to balance the requirements associated with the wall erosion in ITER and thermo-mechanical performances. The coatings structure and composition were evaluated by glow discharge optical emission spectrometry (GDOES), and energy dispersive x-ray spectroscopy measurements (EDX). The adhesion of the coatings to the substrate has been assessed by scratch test method. In order to evaluate their effectiveness as potential markers for fusion applications, the marker coatings have been tested in an electron beam facility at a temperature of 1000 °C and a power density of about 3 MW m-2. A number of 300 pulses with duration of 420 s (35 testing hours) were applied on the marker coated samples.

ATTENUATION OF SOLAR UV RADIATION BY AEROSOLS DURING AIR POLLUTION EPISODES

EPA Science Inventory

Increase in the amount of solar UV radiation reaching the surface due to decrease in stratospheric ozone continues to be a major concern (WMO, 1998). However, recent studies show that absorption and smattering by aerosols during air pollution episode decreases the amount of radi...

Accuracy of activPAL Self-Attachment Methods

ERIC Educational Resources Information Center

Kringen, Nina L.; Healy, Genevieve N.; Winkler, Elisabeth A. H.; Clark, Bronwyn K.

2016-01-01

This study examined the accuracy of self-attachment of the activPAL activity monitor. A convenience sample of 50 participants self-attached the monitor after being presented with written material only (WMO) and then written and video (WV) instructions; and completed a questionnaire regarding the acceptability of the instructional methods.…

Global Atmosphere Watch Workshop on Measurement-Model Fusion for Global Total Atmospheric Deposition (MMF-GTAD)

EPA Science Inventory

The World Meteorological Organization’s (WMO) Global Atmosphere Watch (GAW) Programme coordinates high-quality observations of atmospheric composition from global to local scales with the aim to drive high-quality and high-impact science while co-producing a new generation of pro...

Molybdenite Re/Os dating, zircon U-Pb age and geochemistry of granitoids in the Yangchuling porphyry W-Mo deposit (Jiangnan tungsten ore belt), China: Implications for petrogenesis, mineralization and geodynamic setting

NASA Astrophysics Data System (ADS)

Mao, Jingwen; Xiong, Bikang; Liu, Jun; Pirajno, Franco; Cheng, Yanbo; Ye, Huishou; Song, Shiwei; Dai, Pan

2017-08-01

The Yangchuling W-Mo deposit, located in the Jiangnan porphyry-skarn (JNB) tungsten ore belt, is the first recognized typical porphyry W-Mo deposit in China in the 1980's. Stockworks and disseminated W-Mo mineralization occur in the roof pendant of a 0.3 km2 monzogranitic porphyry stock that intruded into a granodiorite stock, hosted by Neoproterozoic phyllite and slate. LA-ICPMS zircon U-Pb analyses suggest that of the monzogranitic porphyry and granodiorite were formed at 143.8 ± 0.5 Ma and 149.8 ± 0.6 Ma, respectively. Six molybdenite samples yielded a Re-Os weighted mean age of 146.4 ± 1.0 Ma. Geochemical data show that both granodiorite and monzogranitic porphyry are characterized by enrichment of large ion lithophile elements (LILE) relative to high field strength elements (HFSE), indicating a peraluminous nature (A/CNK = 1.01-1.08). Two granitoids are characterized by a negative slope with significant light REE/heavy REE fractionation [(La/Yb)N = 8.38-23.20] and negative Eu anomalies (Eu/Eu* = 0.69-0.76). The P2O5 contents of the Yangchuling granitoids range from 0.12% to 0.17% and exhibit a negative correlation with SiO2, reflecting that they are highly fractionated I-type. They have high initial 87Sr/86Sr ratios (0.7104-0.7116), low negative εNd(t) (- 5.05 to - 5.67), and homogeneous εHf(t) between - 1.39 and - 2.17, indicating similar sources. Additionally, two-stage Nd model ages (TDM2) of 1.3-1.4 Ga and two-stage Hf model ages (TDM2) of 1.2-1.3 Ga are consistent, indicating that Neoproterozoic crustal rocks of the Shuangqiaoshan Group could have contributed to form the Yangchuling magmas. Considering the two groups of parallel Late Mesozoic ore belts, namely the Jiangnan porphyry-skarn tungsten belt (JNB) in the south and the Middle-Lower Yangtze River porphyry-skarn Cu-Au-Mo-Fe ore belt (YRB) in the north, the Nanling granite-related W-Sn ore belt (NLB) in the south, the neighboring Qin-Hang porphyry-skarn Cu-Mo-hydrothermal Pb-Zn-Ag ore belt (QHB) in the north, as well as the Southeastern Coast porphyry-skarn Cu-Mo-Au ore belt (SCB) recognized in South China in this paper, we propose that the latest Jurassic to earliest Cretaceous granitoids and associated ores were formed during a tearing of the subducting Izanagi slab. This tearing of the subduction slab caused the upwelling of asthenosphere and the resulting mantle-crust interaction. The granitoid-related W ore systems in JNB resulted from the remelting of the Proterozoic crust. The mafic-ultramafic volcanic rocks of the Shuangqiaoshan Group intercalated with phyllite and slate, ophiolitic mélange and magmatic arc rocks, mainly comprising I-type granite, basalt, andesite, rhyolite, pyroclastics, together with subduction-related metasomatized lithospheric mantle, would have provided additional mantle material. In this case, the partial melting of rocks of the Shuangqiaoshan Group can produce S-, I- and transitional type granitoids. After strong differentiation it formed tungsten-bearing granitoids characterized by enrichment of high alkali, silicon and volatile components. In the Yangchuling mine area the small monzogranitic porphyry stock has stronger fractionation, volatile content and ore-forming components than the older granodiorite, resulting in the development of the porphyry W-Mo ore system.

BUFR TABLE B - WMO AND LOCAL (NCEP) DESCRIPTORS AS WELL AS THOSE AWAITING

Science.gov Websites

09 Reserved 0 10 Non-coordinate location (vertical) Height, altitude, pressure and derivatives . calibration method, wind profiler mode, radiance channel combinations, hardware configurations, etc. 0 26 Non -coordinate location (time) Defines time and time derivatives that are not coordinates 0 27 Non-coordinate

U.S. Army Research Laboratory Meteorological Measurements for Joint Urban 2003

DTIC Science & Technology

2009-09-01

identical system operated by Arizona State University south to southeast of the CBD. The ARL Lidar system was set up atop a four-story parking garage ... Stereo Height and Motion Analysis: Applications, Fourth Winds Workshop, WMO, 1998. Chang, S. S.; Huynh, G. D.; Klipp, C. L.; Williamson, C. C

Developing air quality forecasts

NASA Astrophysics Data System (ADS)

Lee, Pius; Saylor, Rick; Meagher, James

2012-05-01

Third International Workshop on Air Quality Forecasting Research; Potomac, Maryland, 29 November to 1 December 2011 Elevated concentrations of both near-surface ozone (O3) and fine particulate matter smaller than 2.5 micrometers in diameter have been implicated in increased mortality and other human health impacts. In light of these known influences on human health, many governments around the world have instituted air quality forecasting systems to provide their citizens with advance warning of impending poor air quality so that they can take actions to limit exposure. In an effort to improve the performance of air quality forecasting systems and provide a forum for the exchange of the latest research in air quality modeling, the International Workshop on Air Quality Forecasting Research (IWAQFR) was established in 2009 and is cosponsored by the U.S. National Oceanic and Atmospheric Administration (NOAA), Environment Canada (EC), and the World Meteorological Organization (WMO). The steering committee for IWAQFR's establishment was composed of Véronique Bouchet, Mike Howe, and Craig Stoud (EC); Greg Carmichael (University of Iowa); Paula Davidson and Jim Meagher (NOAA); and Liisa Jalkanen (WMO). The most recent workshop took place in Maryland.

The Wmo Global Atmosphere Watch Programme: Global Framework for Atmospheric Composition Observations and Analysis

NASA Astrophysics Data System (ADS)

Tarasova, O. A.; Jalkanen, L.

2010-12-01

The WMO Global Atmosphere Watch (GAW) Programme is the only existing long-term international global programme providing an international coordinated framework for observations and analysis of the chemical composition of the atmosphere. GAW is a partnership involving contributors from about 80 countries. It includes a coordinated global network of observing stations along with supporting facilities (Central Facilities) and expert groups (Scientific Advisory Groups, SAGs and Expert Teams, ETs). Currently GAW coordinates activities and data from 27 Global Stations and a substantial number of Regional and Contributing Stations. Station information is available through the GAW Station Information System GAWSIS (http://gaw.empa.ch/gawsis/). There are six key groups of variables which are addressed by the GAW Programme, namely: ozone, reactive gases, greenhouse gases, aerosols, UV radiation and precipitation chemistry. GAW works to implement integrated observations unifying measurements from different platforms (ground based in situ and remote, balloons, aircraft and satellite) supported by modeling activities. GAW provides data for ozone assessments, Greenhouse Gas Bulletins, Ozone Bulletins and precipitation chemistry assessments published on a regular basis and for early warnings of changes in the chemical composition and related physical characteristics of the atmosphere. To ensure that observations can be used for global assessments, the GAW Programme has developed a Quality Assurance system. Five types of Central Facilities dedicated to the six groups of measurement variables are operated by WMO Members and form the basis of quality assurance and data archiving for the GAW global monitoring network. They include Central Calibration Laboratories (CCLs) that host primary standards (PS), Quality Assurance/Science Activity Centres (QA/SACs), World Calibration Centers (WCCs), Regional Calibration Centers (RCCs), and World Data Centers (WDCs) with responsibility for archiving and access to GAW data. Education, training, workshops, comparison campaigns, station audits/visits and twinning are also provided to build capacities in atmospheric sciences in Member countries.

High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air

NASA Astrophysics Data System (ADS)

Rella, C. W.; Chen, H.; Andrews, A. E.; Filges, A.; Gerbig, C.; Hatakka, J.; Karion, A.; Miles, N. L.; Richardson, S. J.; Steinbacher, M.; Sweeney, C.; Wastine, B.; Zellweger, C.

2013-03-01

Traditional techniques for measuring the mole fractions of greenhouse gases in the well-mixed atmosphere have required dry sample gas streams (dew point < -25 °C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmosphere Watch programme of the World Meteorological Organisation (WMO/GAW) for carbon dioxide (±0.1 ppm in the Northern Hemisphere and ±0.05 ppm in the Southern Hemisphere) and methane (±2 ppb). Drying the sample gas to low levels of water vapour can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular cavity ring down spectroscopy, have led to the development of greenhouse gas analysers capable of simultaneous measurements of carbon dioxide, methane and water vapour. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapour, these instruments permit accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals (WMO, 2011a) without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapour correction factors, and we summarise a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterised dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to a water vapour concentration of at least 1%. By determining the correction factors for individual instruments once at the start of life, this water vapour concentration range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended up to and even above 4% water vapour concentrations.

Satellite Derived Volcanic Ash Product Inter-Comparison in Support to SCOPE-Nowcasting

NASA Astrophysics Data System (ADS)

Siddans, Richard; Thomas, Gareth; Pavolonis, Mike; Bojinski, Stephan

2016-04-01

In support of aeronautical meteorological services, WMO organized a satellite-based volcanic ash retrieval algorithm inter-comparison activity, to improve the consistency of quantitative volcanic ash products from satellites, under the Sustained, Coordinated Processing of Environmental Satellite Data for Nowcasting (SCOPEe Nowcasting) initiative (http:/ jwww.wmo.int/pagesjprogjsatjscopee nowcasting_en.php). The aims of the intercomparison were as follows: 1. Select cases (Sarychev Peak 2009, Eyjafyallajökull 2010, Grimsvötn 2011, Puyehue-Cordón Caulle 2011, Kirishimayama 2011, Kelut 2014), and quantify the differences between satellite-derived volcanic ash cloud properties derived from different techniques and sensors; 2. Establish a basic validation protocol for satellite-derived volcanic ash cloud properties; 3. Document the strengths and weaknesses of different remote sensing approaches as a function of satellite sensor; 4. Standardize the units and quality flags associated with volcanic cloud geophysical parameters; 5. Provide recommendations to Volcanic Ash Advisory Centers (VAACs) and other users on how to best to utilize quantitative satellite products in operations; 6. Create a "road map" for future volcanic ash related scientific developments and inter-comparison/validation activities that can also be applied to SO2 clouds and emergent volcanic clouds. Volcanic ash satellite remote sensing experts from operational and research organizations were encouraged to participate in the inter-comparison activity, to establish the plans for the inter-comparison and to submit data sets. RAL was contracted by EUMETSAT to perform a systematic inter-comparison of all submitted datasets and results were reported at the WMO International Volcanic Ash Inter-comparison Meeting to held on 29 June - 2 July 2015 in Madison, WI, USA (http:/ /cimss.ssec.wisc.edujmeetings/vol_ash14). 26 different data sets were submitted, from a range of passive imagers and spectrometers and these were inter-compared against each other and against validation data such as CALIPSO lidar, ground-based lidar and aircraft observations. Results of the comparison exercise will be presented together with the conclusions and recommendations arising from the activity.

Overview of the Long-term Ozone Trends and Uncertainties in the Stratosphere(LOTUS) SPARC Activity

NASA Astrophysics Data System (ADS)

Petropavlovskikh, I. V.; Hubert, D.; Godin-Beekman, S.; Damadeo, R. P.; Sofieva, V.; Hassler, B.

2017-12-01

WMO/UNEP Assessments on the state of the ozone layer (aka Ozone Assessments) require an accurate evaluation of both total ozone and ozone profile long-term trends. These trend results are of utmost importance in order to evaluate the success of the Montreal Protocol with regards to the recovery of the ozone layer and the effect of climate change on this recovery, in the main regions of the stratosphere (polar, mid-latitudes, tropics). A previous activity sponsored by SPARC, IO3C, IGACO-O3 and NDACC (SI2N) successfully provided estimates of ozone profile decreasing trend in the period 1979 - 1997 and recovery trend in the period 1998 -2012, from a variety of long term records, however its results were different from those published in the WMO 2014 Ozone Assessment report. For the WMO/UNEP 2018 Ozone Assessment, a clear understanding of ozone trends and their significance as a function of altitude and latitude is still needed, nearly 20 years after the peak of ozone depleting substances in the stratosphere. In the most recent years, new merged satellite data sets and long awaited homogenized ozonesonde data series have been produced. There is thus a strong interest in the scientific community to understand limitations in determining significance of ozone recovery. In order to address the issues left pending after the end of SI2N, a comprehensive evaluation of all long term data sets available together with their relative drifts was performed through the SPARC LOTUS (Long-term Ozone Trends and uncertainties in Stratosphere) activity. Evaluation of consistencies in results from various statistical trend regression models, sensitivity to the selection of predictors, evaluation of sampling-related uncertainties and impact of the measurement error propagation on ozone trend calculation was among subjects of investigation. This presentation will provide overview of the LOTUS project goals, provide highlights of the results and discuss the future goals.

JMA's regional atmospheric transport model calculations for the WMO technical task team on meteorological analyses for Fukushima Daiichi Nuclear Power Plant accident.

PubMed

Saito, Kazuo; Shimbori, Toshiki; Draxler, Roland

2015-01-01

The World Meteorological Organization (WMO) convened a small technical task team of experts to produce a set of meteorological analyses to drive atmospheric transport, dispersion and deposition models (ATDMs) for the United Nations Scientific Committee on the Effects of Atomic Radiation's assessment of the Fukushima Daiichi Nuclear Power Plant (DNPP) accident. The Japan Meteorological Agency (JMA) collaborated with the WMO task team as the regional specialized meteorological center of the country where the accident occurred, and provided its operational 5-km resolution mesoscale (MESO) analysis and its 1-km resolution radar/rain gauge-analyzed precipitation (RAP) data. The JMA's mesoscale tracer transport model was modified to a regional ATDM for radionuclides (RATM), which included newly implemented algorithms for dry deposition, wet scavenging, and gravitational settling of radionuclide aerosol particles. Preliminary and revised calculations of the JMA-RATM were conducted according to the task team's protocol. Verification against Cesium 137 ((137)Cs) deposition measurements and observed air concentration time series showed that the performance of RATM with MESO data was significantly improved by the revisions to the model. The use of RAP data improved the (137)Cs deposition pattern but not the time series of air concentrations at Tokai-mura compared with calculations just using the MESO data. Sensitivity tests of some of the more uncertain parameters were conducted to determine their impacts on ATDM calculations, and the dispersion and deposition of radionuclides on 15 March 2011, the period of some of the largest emissions and deposition to the land areas of Japan. The area with high deposition in the northwest of Fukushima DNPP and the hotspot in the central part of Fukushima prefecture were primarily formed by wet scavenging influenced by the orographic effect of the mountainous area in the west of the Fukushima prefecture. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

An International Coordinated Effort to Further the Documentation & Development of Quality Assurance, Quality Control, and Best Practices for Oceanographic Observations

NASA Astrophysics Data System (ADS)

Bushnell, M.; Waldmann, C.; Hermes, J.; Tamburri, M.

2017-12-01

Many oceanographic observation groups create and maintain QA, QC, and best practices (BP) to ensure efficient and accurate data collection and quantify quality. Several entities - IOOS® QARTOD, AtlantOS, ACT, WMO/IOC JCOMM OCG - have joined forces to document existing practices, identify gaps, and support development of emerging techniques. While each group has a slightly different focus, many underlying QA/QC/BP needs can be quite common. QARTOD focuses upon real-time data QC, and has produced manuals that address QC tests for eleven ocean variables. AtlantOS is a research and innovation project working towards the integration of ocean-observing activities across all disciplines in the Atlantic Basin. ACT brings together research institutions, resource managers, and private companies to foster the development and adoption of effective and reliable sensors for coastal, freshwater, and ocean environments. JCOMM promotes broad international coordination of oceanographic and marine meteorological observations and data management and services. Leveraging existing efforts of these organizations is an efficient way to consolidate available information, develop new practices, and evaluate the use of ISO standards to judge the quality of measurements. ISO standards may offer accepted support for a framework for an ocean data quality management system, similar to the meteorological standards defined by WMO (https://www.wmo.int/pages/prog/arep/gaw/qassurance.html). We will first cooperatively develop a plan to create a QA/QC/BP manual. The resulting plan will describe the need for such a manual, the extent of the manual, the process used to engage the community in creating it, the maintenance of the resultant document, and how these things will be done. It will also investigate standards for metadata. The plan will subsequently be used to develop the QA/QC/BP manual, providing guidance which advances the standards adopted by IOOS, AtlantOS, JCOMM, and others.

TABLE D - WMO AND LOCAL (NCEP) DESCRIPTORS AS WELL AS THOSE AWAITING

Science.gov Websites

sequences common to satellite observations None 3 05 Meteorological or hydrological sequences common to Vertical sounding sequences (conventional data) None 3 10 Vertical sounding sequences (satellite data) None (satellite data) None 3 13 Sequences common to image data None 3 14 Reserved None 3 15 Oceanographic report

Ultraviolet radiation changes

NASA Technical Reports Server (NTRS)

Mckenzie, Richard L.; Frederick, John E.; Ilyas, Mohammad; Filyushkin, V.; Wahner, Andreas; Stamnes, K.; Muthusubramanian, P.; Blumthaler, M.; Roy, Colin E.; Madronich, Sasha

1991-01-01

A major consequence of ozone depletion is an increase in solar ultraviolet (UV) radiation received at the Earth's surface. This chapter discusses advances that were made since the previous assessment (World Meteorological Organization (WMO)) to our understanding of UV radiation. The impacts of these changes in UV on the biosphere are not included, because they are discussed in the effects assessment.

Teaching the Teachers on Building Climatology. (CIB Steering Group S 4, Colloquium, Stockholm, September 4-6, 1972). CIB Proceedings No. 25.

ERIC Educational Resources Information Center

National Swedish Inst. for Building Research, Stockholm.

This publication comprises a collection of papers and synopses of discussions dating from the "Teaching the Teachers in Building Climatology" colloquium which was held under the auspices of the International Council for Building Research (CIB) and the World Meteorological Organization (WMO). The papers deal with the use of various…

Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations

NASA Astrophysics Data System (ADS)

Zellweger, Christoph; Emmenegger, Lukas; Firdaus, Mohd; Hatakka, Juha; Heimann, Martin; Kozlova, Elena; Spain, T. Gerard; Steinbacher, Martin; van der Schoot, Marcel V.; Buchmann, Brigitte

2016-09-01

Until recently, atmospheric carbon dioxide (CO2) and methane (CH4) measurements were made almost exclusively using nondispersive infrared (NDIR) absorption and gas chromatography with flame ionisation detection (GC/FID) techniques, respectively. Recently, commercially available instruments based on spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared (FTIR) spectroscopy have become more widely available and affordable. This resulted in a widespread use of these techniques at many measurement stations. This paper is focused on the comparison between a CRDS "travelling instrument" that has been used during performance audits within the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO) with instruments incorporating other, more traditional techniques for measuring CO2 and CH4 (NDIR and GC/FID). We demonstrate that CRDS instruments and likely other spectroscopic techniques are suitable for WMO/GAW stations and allow a smooth continuation of historic CO2 and CH4 time series. Moreover, the analysis of the audit results indicates that the spectroscopic techniques have a number of advantages over the traditional methods which will lead to the improved accuracy of atmospheric CO2 and CH4 measurements.

A general circulation model study of the climatic effect of observed stratospheric ozone depletion between 1980 and 1990

NASA Technical Reports Server (NTRS)

Dudek, Michael P.; Wang, Wei-Chyung; Liang, Xin-Zhong; Li, Zhu

1994-01-01

The total ozone mapping spectrometer (TOMS) and stratospheric aerosol and gas experiment (SAGE) measurements show a significant reduction in the stratospheric ozone over the middle and high latitudes of both hemispheres between the years 1979 and 1991 (WMO, 1992). This change in ozone will effect both the solar and longwave radiation with climate implications. However, recent studies (Ramaswamy et al., 1992; WMO, 1992) indicate that the net effect depends not only on latitudes and seasons, but also on the response of the lower stratospheric temperature. In this study we use a general circulation model (GCM) to calculate the climatic effect due to stratospheric ozone depletion and compare the effect with that due to observed increases of trace gases CO2, CH4, N2O, and CFC's for the period 1980-1990. In the simulations, we use the observed changes in ozone derived from the TOMS data. The GCM used is a version of the NCAR community climate model referenced in Wang et al. (1991). For the present study we run the model in perpetual January and perpetual July modes in which the incoming solar radiation and climatological sea surface temperatures are held constant.

Results of international Dobson spectrophotometer calibrations at Arosa, Switzerland, 1990

NASA Technical Reports Server (NTRS)

Grass, R. D.; Komhyr, W. D.; Koenig, G. L.; Evans, R. D.

1994-01-01

An international comparison of Dobson ozone spectrophotometers, organized and partially funded by the World Meteorological Organization (WMO), was held at the Lichtklimatisches Observatorium (LKO) in Arosa, Switzerland, July-August 1990. Countries participating with a total of 18 Dobson instruments were Belgium, Czechoslovakia, Denmark, Germany, Greece, Hungary, Iceland, Norway, Poland, Portugal, Rumania, Spain, Switzerland, the United Kingdom, the United States, and the United Soviet Socialist Republics. The reference standard instrument for the comparison was U.S.A. Secondary Standard Dobson Spectrophotometer 65 maintained by the NOAA Climate and Monitoring and Diagnostics Laboratory, Boulder, Colorado. The mean difference in ozone obtained with the Dobson instruments relative to Dobson instrument 65, calculated from ADDSGQP observations in the air mass range 1.15-3.2, was minus 1.0 plus or minus 1.2 (1 sigma) percent. The WMO Standard Brewer Spectrometer 39 also participated. In the mean, the Brewer instrument measured 0.6 plus or minus 0.2 (1 sigma) percent more ozone than did Dobson instrument 65. Results are presented, also, of ozone vertical profile measurements made with the Dobson instruments, two Brewer spectrometers, a LIDAR, a balloon ozonesonde flown from Hohenpeissenberg, Germany, and balloon ozonesondes flown from Payerne, Switzerland.

Communication and logging hub for rapid prototyping of environmental sensors: presenting the Smartphone.

NASA Astrophysics Data System (ADS)

Hut, R.

2017-12-01

When desiging prototype sensors for environmental variables a critical step is a comparison campaign where the new sensor is compared to current state of the art sensors. In this step one of the headaches for researchers can be connecting their sensor to a logging or communication device. I present a simple solution: to use smartphone that scans for Bluetooth Low Energy transmissions and uploads any measurement to a data server. In this way the prototype sensor only has to transmit its measurement values over BLE, which can be done using off-the-shelf components. The sensors don't have to be physically connected to the phone, allowing for very rapid deployment of sensors in locations that have a communication hub (ie. phone) installed. The communication and logging hub consists of nothing more than a low cost Android smartphone running a dedicated app. The phone is encased in a waterproof box with a large powerbank and a solar panel. I will demonstrate this live at the Fall Meeting. By installing these phones along permanent WMO certified station locations, comparisons campaigns can use the "golden standard" from the WMO without much problems.

An evaluation of the uncertainty of extreme events statistics at the WMO/CIMO Lead Centre on precipitation intensity

NASA Astrophysics Data System (ADS)

Colli, M.; Lanza, L. G.; La Barbera, P.

2012-12-01

Improving the quality of point-scale rainfall measurements is a crucial issue fostered in recent years by the WMO Commission for Instruments and Methods of Observation (CIMO) by providing recommendations on the standardization of equipment and exposure, instrument calibration and data correction as a consequence of various comparative campaigns involving manufacturers and national meteorological services from the participating countries. The WMO/CIMO Lead Centre on Precipitation Intensity (LC) was recently constituted, in a joint effort between the Dep. of Civil, Chemical and Environmental Engineering of the University of Genova and the Italian Air Force Met Service, gathering the considerable asset of data and information achieved by the past infield and laboratory campaigns with the aim of researching novel methodologies for improving the accuracy of rainfall intensity (RI) measurement techniques. Among the ongoing experimental activities carried out by the LC laboratory particular attention is paid to the reliability evaluation of extreme rainfall events statistics , a common tool in the engineering practice for urban and non urban drainage system design, based on real world observations obtained from weighing gauges. Extreme events statistics were proven already to be highly affected by the traditional tipping-bucket rain gauge RI measurement inaccuracy (La Barbera et al., 2002) and the time resolution of the available RI series certainly constitutes another key-factor in the reliability of the derived hyetographs. The present work reports the LC laboratory efforts in assembling a rainfall simulation system to reproduce the inner temporal structure of the rainfall process by means of dedicated calibration and validation tests. This allowed testing of catching type rain gauges under non-steady flow conditions and quantifying, in a first instance, the dynamic behaviour of the investigated instruments. Considerations about the influence of the dynamic response on the uncertainty budget of modern rain gauges is also shown . The analysis proceeds with the laboratory simulation of the annual maximum rainfall events recorded for different durations at the Villa Cambiaso meteo-station (University of Genova) over the last two decades. Results are reported and discussed in a comparative form involving the derived extreme events statistics. REFERENCES La Barbera P., Lanza L.G. and Stagi L. (2002). Influence of systematic mechanical errors of tipping-bucket rain gauges on the statistics of rainfall extremes. Water Sci. Techn., 45(2), 1-9. Colli M., Lanza L.G., and Chan P.W. (2011). Co-located tipping-bucket and optical drop counter RI measurements and a simulated correction algorithm, Atmos. Res., doi:10.1016/j.atmosres.2011.07.018 Colli M., Lanza L.G., La Barbera P. (2012). Weighing gauges measurement errors and the design rainfall for urban scale applications. 9th International workshop on precipitation in urban areas. St.Moritz, Switzerland, 6-9 December 2012 Lanza L.G. and Vuerich E. (2009). The WMO Field Intercomparison of Rain Intensity Gauges. Atmos. Res., 94, 534-543.

The CTBTO/WMO Atmospheric Backtracking Response System and the Data Fusion Exercise 2007

DTIC Science & Technology

2008-09-01

sensitivity of the measurement (sample) towards releases at all points on the globe . For a more comprehensive description, see the presentation from last...localization information, including the error ellipse, is comparatively small. The red spots on the right image mark seismic events that occurred on...hours indicated in the calendar of the PTS post-processing software WEB- GRAPE . 2008 Monitoring Research Review: Ground-Based Nuclear

Testing and development of transfer functions for weighing precipitation gauges in WMO-SPICE

NASA Astrophysics Data System (ADS)

Kochendorfer, John; Nitu, Rodica; Wolff, Mareile; Mekis, Eva; Rasmussen, Roy; Baker, Bruce; Earle, Michael E.; Reverdin, Audrey; Wong, Kai; Smith, Craig D.; Yang, Daqing; Roulet, Yves-Alain; Meyers, Tilden; Buisan, Samuel; Isaksen, Ketil; Brækkan, Ragnar; Landolt, Scott; Jachcik, Al

2018-02-01

Weighing precipitation gauges are used widely for the measurement of all forms of precipitation, and are typically more accurate than tipping-bucket precipitation gauges. This is especially true for the measurement of solid precipitation; however, weighing precipitation gauge measurements must still be adjusted for undercatch in snowy, windy conditions. In WMO-SPICE (World Meteorological Organization Solid Precipitation InterComparison Experiment), different types of weighing precipitation gauges and shields were compared, and adjustments were determined for the undercatch of solid precipitation caused by wind. For the various combinations of gauges and shields, adjustments using both new and previously existing transfer functions were evaluated. For most of the gauge and shield combinations, previously derived transfer functions were found to perform as well as those more recently derived. This indicates that wind shield type (or lack thereof) is more important in determining the magnitude of wind-induced undercatch than the type of weighing precipitation gauge. It also demonstrates the potential for widespread use of the previously developed transfer functions. Another overarching result was that, in general, the more effective shields, which were associated with smaller unadjusted errors, also produced more accurate measurements after adjustment. This indicates that although transfer functions can effectively reduce measurement biases, effective wind shielding is still required for the most accurate measurement of solid precipitation.

Calibration of the Total Carbon Column Observing Network using Aircraft Profile Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wunch, Debra; Toon, Geoffrey C.; Wennberg, Paul O.

2010-03-26

The Total Carbon Column Observing Network (TCCON) produces precise measurements of the column average dry-air mole fractions of CO{sub 2}, CO, CH{sub 4}, N{sub 2}O and H{sub 2}O at a variety of sites worldwide. These observations rely on spectroscopic parameters that are not known with sufficient accuracy to compute total columns that can be used in combination with in situ measure ments. The TCCON must therefore be calibrated to World Meteorological Organization (WMO) in situ trace gas measurement scales. We present a calibration of TCCON data using WMO-scale instrumentation aboard aircraft that measured profiles over four TCCON stations during 2008more » and 2009. The aircraft campaigns are the Stratosphere-Troposphere Analyses of Regional Transport 2008 (START-08), which included a profile over the Park Falls site, the HIAPER Pole-to-Pole Observations (HIPPO-1) campaign, which included profiles over the Lamont and Lauder sites, a series of Learjet profiles over the Lamont site, and a Beechcraft King Air profile over the Tsukuba site. These calibrations are compared with similar observations made during the INTEX-NA (2004), COBRA-ME (2004) and TWP-ICE (2006) campaigns. A single, global calibration factor for each gas accurately captures the TCCON total column data within error.« less

Spectroscopic metrology for isotope composition measurements and transfer standards

NASA Astrophysics Data System (ADS)

Anyangwe Nwaboh, Javis; Balslev-Harder, David; Kääriäinen, Teemu; Richmond, Craig; Manninen, Albert; Mohn, Joachim; Kiseleva, Maria; Petersen, Jan C.; Werhahn, Olav; Ebert, Volker

2017-04-01

The World Meteorological Organization (WMO) has identified greenhouse gases such as CO2, CH4 and N2O as critical for global climate monitoring. Other molecules such as CO that has an indirect effect of enhancing global warming are also monitored. WMO has stated compatibility goals for atmospheric concentration and isotope ratio measurements of these gases, e.g. 0.1 ppm for CO2 concentration measurements in the northern hemisphere and 0.01 ‰ for δ13C-CO2. For measurements of the concentration of greenhouse gases, gas analysers are typically calibrated with static gas standards e.g. traceable to the WMO scale or to the International System of Units (SI) through a national metrology institute. However, concentrations of target components, e.g. CO, in static gas standards have been observed to drift, and typically the gas matrix as well as the isotopic composition of the target component does not always reflect field gas composition, leading to deviations of the analyser response, even after calibration. The deviations are dependent on the measurement technique. To address this issue, part of the HIGHGAS (Metrology for high-impact greenhouse gases) project [1] focused on the development of optical transfer standards (OTSs) for greenhouse gases, e.g. CO2 and CO, potentially complementing gas standards. Isotope ratio mass spectrometry (IRMS) [2] is currently used to provide state-of-the-art high precision (in the 0.01 ‰ range) measurements for the isotopic composition of greenhouse gases. However, there is a need for field-deployable techniques such as optical isotope ratio spectroscopy (OIRS) that can be combined with metrological measurement methods. Within the HIGHGAS project, OIRS methods and procedures based on e.g. cavity enhanced spectroscopy (CES) and tunable diode laser absorption spectroscopy (TDLAS), matched to metrological principles have been established for the measurement of 13C/12C and 18O/16O ratios in CO2, 15N/14N ratios in N2O, and 13C/12C and 2H/1H ratios in CH4. Here, based on HIGHGAS project results, we present OTSs for atmospheric CO2 and CO measurements. The results delivered by the OTSs are in excellent agreement with gravimetric values of metrological "primary" static gas standards. The repeatabilities of the OTS results are matching the compatibility goals stated by WMO for atmospheric CO2 and CO measurements. In addition, we present OIRS measurement methods and procedures to demonstrate their applicability and validation. The requirements on, e.g. absorption line data quality and temperature sensitivity of isotope ratio, are discussed. Uncertainty budgets are presented and the traceability of the results is addressed. The current limitations in our measurements are discussed and steps taken to address these limitations are presented. Acknowledgement Parts of this work have been carried out within the European Metrology Research Programme (EMRP) ENV52 project-HIGHGAS. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. References [1] EMRP project ENV52-HIGHGAS, available at: http://www.euramet.org/ [2] Prosenjit Ghosh, Willi A. Brand, International Journal of Mass Spectrometry 228, 1-33 (2003).

Conflicts of Shared Resources: A Case Study of River Nile

DTIC Science & Technology

2012-03-22

as Lake Kivu. Rwanda joined the earlier Nile basin project, Hydromet , in 1967, with the support on the UNDP. 18 Although the country does not...operation Hydromet . In 1967, with the assistance of the United Nations Development Program (UNDP) and the World Meteorological Organization (WMO), Egypt...Kenya, Sudan, Tanzania and Uganda launched the Hydromet Survey project to regulate the water level of the Nile.”30 Rwanda joined later while Ethiopia

CfRadial - CF NetCDF for Radar and Lidar Data in Polar Coordinates.

NASA Astrophysics Data System (ADS)

Dixon, M. J.; Lee, W. C.; Michelson, D.; Curtis, M.

2016-12-01

Since 1990, NCAR has supported over 20 different data formats for radar and lidar data in polar coordinates. Researchers, students and operational users spend unnecessary time handling a multitude of unique formats. CfRadial grew out of the need to simplify the use of these data and thereby to improve efficiency in research and operations. CfRadial adopts the well-known NetCDF framework, along with the Climate and Forecasting (CF) conventions such that data and metadata are accurately represented. Mobile platforms are also supported. The first major release, CfRadial version 1.1, occurred in February 2011, followed by minor updates. CfRadial has been adopted by NCAR as well as other agencies in the US and the UK. CfRadial development was boosted in 2015 through a two-year NSF EarthCube grant to improve CF in general. Version 1.4 was agreed upon in May 2016, adding explicit support for quality control fields and spectra. In Europe and Australia, EUMETNET OPERA's HDF5-based ODIM_H5 standard has been rapidly embraced as the modern standard for exchanging weather radar data for operations. ODIM_H5 exploits data groups, hierarchies, and built-in compression, characteristics that have been added to NetCDF4. A meeting of the WMO Task Team on Weather Radar Data Exchange (TT-WRDE) was held at NCAR in Boulder in July 2016, with a goal of identifying a single global standard for radar and lidar data in polar coordinates. CfRadial and ODIM_H5 were considered alongside the older and more rigid table-driven WMO BUFR and GRIB2 formats. TT-WRDE recommended that CfRadial 1.4 be merged with the sweep-oriented structure of ODIM_H5, making use of NetCDF groups, to produce a single format that will encompass the best ideas of both formats. That has led to the emergence of the CfRadial 2.0 standard. This format should meet the objectives of both the NSF EarthCube CF 2.0 initiative and the WMO TT-WRDE. It has the added benefit of improving data exchange between operational and research users, making operational data more readily available to researchers, and research algorithms more accessible to operational agencies.

Potential and Challenges of Low-Cost and High-Tech Crowd-sensing Approaches in Hydrometeorology for Better Water Resources Management - Insights and Learnings from the Global iMoMo Initiative

NASA Astrophysics Data System (ADS)

Siegfried, Tobias

2016-04-01

In developing and transition countries and despite significant global investments in hydrometeorology, data on water remain scarce/fragmented. One key reason is that traditional sensing in hydrology, hydro- and agro-meteorology does not scale because of high investment costs and difficult maintenance of traditional technology, esp. in remote and/or poor regions. Even where there are data, these are often difficult to access and interpret for local stakeholders due outdated data transmission and the lack of access to modern tools for data management/analysis/synthesis and exchange. In recent years, there have been substantial technology developments in environmental sensing and mobile communication technology that enable the application and deployment of affordable and scalable high-tech solutions for better water monitoring at different scales (local to transboundary levels). The WMO is acknowledging and promoting the potential for application of these technologies. One key aspect is to anchor these technologies in local communities that perform crowd-sensing tasks on a regular basis. The merits as well as challenges (including introduction of human factor, less accuracy as compared to traditional sensing, intermittency of data, …) of such approaches will be discussed in the context of the WMO-led Global iMoMo Initiative and its numerous activities on the ground in Eastern and Southern Africa as well as in Central Asia.

Mexican national pyronometer network calibration

NASA Astrophysics Data System (ADS)

VAldes, M.; Villarreal, L.; Estevez, H.; Riveros, D.

2013-12-01

In order to take advantage of the solar radiation as an alternate energy source it is necessary to evaluate the spatial and temporal availability. The Mexican National Meterological Service (SMN) has a network with 136 meteorological stations, each coupled with a pyronometer for measuring the global solar radiation. Some of these stations had not been calibrated in several years. The Mexican Department of Energy (SENER) in order to count on a reliable evaluation of the solar resource funded this project to calibrate the SMN pyrometer network and validate the data. The calibration of the 136 pyronometers by the intercomparison method recommended by the World Meterological Organization (WMO) requires lengthy observations and specific environmental conditions such as clear skies and a stable atmosphere, circumstances that determine the site and season of the calibration. The Solar Radiation Section of the Instituto de Geofísica of the Universidad Nacional Autónoma de México is a Regional Center of the WMO and is certified to carry out the calibration procedures and emit certificates. We are responsible for the recalibration of the pyronometer network of the SMN. A continuous emission solar simulator with exposed areas with 30cm diameters was acquired to reduce the calibration time and not depend on atmospheric conditions. We present the results of the calibration of 10 thermopile pyronometers and one photovoltaic cell by the intercomparison method with more than 10000 observations each and those obtained with the solar simulator.

Measurement of precipitation using lysimeters

NASA Astrophysics Data System (ADS)

Fank, Johann; Klammler, Gernot

2013-04-01

Austria's alpine foothill aquifers contain important drinking water resources, but are also used intensively for agricultural production. These groundwater bodies are generally recharged by infiltrating precipitation. A sustainable water resources management of these aquifers requires quantifying real evapotranspiration (ET), groundwater recharge (GR), precipitation (P) and soil water storage change (ΔS). While GR and ΔS can be directly measured by weighable lysimeters and P by separate precipitation gauges, ET is determined by solving the climatic water balance ET = P GR ± ΔS. According to WMO (2008) measurement of rainfall is strongly influenced by precipitation gauge errors. Most significant errors result from wind loss, wetting loss, evaporation loss, and due to in- and out-splashing of water. Measuring errors can be reduced by a larger area of the measuring gaugés surface and positioning the collecting vessel at ground level. Modern weighable lysimeters commonly have a surface of 1 m², are integrated into their typical surroundings of vegetation cover (to avoid oasis effects) and allow scaling the mass change of monolithic soil columns in high measuring accuracy (0.01 mm water equivalent) and high temporal resolution. Thus, also precipitation can be quantified by measuring the positive mass changes of the lysimeter. According to Meissner et al. (2007) also dew, fog and rime can be determined by means of highly precise weighable lysimeters. Furthermore, measuring precipitation using lysimeters avoid common measuring errors (WMO 2008) at point scale. Though, this method implicates external effects (background noise, influence of vegetation and wind) which affect the mass time series. While the background noise of the weighing is rather well known and can be filtered out of the mass time series, the influence of wind, which blows through the vegetation and affects measured lysimeter mass, cannot be corrected easily since there is no clear relation between wind speeds and the measured outliers of lysimeter mass. Moreover, the influence of wind seems to be varying for different lysimeters. At the agricultural test site Wagna, Austria, two precipitation gauges in high temporal resolution (weighing-recording gauge and tipping-bucket gauge; both 200 cm² surface; measuring height 1.5 m) are installed. Furthermore, mass time series of various lysimeters cultivated with different vegetation is also available for the same location. Appropriate methods to compensate the influence of wind on measuring precipitation using lysimeters are investigated and results between the different measuring devices are compared. Results show that precipitation measured with lysimeters is generally higher, especially compared to the weighing-recording gauge. In addition it is detected that also the data interval of lysimeter mass time series used for quantifying precipitation (e.g., 1 day, 1 hour, 30 minutes, 10 minutes) is a crucial factor and influences the result. Summarizing, the potential of using highly precise weighable lysimeters for measuring precipitation at the point scale is rather high. However, methods used to compensate external effects on lysimeter weighing have to be enhanced for a global application of using lysimeters as precipitation gauges. Meissner, R., J. Seeger, H. Rupp, M. Seyfarth & H. Borg, 2007: Measurement of dew, fog, and rime with a high-precision gravitation Lysimeter. J. Plant Nutr. Soil Sci. 2007, 170, p. 335-344. WMO (World Meteorological Organization), 2008. Guide to Meteorological Instruments and Methods of Observation. WMO-No. 8, 140 pp.

Station Climatic Summaries, Asia

DTIC Science & Technology

1989-07-01

488640 7108 (CB) ......................................................... 589 CON SON/POULO CONDORE 489180 7105 (CB...STATION NAME BAHRAIN/KJS4ARR9AQ LoM4AIN pERlIOD: FEB 49-FES 81 9 STIN LYtS: 0111 MARCH 1982 LOCATION N26 17 EOS0 Z,7 ILEV 6 FT w gMo .; 325031 wwMoO. m A...357 0 WCLIMATBRIEF OABU NOME LUZON I, PHILIPPINEs PERIOO:1949-63 ’WMO * 98223 Pro ed by ETAC ( MAR 1972 N 1811 E120 2 FIELD ELEMTION: 13 ftSTNLTRS: RPML

Coastal wetlands and global change: overview

USGS Publications Warehouse

Guntenspergen, G.R.; Vairin, B.; Burkett, V.R.

1997-01-01

The potential impacts of climate change are of great practical concern to those interested in coastal wetland resources. Among the areas of greatest risk in the United States are low-lying coastal habitats with easily eroded substrates which occur along the northern Gulf of Mexico and southeast Atlantic coasts. The Intergovernmental Panel on Climate Change (IPCC) and the World Meteorological Organization (WMO) have identified coastal wetlands as ecosystems most vulnerable to direct, large-scale impacts of climate change, primarily because of their sensitivity to increases in sea-level rise.

Planning and conducting an international seismic data exchange experiment at the center for seismic studies

NASA Astrophysics Data System (ADS)

Romney, C.; Huszar, L.; Frazier, G. A.; Campanella, A.; Tiberio, M. A.

1986-01-01

This report covers preparations for and the conduct of an international seismic data exchange experiment sponsored by the Group of Scientific Experts, U.N. Conference on Disarmament. Seismic data reports from 37 countries were transmitted over circuits of the WMO/GTS. The data were analyzed at centers in Washington, Moscow and Stockholm and epicenter lists were broadcast to participants. The experiment tested a number of aspects of a proposed nuclear test monitoring system.

Optical, structural and electrochromic properties of sputter- deposited W-Mo oxide thin films

NASA Astrophysics Data System (ADS)

Gesheva, K.; Arvizu, M. A.; Bodurov, G.; Ivanova, T.; Niklasson, G. A.; Iliev, M.; Vlakhov, T.; Terzijska, P.; Popkirov, G.; Abrashev, M.; Boyadjiev, S.; Jágerszki, G.; Szilágyi, I. M.; Marinov, Y.

2016-10-01

Thin metal oxide films were investigated by a series of characterization techniques including impedance spectroscopy, spectroscopic ellipsometry, Raman spectroscopy, and Atomic Force Microscopy. Thin film deposition by reactive DC magnetron sputtering was performed at the Ångström Laboratory. W and Mo targets (5 cm diameter) and various oxygen gas flows were employed to prepare samples with different properties, whereas the gas pressure was kept constant at about 30 mTorr. The substrates were 5×5 cm2 plates of unheated glass pre-coated with ITO having a resistance of 40 ohm/sq. Film thicknesses were around 300 nm as determined by surface profilometry. Newly acquired equipment was used to study optical spectra, optoelectronic properties, and film structure. Films of WO3 and of mixed W- Mo oxide with three compositions showed coloring and bleaching under the application of a small voltage. Cyclic voltammograms were recorded with a scan rate of 5 mV s-1. Ellipsometric data for the optical constants show dependence on the amount of MoOx in the chemical composition. Single MoOx film, and the mixed one with only 8% MoOx have the highest value of refractive index, and similar dispersion in the visible spectral range. Raman spectra displayed strong lines at wavenumbers between 780 cm-1 and 950 cm-1 related to stretching vibrations of WO3, and MoO3. AFM gave evidence for domains of different composition in mixed W-Mo oxide films.

Results from the Fourth WMO Filter Radiometer Comparison for aerosol optical depth measurements

NASA Astrophysics Data System (ADS)

Kazadzis, Stelios; Kouremeti, Natalia; Diémoz, Henri; Gröbner, Julian; Forgan, Bruce W.; Campanelli, Monica; Estellés, Victor; Lantz, Kathleen; Michalsky, Joseph; Carlund, Thomas; Cuevas, Emilio; Toledano, Carlos; Becker, Ralf; Nyeki, Stephan; Kosmopoulos, Panagiotis G.; Tatsiankou, Viktar; Vuilleumier, Laurent; Denn, Frederick M.; Ohkawara, Nozomu; Ijima, Osamu; Goloub, Philippe; Raptis, Panagiotis I.; Milner, Michael; Behrens, Klaus; Barreto, Africa; Martucci, Giovanni; Hall, Emiel; Wendell, James; Fabbri, Bryan E.; Wehrli, Christoph

2018-03-01

This study presents the results of the Fourth Filter Radiometer Comparison that was held in Davos, Switzerland, between 28 September and 16 October 2015. Thirty filter radiometers and spectroradiometers from 12 countries participated including reference instruments from global aerosol networks. The absolute differences of all instruments compared to the reference have been based on the World Meteorological Organization (WMO) criterion defined as follows: 95% of the measured data has to be within 0.005 ± 0.001/m (where m is the air mass). At least 24 out of 29 instruments achieved this goal at both 500 and 865 nm, while 12 out of 17 and 13 out of 21 achieved this at 368 and 412 nm, respectively. While searching for sources of differences among different instruments, it was found that all individual differences linked to Rayleigh, NO2, ozone, water vapor calculations and related optical depths and air mass calculations were smaller than 0.01 in aerosol optical depth (AOD) at 500 and 865 nm. Different cloud-detecting algorithms used have been compared. Ångström exponent calculations showed relatively large differences among different instruments, partly because of the high calculation uncertainty of this parameter in low AOD conditions. The overall low deviations of these AOD results and the high accuracy of reference aerosol network instruments demonstrated a promising framework to achieve homogeneity, compatibility and harmonization among the different spectral AOD networks in the near future.

Interaction of the Global Energy and Water Cycle Experiment (GEWEX) Water Resources Applications Project (WRAP) and Coordinated Enhanced Observing Project (CEOP) in Support of Water Resource Management and Planning

NASA Astrophysics Data System (ADS)

Martz, L.

2004-05-01

The Water Resources Applications Project (WRAP) has been developed within the Global Energy and Water Cycle Experiment (GEWEX) to facilitate the testing of GEWEX products and their transfer to operational water managers. The WRAP activity builds upon projects within the GEWEX Continental Scale Experiments (CSEs), and facilitates dialogue between these CSEs and their local water management communities regarding their information needs and opportunities for GEWEX products to meet those needs. Participating Continental Scale Experiments are located in the United States, the Mackenzie River Basin in Canada, the Amazon River Basin in Brazil, the Baltic Sea drainage area, eastern Asia and the Murray-Darling Basin in Australia. In addition, the development of WRAP is facilitating the transfer of techniques and demonstration projects to other areas through collaboration with IAHS, UNESCO/WMO HELP, WMO Hydrology and WWAP. The initiation of CEOP presents a significant new opportunity for collaborations to support the application of global hydro-climatological scientific data and techniques to water resource management. Some important scientific and operational issues identified by water resource management professionals in earlier workshops will be reviewed, some scientific initiatives needed to address these issues will be presented, and some case study examples of the application of GEWEX knowledge to water resource problems will be presented. Against this background, the unique opportunities that CEOP provides to improve our use and management of water resources globally will be discussed.

Evaluating the Impact of Aerosols on Numerical Weather Prediction

NASA Astrophysics Data System (ADS)

Freitas, Saulo; Silva, Arlindo; Benedetti, Angela; Grell, Georg; Members, Wgne; Zarzur, Mauricio

2015-04-01

The Working Group on Numerical Experimentation (WMO, http://www.wmo.int/pages/about/sec/rescrosscut/resdept_wgne.html) has organized an exercise to evaluate the impact of aerosols on NWP. This exercise will involve regional and global models currently used for weather forecast by the operational centers worldwide and aims at addressing the following questions: a) How important are aerosols for predicting the physical system (NWP, seasonal, climate) as distinct from predicting the aerosols themselves? b) How important is atmospheric model quality for air quality forecasting? c) What are the current capabilities of NWP models to simulate aerosol impacts on weather prediction? Toward this goal we have selected 3 strong or persistent events of aerosol pollution worldwide that could be fairly represented in current NWP models and that allowed for an evaluation of the aerosol impact on weather prediction. The selected events includes a strong dust storm that blew off the coast of Libya and over the Mediterranean, an extremely severe episode of air pollution in Beijing and surrounding areas, and an extreme case of biomass burning smoke in Brazil. The experimental design calls for simulations with and without explicitly accounting for aerosol feedbacks in the cloud and radiation parameterizations. In this presentation we will summarize the results of this study focusing on the evaluation of model performance in terms of its ability to faithfully simulate aerosol optical depth, and the assessment of the aerosol impact on the predictions of near surface wind, temperature, humidity, rainfall and the surface energy budget.

Gas adsorption and desorption effects on high pressure small volume cylinders and their relevance to atmospheric trace gas analysis

NASA Astrophysics Data System (ADS)

Satar, Ece; Nyfeler, Peter; Pascale, Céline; Niederhauser, Bernhard; Leuenberger, Markus

2017-04-01

Long term atmospheric monitoring of trace gases requires great attention to precision and accuracy of the measurement setups. For globally integrated and well established greenhouse gas observation networks, the World Meteorological Organization (WMO) has set recommended compatibility goals within the framework of its Global Atmosphere Watch (GAW) Programme [1]. To achieve these challenging limits, the measurement systems are regularly calibrated with standard gases of known composition. Therefore, the stability of the primary and secondary gas standards over time is an essential issue. Past studies have explained the small instabilities in high pressure standard gas cylinders through leakage, diffusion, regulator effects, gravimetric fractionation and surface processes [2, 3]. The latter include adsorption/desorption, which are functions of temperature, pressure and surface properties. For high pressure standard gas mixtures used in atmospheric trace gas analysis, there exists only a limited amount of data and few attempts to quantify the surface processes [4, 5]. Specifically, we have designed a high pressure measurement chamber to investigate trace gases and their affinity for adsorption on different surfaces over various temperature and pressure ranges. Here, we focus on measurements of CO2, CH4 and CO using a cavity ring down spectroscopy analyzer and quantify the concentration changes due to adsorption/desorption. In this study, the first results from these prototype cylinders of steel and aluminum will be presented. References [1] World Meteorological Organization (WMO), Global Atmosphere Watch.(GAW): Report No. 229, 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques (GGMT-2015), 2016. [2] Keeling, R. F., Manning, A. C., Paplawsky, W. J., and Cox, A. C.: On the long-term stability of reference gases for atmospheric O2 /N2 and CO2 measurements, Tellus B, 59, 10.3402/tellusb.v59i1.16964, 2007. [3] Langenfelds, R. L., van der Schoot, M. V., Francey, R. J., Steele, L. P., Schmidt, M., and Mukai, H.: Modification of air standard composition by diffusive and surface processes, Journal of Geophysical Research: Atmospheres, 110, n/a-n/a, 10.1029/2004JD005482, 2005. [4] Leuenberger, M. C., Schibig, M. F., and Nyfeler, P.: Gas adsorption and desorption effects on cylinders and their importance for long-term gas records, Atmos. Meas. Tech., 8, 5289-5299, 10.5194/amt-8-5289-2015, 2015 [5] Miller, W. R., Rhoderick, G. C., and Guenther, F. R.: Investigating Adsorption/Desorption of Carbon Dioxide in Aluminum Compressed Gas Cylinders, Analytical Chemistry, 87, 1957-1962, 10.1021/ac504351b, 2015.

Air Weather Service Master Station Catalog USAFETAC Climatic Database Users Handbook No. 6

DTIC Science & Technology

1993-03-01

PENNSYLVANIA PA INDIANA IN RHODE ISLAND RI IOWA IA SOUTH CAROLINA SC KANSAS KS SOUTH DAKOTA SD KENTUCKY KY TENNESSEE TN LOUISIANA LA TEXAS TX MAINE ME...ASSOCIATED WMO BLOCKS AB ALBANIA 13 AG ARGENTINA 87,88 AH AFGHANISTAN 40 Al ASCENSION ISLAND 61 AL ALGERIA 60 AN ANGOLA 66 AT ANTIGUA, ST.KITTS...BENIN 65 BM BURMA/MYANMAR 48 BN BAHRAIN 40,41 BO BOLIVIA 85 BR BARBADOS 78 BT’ BRITISH INDIAN OCEAN TERRITORY 61 BU BULGARIA 15 BV BOUVET ISLAND 68 BW

Long-term stability measurements of low concentration Volatile Organic Compound gas mixtures

NASA Astrophysics Data System (ADS)

Allen, Nick; Amico di Meane, Elena; Brewer, Paul; Ferracci, Valerio; Corbel, Marivon; Worton, David

2017-04-01

VOCs (Volatile Organic Compounds) are a class of compounds with significant influence on the atmosphere due to their large anthropogenic and biogenic emission sources. VOC emissions have a significant impact on the atmospheric hydroxyl budget and nitrogen reservoir species, while also contributing indirectly to the production of tropospheric ozone and secondary organic aerosol. However, the global budget of many of these species are poorly constrained. Moreover, the World Meteorological Organization's (WMO) Global Atmosphere Watch (GAW) have set challenging data quality objectives for atmospheric monitoring programmes for these classes of traceable VOCs, despite the lack of available stable gas standards. The Key-VOCs Joint Research Project is an ongoing three-year collaboration with the aim of improving the measurement infrastructure of important atmospheric VOCs by providing traceable and comparable reference gas standards and by validating new measurement systems in support of the air monitoring networks. It focuses on VOC compounds that are regulated by European legislation, that are relevant for indoor air monitoring and for air quality and climate monitoring programmes like the VOC programme established by the WMO GAW and the European Monitoring and Evaluation Programme (EMEP). These VOCs include formaldehyde, oxy[genated]-VOCs (acetone, ethanol and methanol) and terpenes (a-pinene, 1,8-cineole, δ-3-carene and R-limonene). Here we present the results of a novel long term stability study for low concentration formaldehyde, oxy-VOC and terpenes gas mixtures produced by the Key-VOCs consortium with discussion regarding the implementation of improved preparation techniques and the use of novel cylinder passivation chemistries to guarantee mixture stability.

Streamflow model of the six-country transboundary Ganges-Bhramaputra and Meghna river basin

NASA Astrophysics Data System (ADS)

Rahman, K.; Lehmann, A.; Dennedy-Frank, P. J.; Gorelick, S.

2014-12-01

Extremely large-scale river basin modelling remains a challenge for water resources planning in the developing world. Such planning is particularly difficult in the developing world because of the lack of data on both natural (climatological, hydrological) processes and complex anthropological influences. We simulate three enormous river basins located in south Asia. The Ganges-Bhramaputra and Meghna (GBM) River Basins cover an area of 1.75 million km2 associated with 6 different countries, including the Bengal delta, which is the most densely populated delta in the world with ~600 million people. We target this developing region to better understand the hydrological system and improve water management planning in these transboundary watersheds. This effort uses the Soil and Water Assessment Tool (SWAT) to simulate streamflow in the GBM River Basins and assess the use of global climatological datasets for such large scale river modeling. We evaluate the utility of three global rainfall datasets to reproduce measured river discharge: the Tropical Rainfall Measuring Mission (TRMM) from NASA, the National Centers for Environmental Prediction (NCEP) reanalysis, and the World Metrological Organization (WMO) reanalysis. We use global datasets for spatial information as well: 90m DEM from the Shuttle Radar Topographic Mission, 300m GlobCover land use maps, and 1000 km FAO soil map. We find that SWAT discharge estimates match the observed streamflow well (NSE=0.40-0.66, R2=0.60-0.70) when using meteorological estimates from the NCEP reanalysis. However, SWAT estimates diverge from observed discharge when using meteorological estimates from TRMM and the WMO reanalysis.

Atmospheric CO2 Record from In Situ Measurements at Amsterdam Island (1980-1995)

DOE Data Explorer

Gaudry, A. [Centre des Faibles Radioactivites, Laboratoire de Modelisation du Climat et de l'Environnement, Centre d'Etudes de Saclay, France; Kazan, V. [Centre des Faibles Radioactivites, Laboratoire de Modelisation du Climat et de l'Environnement, Centre d'Etudes de Saclay, France; Monfray, P. [Centre des Faibles Radioactivites, Laboratoire de Modelisation du Climat et de l'Environnement, Centre d'Etudes de Saclay, France

1996-09-01

Until 1993 air samples were collected continuously through an air intake located at the top of a tower, 9 m above ground and 65 m above mean sea level. Since 1994, the intake has been situated 20 m above ground and 76 m above mean sea level. The tower is located at the north-northwest end of the island on the edge of a 55 m cliff. The air is dried by means of a cryogenic water trap at -60°C. Until 1990, determinations of CO2 were made by using successively two Hartmann-Braun URAS 2T nondispersive infrared (NDIR) analyzers. Since 1991, CO2 determinations have been made using a Siemens ULTRAMAT 5F NDIR. Standard gases in use from October 1980 to December of 1984 were CO2-in-N2 mixtures certified by Scripps Institution of Oceanography (SIO). The N2 scale was corrected for the carrier gas effect to obtain the air scale (WMO mole fraction scale). In 1985, CO2-in-air mixtures expressed in the 1985 WMO mole fraction in air scale were introduced. In 1990, a new series of 12 primary standard gases were gravimetrically prepared, then linearly adjusted at the laboratory and checked several times (i.e., 1990, 1992, and 1993) through intercalibrations with DSIR in New Zealand and NOAA/CMDL, which both used the 1985 mole fraction scale. The agreement was always better than 0.1 ppm (Monfray et al. 1992). Since 1993, the 1993 mole fraction scale has been used thanks to a new series of 10 cylinders provided by SIO.

Visualization of uncertainties and forecast skill in user-tailored seasonal climate predictions for agriculture

NASA Astrophysics Data System (ADS)

Sedlmeier, Katrin; Gubler, Stefanie; Spierig, Christoph; Flubacher, Moritz; Maurer, Felix; Quevedo, Karim; Escajadillo, Yury; Avalos, Griña; Liniger, Mark A.; Schwierz, Cornelia

2017-04-01

Seasonal climate forecast products potentially have a high value for users of different sectors. During the first phase (2012-2015) of the project CLIMANDES (a pilot project of the Global Framework for Climate Services led by WMO [http://www.wmo.int/gfcs/climandes]), a demand study conducted with Peruvian farmers indicated a large interest in seasonal climate information for agriculture. The study further showed that the required information should by precise, timely, and understandable. In addition to the actual forecast, two complex measures are essential to understand seasonal climate predictions and their limitations correctly: forecast uncertainty and forecast skill. The former can be sampled by using an ensemble of climate simulations, the latter derived by comparing forecasts of past time periods to observations. Including uncertainty and skill information in an understandable way for end-users (who are often not technically educated) poses a great challenge. However, neglecting this information would lead to a false sense of determinism which could prove fatal to the credibility of climate information. Within the second phase (2016-2018) of the project CLIMANDES, one goal is to develop a prototype of a user-tailored seasonal forecast for the agricultural sector in Peru. In this local context, the basic education level of the rural farming community presents a major challenge for the communication of seasonal climate predictions. This contribution proposes different graphical presentations of climate forecasts along with possible approaches to visualize and communicate the associated skill and uncertainties, considering end users with varying levels of technical knowledge.

Stratospheric processes: Observations and interpretation

NASA Technical Reports Server (NTRS)

Brune, William H.; Cox, R. Anthony; Turco, Richard; Brasseur, Guy P.; Matthews, W. Andrew; Zhou, Xiuji; Douglass, Anne; Zander, Rudi J.; Prendez, Margarita; Rodriguez, Jose M.

1991-01-01

Explaining the observed ozone trends discussed in an earlier update and predicting future trends requires an understanding of the stratospheric processes that affect ozone. Stratospheric processes occur on both large and small spatial scales and over both long and short periods of time. Because these diverse processes interact with each other, only in rare cases can individual processes be studied by direct observation. Generally the cause and effect relationships for ozone changes were established by comparisons between observations and model simulations. Increasingly, these comparisons rely on the developing, observed relationships among trace gases and dynamical quantities to initialize and constrain the simulations. The goal of this discussion of stratospheric processes is to describe the causes for the observed ozone trends as they are currently understood. At present, we understand with considerable confidence the stratospheric processes responsible for the Antarctic ozone hole but are only beginning to understand the causes of the ozone trends at middle latitudes. Even though the causes of the ozone trends at middle latitudes were not clearly determined, it is likely that they, just as those over Antarctica, involved chlorine and bromine chemistry that was enhanced by heterogeneous processes. This discussion generally presents only an update of the observations that have occurred for stratospheric processes since the last assessment (World Meteorological Organization (WMO), 1990), and is not a complete review of all the new information about stratospheric processes. It begins with an update of the previous assessment of polar stratospheres (WMO, 1990), followed by a discussion on the possible causes for the ozone trends at middle latitudes and on the effects of bromine and of volcanoes.

Abundances of isotopologues and calibration of CO2 greenhouse gas measurements

NASA Astrophysics Data System (ADS)

Tans, Pieter P.; Crotwell, Andrew M.; Thoning, Kirk W.

2017-07-01

We have developed a method to calculate the fractional distribution of CO2 across all of its component isotopologues based on measured δ13C and δ18O values. The fractional distribution can be used with known total CO2 to calculate the amount of substance fraction (mole fraction) of each component isotopologue in air individually. The technique is applicable to any molecule where isotopologue-specific values are desired. We used it with a new CO2 calibration system to account for isotopic differences among the primary CO2 standards that define the WMO X2007 CO2-in-air calibration scale and between the primary standards and standards in subsequent levels of the calibration hierarchy. The new calibration system uses multiple laser spectroscopic techniques to measure mole fractions of the three major CO2 isotopologues (16O12C16O, 16O13C16O, and 16O12C18O) individually. The three measured values are then combined into total CO2 (accounting for the rare unmeasured isotopologues), δ13C, and δ18O values. The new calibration system significantly improves our ability to transfer the WMO CO2 calibration scale with low uncertainty through our role as the World Meteorological Organization Global Atmosphere Watch Central Calibration Laboratory for CO2. Our current estimates for reproducibility of the new calibration system are ±0.01 µmol mol-1 CO2, ±0.2 ‰ δ13C, and ±0.2 ‰ δ18O, all at 68 % confidence interval (CI).

Scientific Data as the Core Legacy of IPY

NASA Astrophysics Data System (ADS)

Parsons, M. A.

2008-12-01

The interdisciplinary breadth of the International Polar Year is unprecedented. The IPY has explicit objectives to link researchers across different fields to address questions and issues lying beyond the scope of individual disciplines and to strengthen international coordination of research and enhance international collaboration and cooperation. The IPY Data Policy and Management Subcommittee have developed a policy to help meet these objectives and an international collaboration of investigators and data managers, the IPY Data and Information Service, are working to make IPY data widely available. I will present an overview of the primary data management considerations for IPY and how diverse organizations are making IPY and related data available. Centralized discovery mechanisms for widely distributed data plus targeted access mechanisms for specific disciplines will be presented. These range from near real time access to satellite remote sensing data and GCM output to fair and appropriate access to traditional knowledge of the Arctic. These mechanisms reflect significant advancement in polar data management, but they belie the major challenges that remain. These challenges include fostering a culture change in science that puts greater value on data publication and open data access as well as developing sustained systems and business models for the long-term preservation of IPY data. This will be crucial to ensuring the legacy of IPY, a major objective of IPY sponsors, ICSU and WMO. New efforts to ensure this legacy include the development of the WMO Information System, the Sustained Arctic Observing Network, and the Global Earth Observing System of Systems; the reform of ICSU's World Data Center System; and the results of the Electronic Geophysical Year.

S201 Catalog of Far-Ultraviolet Objects. Revised.

DTIC Science & Technology

1982-05-06

separate report [9,291 and paper [301). The method for determining the UV brightnesses, of necessity, has been a computer-based pro - cess using a...indicates that the measured position is be*.,een 5 and 10 arc-min from the cataloged position ( con - sidered a doubtful identification). Thus a...m~ PS P m~ 0. ats 0 19 PAGE, CARRUTHERS, AND HECKATHORN w r-oWmwM ; M gMO -r o ’wmo- ’w I-W m- 2 f 30 L.9 ~ ~ ~ ~ ~ m W9±2N 00 0 0I0 00 000M00p.-0fmmm

Intercomparison of principal hydrometric instruments; Third phase, Evaluation of ultrasonic velocity meters for flow measurement in streams, canals, and estuaries

USGS Publications Warehouse

Melching, Charles S.; Meno, Michael W.

1998-01-01

As part of the World Meteorological Organization (WMO) project Intercomparison of Principal Hydrometric Instruments, Third Phase, a questionnaire was prepared by the U.S. Geological Survey (USGS) on the application of Ultrasonic Velocity Meters (UVM's) for flowmeasurement in streams, canals, and estuaries. In 1996, this questionnaire was distributed internationally by the WMO and USGS, and distributed within the United States by the USGS. Completed questionnaires were returned by 26 agencies in 7 countries (Canada, France, Germany, The Netherlands, Switzerland, the United Kingdom, and the United States). The completed questionnaires described geometric and streamflow conditions, system configurations, and reasons for applying UVM systems for 260 sites, thus providing information on the applicability of UVM systems throughout the world. The completed questionnaires also provided information on operational issues such as (1) methods used to determine and verify UVM ratings, (2) methods used to determine the mean flow velocity for UVM systems, (3) operational reliability of UVM systems, (4) methods to estimate missing data, (5) common problems with UVM systems and guidelines to mitigate these problems, and (6) personnel training issues. The completed questionnaires also described a few unique or novel applications of UVM systems. In addition to summarizing the completed questionnaires, this report includes a brief overview of UVM application and operation, and a short summary of current (1998) information from UVM system manufacturers regarding system cost and capabilities. On the basis of the information from the completed questionnaires and provided by the manufacturers, the general applicability of UVM systems is discussed. In the finalisation of this report the financial support provided by the US National Committee for Scientific Hydrology is gratefully acknowledged.

High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air

NASA Astrophysics Data System (ADS)

Rella, C. W.; Chen, H.; Andrews, A. E.; Filges, A.; Gerbig, C.; Hatakka, J.; Karion, A.; Miles, N. L.; Richardson, S. J.; Steinbacher, M.; Sweeney, C.; Wastine, B.; Zellweger, C.

2012-08-01

Traditional techniques for measuring the mole fractions of greenhouse gas in the well-mixed atmosphere have required extremely dry sample gas streams (dew point < -25 °C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmospheric Watch program of the World Meteorological Organization (WMO/GAW) for carbon dioxide (±0.1 ppm) and methane (±2 ppb). Drying the sample gas to low levels of water vapor can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular Cavity Ring Down Spectroscopy (CRDS), have led to the development of highly stable and precise greenhouse gas analyzers capable of highly accurate measurements of carbon dioxide, methane, and water vapor. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapor, these instruments permit for the first time accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapor correction factors, and we summarize a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterized dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to at least 1% water vapor. By determining the correction factors for individual instruments once at the start of life, this range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended above 4%.

Extended Edited Synoptic Cloud Reports from Ships and Land Stations Over the Globe, 1952-2009 (NDP-026C)

DOE Data Explorer

Hahn, C. J. [University of Arizona; Warren, S. G. [University of Washington; Eastman, R.

1999-08-01

This database contains surface synoptic weather reports for the entire globe, gathered from various available data sets. The reports were processed, edited, and rewritten to provide a single dataset of individual observations of clouds, spanning the 57 years 1952-2008 for ship data and the 39 years 1971-2009 for land station data. In addition to the cloud portion of the synoptic report, each edited report also includes the associated pressure, present weather, wind, air temperature, and dew point (and sea surface temperature over oceans). This data set is called the "Extended Edited Cloud Report Archive" (EECRA). The EECRA is based solely on visual cloud observations from weather stations, reported in the WMO synoptic code (WMO, 1974). Reports must contain cloud-type information to be included in the archive. Past data sources include those from the Fleet Numerical Oceanographic Center (FNOC, 1971-1976) and the National Centers for Environmental Prediction (NCEP, 1977-1996). This update uses data from a new source, the 'Integrated Surface Database' (ISD, 1997-2009; Smith et al., 2011). Our past analyses of the EECRA identified a subset of 5388 weather stations that were determined to produce reliable day and night observations of cloud amount and type. The update contains observations only from this subset of stations. Details concerning processing, previous problems, contents, and comments are available in the archive's original documentation . The EECRA contains about 81 million cloud observations from ships and 380 million from land stations. The data files have been compressed using unix. Unix/linux users can "uncompress" or "gunzip" the files after downloading. If you're interested in the NDP-026C database, then you'll also want to explore its related data products, NDP-026D and NDP-026E.

Towards Consistent Aerosol and Cloud Climate Data Records from the Along Track Scanning Radiometer instruments

NASA Astrophysics Data System (ADS)

Thomas, G.

2015-12-01

The ESA Climate Change Initiative (CCI) programme has provided a mechanism for the production of new long-term data records of essential climate variables (ECVs) defined by WMO Global Climate Observing System (GCOS). These include consistent cloud (from the MODIS, AVHRR, ATSR-2 and AATSR instruments) and aerosol (from ATSR-2 and AATSR) products produced using the Optimal Retrieval of Aerosol and Cloud (ORAC) scheme. This talk will present an overview of the newly produced ORAC cloud and aerosol datasets, their evaluation and a joint aerosol-cloud product produced for the 1995-2012 ATSR-2-AATSR data record.

Evaluation of a dimension-reduction-based statistical technique for Temperature, Water Vapour and Ozone retrievals from IASI radiances

NASA Astrophysics Data System (ADS)

Amato, Umberto; Antoniadis, Anestis; De Feis, Italia; Masiello, Guido; Matricardi, Marco; Serio, Carmine

2009-03-01

Remote sensing of atmosphere is changing rapidly thanks to the development of high spectral resolution infrared space-borne sensors. The aim is to provide more and more accurate information on the lower atmosphere, as requested by the World Meteorological Organization (WMO), to improve reliability and time span of weather forecasts plus Earth's monitoring. In this paper we show the results we have obtained on a set of Infrared Atmospheric Sounding Interferometer (IASI) observations using a new statistical strategy based on dimension reduction. Retrievals have been compared to time-space colocated ECMWF analysis for temperature, water vapor and ozone.

New and Updated Gridded Analysis Products provided by the Global Precipitation Climatology Centre (GPCC)

NASA Astrophysics Data System (ADS)

Ziese, Markus; Schneider, Udo; Meyer-Christoffer, Anja; Finger, Peter; Schamm, Kirstin; Rustemeier, Elke; Becker, Andreas

2016-04-01

Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires an accordingly high density of measurement data. Data collected from national meteorological and hydrological services are the core of the GPCC data base, supported by global and regional data collections. Also the GPCC receives SYNOP and CLIMAT reports via WMO-GTS, which are mainly applied for near-real-time products. A high quality control effort is undertaken to remove miscoded and temporal or spatial dislocated data before entry into the GPCC archive, serving the basis for further interpolation and product generation. The GPCC archive holds records from almost 100 000 stations, among those three quarters with records long enough to serve the data basis of the GPCC suite of global precipitation products, comprising near-real-time as well as non-real-time products. Near-real-time products are the 'First Guess Monthly', 'First Guess Daily', 'Monitoring Product' and 'GPCC Drought Index'. These products are based on WMO-GTS data, e.g., SYNOP and CLIMAT reports and monthly totals calculated at CPC. Non-real-time products are the 'Full Data Monthly', 'Full Data Daily', 'Climatology', and 'HOMPRA-Europe'. Data from national meteorological and hydrological services and regional and global data collections are mainly used to calculate these products. Also WMO-GTS data are used if no other data are available. The majority of the products were released in an updated version, but 'Full Data Daily' and HOMPRA-Europe' are new products provided the first time. 'Full Data Daily' is a global analysis of daily precipitation totals from 1988 to 2013. 'HOMPRA-Europe' is an analysis of monthly precipitation totals from 5452 homogenized gauges in Europe with at least 90% data coverage for the period 1951 to 2005. The break detection and homogenizations were done by an adaptation of the PRODIGE scheme running in an automated mode. All GPCC products are available free of charge from the GPCC website at ftp://ftp-anon.dwd.de/pub/data/gpcc/html/download_gate.html and referenced by a digital object identifier (DOI) for easier citation, long lasting availability and a well-documented dissemination of the data files in the OGC compliant netCDF format An overview to the above mentioned GPCC products and data base will be given with a comparison of the products and example use cases. After all, GPCC products serve not only the agendas of GCOS, WCRP, GEWEX, UNEP, FAO, IPCC, UNESCO, but are basically providing reference observational data for the scientific community.

LFSTAT - Low-Flow Analysis in R

NASA Astrophysics Data System (ADS)

Koffler, Daniel; Laaha, Gregor

2013-04-01

The calculation of characteristic stream flow during dry conditions is a basic requirement for many problems in hydrology, ecohydrology and water resources management. As opposed to floods, a number of different indices are used to characterise low flows and streamflow droughts. Although these indices and methods of calculation have been well documented in the WMO Manual on Low-flow Estimation and Prediction [1], a comprehensive software was missing which enables a fast and standardized calculation of low flow statistics. We present the new software package lfstat to fill in this obvious gap. Our software package is based on the statistical open source software R, and expands it to analyse daily stream flow data records focusing on low-flows. As command-line based programs are not everyone's preference, we also offer a plug-in for the R-Commander, an easy to use graphical user interface (GUI) provided for R which is based on tcl/tk. The functionality of lfstat includes estimation methods for low-flow indices, extreme value statistics, deficit characteristics, and additional graphical methods to control the computation of complex indices and to illustrate the data. Beside the basic low flow indices, the baseflow index and recession constants can be computed. For extreme value statistics, state-of-the-art methods for L-moment based local and regional frequency analysis (RFA) are available. The tools for deficit characteristics include various pooling and threshold selection methods to support the calculation of drought duration and deficit indices. The most common graphics for low flow analysis are available, and the plots can be modified according to the user preferences. Graphics include hydrographs for different periods, flexible streamflow deficit plots, baseflow visualisation, recession diagnostic, flow duration curves as well as double mass curves, and many more. From a technical point of view, the package uses a S3-class called lfobj (low-flow objects). This objects are usual R-data-frames including date, flow, hydrological year and possibly baseflow information. Once these objects are created, analysis can be performed by mouse-click and a script can be saved to make the analysis easily reproducible. At the moment we are offering implementation of all major methods proposed in the WMO manual on Low-flow Estimation and Predictions [1]. Future plans include a dynamic low flow report in odt-file format using odf-weave which allows automatic updates if data or analysis change. We hope to offer a tool to ease and structure the analysis of stream flow data focusing on low-flows and to make analysis transparent and communicable. The package can also be used in teaching students the first steps in low-flow hydrology. The software packages can be installed from CRAN (latest stable) and R-Forge: http://r-forge.r-project.org (development version). References: [1] Gustard, Alan; Demuth, Siegfried, (eds.) Manual on Low-flow Estimation and Prediction. Geneva, Switzerland, World Meteorological Organization, (Operational Hydrology Report No. 50, WMO-No. 1029).

Definite Project Report for Section 205 Flood Control, Illinois River, Liverpool, Illinois, with Final Environmental Impact Statement

DTIC Science & Technology

1989-10-01

consisting of fat clay, sandy lean clay, and clayey sand. 7 Climate The climate of Fulton County is humid continental and is characterized by cold...Tp a. FAT Can U0I S go in on &- WI - WU. GAJm. In.~a Ts IPA a 0.2 ft 17. AW’U.Z I 9 £1 t som alsieIpm n lawe W. . MY4 CIA am a s V 0 WMO a~~~a ". MVU...feet of Cahokia alluvium. The alluvium is made up of 5 feet of fat clay overlying 4 feet of sandy lean clay. Indicated in situ shear strengths range

Model evaluation of the radiative and temperature effects of the ozone content changes in the global atmosphere of 1980's

NASA Technical Reports Server (NTRS)

Karol, Igor L.; Frolkis, Victor A.

1994-01-01

Radiative and temperature effects of the observed ozone and greenhouse gas atmospheric content changes in 1980 - 1990 are evaluated using the two-dimensional energy balance radiative-convective model of the zonally and annually averaged troposphere and stratosphere. Calculated radiative flux changes for standard conditions quantitatively agree with their estimates in WMO/UNEP 1991 review. Model estimates indicate rather small influence of ozone depletion in the lower stratosphere on the greenhouse tropospheric warming rate, being more significant in the non-tropical Southern Hemisphere. The calculated cooling of the lower stratosphere is close to the observed temperature trends there in the last decade.

Atmospheric Carbon Dioxide Mixing Ratios from the NOAA CMDL Carbon Cycle Cooperative Global Air Sampling Network (2009)

DOE Data Explorer

Conway, Thomas [NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO (USA); Tans, Pieter [NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO (USA)

2009-01-01

The National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) has measured CO2 in air samples collected weekly at a global network of sites since the late 1960s. Atmospheric CO2 mixing ratios reported in these files were measured by a nondispersive infrared absorption technique in air samples collected in glass flasks. All CMDL flask samples are measured relative to standards traceable to the World Meteorological Organization (WMO) CO2 mole fraction scale. These measurements constitute the most geographically extensive, carefully calibrated, internally consistent atmospheric CO2 data set available and are essential for studies aimed at better understanding the global carbon cycle budget.

World Calibration Center for VOC (WCC-VOC), a new Facility for the WMO-GAW-Programme

NASA Astrophysics Data System (ADS)

Rappenglueck, B.-

2002-12-01

Volatile organic compounds (VOC) are recognized to be important precursors of tropospheric ozone as well as other oxidants and organic aerosols. In order to design effective control measures for the reduction of photooxidants, photochemical processes have to be understood and the sources of the precursors known. Reliable and representative measurements of VOCs are necessary to describe the anthropogenic and biogenic sources, to follow the photochemical degradation of VOCs in the troposphere. Measurement of VOCs is of key importance for the understanding of tropospheric chemistry. Tropospheric VOCs have been one of the recommended measurements to be made within the GAW programme. The purpose will be to monitor their atmospheric abundance, to characterize the various compounds with regard to anthropogenic and biogenic sources and to evaluate their role in the tropospheric ozone formation process. An international WMO/GAW panel of experts for VOC measurements developed the rational and objectives for this GAW activity and recommended the configuration and required activities of the WCC-VOC. In reflection of the complexity of VOC measurements and the current status of measurement technology, a "staged" approach was adopted. Stage 1 measurements: C2-C9 hydrocarbons, including alkanes, alkenes, alkynes, dienes and monocyclics. (The WCC-VOC operates currently under this mode). Stage 2 measurements: C10-C14 hydrocarbons, including higher homologs of the Stage 1 set as well as biogenic hydrocarbon compounds. Stage 3 measurements: Oxygenated VOCs, including alcohols, carbonyls, carboxylic acids. The Quality Assurance/Science Activity Centre (QA/SAC) Germany currently has established the World Calibration Centre for VOC (WCC-VOC). The WCC-VOC has operated in the research mode und has become operational recently. From now on, the WCC-VOC conducts one round-robin calibration audit per year at all global stations that measure VOCs and assists other stations in setting up VOC measurement capabilities. Furthermore, the WCC-VOC will promote inter-com-parison experiments with networks related to other programmes, notably EMEP and IGAC.

Seasonal forecasts for the agricultural sector in Peru through user-tailored indices

NASA Astrophysics Data System (ADS)

Sedlmeier, Katrin; Gubler, Stefanie; Spierig, Christoph; Quevedo, Karim; Escajadillo, Yury; Avalos, Griña; Liniger, Mark A.; Schwierz, Cornelia

2017-04-01

In the agricultural sector, the demand for seasonal forecast information is high since agriculture depends strongly on climatic conditions during the growing season. Unfavorable weather and climate events, such as droughts or frost events, can lead to crop losses and thereby to large economic damages or life-threatening conditions in case of subsistence farming. The generally used presentation form of tercile probabilities of seasonally averaged meteorological quantities are not specific enough for end users. More user-tailored seasonal information is necessary. For example, warmer than average temperatures might be favorable for a crop as long as they remain below a plant-specific critical threshold. If, on the other hand, too many days show temperatures above this critical threshold, a mitigation action such as e.g. changing the crop type would be required. In the framework of the CLIMANDES project (a pilot project of the Global Framework for Climate Services led by WMO [http://www.wmo.int/gfcs/climandes]), user-tailored seasonal forecast products are developed for the agricultural sector in the Peruvian Andes. Such products include indices such as e.g. the frost risk, the occurrence of long dry periods, or the start of the rainy season which is crucial to schedule sowing. Furthermore, more specific indices derived from crop requirement studies are elaborated such as the number of days exceeding or falling below plant specific temperature thresholds for given phenological stages. The applicability of these products highly depends on forecast skill. In this study, the potential predictability and the skill of selected indicators are presented using seasonal hindcast data of the ECMWF system 4 for Peru during the time period 1981-2010. Furthermore, the influence of ENSO on the prediction skill is investigated. In this study, reanalysis data, ground measurements, and a gridded precipitation dataset are used for verification. The results indicate that temperature-based indicators show sizeable skill in the Peruvian highlands while precipitation-based forecasts are much more challenging.

Quantification of precipitation measurement discontinuity induced by wind shields on national gauges

USGS Publications Warehouse

Yang, Daqing; Goodison, Barry E.; Metcalfe, John R.; Louie, Paul; Leavesley, George H.; Emerson, Douglas G.; Hanson, Clayton L.; Golubev, Valentin S.; Elomaa, Esko; Gunther, Thilo; Pangburn, Timothy; Kang, Ersi; Milkovic, Janja

1999-01-01

Various combinations of wind shields and national precipitation gauges commonly used in countries of the northern hemisphere have been studied in this paper, using the combined intercomparison data collected at 14 sites during the World Meteorological Organization's (WMO) Solid Precipitation Measurement Intercomparison Project. The results show that wind shields improve gauge catch of precipitation, particularly for snow. Shielded gauges, on average, measure 20–70% more snow than unshielded gauges. Without a doubt, the use of wind shields on precipitation gauges has introduced a significant discontinuity into precipitation records, particularly in cold and windy regions. This discontinuity is not constant and it varies with wind speed, temperature, and precipitation type. Adjustment for this discontinuity is necessary to obtain homogenous precipitation data for climate change and hydrological studies. The relation of the relative catch ratio (RCR, ratio of measurements of shielded gauge to unshielded gauge) versus wind speed and temperature has been developed for Alter and Tretyakov wind shields. Strong linear relations between measurements of shielded gauge and unshielded gauge have also been found for different precipitation types. The linear relation does not fully take into account the varying effect of wind and temperature on gauge catch. Overadjustment by the linear relation may occur at those sites with lower wind speeds, and underadjustment may occur at those stations with higher wind speeds. The RCR technique is anticipated to be more applicable in a wide range of climate conditions. The RCR technique and the linear relation have been tested at selected WMO intercomparison stations, and reasonable agreement between the adjusted amounts and the shielded gauge measurements was obtained at most of the sites. Test application of the developed methodologies to a regional or national network is therefore recommended to further evaluate their applicability in different climate conditions. Significant increase of precipitation is expected due to the adjustment particularly in high latitudes and other cold regions. This will have a meaningful impact on climate variation and change analyses.

LFSTAT - An R-Package for Low-Flow Analysis

NASA Astrophysics Data System (ADS)

Koffler, D.; Laaha, G.

2012-04-01

When analysing daily streamflow data focusing on low flow and drought, the state of the art is well documented in the Manual on Low-Flow Estimation and Prediction [1] published by the WMO. While it is clear what has to be done, it is not so clear how to preform the analysis and make the calculation as reproducible as possible. Our software solution expands the high preforming statistical open source software package R to analyse daily stream flow data focusing on low-flows. As command-line based programs are not everyone's preference, we also offer a plug-in for the R-Commander, an easy to use graphical user interface (GUI) to analyse data in R. Functionality includes estimation of the most important low-flow indices. Beside standardly used flow indices also BFI and Recession constants can be computed. The main applications of L-moment based Extreme value analysis and regional frequency analysis (RFA) are available. Calculation of streamflow deficits is another important feature. The most common graphics are prepared and can easily be modified according to the users preferences. Graphics include hydrographs for different periods, flexible streamflow deficit plots, baseflow visualisation, flow duration curves as well as double mass curves just to name a few. The package uses a S3-class called lfobj (low-flow objects). Once this objects are created, analysis can be preformed by mouse-click, and a script can be saved to make the analysis easy reproducible. At the moment we are offering implementation of all major methods proposed in the WMO manual on Low-flow Estimation and Predictions. Future plans include e.g. report export in odt-file using odf-weave. We hope to offer a tool to ease and structure the analysis of stream flow data focusing on low-flows and to make analysis transparent and communicable. The package is designed for hydrological research and water management practice, but can also be used in teaching students the first steps in low-flow hydrology.

Atmospheric Carbon Tetrachloride: Mysterious Emissions Gap Almost Closed

NASA Astrophysics Data System (ADS)

Liang, Q.; Newman, P. A.; Reimann, S.

2016-12-01

Carbon tetrachloride (CCl4) is a major ozone-depleting substance and its production and consumption is controlled under the Montreal Protocol for emissive uses. The most recent WMO/UNEP Scientific Assessment of Ozone Depletion [WMO, 2014] estimated a 2007-2012 CCl4 bottom-up emission of 1-4 Gg yr-1, based on country-by-country reports to UNEP, vs. a global top-down emissions estimate of 57 Gg yr-1, based on atmospheric measurements. To understand the gap between the top-down and bottom-up emissions estimates, a CCl4 activity was formed under the auspices of the Stratosphere-Troposphere Processes And their Role in Climate (SPARC) project. Several new findings were brought forward by the SPARC CCl4 activity. CCl4 is destroyed in the stratosphere, oceans, and soils. The total lifetime estimate has been increased from 26 to 33 years. The new 33-year total lifetime lowers the top-down emissions estimate to 40 (25-55) Gg yr-1. In addition, a persistent hemispheric difference implies substantial ongoing Northern Hemisphere emissions, yielding an independent emissions estimate of 30 Gg yr-1. The combination of these two yields an emissions estimate of 35 Gg yr-1. Regional estimates have been made for Australia, North America, East Asia, and Western Europe. The sum of these estimates results in emissions of 21 Gg yr-1, albeit this does not include all regions of the world. Four bottom-up CCl4 emissions pathways have been identified, i.e., fugitive, unreported non-feedstock, unreported inadvertent, and legacy emissions. The new industrial bottom-up emissions estimate includes emissions from chloromethanes plants (13 Gg yr-1) and feedstock fugitive emissions (2 Gg yr-1). When combined with legacy emissions and unreported inadvertent emissions ( 10 Gg yr-1), the total global emissions are 20±5 Gg yr-1. While the new bottom-up value is still less than the aggregated top-down values, these estimates reconcile the CCl4 budget discrepancy when considered at the edges of their uncertainties.

Science Coordination in Support of the US Weather Research Program Office of the Lead Scientist (OLS) and for Coordination with the World Weather Research (WMO) Program

NASA Technical Reports Server (NTRS)

Gall, Robert

2005-01-01

This document is the final report of the work of the Office of the Lead Scientist (OLS) of the U.S. Weather Research Program (USWRP) and for Coordination of the World Weather Research Program (WWRP). The proposal was for a continuation of the duties and responsibilities described in the proposal of 7 October, 1993 to NSF and NOAA associated with the USWRP Lead Scientist then referred to as the Chief Scientist. The activities of the Office of the Lead Scientist (OLS) ended on January 31, 2005 and this report describes the activities undertaken by the OLS from February 1, 2004 until January 3 1, 2005. The OLS activities were under the cosponsorship of the agencies that are members of the Interagency Working Group (IWG) of the US WRP currently: NOAA, NSF, NASA, and DOD. The scope of the work described includes activities that were necessary to develop, facilitate and implement the research objectives of the USWRP consistent with the overall program goals and specific agency objectives. It included liaison with and promotion of WMO/WWW activities that were consistent with and beneficial to the USWRP programs and objectives. Funds covered several broad categories of activity including meetings convened by the Lead Scientist, OLS travel, partial salary and benefits support, publications, hard-copy dissemination of reports and program announcements and the development and maintenance of the USWRP website. In addition to funding covered by this grant, NCAR program funds provided co-sponsorship of half the salary and benefits resources of the USWRP Lead Scientist (.25 FTE) and the WWRP Chairman/Liaison (.167 FTE). Also covered by the grant were partial salaries for the Science Coordinator for the hurricane portion of the program and partial salary for a THORPEX coordinator.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komhyr, W.D.; Quincy, D.M.; Grass, R.D.

This report describes work to improve the quality of total ozone and Umkehr data obtained in the past at the NOAA Climate Monitoring and Diagnostics Laboratory and the Dobson spectrophotometer ozone observatories. The authors present results of total ozone data re-evaluations for ten stations: Byrd, Antarctica; Fairbanks, Alaska; Hallett, Antarctica; Huancayo, Peru; Haute Provence, France; Lauder, New Zealand; Perth, Australia; Poker Flat, Alaska; Puerto Montt, Chile; and South Pole, Antarctica. The improved data will be submitted in early 1996 to the World Meteorological Organization (WMO) World Ozone Data Center (WODC), and the Atmospheric Environment Service for archiving. Considerable work hasmore » been accomplished, also, in reevaluating Umkehr data from seven of the stations, viz., Huancayo, Haute Provence, Lauder, Perth, Poker Flat, Boulder, Colorado; and Mauna Loa, Hawaii.« less

Impact of Urban Surfaces on Precipitation Processes

NASA Technical Reports Server (NTRS)

Shepherd, J. M.

2004-01-01

The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the "risk of human-induced climate change". Such reports are used by decision-makers around the world to assess how our climate is changing. Its reports are widely respected and cited and have been highly influential in forming national and international responses to climate change. The Fourth Assessment report includes a section on the effects of surface processes on climate. This sub-chapter provides an overview of recent developments related to the impact of cities on rainfall. It highlights the possible mechanisms that buildings, urban heat islands, urban aerosols or pollution, and other human factors in cities that can affect rainfall.

Trends in atmospheric heavy metals abundances over the Russian part of EMEP region in 1990-2012

NASA Astrophysics Data System (ADS)

Gromov, Sergey A.; Konkova, Elizaveta S.

2016-04-01

The European part of Russia is covered by two atmospheric environment monitoring networks established in the 1970s-1980s to monitor and evaluate anthropogenic pollution of regional/background natural environment. These are EMEP - European Monitoring and Evaluation Program of transboundary atmospheric pollutant transmission (under the UN ECE Convention on Long-Range Transboundary Air Pollution) and IBMoN - Integrated Background Monitoring Network of environmental toxic pollution (prior to 1990 under the UNEP/GEMS supervision, mostly for East European countries). IGCE laboratories operate as analytical centers for both networks. Historically, IBMoN was partly implemented at EMEP sites to support this international program with additional (optional) data. IBMoN datasets were selected for analysis of atmospheric heavy metal trends in the Russian territory of EMEP region for the last twenty three years due to more intensive operation up to now [1, 2]. Atmospheric heavy metals are collected at the remote sites with the air samples of atmospheric aerosols deposited on Petryanov's cellulose acetate filters through high-volume pumping during 24 hours. To measure lead and cadmium content, filters are transferred into the solution to determine total amounts by the Atomic Absorption Spectroscopy (AAS) with flameless atomization. Precipitation samples (collected monthly with acidic preserving) are directly injected into the AAS detection module after filtering. The sampling procedure, special processing and analytical techniques allow us to measure concentrations at substantially low levels [3, 2]. In this study we investigate the long term trends of lead and cadmium in air and precipitation at two stations, viz. Astrakhan Biosphere Reserve (46°N, 49°E) and Danki (Oka-Terrace Biosphere Reserve, 54.9°N, 37.8°E). Following the EMEP general recommendations, the evaluation was done for two continuous periods covering 1990-2001 and 2002-2012, respectively. We apply the common methodology recommended by WMO/EMEP Task Force for trend evaluation, implemented in software developed and distributed by EMEP [4]. This methodology allows approximation of apparent trends using the superposition of the exponential (main) and residual components obtained using the ad hoc trend regression model. We further use so-called reduction parameters to investigate quantitatively the nature of trends: The total over the period (Rtot) and annual average (Rave), with the latter corresponding to increasing trend at negative values. Overall, temporal tendencies of airborne cadmium and lead demonstrate similar behaviour, however on top of different average concentration levels. For both species our analysis confirms the increase in air and precipitation abundances at the regional and remote sites over the European part of Russia for the period of 2002-2012. References: 1. Gromov S.A., and S.G. Paramonov, 2015. Current status and prospects for the development of integrated background monitoring of environmental pollution. Problems of Ecological Monitoring and Ecosystem Modelling, v. XXVI, N 1, p. 205-221. 2. Rovinsky F.Ya. (Ed.), 1989. Analytical review of environmental pollution with heavy metals in background areas of the CMEA member countries (1982-1989). Moscow, Gidrometeoizdat, 88 p. 3. Izrael Yu.A., and F.Ya. Rovinsky, 1991. Integrated background monitoring of environmental pollution in mid-latitude Eurasia. WMO Global Atmospheric Watch No 72, WMO/TD No. 434, 104 p. 4. MSC-East, 2015. Methodology of trend analysis of air quality data (http://www.msceast.org/documents/ Methodology_of_trend_analysis.pdf).

A spectroscopic transfer standard for accurate atmospheric CO measurements

NASA Astrophysics Data System (ADS)

Nwaboh, Javis A.; Li, Gang; Serdyukov, Anton; Werhahn, Olav; Ebert, Volker

2016-04-01

Atmospheric carbon monoxide (CO) is a precursor of essential climate variables and has an indirect effect for enhancing global warming. Accurate and reliable measurements of atmospheric CO concentration are becoming indispensable. WMO-GAW reports states a compatibility goal of ±2 ppb for atmospheric CO concentration measurements. Therefore, the EMRP-HIGHGAS (European metrology research program - high-impact greenhouse gases) project aims at developing spectroscopic transfer standards for CO concentration measurements to meet this goal. A spectroscopic transfer standard would provide results that are directly traceable to the SI, can be very useful for calibration of devices operating in the field, and could complement classical gas standards in the field where calibration gas mixtures in bottles often are not accurate, available or stable enough [1][2]. Here, we present our new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor capable of performing absolute ("calibration free") CO concentration measurements, and being operated as a spectroscopic transfer standard. To achieve the compatibility goal stated by WMO for CO concentration measurements and ensure the traceability of the final concentration results, traceable spectral line data especially line intensities with appropriate uncertainties are needed. Therefore, we utilize our new high-resolution Fourier-transform infrared (FTIR) spectroscopy CO line data for the 2-0 band, with significantly reduced uncertainties, for the dTDLAS data evaluation. Further, we demonstrate the capability of our sensor for atmospheric CO measurements, discuss uncertainty calculation following the guide to the expression of uncertainty in measurement (GUM) principles and show that CO concentrations derived using the sensor, based on the TILSAM (traceable infrared laser spectroscopic amount fraction measurement) method, are in excellent agreement with gravimetric values. Acknowledgement Parts of this work have been carried out within the European Metrology Research Programme (EMRP) ENV52 project-HIGHGAS (Metrology for high-impact greenhouse gases). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. References [1] EMRP project ENV52-HIGHGAS (Metrology for high-impact greenhouse gases), available at: http://www.euramet.org/. [2] J. Nwaboh, A. Manninen, J. Mohn, J. C. Petersen, O. Werhahn, and V.Ebert, European Geosciences Union General Assembly 2015, EGU2015-13542, 2015, Vienna Austria

The CAMI Project - Weather and Climate Services for Caribbean Food Security

NASA Astrophysics Data System (ADS)

Trotman, Adrian; Van Meerbeeck, Cedric

2013-04-01

Food security is major focus of Caribbean governments, with production being of particular concern. For the past three decades, Caribbean agriculture has been declining in relative importance, both in terms of its contribution to GDP and its share of the labour force. One of the problems Caribbean agriculture faces is the destructive impacts from weather and climate extremes. These include flood, drought, extreme temperatures, and strong winds from tropical cyclones. Other potential disasters, such as from pests and diseases attacks, are also weather and climate driven. These make weather and climate information critically important to decision-making in agriculture in the Caribbean region. In an effort to help reduce weather and climate related risks to the food security sector, The Caribbean Institute for Meteorology and Hydrology, along with its partners the Caribbean Agricultural Research and Development Institute, the World Meteorological Organization (WMO) and ten National Meteorological Services from within the Caribbean Community launched and implemented the Caribbean Agrometeorological Initiative (CAMI). From 2010 to 2013, CAMI set out to provide relevant information to farmers, and the industry in general, for decision and policy making. The project is funded by the European Union through the Science and Technology Programme of the African, Caribbean and Pacific Group of Countries' (ACP). The overarching objective of CAMI was to increase and sustain agricultural productivity at the farm level in the Caribbean region through improved applications of weather and climate information, using an integrated and coordinated approach. Currently, this is done through (i) provision of relevant climate information appropriately disseminated, (ii) predictions on seasonal rainfall and temperature, (iii) support for improved irrigation management, (iv) the development of strategically selected weather-driven pest and disease models, (v) use of crop simulation models, (vi) training of staff of National Meteorological Services (NMS) and two relevant regional research institutions (vi) and the staging of forums for farmers and Agriculture Extension officers. With its innovative actions and generated products, the thrusts of CAMI link well to the components of the WMO's Global Framework for Climate Services.

Memories and Perceptions of Weather and Climate in the Denver Metropolitan Area: Calibrating the Human Thermometer

NASA Astrophysics Data System (ADS)

Malmberg, J.; Blanken, P.

2006-12-01

Due to a lack of World Meteorological Organization (WMO) data in locations such as polar regions, non- traditional datasets such as indigenous local knowledge are sometimes used as an indicator of climate change. Local indigenous knowledge depends on human memory of weather and climate, yet the accuracy of this knowledge has not been checked. The purpose of this study is to determine how accurate recollections of memory and climate are, and what may influence these memories. This pilot study examined recollections of weather and climate in the Denver metropolitan area, a WMO location, in periods varying from days to years. The approximately 400 respondents answered questions about the weather, climate, and various factors (e.g. gender, education, occupation) that may influence memories of weather and climate via an online survey. Results were compared to the actual meteorological conditions recorded at the Denver-Boulder National Weather Service Forecast Office and at the Western Regional Climate Center. When asked to give the minimum and maximum daily temperature ranges and significant weather, participants' accuracy decreased as the length of time since the day or event increased. For example, more than 85% of participants had an accurate response one day in the past, and this decreased to less than 50% for conditions seven days in the past. When asked about climate data two years ago, most respondents recalled the temperature trend (e.g. higher, about the same, or lower), however, participants did not agree about precipitation amounts (e.g. more, about the same amount, or less). Other factors (e.g gender, education, occupation) did not seem to influence weather memories two years prior to the survey. When asked to recall climate 20 years prior to the survey, more participants (up to 44%) reported that they did not remember. Of participants who did select a trend, the temperature trend was again more accurate than the precipitation trend. The role of factors that had a significant effect on responses, including, gender, time spend outdoors, and education, will be discussed.

Long-term prognosis of young breast cancer patients (≤40 years) who did not receive adjuvant systemic treatment: protocol for the PARADIGM initiative cohort study.

PubMed

Dackus, Gwen Mhe; Ter Hoeve, Natalie D; Opdam, Mark; Vreuls, Willem; Varga, Zsuzsanna; Koop, Esther; Willems, Stefan M; Van Deurzen, Carolien Hm; Groen, Emilie J; Cordoba, Alicia; Bart, Jos; Mooyaart, Antien L; van den Tweel, Jan G; Zolota, Vicky; Wesseling, Jelle; Sapino, Anna; Chmielik, Ewa; Ryska, Ales; Amant, Frederic; Broeks, Annegien; Kerkhoven, Ron; Stathonikos, Nikolas; Veta, Mitko; Voogd, Adri; Jozwiak, Katarzyna; Hauptmann, Michael; Hoogstraat, Marlous; Schmidt, Marjanka K; Sonke, Gabe; van der Wall, Elsken; Siesling, Sabine; van Diest, Paul J; Linn, Sabine C

2017-11-14

Currently used tools for breast cancer prognostication and prediction may not adequately reflect a young patient's prognosis or likely treatment benefit because they were not adequately validated in young patients. Since breast cancers diagnosed at a young age are considered prognostically unfavourable, many treatment guidelines recommend adjuvant systemic treatment for all young patients. Patients cured by locoregional treatment alone are, therefore, overtreated. Lack of prognosticators for young breast cancer patients represents an unmet medical need and has led to the initiation of the PAtients with bReAst cancer DIaGnosed preMenopausally (PARADIGM) initiative. Our aim is to reduce overtreatment of women diagnosed with breast cancer aged ≤ 40 years. All young, adjuvant systemic treatment naive breast cancer patients, who had no prior malignancy and were diagnosed between 1989 and 2000, were identified using the population based Netherlands Cancer Registry (n=3525). Archival tumour tissues were retrieved through linkage with the Dutch nationwide pathology registry. Tissue slides will be digitalised and placed on an online image database platform for clinicopathological revision by an international team of breast pathologists. Immunohistochemical subtype will be assessed using tissue microarrays. Tumour RNA will be isolated and subjected to next-generation sequencing. Differences in gene expression found between patients with a favourable and those with a less favourable prognosis will be used to establish a prognostic classifier, using the triple negative patients as proof of principle. Observational data from the Netherlands Cancer Registry and left over archival patient material are used. Therefore, the Dutch law on Research Involving Human Subjects Act (WMO) is not applicable. The PARADIGM study received a 'non-WMO' declaration from the Medical Ethics Committee of the Netherlands Cancer Institute - Antoni van Leeuwenhoek hospital, waiving individual patient consent. All data and material used are stored in a coded way. Study results will be presented at international (breast cancer) conferences and published in peer-reviewed, open-access journals. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Development of a method of robust rain gauge network optimization based on intensity-duration-frequency results

NASA Astrophysics Data System (ADS)

Chebbi, A.; Bargaoui, Z. K.; da Conceição Cunha, M.

2012-12-01

Based on rainfall intensity-duration-frequency (IDF) curves, a robust optimization approach is proposed to identify the best locations to install new rain gauges. The advantage of robust optimization is that the resulting design solutions yield networks which behave acceptably under hydrological variability. Robust optimisation can overcome the problem of selecting representative rainfall events when building the optimization process. This paper reports an original approach based on Montana IDF model parameters. The latter are assumed to be geostatistical variables and their spatial interdependence is taken into account through the adoption of cross-variograms in the kriging process. The problem of optimally locating a fixed number of new monitoring stations based on an existing rain gauge network is addressed. The objective function is based on the mean spatial kriging variance and rainfall variogram structure using a variance-reduction method. Hydrological variability was taken into account by considering and implementing several return periods to define the robust objective function. Variance minimization is performed using a simulated annealing algorithm. In addition, knowledge of the time horizon is needed for the computation of the robust objective function. A short and a long term horizon were studied, and optimal networks are identified for each. The method developed is applied to north Tunisia (area = 21 000 km2). Data inputs for the variogram analysis were IDF curves provided by the hydrological bureau and available for 14 tipping bucket type rain gauges. The recording period was from 1962 to 2001, depending on the station. The study concerns an imaginary network augmentation based on the network configuration in 1973, which is a very significant year in Tunisia because there was an exceptional regional flood event in March 1973. This network consisted of 13 stations and did not meet World Meteorological Organization (WMO) recommendations for the minimum spatial density. So, it is proposed to virtually augment it by 25, 50, 100 and 160% which is the rate that would meet WMO requirements. Results suggest that for a given augmentation robust networks remain stable overall for the two time horizons.

Development of a method of robust rain gauge network optimization based on intensity-duration-frequency results

NASA Astrophysics Data System (ADS)

Chebbi, A.; Bargaoui, Z. K.; da Conceição Cunha, M.

2013-10-01

Based on rainfall intensity-duration-frequency (IDF) curves, fitted in several locations of a given area, a robust optimization approach is proposed to identify the best locations to install new rain gauges. The advantage of robust optimization is that the resulting design solutions yield networks which behave acceptably under hydrological variability. Robust optimization can overcome the problem of selecting representative rainfall events when building the optimization process. This paper reports an original approach based on Montana IDF model parameters. The latter are assumed to be geostatistical variables, and their spatial interdependence is taken into account through the adoption of cross-variograms in the kriging process. The problem of optimally locating a fixed number of new monitoring stations based on an existing rain gauge network is addressed. The objective function is based on the mean spatial kriging variance and rainfall variogram structure using a variance-reduction method. Hydrological variability was taken into account by considering and implementing several return periods to define the robust objective function. Variance minimization is performed using a simulated annealing algorithm. In addition, knowledge of the time horizon is needed for the computation of the robust objective function. A short- and a long-term horizon were studied, and optimal networks are identified for each. The method developed is applied to north Tunisia (area = 21 000 km2). Data inputs for the variogram analysis were IDF curves provided by the hydrological bureau and available for 14 tipping bucket type rain gauges. The recording period was from 1962 to 2001, depending on the station. The study concerns an imaginary network augmentation based on the network configuration in 1973, which is a very significant year in Tunisia because there was an exceptional regional flood event in March 1973. This network consisted of 13 stations and did not meet World Meteorological Organization (WMO) recommendations for the minimum spatial density. Therefore, it is proposed to augment it by 25, 50, 100 and 160% virtually, which is the rate that would meet WMO requirements. Results suggest that for a given augmentation robust networks remain stable overall for the two time horizons.

Generating daily weather data for ecosystem modelling in the Congo River Basin

NASA Astrophysics Data System (ADS)

Petritsch, Richard; Pietsch, Stephan A.

2010-05-01

Daily weather data are an important constraint for diverse applications in ecosystem research. In particular, temperature and precipitation are the main drivers for forest ecosystem productivity. Mechanistic modelling theory heavily relies on daily values for minimum and maximum temperatures, precipitation, incident solar radiation and vapour pressure deficit. Although the number of climate measurement stations increased during the last centuries, there are still regions with limited climate data. For example, in the WMO database there are only 16 stations located in Gabon with daily weather measurements. Additionally, the available time series are heavily affected by measurement errors or missing values. In the WMO record for Gabon, on average every second day is missing. Monthly means are more robust and may be estimated over larger areas. Therefore, a good alternative is to interpolate monthly mean values using a sparse network of measurement stations, and based on these monthly data generate daily weather data with defined characteristics. The weather generator MarkSim was developed to produce climatological time series for crop modelling in the tropics. It provides daily values for maximum and minimum temperature, precipitation and solar radiation. The monthly means can either be derived from the internal climate surfaces or prescribed as additional inputs. We compared the generated outputs observations from three climate stations in Gabon (Lastourville, Moanda and Mouilla) and found that maximum temperature and solar radiation were heavily overestimated during the long dry season. This is due to the internal dependency of the solar radiation estimates to precipitation. With no precipitation a cloudless sky is assumed and thus high incident solar radiation and a large diurnal temperature range. However, in reality it is cloudy in the Congo River Basin during the long dry season. Therefore, we applied a correction factor to solar radiation and temperature range based on the ratio of values on rainy days and days without rain, respectively. For assessing the impact of our correction, we simulated the ecosystem behaviour using the climate data from Lastourville, Moanda and Mouilla with the mechanistic ecosystem model Biome-BGC. Differences in terms of the carbon, nitrogen and water cycle were subsequently analysed and discussed.

Geochronology, petrogenesis and tectonic settings of pre- and syn-ore granites from the W-Mo deposits (East Kounrad, Zhanet and Akshatau), Central Kazakhstan

NASA Astrophysics Data System (ADS)

Li, GuangMing; Cao, MingJian; Qin, KeZhang; Evans, Noreen J.; Hollings, Pete; Seitmuratova, Eleonora Yusupovha

2016-05-01

There is significant debate regarding the mineralization ages of the East Kounrad, Zhanet and Akshatau W-Mo deposits of Central Kazakhstan, and the petrogenesis and tectono-magmatic evolution of the granites associated with these deposits. To address these issues, we present molybdenite Re-Os dating, zircon U-Pb dating, whole rock geochemistry as well as Sr-Nd-Pb and zircon O-Hf isotopic analyses on the pre-mineralization and ore-forming granites. U-Pb dating of zircons from pre-mineralization granitic rocks yield Late Carboniferous ages of 320-309 Ma, whereas ore-forming granites have Early Permian ages of 298-285 Ma. Molybdenite Re-Os isotopic data indicate a mineralization age of 296 Ma at East Kounrad, 294 Ma at Akshatau and 285 Ma at Zhanet. The pre-ore and ore-forming granites are high-K calc-alkaline, metaluminous to slightly peraluminous I-type granites. The pre-mineralization granites are relatively unfractionated, whereas the ore-forming granites are highly fractionated. The fractionating mineral phases are probably K-feldspar, apatite, Ti-bearing phases and minor plagioclase. The pre-mineralization and ore-forming rocks are characterized by similar Sr-Nd-Pb-Hf-O isotopic compositions ((87Sr/86Sr)i = 0.70308-0.70501, εNd (t) = - 0.5 to + 2.8, 207Pb/204Pb = 15.60-15.82, zircon εHf (t) = + 1.2 to + 15.6 and δ18O = + 4.6 to + 10.3‰), whole rock TDMC (Nd) (840-1120 Ma) and zircon TDMC (Hf) (320-1240 Ma). The isotopic characteristics are consistent with a hybrid magma source caused by 10-30% assimilation of ancient crust by juvenile lower crust. The geochronology and geochemistry of these granites show that the Late Carboniferous pre-mineralization granitic rocks formed during subduction, whereas the Early Permian ore-forming, highly fractionated granite probably underwent significant fractionation with a restite assemblage of K-feldspar, apatite, Ti-bearing phases and minor plagioclase and developed during collision between the Yili and Kazakhstan terranes commenced at the latest Late Carboniferous.

Towards an exploitation of IAGOS atmospheric composition measurements

NASA Astrophysics Data System (ADS)

Marshall, Julia; Gerbig, Christoph; Petzold, Andreas; Zahn, Andreas

2015-04-01

IAGOS, In-service Aircraft for a Global Observing System, has installed instrumentation on a growing fleet of commercial airliners in order to continuously monitor atmospheric composition around the globe. IAGOS is providing accurate in situ observations of greenhouse gases (GHGs), reactive gases, aerosols, and cloud particles at high spatial resolution in the free atmosphere, thereby covering the essential climate variables (ECVs) for atmospheric composition as designated by the GCOS programme (Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC, 2010). The greenhouse gas measurements made by IAGOS will be submitted to the WMO/GAW World Data Centre for Greenhouse Gases (WDCGG). Within the EU FP7 project IGAS (IAGOS for the GMES Atmospheric Service), the links between this new data stream and scientific users, including the Copernicus Atmosphere Monitoring Service, are being improved. This includes the provision of measurements in both near-real-time and delayed mode, and improved accessibility to the data through linkages to the databases of both the German Aerospace Centre (DLR) flight campaign archive and the Copernicus data archive. Work has been undertaken to investigate the use of the near-real-time profile measurements in order to correct bias in satellite measurements assimilated by the Copernicus Atmosphere Monitoring Service. Documentation of the QA/QC procedures and measurement techniques for each instrument have been formalized and reviewed by external experts, to provide users with a measurement traceable to WMO standards. The representativeness of the measurements has been assessed, to better interpret results in polluted regions and near the tropopause. The potential impact of the GHG measurements on regional scale flux inversions has been quantified, which is relevant for ICOS (Integrated Carbon Observing System). Finally, tools have been developed to use the measurements for validation of satellite column measurements, including collocation with satellite soundings, extension of the profiles to the full column, and convolution with the relevant averaging kernel. This presentation provides an overview of the activities undertaken in order to facilitate the use of the measurements provided by the IAGOS infrastructure. For more details, visit the websites www.iagos.org and www.igas-project.org.

A synthetic zero air standard

NASA Astrophysics Data System (ADS)

Pearce, Ruth

2016-04-01

A Synthetic Zero Air Standard R. E. Hill-Pearce, K. V. Resner, D. R. Worton, P. J. Brewer The National Physical Laboratory Teddington, Middlesex TW11 0LW UK We present work towards providing traceability for measurements of high impact greenhouse gases identified by the World Meteorological Organisation (WMO) as critical for global monitoring. Standards for these components are required with challengingly low uncertainties to improve the quality assurance and control processes used for the global networks to better assess climate trends. Currently the WMO compatibility goals require reference standards with uncertainties of < 100 nmolmol-1 for CO2 (northern hemisphere) and < 2 nmolmol-1 for CH4 and CO. High purity zero gas is required for both the balance gas in the preparation of reference standards and for baseline calibrations of instrumentation. Quantification of the amount fraction of the target components in the zero gas is a significant contributor to the uncertainty and is challenging due to limited availability of reference standard at the amount fraction of the measurand and limited analytical techniques with sufficient detection limits. A novel dilutor was used to blend NPL Primary Reference Gas Mixtures containing CO2, CH4 and CO at atmospheric amount fractions with a zero gas under test. Several mixtures were generated with nominal dilution ratios ranging from 2000:1 to 350:1. The baseline of two cavity ring down spectrometers was calibrated using the zero gas under test after purification by oxidative removal of CO and hydrocarbons to < 1 nmolmol-1 (SAES PS15-GC50) followed by the removal of CO2 and water vapour to < 100 pmolmol-1 (SAES MC190). Using the standard addition method.[1] we have quantified the amount fraction of CO, CO2, and CH4 in scrubbed whole air (Scott Marrin) and NPL synthetic zero air. This is the first synthetic zero air standard with a matrix of N2, O2 and Ar closely matching ambient composition with gravimetrically assigned values and with accurate quantification of the CO, CO2, and CH4 impurities. [1] Brown, R.J.C et al.,Analytica Chimica Acta 587, 158-163 (2007)

Global Temperature and Salinity Pilot Project

NASA Technical Reports Server (NTRS)

Searle, Ben

1992-01-01

Data exchange and data management programs have been evolving over many years. Within the international community there are two main programs to support the exchange, management and processing of real time and delayed mode data. The Intergovernmental Oceanographic Commission (IOC) operate the International Oceanographic Data and Information Exchange (IODE) program which coordinates the exchange of delayed mode data between national oceanographic data centers, World Data Centers and the user community. The Integrated Global Ocean Services System is a joint IOC/World Meteorological Organization (WMO) program for the exchange and management of real-time data. These two programs are complemented by mechanisms that have been established within scientific programs to exchange and manage project data sets. In particular TOGA and WOCE have identified a data management requirement and established the appropriate infrastructure to achieve this. Where GTSPP fits into this existing framework is discussed.

Total column CO2 measurements at Darwin, Australia - site description and calibration against in situ aircraft profiles

NASA Astrophysics Data System (ADS)

Deutscher, N. M.; Griffith, D. W. T.; Bryant, G. W.; Wennberg, P. O.; Toon, G. C.; Washenfelder, R. A.; Keppel-Aleks, G.; Wunch, D.; Yavin, Y.; Allen, N. T.; Blavier, J.-F.; Jiménez, R.; Daube, B. C.; Bright, A. V.; Matross, D. M.; Wofsy, S. C.; Park, S.

2010-03-01

An automated Fourier Transform Spectroscopic (FTS) solar observatory was established in Darwin, Australia in August 2005. The laboratory is part of the Total Carbon Column Observing Network, and measures atmospheric column abundances of CO2 and O2 and other gases. Measured CO2 columns were calibrated against integrated aircraft profiles obtained during the TWP-ICE campaign in January-February 2006, and show good agreement with calibrations for a similar instrument in Park Falls, Wisconsin. A clear-sky low airmass relative precision of 0.1% is demonstrated in the CO2 and O2 retrieved column-averaged volume mixing ratios. The 1% negative bias in the FTS XCO2 relative to the World Meteorological Organization (WMO) calibrated in situ scale is within the uncertainties of the NIR spectroscopy and analysis.

Total column CO2 measurements at Darwin, Australia - site description and calibration against in situ aircraft profiles

NASA Astrophysics Data System (ADS)

Deutscher, N. M.; Griffith, D. W. T.; Bryant, G. W.; Wennberg, P. O.; Toon, G. C.; Washenfelder, R. A.; Keppel-Aleks, G.; Wunch, D.; Yavin, Y.; Allen, N. T.; Blavier, J.-F.; Jiménez, R.; Daube, B. C.; Bright, A. V.; Matross, D. M.; Wofsy, S. C.; Park, S.

2010-07-01

An automated Fourier Transform Spectroscopic (FTS) solar observatory was established in Darwin, Australia in August 2005. The laboratory is part of the Total Carbon Column Observing Network, and measures atmospheric column abundances of CO2 and O2 and other gases. Measured CO2 columns were calibrated against integrated aircraft profiles obtained during the TWP-ICE campaign in January-February 2006, and show good agreement with calibrations for a similar instrument in Park Falls, Wisconsin. A clear-sky low airmass relative precision of 0.1% is demonstrated in the CO2 and O2 retrieved column-averaged volume mixing ratios. The 1% negative bias in the FTS XCO2 relative to the World Meteorological Organization (WMO) calibrated in situ scale is within the uncertainties of the NIR spectroscopy and analysis.

A new improved database to support spanish phenological observations

NASA Astrophysics Data System (ADS)

Romero-Fresneda, Ramiro; Martínez-Núñez, Lourdes; Botey-Fullat, Roser; Gallego-Abaroa, Teresa; De Cara-García, Juan Antonio; Rodríguez-Ballesteros, César

2017-04-01

Since the last 30 years, phenology has regained scientific interest as the most reported biological indicator of anthropogenic climate change. AEMET (Spanish National Meteorological Agency) has long records in the field of phenological observations, since the 1940s. However, there is a large variety of paper records which are necessary to digitalize. On the other hand, it had been necessary to adapt our methods to the World Meteorological Organization (WMO) guidelines (BBCH code, data documentation- metadata…) and to standardize phenological stages and species in order to provide information to PEP725 (Pan European Phenology Database). Consequently, AEMET is developing a long-term, multi-taxa phenological database to support research and scientific studies about climate, their variability and influence on natural ecosystems, agriculture, etc. This paper presents the steps that are being carried out in order to achieve this goal.

Superalloy for high-temperature hydrogen environmental applications

NASA Technical Reports Server (NTRS)

McKannan, Eugene C. (Inventor); McPherson, William B. (Inventor); Ahmed, Shaffiq (Inventor); Chandler, Shirley S. (Inventor)

1991-01-01

A nickel-based superalloy is provided which is resistant to deterioration in hydrogen at high operating temperatures and pressures, and which thus can be used in hydrogen-fueled spacecraft such as the Space Shuttle. The superalloy is characterized by a two-phase microstructure and consists of a gamma-prime precipitated phase in a gamma matrix. The gamma matrix phase is a primary solid solution and the gamma precipitated phase will be an intermetallic compound of the type A.sub.3 B, such as nickel aluminide or titanide. Both phases are coherent, ordered, and compatible, and thus will retain most of their strength at elevated temperatures. The alloy consists essentially of (by weight): Ni 50-60%, Cr 10-20%, Al 2-6%, Co 2-5%, Ti 3-8%, W 5-12%, Mo 5-10%, Nb 1-3%, wherein the ratio W/MO is approximately equal to 1, and Ti/Al ranges from about 1 to about 2.

The new portfolio of global precipitation data products of the Global Precipitation Climatology Centre suitable to assess and quantify the global water cycle and resources

NASA Astrophysics Data System (ADS)

Schneider, Udo; Ziese, Markus; Meyer-Christoffer, Anja; Finger, Peter; Rustemeier, Elke; Becker, Andreas

2016-10-01

Precipitation plays an important role in the global energy and water cycle. Accurate knowledge of precipitation amounts reaching the land surface is of special importance for fresh water assessment and management related to land use, agriculture and hydrology, incl. risk reduction of flood and drought. High interest in long-term precipitation analyses arises from the needs to assess climate change and its impacts on all spatial scales. In this framework, the Global Precipitation Climatology Centre (GPCC) has been established in 1989 on request of the World Meteorological Organization (WMO). It is operated by Deutscher Wetterdienst (DWD, National Meteorological Service of Germany) as a German contribution to the World Climate Research Programme (WCRP). This paper provides information on the most recent update of GPCC's gridded data product portfolio including example use cases.

WMO World Record Lightning Extremes: Longest Reported Flash Distance and Longest Reported Flash Duration

PubMed Central

Lang, Timothy J.; Pédeboy, Stéphane; Rison, William; Cerveny, Randall S.; Montanyà, Joan; Chauzy, Serge; MacGorman, Donald R.; Holle, Ronald L.; Ávila, Eldo E.; Zhang, Yijun; Carbin, Gregory; Mansell, Edward R.; Kuleshov, Yuriy; Peterson, Thomas C.; Brunet, Manola; Driouech, Fatima; Krahenbuhl, Daniel S.

2017-01-01

A World Meteorological Organization weather and climate extremes committee has judged that the world’s longest reported distance for a single lightning flash occurred with a horizontal distance of 321 km (199.5 mi) over Oklahoma in 2007, while the world’s longest reported duration for a single lightning flash is an event that lasted continuously for 7.74 seconds over southern France in 2012. In addition, the committee has unanimously recommended amendment of the AMS Glossary of Meteorology definition of lightning discharge as a “series of electrical processes taking place within 1 second” by removing the phrase “within one second” and replacing with “continuously.” Validation of these new world extremes (a) demonstrates the recent and on-going dramatic augmentations and improvements to regional lightning detection and measurement networks, (b) provides reinforcement regarding the dangers of lightning, and (c) provides new information for lightning engineering concerns. PMID:28111477

Atmospheric CO2 Concentrations from Aircraft for 1972-1981, CSIRO Monitoring Program

DOE Data Explorer

Beardsmore, David J. [Commonwealth Scientific and Industrial Research Organization (CSIRO), Victoria, Australia; Pearman, Graeme I. [Commonwealth Scientific and Industrial Research Organization (CSIRO), Victoria, Australia

2012-01-01

From 1972 through 1981, air samples were collected in glass flasks from aircraft at a variety of latitudes and altitudes over Australia, New Zealand, and Antarctica. The samples were analyzed for CO2 concentrations with nondispersive infrared gas analysis. The resulting data contain the sampling dates, type of aircraft, flight number, flask identification number, sampling time, geographic sector, distance in kilometers from the listed distance measuring equipment (DME) station, station number of the radio navigation distance measuring equipment, altitude of the aircraft above mean sea level, sample analysis date, flask pressure, tertiary standards used for the analysis, analyzer used, and CO2 concentration. These data represent the first published record of CO2 concentrations in the Southern Hemisphere expressed in the WMO 1981 CO2 Calibration Scale and provide a precise record of atmospheric CO2 concentrations in the troposphere and lower stratosphere over Australia and New Zealand.

Atmospheric Carbon Dioxide Record from Flask Measurements at Lampedusa Island (May 1992- December 2000)

DOE Data Explorer

Chamard, Paolo [ENEA, GEM-CLIM, Rome, Italy; Ciattaglia, Luigi [ENEA, GEM-CLIM, Rome, Italy; di Sarra, Alcide [ENEA, GEM-CLIM, Rome, Italy; Monteleone, Francesco [ENEA, GEM-CLIM, Rome, Italy

2001-01-01

Lampedusa Station rests on a rocky seashore on the eastern tip of Lampedusa Island, located south of Sicily in the central Mediterranean Sea. Air samples at Lampedusa Station are collected each Friday in two pairs of 2-L glass flasks. Flasks are evacuated and then pressurized to 280-300 kPa with ambient air at the sampling site. Determinations of CO2 are made by using a Siemens Ultramat 5E nondispersive infrared gas analyzer. Water vapor is removed during the sampling process by means of a chemical trap (Magnesium Perchlorate). During the measurement, residual water vapor is removed by means of a cold trap at -70°C. From the inception of the monitoring program at Lampedusa Station, CO2-in-synthetic air calibration gases have been used. Values are relative to the dry air WMO mole fraction scale.

Comparison of Tungsten and Molybdenum Based Emitters for Advanced Thermionic Space Nuclear Reactors

NASA Astrophysics Data System (ADS)

Lee, Hsing H.; Dickinson, Jeffrey W.; Klein, Andrew C.; Lamp, Thomas R.

1994-07-01

Variations to the Advanced Thermionic Initiative thermionic fuel element are analyzed. Analysis included neutronic modeling with MCNP for criticality determination and thermal power distribution, and thermionic performance modeling with TFEHX. Changes to the original ATI configuration include the addition of W-HfC wire to the emitter for high temperature creep resistance improvement and substitution of molybdenum for the tungsten base material. Results from MCNP showed that all the tungsten used in the coating and base material must be 100% W-184 to obtain criticality. The presence of molybdenum in the emitter base affects the neutronic performance of the TFE by increasing the emitter neutron absorption cross section. Due to the reduced thermal conductivity for the molybdenum based emitter, a higher temperature is obtained resulting in a greater electrical power production. The thermal conductivity and resistivity of the composite emitter region were derived for the W-Mo composite and used in TFEHX.

Enhanced efficiency of luminescence with stoichiometry control in LiGd(W(1-x)MoxO4)2:Eu3+ red phosphors

NASA Astrophysics Data System (ADS)

Kavi Rasu, K.; Balaji, D.; Moorthy Babu, S.

2017-06-01

A series of LiGd(W(1-x)MoxO4)2 [hereafter LGWM]:Eu3+(x=0.00 to 1.00) red-emitting phosphors were synthesized by sol-gel method. Metal nitrates were used as starting materials with citric acid as chelator and ethylene glycol as binder. Synthesized gel was pre-fired at 523 K and calcined at 1073 K using resistive furnace in air atmosphere. The crystallinity, surface morphology and luminescent properties of the phosphors were investigated using powder X-ray diffraction (XRD), scanning electron microscope (SEM) and fluorescence spectrophotometry respectively. The intensity of the red emission at 615 nm for 5D0→7F2 electric dipole transition increases as the content of Mo6+ was increased and reach a maximum, when the relative ratio of W/Mo is 1:1 under 396 nm excitation.

Real-Time Thermal Mapping for Heat & Cool Archipelagos of Bengaluru, India

NASA Astrophysics Data System (ADS)

Gopinath, Rajesh; Banerjee, Aditya; Sachin, S.; Tiwari, Prakhar; Wilson, Sunny

2017-12-01

Blessed with a salubrious climate, the city of Bengaluru over the past few decades has constantly witnessed thermal discomfort owing to several Urban Heat islands that have mushroomed within the city. The subsequent increase in builtup area, consequent loss of productive agricultural lands/green zones, encroachment of surface water bodies coupled with the ill-preparedness of decision makers to handle the demand for land have invariably crumbled the natural micro-climate of the city. In this present research, an attempt has been made to detect the distribution of Urban Heat Islands in Bengaluru City by conducting real-time survey at 100 observatories marked across the entire urban & rural locations; with thermohygrometers as per the W.M.O. guidelines. The study confirmed the violation of the Human Thermal Comfort Range in 9, 83, 98, 99, 98 and 80 observatories for the monitoring at 6 AM, 9 AM, 12 PM, 3 PM, 6 PM and 9 PM respectively.

WMO World Record Lightning Extremes: Longest Reported Flash Distance and Longest Reported Flash Duration.

PubMed

Lang, Timothy J; Pédeboy, Stéphane; Rison, William; Cerveny, Randall S; Montanyà, Joan; Chauzy, Serge; MacGorman, Donald R; Holle, Ronald L; Ávila, Eldo E; Zhang, Yijun; Carbin, Gregory; Mansell, Edward R; Kuleshov, Yuriy; Peterson, Thomas C; Brunet, Manola; Driouech, Fatima; Krahenbuhl, Daniel S

2017-06-01

A World Meteorological Organization weather and climate extremes committee has judged that the world's longest reported distance for a single lightning flash occurred with a horizontal distance of 321 km (199.5 mi) over Oklahoma in 2007, while the world's longest reported duration for a single lightning flash is an event that lasted continuously for 7.74 seconds over southern France in 2012. In addition, the committee has unanimously recommended amendment of the AMS Glossary of Meteorology definition of lightning discharge as a "series of electrical processes taking place within 1 second" by removing the phrase "within one second" and replacing with "continuously." Validation of these new world extremes (a) demonstrates the recent and on-going dramatic augmentations and improvements to regional lightning detection and measurement networks, (b) provides reinforcement regarding the dangers of lightning, and (c) provides new information for lightning engineering concerns.

Novel lidar algorithms for atmospheric slantrange visibility, planetary boundary layer height, meteorogical phenomena and atmospheric layering measurements

NASA Astrophysics Data System (ADS)

Pantazis, Alexandros; Papayannis, Alexandros; Georgoussis, Georgios

2018-04-01

In this paper we present a development of novel algorithms and techniques implemented within the Laser Remote Sensing Laboratory (LRSL) of the National Technical University of Athens (NTUA), in collaboration with Raymetrics S.A., in order to incorporate them into a 3-Dimensional (3D) lidar. The lidar is transmitting at 355 nm in the eye safe region and the measurements then are transposed to the visual range at 550 nm, according to the World Meteorological Organization (WMO) and the International Civil Aviation Organization (ICAO) rules of daytime visibility. These algorithms are able to provide horizontal, slant and vertical visibility for tower aircraft controllers, meteorologists, but also from pilot's point of view. Other algorithms are also provided for detection of atmospheric layering in any given direction and vertical angle, along with the detection of the Planetary Boundary Layer Height (PBLH).

Global Climatic Indices Influence on Rainfall Spatiotemporal Distribution : A Case Study from Morocco

NASA Astrophysics Data System (ADS)

Elkadiri, R.; Zemzami, M.; Phillips, J.

2017-12-01

The climate of Morocco is affected by the Mediterranean Sea, the Atlantic Ocean the Sahara and the Atlas mountains, creating a highly variable spatial and temporal distribution. In this study, we aim to decompose the rainfall in Morocco into global and local signals and understand the contribution of the climatic indices (CIs) on rainfall. These analyses will contribute in understanding the Moroccan climate that is typical of other Mediterranean and North African climatic zones. In addition, it will contribute in a long-term prediction of climate. The constructed database ranges from 1950 to 2013 and consists of monthly data from 147 rainfall stations and 37 CIs data provided mostly by the NOAA Climate Prediction Center. The next general steps were followed: (1) the study area was divided into 9 homogenous climatic regions and weighted precipitation was calculated for each region to reduce the local effects. (2) Each CI was decomposed into nine components of different frequencies (D1 to D9) using wavelet multiresolution analysis. The four lowest frequencies of each CI were selected. (3) Each of the original and resulting signals were shifted from one to six months to account for the effect of the global patterns. The application of steps two and three resulted in the creation of 1225 variables from the original 37 CIs. (4) The final 1225 variables were used to identify links between the global and regional CIs and precipitation in each of the nine homogenous regions using stepwise regression and decision tree. The preliminary analyses and results were focused on the north Atlantic zone and have shown that the North Atlantic Oscillation (PC-based) from NCAR (NAOPC), the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), the Western Mediterranean Oscillation (WMO) and the Extreme Eastern Tropical Pacific Sea Surface Temperature (NINO12) have the highest correlation with rainfall (33%, 30%, 27%, 21% and -20%, respectively). In addition the 4-months lagged NINO12 and the 6-months lagged NAOPC and WMO have a collective contribution of more than 45% of the rainfall signal. Low frequencies are also represented in the rainfall; especially the 5th and 4th components of the decomposed CIs (48% and 42% of the frequencies, respectively) suggesting their potential contribution in the interannual rainfall variability.

A cloud based brokering framework to support hydrology at global scale

NASA Astrophysics Data System (ADS)

Boldrini, E.; Pecora, S.; Bordini, F.; Nativi, S.

2016-12-01

This work presents the hydrology broker designed and deployed in the context of a collaboration between the Regional Agency for Environmental Protection in the Italian region Emilia-Romagna (ARPA-ER) and CNR-IIA (National Research Council of Italy). The hydrology brokering platform eases the task of discovering and accessing hydrological observation data, usually acquired and made available by national agencies by means of a set of heterogeneous services (e.g. CUAHSI HIS servers, OGC services, FTP servers) and formats (e.g. WaterML, O&M, ...). The hydrology broker makes all the already published data available according to one or more of the desired and well known discovery protocols, access protocols, and formats . As a result, the user is able to search and access the available hydrological data through his preferred client (e.g. CUAHSI HydroDesktop, 52North SWE client). It is also easy to build a hydrological web portal on top of the broker, using the user friendly js API. The hydrology broker has been deployed on the Amazon cloud to ensure scalability and tested in the context of the work of the Commission for Hydrology of WMO on three different scenarios: the La Plata river basin, the Sava river basin and the Arctic-HYCOS project. In each scenario the hydrology broker discovered and accessed heterogeneous data formats (e.g. Waterml 1.0/2.0, proprietary CSV documents) from the heterogeneous services (e.g. CUAHSI HIS servers, FTP service and agency proprietary services) managed by several national agencies and international commissions. The hydrology broker made possible to present all the available data uniformly through the user desired service type and format (e.g. an HIS server publishing Waterml 2.0), producing a great improvement in both system interoperability and data exchange. Interoperability tests were also successfully conducted with WMO Information System (WIS) nodes, making possible for a specific Global Information Center System (GISC) to gather the available hydrological records as ISO 19115:2007 metadata documents through the OAI-PMH interface exposed by the broker. The framework flexibility makes it also easy to add other sources, as well as additional published interfaces, in order to cope with the future standard requirements needed by the hydrological community.

Hydrologic Geospatial Fabric as Community Cyberinfrastructure: International standardization best practices and the U.S. Open Water Data Initiative implementation.

NASA Astrophysics Data System (ADS)

Blodgett, D. L.

2016-12-01

Recent prolonged droughts, catastrophic flooding, and the need to protect and restore aquatic ecosystems, has increased the emphasis on information sharing in the water resources science and engineering domains. Internationally the joint World Meteorological Organization (WMO) and Open Geospatial Consortium (OGC) Hydrology Domain Working Group (HDWG) has been working toward a comprehensive system of standards and best practices for the Hydrology Domain. In the U.S. the multi-agency led and open to all U.S. Advisory Committee on Water Information (ACWI) was tasked to implement an Open Water Data Initiative (OWDI), "that will integrate currently fragmented water information into a connected, national water data framework"[1]. The status of both will be presented with focus on a community hydrologic geospatial fabric. Hydrology observations data standardization was the emphasis of the first 5 years of the HDWG. This work included WaterML 2.0 parts 1 - timeseries and part 2 - ratings and gagings. In 2016, the first of two new hydrographic feature models, GroundwaterML2, was completed and the second, for surface water features, was in active development. The WMO Commission for Hydrology is considering adoption of all these standards and their adoption is central to the U.S. OWDI. OWDI participants have produced a special collection in the Journal of American Water Resources Association and several initiative working groups have concluded their activities. One early deliverable from the OWDI was a new easier to use structure for the NHDPlus dataset. Building on this, a project to create a national Network Linked Data Index (NLDI) is being undertaken as an open-source community endeavor. The NLDI centralizes river network data, network navigation tools, crawlers that index data to the network, and utilities to register or remove data from the network. Research that informed the design of the NLDI will be presented along with recent development and findings of the project. This specific activity will be put in the context of the methods for and status of international standards and best practices development intended to help realize such national and international goals. [1] http://acwi.gov/spatial/open_water_data_charge_to_fgdc_june23_2014.pdf

Analysis of multi-year near-surface ozone observations at the WMO/GAW "Concordia" station (75°06‧S, 123°20‧E, 3280 m a.s.l. - Antarctica)

NASA Astrophysics Data System (ADS)

Cristofanelli, Paolo; Putero, Davide; Bonasoni, Paolo; Busetto, Maurizio; Calzolari, Francescopiero; Camporeale, Giuseppe; Grigioni, Paolo; Lupi, Angelo; Petkov, Boyan; Traversi, Rita; Udisti, Roberto; Vitale, Vito

2018-03-01

This work focuses on the near-surface O3 variability over the eastern Antarctic Plateau. In particular, eight years (2006-2013) of continuous observations at the WMO/GAW contributing station "Concordia" (Dome C-DMC: 75°06‧S, 123°20‧E, 3280 m) are presented, in the framework of the Italian Antarctic Research Programme (PNRA). First, the characterization of seasonal and diurnal O3 variability at DMC is provided. Then, for the period of highest data coverage (2008-2013), we investigated the role of specific atmospheric processes in affecting near-surface summer O3 variability, when O3 enhancement events (OEEs) are systematically observed at DMC (average monthly frequency peaking up to 60% in December). As deduced by a statistical selection methodology, these OEEs are affected by a significant interannual variability, both in their average O3 values and in their frequency. To explain part of this variability, we analyzed OEEs as a function of specific atmospheric variables and processes: (i) total column of O3 (TCO) and UV-A irradiance, (ii) long-range transport of air masses over the Antarctic Plateau (by Lagrangian back-trajectory analysis - LAGRANTO), (iii) occurrence of "deep" stratospheric intrusion events (by using the Lagrangian tool STLEFLUX). The overall near-surface O3 variability at DMC is controlled by a day-to-day pattern, which strongly points towards a dominating influence of processes occurring at "synoptic" scales rather than "local" processes. Even if previous studies suggested an inverse relationship between OEEs and TCO, we found a slight tendency for the annual frequency of OEEs to be higher when TCO values are higher over DMC. The annual occurrence of OEEs at DMC seems related to the total time spent by air masses over the Antarctic plateau before their arrival to DMC, suggesting the accumulation of photochemically-produced O3 during the transport, rather than a more efficient local production. Moreover, the identification of recent (i.e., 4-day old) stratospheric intrusion events by STEFLUX suggested only a minor influence (up to 3% of the period, in November) of "deep" events on the variability of near-surface summer O3 at DMC.

IAHS Third Scientific Assembly

NASA Astrophysics Data System (ADS)

The International Association of Hydrological Sciences (IAHS) convened its Third Scientific Assembly in Baltimore, Md., May 10-19, 1989. The Assembly was attended by about 450 scientists and engineers. The attendance was highest from the U.S., as could be expected; 37 were from Canada; 22 each, Netherlands and United Kingdom; 14, Italy; 12, China; 10, Federal Republic of Germany; 8 each from France, the Republic of South Africa, and Switzerland; 7, Austria; 6 each, Finland and Japan; others were scattered among the remainder of 48 countries total.one of the cosponsors and also handled business matters for the Assembly. Other cosponsors included the International Association of Meteorology and Atmospheric Physics (IAMAP), United Nations Environmental Program (UNEP), United Nations Educational, Scientific, and Cultural Organization (UNESCO), World Meteorological Organization (WMO), and U.K. Overseas Development Authority (ODA). U.S. federal agencies serving as cosponsors included the Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, National Weather Service, Department of Agriculture, Department of State, and U.S. Geological Survey.

Measuring progress of the global sea level observing system

NASA Astrophysics Data System (ADS)

Woodworth, Philip L.; Aarup, Thorkild; Merrifield, Mark; Mitchum, Gary T.; Le Provost, Christian

Sea level is such a fundamental parameter in the sciences of oceanography geophysics, and climate change, that in the mid-1980s, the Intergovernmental Oceanographic Commission (IOC) established the Global Sea Level Observing System (GLOSS). GLOSS was to improve the quantity and quality of data provided to the Permanent Service for Mean Sea Level (PSMSL), and thereby, data for input to studies of long-term sea level change by the Intergovernmental Panel on Climate Change (IPCC). It would also provide the key data needed for international programs, such as the World Ocean Circulation Experiment (WOCE) and later, the Climate Variability and Predictability Programme (CLIVAR).GLOSS is now one of the main observation components of the Joint Technical Commission for Oceanography and Marine Meteorology (JCOMM) of IOC and the World Meteorological Organization (WMO). Progress and deficiencies in GLOSS were presented in July to the 22nd IOC Assembly at UNESCO in Paris and are contained in the GLOSS Assessment Report (GAR) [IOC, 2003a].

The Effect of Representing Bromine from VSLS on the Simulation and Evolution of Antarctic Ozone

NASA Technical Reports Server (NTRS)

Oman, Luke D.; Douglass, Anne R.; Salawitch, Ross J.; Canty, Timothy P.; Ziemke, Jerald R.; Manyin, Michael

2016-01-01

We use the Goddard Earth Observing System Chemistry Climate Model (GEOSCCM), a contributor to both the 2010 and 2014 WMO Ozone Assessment Reports, to show that inclusion of 5 parts per trillion (ppt) of stratospheric bromine(Br(sub y)) from very short lived substances (VSLS) is responsible for about a decade delay in ozone hole recovery. These results partially explain the significantly later recovery of Antarctic ozone noted in the 2014 report, as bromine from VSLS was not included in the 2010 Assessment. We show multiple lines of evidence that simulations that account for VSLS Br(sub y) are in better agreement with both total column BrO and the seasonal evolution of Antarctic ozone reported by the Ozone Monitoring Instrument (OMI) on NASAs Aura satellite. In addition, the near zero ozone levels observed in the deep Antarctic lower stratospheric polar vortex are only reproduced in a simulation that includes this Br(sub y) source from VSLS.

The Global Ocean Observing System: One perspective

NASA Technical Reports Server (NTRS)

Wilson, J. Ron

1992-01-01

This document presents a possible organization for a Global Ocean Observing System (GOOS) within the Intergovernmental Oceanographic Commission and the joint ocean programs with the World Meteorological Organization. The document and the organization presented here is not intended to be definitive, complete or the best possible organization for such an observation program. It is presented at this time to demonstrate three points. The first point to be made is that an international program office for GOOS along the lines of the WOCE and TOGA IPOs is essential. The second point is that national programs will have to continue to collect data at the scale of WOCE plus TOGA and more. The third point is that there are many existing groups and committees within the IOC and joint IOC/WMO ocean programs that can contribute essential experience to and form part of the basis of a Global Ocean Observing System. It is particularly important to learn from what has worked and what has not worked in the past if a successful ocean observing system is to result.

Increasing frequency of extremely severe cyclonic storms over the Arabian Sea

NASA Astrophysics Data System (ADS)

Murakami, Hiroyuki; Vecchi, Gabriel A.; Underwood, Seth

2017-12-01

In 2014 and 2015, post-monsoon extremely severe cyclonic storms (ESCS)—defined by the WMO as tropical storms with lifetime maximum winds greater than 46 m s-1—were first observed over the Arabian Sea (ARB), causing widespread damage. However, it is unknown to what extent this abrupt increase in post-monsoon ESCSs can be linked to anthropogenic warming, natural variability, or stochastic behaviour. Here, using a suite of high-resolution global coupled model experiments that accurately simulate the climatological distribution of ESCSs, we show that anthropogenic forcing has likely increased the probability of late-season ECSCs occurring in the ARB since the preindustrial era. However, the specific timing of observed late-season ESCSs in 2014 and 2015 was likely due to stochastic processes. It is further shown that natural variability played a minimal role in the observed increase of ESCSs. Thus, continued anthropogenic forcing will further amplify the risk of cyclones in the ARB, with corresponding socio-economic implications.

Toward Global Harmonization of Derived Cloud Products

NASA Technical Reports Server (NTRS)

Wu, Dong L.; Baum, Bryan A.; Choi, Yong-Sang; Foster, Michael J.; Karlsson, Karl-Goeran; Heidinger, Andrew; Poulsen, Caroline; Pavolonis, Michael; Riedi, Jerome; Roebeling, Robert

2017-01-01

Formerly known as the Cloud Retrieval Evaluation Workshop (CREW; see the list of acronyms used in this paper below) group (Roebeling et al. 2013, 2015), the International Cloud Working Group (ICWG) was created and endorsed during the 42nd Meeting of CGMS. The CGMS-ICWG provides a forum for space agencies to seek coherent progress in science and applications and also to act as a bridge between space agencies and the cloud remote sensing and applications community. The ICWG plans to serve as a forum to exchange and enhance knowledge on state-of-the-art cloud parameter retrievals algorithms, to stimulate support for training in the use of cloud parameters, and to encourage space agencies and the cloud remote sensing community to share knowledge. The ICWG plans to prepare recommendations to guide the direction of future research-for example, on observing severe weather events or on process studies-and to influence relevant programs of the WMO, WCRP, GCOS, and the space agencies.

Measuring what we manage - the importance of hydrological data to water resources management

NASA Astrophysics Data System (ADS)

Stewart, B.

2015-04-01

Water resources cannot be managed, unless we know where they are, in what quantity and quality, and how variable they are likely to be in the foreseeable future. Data from hydrological networks are used by public and private sectors for a variety of different applications. This paper discusses the value proposition behind the collection, analysis and use of hydrological data in support of these applications. The need for hydrological data and the requirements for the data are outlined, and information is provided on topics such as status of networks and data access and sharing. This paper outlines elements of the contribution by the World Meteorological Organization (WMO) to hydrological data collection and covers aspects related to quality management in the collection of hydrological data, especially regarding streamflow gauging, network design and capacity building for services delivery. It should be noted that the applications which make use of hydrological data may also be significantly impacted by climate change.

In Situ Synthesis and Characterization of Fe-Based Metallic Glass Coatings by Electrospark Deposition Technique

NASA Astrophysics Data System (ADS)

Burkov, Alexander A.; Pyachin, S. A.; Ermakov, M. A.; Syuy, A. V.

2017-02-01

Crystalline FeWMoCrBC electrode materials were prepared by conventional powder metallurgy. Metallic glass (MG) coatings were produced by electrospark deposition onto AISI 1035 steel in argon atmosphere. X-ray diffraction and scanning electron microscopy verified the amorphous structure of the as-deposited coatings. The coatings have a thickness of about 40 microns and a uniform structure. The results of dry sliding wear tests against high-speed steel demonstrated that Fe-based MG coatings had a lower friction coefficient and more than twice the wear resistance for 20 km sliding distance with respect to AISI 1035 steel. High-temperature oxidation treatment of the metal glass coatings at 1073 K in air for 12 h revealed that the oxidation resistance of the best coating was 36 times higher than that for bare AISI 1035 steel. These findings are expected to broaden the applications of electrospark Fe-based MG as highly protective and anticorrosive coatings for mild steel.

Global Floods and Droughts Simulation to Support International Flood Initiative and International Drought Initiative of the UNESCO International Hydrological Program

NASA Astrophysics Data System (ADS)

Gusyev, M.; Takeuchi, K.; Magome, J.; Masood, M.

2015-12-01

One of the main achievements of the IHD/IHP programs is the promotion and enhancement of hydrological data exchange within the global water community. World Catalogue of Very Large Floods, World Water Balance and Water Resources of the Earth are the great examples of some initial collaborative efforts and the FRIEND and Catalogue of Rivers for Southeast Asia and the Pacific are the more recent outcomes. Along with similar efforts by WMO, FAO, IGBP, CEOS and many other national and international institutes, the global hydrological monitoring and nowcast have made a considerable progress last decade and are about to put into practice. Such efforts include global streamflow alert system of U Maryland and GFAS-streamflow of ICHARM and U Yamanshi. Especially the recent achievements of GFAS-streamflow support the current efforts of IHP International Flood Initiative (IFI) and International Drought Initiatives (IDI) by global nowcasts and easily visible indicators in 20-km resolution.

The Effect of Representing Bromine from VSLS on the Simulation and Evolution of Antarctic Ozone

PubMed Central

Oman, Luke D.; Douglass, Anne R.; Salawitch, Ross J.; Canty, Timothy P.; Ziemke, Jerald R.; Manyin, Michael

2018-01-01

We use the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM), a contributor to both the 2010 and 2014 WMO Ozone Assessment Reports, to show that inclusion of 5 parts per trillion (ppt) of stratospheric bromine (Bry) from very short-lived substances (VSLS) is responsible for about a decade delay in ozone hole recovery. These results partially explain the significantly later recovery of Antarctic ozone noted in the 2014 report, as bromine from VSLS was not included in the 2010 Assessment. We show multiple lines of evidence that simulations that account for VSLS Bry are in better agreement with both total column BrO and the seasonal evolution of Antarctic ozone reported by the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite. In addition, the near zero ozone levels observed in the deep Antarctic lower stratospheric polar vortex are only reproduced in a simulation that includes this Bry source from VSLS. PMID:29551840

Precipitable Water Vapour at the Canarian Observatories (Teide and Roque de los Muchachos) from routine GPS

NASA Astrophysics Data System (ADS)

Castro-Almazán, Julio A.; Muñoz-Tuñón, Casiana; García-Lorenzo, Begoña.; Pérez-Jordán, Gabriel; Varela, Antonia M.; Romero, Ignacio

2016-07-01

We are presenting two years (2012 and 2013) of preliminary statistical results of calibrated PWV values from the GPS geodesic antennas (LPAL and IZAN) at Teide and Roque de los Muchachos Observatories (OT and ORM), Canary Islands. To calibrate the PWV from both GPS antennas we have selected a set of simultaneous high vertical resolution radio-sounding profiles from the closest operational balloon station, Güímar (GUI-WMO 60018; ≍15 km distant from OT and ≍150 km from ORM). The calibrations showed a correlation of 0.994 and 0.970 for OT and ORM, respectively, with rmse of 0.44 and 0.70 mm. The calibrated PWV series brought median values of 3.5 mm at OT and 4.0 mm at ORM. The difference is explained by the 200 m of difference in height of the antennas (LPAL antenna is below the telescopes altitude). Twenty five percent of the time, PWV is less than 1.7 mm.

Evaluation of new laser spectrometer techniques for in-situ carbon monoxide measurements

NASA Astrophysics Data System (ADS)

Zellweger, C.; Steinbacher, M.; Buchmann, B.

2012-10-01

Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. The current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came to market with promising properties for trace gas analytics. The current study compares three instruments that have recently become commercially available (since 2011) with the best currently available technique (Vacuum UV Fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques perform considerably better compared to previous techniques, although some issues, such as temperature influence and cross sensitivities, need further attention.

VizieR Online Data Catalog: Optical reverberation mapping campaign of 5 AGNs (Fausnaugh+, 2017)

NASA Astrophysics Data System (ADS)

Fausnaugh, M. M.; Grier, C. J.; Bentz, M. C.; Denney, K. D.; De Rosa, G.; Peterson, B. M.; Kochanek, C. S.; Pogge, R. W.; Adams, S. M.; Barth, A. J.; Beatty, T. G.; Bhattacharjee, A.; Borman, G. A.; Boroson, T. A.; Bottorff, M. C.; Brown, J. E.; Brown, J. S.; Brotherton, M. S.; Coker, C. T.; Crawford, S. M.; Croxall, K. V.; Eftekharzadeh, S.; Eracleous, M.; Joner, M. D.; Henderson, C. B.; Holoien, T. W.-S.; Horne, K.; Hutchison, T.; Kaspi, S.; Kim, S.; King, A. L.; Li, M.; Lochhaas, C.; Ma, Z.; Macinnis, F.; Manne-Nicholas, E. R.; Mason, M.; Montuori, C.; Mosquera, A.; Mudd, D.; Musso, R.; Nazarov, S. V.; Nguyen, M. L.; Okhmat, D. N.; Onken, C. A.; Ou-Yang, B.; Pancoast, A.; Pei, L.; Penny, M. T.; Poleski, R.; Rafter, S.; Romero-Colmenero, E.; Runnoe, J.; Sand, D. J.; Schimoia, J. S.; Sergeev, S. G.; Shappee, B. J.; Simonian, G. V.; Somers, G.; Spencer, M.; Starkey, D. A.; Stevens, D. J.; Tayar, J.; Treu, T.; Valenti, S.; van Saders, J.; Villanueva, S., Jr.; Villforth, C.; Weiss, Y.; Winkler, H.; Zhu, W.

2017-11-01

We obtained spectra on an approximately daily cadence between 2014 January 04 and July 06 UTC using the Boller and Chivens CCD Spectrograph on the 1.3m McGraw-Hill telescope at the MDM Observatory. We also obtained six epochs of observations with the 2.3m telescope at Wyoming Infrared Observatory (WIRO) and the WIRO Long Slit Spectrograph. Our spectroscopic observations are supplemented with broadband imaging observations. Contributing telescopes were the 0.7m at the Crimean Astrophysical Observatory (CrAO), the 0.5m Centurian 18 at Wise Observatory (WC18), and the 0.9m at West Mountain Observatory (WMO). In addition, we obtained ugriz imaging with the LCO 1m network, which consists of nine identical 1m telescopes at four observatories spread around the globe. These data were originally acquired as part of LCO's AGN Key project (Valenti+ 2015ApJ...813L..36V). (11 data files).

The impact and importance of intercalibration and intercomparisons for greenhouse gas observational networks

NASA Astrophysics Data System (ADS)

Stavert, Ann; O'Doherty, Simon; Rigby, Matthew; Palmer, Paul; Stanley, Kieran; Young, Dickon; Lunt, Mark; Grant, Aoife; Pitt, Joseph; Bauguitte, Stephane; Helfter, Carole; Mullinger, Neil; Robinson, Andrew; Harris, Neil; Riddick, Stuart; Sonderfeld, Hannah; Boesch, Hartmut; Foster, Grant

2016-04-01

Motivated by the UK 2008 Climate Change Act, which requires the UK to decrease its greenhouse gas (GHG) emissions by 80% of 1990 levels by 2050, the Greenhouse gAs Uk and Global Emissons (GAUGE) project aims to better quantify UK CO2, CH4 and N2O emissions. As part of this project a UK-focused GHG observational network has been established, drawing together new and existing GHG data streams from regional to global scales. These included high-density regional studies, tall-tower sites, moving platforms (ferry and aircraft) and satellite observations. Under the project these observations will be combined with modelling approaches to better quantify and characterise UK GHG emissions and place them within a global context. This presentation will describe the efforts made to ensure that common calibration scales were used within the GAUGE project and an assessment of the intercomparability of the stationary sites and moving platforms (including 6 near surface regional focused sites, 6 tall tower sites, ferry and aircraft measurements). This assessment was undertaken using both a cylinder intercomparison program (ICP) and a comparison between co-located flask and in situ measurements. The majority of the sites agreed within the WMO comparability guidelines, however, small relative biases in CO2 and CH4 were identified at some sites. These biases generally increased with concentration, with differences up to 0.3ppm in CO2 and 3ppb CH4 observed between tall tower sites and mobile platforms, while larger biases were found at some of the regional study sites. In order to investigate the impact of biases of these types an experiment using pseudo emissions and observations was conducted. To achieve this, sets of emissions estimates for key GHG sources (e.g. for CH4 the sum of anthropogenic, biomass burning, wetlands, rice and oceans and other natural sources) were used to estimate the GHG concentrations at the GAUGE observation sites and mobile platforms via the Met office NAME model. These pseudo observations were then adjusted using a range of biases and simulated calibration offsets. Regional UK emissions were then determined based on inversions performed using the Met office NAME model and hierarchical Bayesian inversion method. Using these emissions estimates we quantified the impact of systematic site biases on derived fluxes, assessing the relevance of the WMO comparability guidelines for our UK study and highlighting the importance of rigorous inter-calibration and comparability of data streams for regional emissions estimation.

High accuracy Primary Reference gas Mixtures for high-impact greenhouse gases

NASA Astrophysics Data System (ADS)

Nieuwenkamp, Gerard; Zalewska, Ewelina; Pearce-Hill, Ruth; Brewer, Paul; Resner, Kate; Mace, Tatiana; Tarhan, Tanil; Zellweger, Christophe; Mohn, Joachim

2017-04-01

Climate change, due to increased man-made emissions of greenhouse gases, poses one of the greatest risks to society worldwide. High-impact greenhouse gases (CO2, CH4 and N2O) and indirect drivers for global warming (e.g. CO) are measured by the global monitoring stations for greenhouse gases, operated and organized by the World Meteorological Organization (WMO). Reference gases for the calibration of analyzers have to meet very challenging low level of measurement uncertainty to comply with the Data Quality Objectives (DQOs) set by the WMO. Within the framework of the European Metrology Research Programme (EMRP), a project to improve the metrology for high-impact greenhouse gases was granted (HIGHGAS, June 2014-May 2017). As a result of the HIGHGAS project, primary reference gas mixtures in cylinders for ambient levels of CO2, CH4, N2O and CO in air have been prepared with unprecedented low uncertainties, typically 3-10 times lower than usually previously achieved by the NMIs. To accomplish these low uncertainties in the reference standards, a number of preparation and analysis steps have been studied and improved. The purity analysis of the parent gases had to be performed with lower detection limits than previously achievable. E.g., to achieve an uncertainty of 2•10-9 mol/mol (absolute) on the amount fraction for N2O, the detection limit for the N2O analysis in the parent gases has to be in the sub nmol/mol domain. Results of an OPO-CRDS analyzer set-up in the 5µm wavelength domain, with a 200•10-12 mol/mol detection limit for N2O, will be presented. The adsorption effects of greenhouse gas components at cylinder surfaces are critical, and have been studied for different cylinder passivation techniques. Results of a two-year stability study will be presented. The fit-for-purpose of the reference materials was studied for possible variation on isotopic composition between the reference material and the sample. Measurement results for a suit of CO2 in air mixtures with varying δ13C values (from -5‰ to -40‰) analyzed with both cavity ringdown spectroscopy (CRDS) and isotope-ratio mass spectrometry (IRMS) will be presented. Round robins were organized to assess the agreement of the new reference gas mixtures developed by different project partners and to compare the new reference gases with the reference standards currently used by the atmospheric monitoring community (NOAA and AGAGE). These results will also be presented.

The Global Atmosphere Watch Aerosol Programme

NASA Astrophysics Data System (ADS)

Baltensperger, U.

2003-04-01

The Global Atmosphere Watch (GAW) programme is a WMO sponsored activity and currently supported by about 80 WMO member countries. It is the goal of GAW to develop and maintain long-term measurements of atmospheric constituents in order to detect trends, develop aerosol predictive capabilities and understand proc- esses. With respect to aerosols, the objective of GAW is to support a global network determining the spatio-temporal distribution of aerosol properties related to climate forcing and air quality up to multi-decadal time scales. The GAW network consists of 22 Global stations and some 300 Regional stations. The Scientific Advisory Group (SAG) for Aerosols will soon publish their recommendations for aerosol measurements. Each site should have an acceptable aerosol sampling inlet. Regional stations measure aerosol optical depth, as well as the aerosol light scattering and absorption coefficient. If possible these should be complemented by routine mass concentration and composition measurements in two aerosol size fractions. At Global stations, a larger number of measurements are desirable. These include the Regional parameters list above as well as the light scattering, hemispheric backscat- tering, and absorption coefficients at various wavelengths, aerosol number concen- tration, cloud condensation nuclei (CCN) concentration at 0.5% supersaturation, and diffuse, global and direct solar radiation. Additional parameters such as the aerosol size distribution, detailed size fractionated chemical composition, dependence of aerosol properties on relative humidity, CCN concentration at various supersatura- tions, and the vertical distribution of aerosol properties should be measured intermit- tently at Global stations. Examples from the Jungfraujoch (Swiss Alps, 3580 m asl) will be given, where many of the parameters listed above are measured. Data are delivered to and made available by the World Data Centre for Aerosols (WDCA, located in Ispra, Italy http://ies.jrc.cec.eu.int/wdca/) using the NARSTO data exchange standard. The Institute for Tropospheric Research in Leipzig hosts a GAW World Calibration Centre (WCC) for physical aerosol parameters. A host for the chemical parameters still must be located. None of the Global sites perform a full set of measurements, and many Regional sites have not yet started with aerosol ac- tivities at all. Capacity building and fund raising are therefore important priorities in order to achieve the goals of the GAW global aerosol programme. It should be em- phasized that GAW works with many partners in the World Meteorological Organi- zation as well as other agencies in an attempt to develop an integrated system of satellite and non-satellite observations of the global aerosol.

Data Democratization - Promoting Real-Time Data Sharing and Use throughout the Americas

NASA Astrophysics Data System (ADS)

Yoksas, T. C.

2006-05-01

The Unidata Program Center (Unidata) of the University Corporation of Atmospheric Research (UCAR) is actively involved in international collaborations whose goals are real-time sharing of hydro-meteorological data by institutions of higher education throughout the Americas; in the distribution of analysis and visualization tools for those data; and in the establishment of server sites that provide easy-to-use, programmatic remote- access to a wide variety of datasets. Data sharing capabilities are being provided by Unidata's Internet Data Distribution (IDD) system, a community-based effort that has been the primary source of real-time meteorological data for approximately 150 US universities for over a decade. A collaboration among Unidata, Brazil's Centro de PreviSão de Tempo e Estudos Climáticos (CPTEC), the Universidad Federal do Rio de Janeiro (UFRJ), and the Universidade de São Paulo (USP) has resulted in the creation of a Brazilian peer of the North American IDD, the IDD-Brasil. Collaboration among Unidata, the Universidad de Costa Rica (UCR), and the University of Puerto Rico at Mayaguez (UPRM) seeks to extend IDD data sharing throughout Central America and the Caribbean in an IDD-Caribe. Collaboration between Unidata and the Caribbean Institute for Meteorology and Hydrology (CIMH), a World Meteorological Organization (WMO) Regional Meteorological Training Center (RMTC) based in Barbados, has been launched to investigate the possibility of expansion of IDD data sharing throughout Caribbean RMTC member countries. Most recently, efforts aimed at creating a data sharing network for researchers on the Antarctic continent have resulted in the establishment of the Antarctic-IDD. Data analysis and visualization capabilities are being provided by Unidata through a suite of freely-available applications: the National Centers for Environmental Prediction (NCEP) GEneral Meteorology PAcKage (GEMPAK); the Unidata Integrated Data Viewer (IDV); and University of Wisconsin, Space Science and Engineering Center (SSEC) Man-computer Interactive Data Access System (McIDAS). Remote data access capabilities are provided by Unidata's Thematic Realtime Environmental Data Services (THREDDS) servers (which incorporate Open-source Project for a Network Data Access (OPeNDAP) data services), and the Abstract Data Distribution Environment (ADDE) of McIDAS. It is envisioned that the data sharing capabilities available in the IDD, IDD-Brasil, and IDD-Caribe, remote data access capabilities available in THREDDS and ADDE, and analysis capabilities available in GEMPAK, the IDV, and McIDAS will help foster new collaborations among prominent university educators and researchers, national meteorological agencies, and WMO Regional Meteorological Training Centers throughout North, Central, and South America.

Early paleozoic granodioritic plutons in the Shedong W-Mo ore district, Guangxi, southern China: Products of re-melting of middle Proterozoic crust due to magma underplating

NASA Astrophysics Data System (ADS)

Jiang, Xingzhou; Kang, Zhiqiang; Xu, Jifeng; Feng, Zuohai; Pang, Chongjin; Fang, Guicong; Wu, Jiachang; Xiong, Songquan

2017-06-01

The Shedong W-Mo ore district in the south-central Dayaoshan Uplift of Guangxi, southern China hosts the Baoshan and Pingtoubei deposits, both of which occur in granodioritic plutons. Zircon U-Pb dating of granodiorites and its mafic microgranular enclaves (MMEs) in the Baoshan deposit yielded ages of 439.8 ± 3.2 and 441.1 ± 2.2 Ma, respectively. Granodiorites have moderate SiO2 (54.5-63.0 wt.%) and high Al2O3 (15.4-17.8 wt.%) contents, wide variations in major element ratios, significant rare earth element fractionation, and small negative Eu anomalies. They are rich in Th, U, Zr, and Hf, and depleted in Ba, Nb, and Ti. Their initial 87Sr/86Sr, εNd(t), and εHf(t) values are in the range of 0.7086-0.7091, -5.2 to -6.6 and -6.3 to +1.6, respectively. Rounded or lenticular MMEs have relatively low silica and high mafic components, depletion in Eu, Sr, and Zr, and marked negative Eu anomalies. Rb/Sr and Nb/Ta ratios, and εNd(t) and εHf(t) values of the MMEs are higher than those of host granodiorites, indicating a different magmatic source. Zircon U-Pb dating of the unexposed granodiorite porphyry in the Pingtoubei deposit yielded an age of 440.0 ± 1.7 Ma. The granodiorite porphyries have high SiO2 and low K2O, FeOT, and MgO contents, with similar trace element features to the granodiorites at the Baoshan deposit, although the former has small negative Eu anomalies. Its initial 87Sr/86Sr values range from 0.7162 to 0.7173, εNd(t) values from -8.7 to -12.3, and εHf(t) values from -7.8 to +1.3, indicative of a crustal source. Nd and Hf two-stage model ages of the granodiorites, MMEs, and granodiorite porphyries have a narrow range between 1.3 and 2.2 Ga. We propose that the granodiorites and MMEs at the Baoshan deposit were produced through re-melting of middle Proterozoic crust as a result of underplating of mantle-derived magmas in a transitional compression-to-extension tectonic setting. Mantle-derived magmas provided the heat and material for the formation of the granodiorites and MMEs.

Some statistics of freezing precipitation and rime for the territory of the former USSR from ground-based weather observations

NASA Astrophysics Data System (ADS)

Bezrukova, Natalia A.; Jeck, Richard K.; Khalili, Marat F.; Minina, Ludmila S.; Naumov, Alexander Ya.; Stulov, Evgeny A.

2006-11-01

This work is a continuation of the previous climatological study of freezing precipitation and rime over the USSR territory [ Bezrukova, N.A., Minina, L.S., Naumov, A.Ya., 2000. Freezing precipitation climatology in the former European USSR. Proceedings of the 13th International Conference on Clouds and Precipitation, pp.737-739, Reno, Nevada, USA, 14-18 August 2000; Bezrukova, N.A., Jeck, R.K., Minina, L.S., Khalili, M.F., Stulov, E.A., 2004. 10-year Statistics on Freezing Precipitation across the former USSR from surface weather observations. Proceedings of the 14th International Conference on Clouds and Precipitation, pp.731-734, Bologna, Italy, 19-23 August 2004.] aimed at creating an atlas of the frequency of these phenomena. This study gives considerable information about and a statistical analysis of freezing precipitation and rime events observed over the territory of the former USSR during a decade (1981-1990) and over the European territory of the USSR during two decades (1971-1990). This paper intends to draw the attention of the reader to the atlas and statistics by showing some interesting points. The authors used the data provided by the ground-based weather stations involved in the international exchange of meteorological data. The USSR network's Monthly Meteorological Tables (1971-1990) [Monthly Meteorological Tables, 1971-1990. Part 1, Novosibirsk-Obninsk. (in Russian).] comprising selected daily ground-based meteorological observations from more than 220 stations served as a basis for the analysis. All the types of freezing precipitation (FP) events were given as WMO Codes 56, 57, 66, 67, 24 and freezing fog (FF) deposited rime as WMO Codes 48, 49. The entire territory was divided into six major regions: the Arctic, the European part of the USSR, the Trans-Caucasus, Central Asia, Siberia, and the Far East. The frequency and distribution of events by regions versus temperature, atmospheric pressure, clouds base height, and some other meteorological parameters concerned were obtained. Climatic maps of annual mean, monthly mean, and seasonal mean occurrences of FP and FF were constructed for these regions. The study also analyzes the space-time variability of monthly mean ice-coating duration in hours for the 20-year period of 1971-1990 as observed at over 80 stations in the European part of the USSR (ET), and climatic maps of annual mean and monthly mean ice coating duration for the ET are constructed. The correlation between ice coating duration and height has been evaluated.

CARICOF - The Caribbean Regional Climate Outlook Forum

NASA Astrophysics Data System (ADS)

Van Meerbeeck, Cedric

2013-04-01

Regional Climate Outlook Forums (RCOFs) are viewed as a critical building block in the Global Framework for Climate Services (GFCS) of the World Meteorological Organization (WMO). The GFCS seeks to extend RCOFs to all vulnerable regions of the world such as the Caribbean, of which the entire population is exposed to water- and heat-related natural hazards. An RCOF is initially intended to identify gaps in information and technical capability; facilitate research cooperation and data exchange within and between regions, and improve coordination within the climate forecasting community. A focus is given on variations in climate conditions on a seasonal timescale. In this view, the relevance of a Caribbean RCOF (CARICOF) is the following: while the seasonality of the climate in the Caribbean has been well documented, major gaps in knowledge exist in terms of the drivers in the shifts of amplitude and phase of seasons (as evidenced from the worst region-wide drought period in recent history during 2009-2010). To address those gaps, CARICOF has brought together National Weather Services (NWSs) from 18 territories under the coordination of the Caribbean Institute for Meteorology and Hydrology (CIMH), to produce region-wide, consensus, seasonal climate outlooks since March 2012. These outlooks include tercile rainfall forecasts, sea and air surface temperature forecasts as well as the likely evolution of the drivers of seasonal climate variability in the region, being amongst others the El Niño Southern Oscillation or tropical Atlantic and Caribbean Sea temperatures. Forecasts for both the national-scale forecasts made by the NWSs and CIMH's regional-scale forecast amalgamate output from several forecasting tools. These currently include: (1) statistical models such as Canonical Correlation Analysis run with the Climate Predictability Tool, providing tercile rainfall forecasts at weather station scale; (2) a global outlooks published by the WMO appointed Global Producing Centres (GPCs). Indications are that the current seasonal forecasting system used by CARICOF has produced reliable outlooks than previously available. Nevertheless, through its forum platform, areas for further development are continuously being defined, which are then implemented through efficient information exchanges between and hands-on training of forecasters. Finally, the disaster research and emergency management communities have shown that effective early warnings of impending hazards need to be complemented by information on the risks actually posed by the hazards and pathways for action. CARICOF is to address this issue by designing the outputs of the seasonal climate outlooks such that they can then effectively feed into an early warning information system of seasonal climate variability related hazards to its constituent countries' and territories major socio-economic sectors.

Recent developments in the Trans-African Hydrological Observatory (TAHMO)

NASA Astrophysics Data System (ADS)

van de Giesen, Nicolaas; Selker, John; Annor, Frank

2017-04-01

The Trans-African Hydro-Meteorological Observatory (TAHMO) is an initiative that seeks to make Africa an extremely well monitored continent. Ideally, there would be one station every thirty kilometers, or 20,000 in total. The stations we use are robust and have no moving parts, thereby greatly reducing the burden of maintenance. The costs are relatively moderate given the high performance, meeting the WMO standards. Most stations are placed at schools where they are integrated in the curriculum, while receiving physical and social protection. Perhaps most challenging is the fact that we try to cover the costs through selling data for commercial purposes. During the past year, TAHMO network development has accelerated tremendously. In this presentation, we describe the various pathways along which this has taken place. The transition from a "nice idea", to a professional organization operating in fifteen countries is interesting and far from trivial. We have encountered various pitfalls along the way but also have learned a lot about operating the network. Finally, the different innovations in sensors and an outlook to further development will be given.

Long-term changes (1980-2003) in total ozone time series over Northern Hemisphere midlatitudes

NASA Astrophysics Data System (ADS)

Białek, Małgorzata

2006-03-01

Long-term changes in total ozone time series for Arosa, Belsk, Boulder and Sapporo stations are examined. For each station we analyze time series of the following statistical characteristics of the distribution of daily ozone data: seasonal mean, standard deviation, maximum and minimum of total daily ozone values for all seasons. The iterative statistical model is proposed to estimate trends and long-term changes in the statistical distribution of the daily total ozone data. The trends are calculated for the period 1980-2003. We observe lessening of negative trends in the seasonal means as compared to those calculated by WMO for 1980-2000. We discuss a possibility of a change of the distribution shape of ozone daily data using the Kolmogorov-Smirnov test and comparing trend values in the seasonal mean, standard deviation, maximum and minimum time series for the selected stations and seasons. The distribution shift toward lower values without a change in the distribution shape is suggested with the following exceptions: the spreading of the distribution toward lower values for Belsk during winter and no decisive result for Sapporo and Boulder in summer.

Results of Second Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reda, I.; Grobner, J.; Wacker, S.

The Absolute Cavity Pyrgeometer (ACP) and InfraRed Integrating Sphere radiometer (IRIS) are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are un-windowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The second outdoor comparison between the two designs was held from September 30 to October 11, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of the IRIS was within 1 W/m2 (3 IRISs: PMOD + Australia + Germany). From the first and second comparisons, a differencemore » of 4-6 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG). This presentation includes results from the first and second comparison in an effort to establish the world reference for pyrgeometer calibrations, a key deliverable for the World Meteorological Organization (WMO), and the DOE-ASR.« less

Mexican Space Weather Service (SCIESMEX)

NASA Astrophysics Data System (ADS)

Gonzalez-Esparza, A.; De la Luz, V.; Mejia-Ambriz, J. C.; Aguilar-Rodriguez, E.; Corona-Romero, P.; Gonzalez, L. X.

2015-12-01

Recent modifications of the Civil Protection Law in Mexico include now specific mentions to space hazards and space weather phenomena. During the last few years, the UN has promoted international cooperation on Space Weather awareness, studies and monitoring. Internal and external conditions motivated the creation of a Space Weather Service in Mexico (SCIESMEX). The SCIESMEX (www.sciesmex.unam.mx) is operated by the Geophysics Institute at the National Autonomous University of Mexico (UNAM). The UNAM has the experience of operating several critical national services, including the National Seismological Service (SSN); besides that has a well established scientific group with expertise in space physics and solar- terrestrial phenomena. The SCIESMEX is also related with the recent creation of the Mexican Space Agency (AEM). The project combines a network of different ground instruments covering solar, interplanetary, geomagnetic, and ionospheric observations. The SCIESMEX has already in operation computing infrastructure running the web application, a virtual observatory and a high performance computing server to run numerical models. SCIESMEX participates in the International Space Environment Services (ISES) and in the Inter-progamme Coordination Team on Space Weather (ICTSW) of the Word Meteorological Organization (WMO).

Evaluating aerosol impacts on Numerical Weather Prediction in two extreme dust and biomass-burning events

NASA Astrophysics Data System (ADS)

Remy, Samuel; Benedetti, Angela; Jones, Luke; Razinger, Miha; Haiden, Thomas

2014-05-01

The WMO-sponsored Working Group on Numerical Experimentation (WGNE) set up a project aimed at understanding the importance of aerosols for numerical weather prediction (NWP). Three cases are being investigated by several NWP centres with aerosol capabilities: a severe dust case that affected Southern Europe in April 2012, a biomass burning case in South America in September 2012, and an extreme pollution event in Beijing (China) which took place in January 2013. At ECMWF these cases are being studied using the MACC-II system with radiatively interactive aerosols. Some preliminary results related to the dust and the fire event will be presented here. A preliminary verification of the impact of the aerosol-radiation direct interaction on surface meteorological parameters such as 2m Temperature and surface winds over the region of interest will be presented. Aerosol optical depth (AOD) verification using AERONET data will also be discussed. For the biomass burning case, the impact of using injection heights estimated by a Plume Rise Model (PRM) for the biomass burning emissions will be presented.

Influence of open vegetation fires on black carbon and ozone variability in the southern Himalayas (NCO-P, 5079 m a.s.l.).

PubMed

Putero, D; Landi, T C; Cristofanelli, P; Marinoni, A; Laj, P; Duchi, R; Calzolari, F; Verza, G P; Bonasoni, P

2014-01-01

We analysed the variability of equivalent black carbon (BC) and ozone (O3) at the global WMO/GAW station Nepal Climate Observatory-Pyramid (NCO-P, 5079 m a.s.l.) in the southern Himalayas, for evaluating the possible contribution of open vegetation fires to the variability of these short-lived climate forcers/pollutants (SLCF/SLCP) in the Himalayan region. We found that 162 days (9% of the data-set) were characterised by acute pollution events with enhanced BC and O3 in respect to the climatological values. By using satellite observations (MODIS fire products and the USGS Land Use Cover Characterization) and air mass back-trajectories, we deduced that 56% of these events were likely to be affected by emissions from open fires along the Himalayas foothills, the Indian Subcontinent and the Northern Indo-Gangetic Plain. These results suggest that open fire emissions are likely to play an important role in modulating seasonal and inter-annual BC and O3 variability over south Himalayas. Copyright © 2013 Elsevier Ltd. All rights reserved.

Implementation of weather stations at Ghanaian high schools

NASA Astrophysics Data System (ADS)

Pieron, M.

2012-04-01

The Trans-African Hydro-Meteorological Observatory (www.tahmo.org) is an initiative that aims to develop a dense weather observation network in Sub-Sahara Africa. The ambition is to have 20.000 low-cost innovative weather stations in place in 2015. An increased amount of weather data is locally required to provide stakeholders that are dependent on the weather, such as farmers and fishermen, with accurate forecasts. As a first proof of concept, showing that sensors can be built at costs lower than commercially available, a disdrometer was developed. In parallel with the design of the measurement instruments, a high school curriculum is developed that covers environmental sciences. In order to find out which requirements the TAHMO weather station and accompanying educational materials should meet for optimal use at Junior High Schools research was done at Ghanaian schools. Useful insights regarding the future African context of the weather station and requirements for an implementation strategy were obtained during workshops with teachers and students, visits to WMO observatories and case studies regarding use of educational materials. The poster presents the conclusions of this research, which is part of the bigger TAHMO framework.

Integrated Global Observation Strategy - Ozone and Atmospheric Chemistry Project

NASA Technical Reports Server (NTRS)

Hilsenrath, Ernest; Readings, C. J.; Kaye, J.; Mohnen, V.; Einaudi, Franco (Technical Monitor)

2000-01-01

The "Long Term Continuity of Stratospheric Ozone Measurements and Atmospheric Chemistry" project was one of six established by the Committee on Earth Observing Satellites (CEOS) in response to the Integrated Global Observing Strategy (IGOS) initiative. IGOS links satellite and ground based systems for global environmental observations. The strategy of this project is to develop a consensus of user requirements including the scientific (SPARC, IGAC, WCRP) and the applications community (WMO, UNEP) and to develop a long-term international plan for ozone and atmospheric chemistry measurements. The major components of the observing system include operational and research (meeting certain criteria) satellite platforms planned by the space faring nations which are integrated with a well supported and sustained ground, aircraft, and balloon measurements program for directed observations as well satellite validation. Highly integrated and continuous measurements of ozone, validation, and reanalysis efforts are essential to meet the international scientific and applications goals. In order to understand ozone trends, climate change, and air quality, it is essential to conduct long term measurements of certain other atmospheric species. These species include key source, radical, and reservoir constituents.

Evaluation of three new laser spectrometer techniques for in-situ carbon monoxide measurements

NASA Astrophysics Data System (ADS)

Zellweger, C.; Steinbacher, M.; Buchmann, B.

2012-07-01

Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However, the current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came on the market with promising properties for trace gas analytics. The current study compares three instruments that are recently commercially available (since 2011) with the up to now best available technique (vacuum UV fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques provide a considerably better performance compared to previous techniques, although some issues such as temperature influence and cross sensitivities need further attention.

Criticality assessment of LLRWDF closure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarrack, A.G.; Weber, J.H.; Woody, N.D.

1992-10-06

During the operation of the Low Level Radioactive Waste Disposal Facility (LLRWDF), large amounts (greater than 100 kg) of enriched uranium (EU) were buried. This EU came primarily from the closing and decontamination of the Naval Fuels Facility in the time period from 1987--1989. Waste Management Operations (WMO) procedures were used to keep the EU boxes separated to prevent possible criticality during normal operation. Closure of the LLRWDF is currently being planned, and waste stabilization by Dynamic Compaction (DC) is proposed. Dynamic compaction will crush the containers in the LLRWDF and result in changes in their geometry. Research of themore » LLRWDF operations and record keeping practices have shown that the EU contents of trenches are known, but details of the arrangement of the contents cannot be proven. Reviews of the trench contents, combined with analysis of potential critical configurations, revealed that some portions of the LLRWDF can be expected to be free of criticality concerns while other sections have credible probabilities for the assembly of a critical mass, even in the uncompacted configuration. This will have an impact on the closure options and which trenches can be compacted.« less

World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT)

NASA Astrophysics Data System (ADS)

Bittner, Michael; Höppner, Kathrin; Hildenbrand, Beate

Since 2003 the Applied Remote Sensing Cluster of DLR has hosted and operated the World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT, http://wdc.dlr.de) under the non-governmental auspices of the International Council of Science (ICSU). WDC-RSAT offers scientists and the general public free access to a continuously growing collection of satellite-based atmosphere-related data sets and services. These data holdings range from raw data collected by remote sensors, to information products derived from the raw data ("value adding"). The current WDC-RSAT data holding contains data and information products addressing atmospheric trace gases, clouds, surface parameters, solar radiation, and special services as near-real time (NRT) information related to e.g. European air quality, UV radiation forecasts, global ozone level maps. In addition to archiving data sets, WDC-RSAT cooperates with other data centers and strives to provide additional services, which include data analysis and value adding, data summaries, campaign planning support, and data set validation and publication. In Germany, three current ICSU World Data Centers, namely WDC-Climate (hosted by the German Climate Computer Center, DKRZ), WDC-MARE (co-hosted by AWI and the University of Bremen), WDC-RSAT (hosted by DLR), and the pending WDC-Terra (to be hosted by GFZ) founded in 2004 the German WDC cluster for "Earth System Research", in order to promote Earth System Science and Research in Germany and abroad. This Cluster is actively pursuing a strategy, using information technology, to make data related to Earth Systems available to an as wide and as interdisciplinary possible audience. In early 2006 a scientific advisory committee for WDC-RSAT was established. External experts representing space agencies, weather services, atmospheric remote sensing technologies, and atmospheric science help to guide WDC-RSAT in setting and reaching its goals. In cooperation with the World Meteorological Organization (WMO), WDC-RSAT is aiming to become part of a data integration center to be created within the Global Atmosphere Watch (GAW)-program of the WMO. This center would concern itself with linking different GAW- relevant data sets both with each other and with models. In this context WDC-RSAT will also handle non-satellite based data which is relevant within the context of validation. WDC-RSAT is envisaged to play a major role within the recently established international and global Network for the Detection of Mesopause Change (NDMC) with the mission to promote international cooperation among research groups active in the mesopause region ( 80-100 km height) to enhance the suitability of airglow observations for the detection of long-term trends. WDC-RSAT will serve as a communication and data management platform for this worldwide network of ground-based measurements.

Implementing Geological Disposal of Radioactive Waste Technology Platform From the Strategic Research Agenda to its Deployment - 12015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouzounian, P.; Palmu, Marjatta; Eng, Torsten

2012-07-01

Several European waste management organizations (WMOs) have initiated a technology platform for accelerating the implementation of deep geological disposal of radioactive waste in Europe. The most advanced waste management programmes in Europe (i.e. Finland, Sweden, and France) have already started or are prepared to start the licensing process of deep geological disposal facilities within the next decade. A technology platform called Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP) was launched in November 2009. A shared vision report for the platform was published stating that: 'Our vision is that by 2025, the first geological disposal facilities for spent fuel,more » high-level waste, and other long-lived radioactive waste will be operating safely in Europe'. In 2011, the IGD-TP had eleven WMO members and about 70 participants from academia, research, and the industry committed to its vision. The IGD-TP has started to become a tool for reducing overlapping work, to produce savings in total costs of research and implementation and to make better use of existing competence and research infrastructures. The main contributor to this is the deployment of the IGD-TP's newly published Strategic Research Agenda (SRA). The work undertaken for the SRA defined the pending research, development and demonstration (RD and D) issues and needs. The SRA document describing the identified issues that could be worked on collaboratively was published in July 2011. It is available on the project's public web site (www.igdtp.eu). The SRA was organized around 7 Key Topics covering the Safety Case, Waste forms and their behaviour, Technical feasibility and long-term performance of repository components, Development strategy of the repository, Safety of construction and operations, Monitoring, and Governance and stakeholder involvement. Individual Topics were prioritized within the Key Topics. Cross-cutting activities like Education and Training or Knowledge Management as well as activities remaining specific for the WMOs were as well identified in the document. For example, each WMO has to develop their own waste acceptance rules, and plan for the economics and the funding of their waste management programmes. The challenge at hand for the IGD-TP is to deploy the SRA. This is carried out by agreeing on a Deployment Plan (DP) that guides organizing the concrete joint activities between the WMOs and the other participants of the IGD-TP. The first DP points out the coordinated RD and D projects and other activities that need to be launched to produce these results over the next four to five years (by the end of 2016). The DP also describes general principles for how the joint work can be organised and funded. (authors)« less

Real Time Data in Synoptic Meteolorolgy and Weather Forecasting Education

NASA Astrophysics Data System (ADS)

Campetella, C. M.; Gassmann, M. I.

2006-05-01

The Department of Atmospheric and Oceanographic Sciences (DAOS) of the University of Buenos Aires is the university component of the World Meteorological Organization (WMO) Regional Meteorological Training Center (RMTC) in Region III. In January, 2002 our RMTC was invited to take part in the MeteoForum pilot project that was developed jointly by the COMET and Unidata programs of the University Corporation for Atmospheric Research (UCAR). MeteoForum comprises an international network of WMO Region III and IV RMTCs working collaboratively with universities to enhance their roles of training and education through information technologies and multilingual collections of resources. The DAOS undertook to improve its infrastructure to be able to access hydro-meteorological information in real-time as part of the Unidata community. In 2003, the DAOS received some Unidata equipment grant funds to update its computer infrastructure, improving communications with an operationally quicker system. Departmental networking was upgraded to 100 Mb/s capability while, at the same time, new computation resources were purchased that increased the number of computers available for student use from 5 to 8. This upgrade has also resulted in more and better computers being available for student and faculty research. A video projection system, purchased with funds provided by the COMET program as part of Meteoforum, is used in classrooms with Internet connections for a variety of educational activities. The upgraded computing and networking facilities have contributed to the development of educational modules using real-time hydro-meteorological and other digital data for the classroom. With the aid of Unidata personal, the Unidata Local Data Management (LDM) software was installed and configured to request and process real-time feeds of global observational data; global numerical model output from the US National Centers for Environmental Prediction (NCEP) models; and all imager channels from GOES-12 from the Unidata Internet Data Distribution (IDD) system. The data now being routinely received have impacted not only the meteorological education in the DAOS, but also have been instructive in techniques for Internet-based data sharing for our students. The DAOS has made a substantial effort to provide undergraduate students with experience in manipulating, displaying, and analyzing weather data in real-time through interactive displays of data using visualization tools provided by Unidata. Two of the specific courses whose curriculum have been improved are synoptic meteorology and a laboratory on weather prediction. Some laboratory materials have been developed to reflect current data as applied to the lecture material. This talk will briefly describe the data compiled and the fields used to analyze an intense cyclogenesis event that occurred over the La Plata River in August, 2005. This event was used as a case study for discussions in the Synoptic Weather Laboratory degree course of Atmospheric Sciences Licentiate.

Benefits of Sharing Information: Supermodel Ensemble and Applications in South America

NASA Astrophysics Data System (ADS)

Dias, P. L.

2006-05-01

A model intercomparison program involving a large number of academic and operational institutions has been implemented in South America since 2003, motivated by the SALLJEX Intercomparison Program in 2003 (a research program focused on the identification of the role of the Andes low level jet moisture transport from the Amazon to the Plata basin) and the WMO/THORPEX (www.wmo.int/thorpex) goals to improve predictability through the proper combination of numerical weather forecasts. This program also explores the potential predictability associated with the combination of a large number of possible scenarios in the time scale of a few days to up to 15 days. Five academic institutions and five operational forecasting centers in several countries in South America, 1 academic institution in the USA, and the main global forecasting centers (NCEP, UKMO, ECMWF) agreed to provide numerical products based on operational and experimental models. The metric for model validation is concentrated on the fit of the forecast to surface observations. Meteorological data from airports, synoptic stations operated by national weather services, automatic data platforms maintained by different institutions, the PIRATA buoys etc are all collected through LDM/NCAR or direct transmission. Approximately 40 models outputs are available on a daily basis, twice a day. A simple procedure based on data assimilation principles was quite successful in combining the available forecasts in order to produce temperature, dew point, wind, pressure and precipitation forecasts at station points in S. America. The procedure is based on removing each model bias at the observational point and a weighted average based on the mean square error of the forecasts. The base period for estimating the bias and mean square error is of the order of 15 to 30 days. Products of the intercomparison model program and the optimal statistical combination of the available forecasts are public and available in real time (www.master.iag.usp.br/). Monitoring of the use of the products reveal a growing trend in the last year (reaching about 10.000 accesses per day in recent months). The intercomparison program provides a rich data set for educational products (real time use in Synoptic Meteorology and Numerical Weather Forecasting lectures), operational weather forecasts in national or regional weather centers and for research purposes. During the first phase of the program it was difficult to convince potential participants to share the information in the public homepage. However, as the system evolved, more and more institutions became associated with the program. The general opinion of the participants is that the system provides an unified metric for evaluation, a forum for discussion of the physical origin of the model forecast differences and therefore improvement of the quality of the numerical guidance.

Comparison of atmospheric CO2 mole fractions and source-sink characteristics at four WMO/GAW stations in China

NASA Astrophysics Data System (ADS)

Cheng, Siyang; Zhou, Lingxi; Tans, Pieter P.; An, Xingqin; Liu, Yunsong

2018-05-01

As CO2 is a primary driving factor of climate change, the mole fraction and source-sink characteristics of atmospheric CO2 over China are constantly inferred from multi-source and multi-site data. In this paper, we compared ground-based CO2 measurements with satellite retrievals and investigated the source-sink regional representativeness at China's four WMO/GAW stations. The results indicate that, firstly, atmospheric CO2 mole fractions from ground-based sampling measurement and Greenhouse Gases Observing Satellite (GOSAT) products reveal similar seasonal variation. The seasonal amplitude of the column-averaged CO2 mole fractions is smaller than that of the ground-based CO2 at all stations. The extrema of the seasonal cycle of ground-based and column CO2 mole fractions are basically synchronous except a slight phase delay at Lin'an (LAN) station. For the two-year average, the column CO2 is lower than ground-based CO2, and both of them reveal the lowest CO2 mole fraction at Waliguan (WLG) station. The lowest (∼4 ppm) and largest (∼8 ppm) differences between the column and ground-based CO2 appear at WLG and Longfengshan (LFS) stations, respectively. The CO2 mole fraction and its difference between GOSAT and ground-based measurement are smaller in summer than in winter. The differences of summer column CO2 among these stations are also much smaller than their ground-based counterparts. In winter, the maximum of ground-based CO2 mole fractions and the greatest difference between the two (ground-based and column) datasets appear at the LFS station. Secondly, the representative areas of the monthly CO2 background mole fractions at each station were found by employing footprints and emissions. Smaller representative areas appeared at Shangdianzi (SDZ) and LFS, whereas larger ones were seen at WLG and LAN. The representative areas in summer are larger than those in winter at WLG and SDZ, but the situation is opposite at LAN and LFS. The representative areas for the stations are different in summer and winter, distributed in four typical regions. The CO2 net fluxes in these representative areas show obvious seasonal cycles with similar trends but different varying ranges and different time of the strongest sink. The intensities and uncertainties of the CO2 fluxes are different at different stations in different months and source-sink sectors. Overall, the WLG station is almost a carbon sink, but the other three stations present stronger carbon sources for most of the year. These findings could be conducive to the application of multi-source CO2 data and the understanding of regional CO2 source-sink characteristics and patterns over China.

Science in Support of Aviation-Risk Management since the April 2010 Eruption of Eyjafjallajökull, Iceland

NASA Astrophysics Data System (ADS)

Guffanti, M.; Mastin, L. G.; Schneider, D. J.; Tupper, A.

2010-12-01

The nearly week-long airspace closure over large parts of Europe and the North Atlantic in April 2010 that resulted from dispersion of ash from the eruption of Eyjafjallajökull prompted a shift from the accepted global policy of strict avoidance by aircraft of ash-contaminated airspace to one of allowing flight through zones of dilute ash under some circumstances. This shift was made in a crisis environment of rapidly mounting economic losses and social disruptions extending well beyond the European region. To get the global air transportation system moving again, European aviation authorities and associated meteorological offices created a new type of advisory product depicting forecasted zones of low ash concentrations in Eyjafjallajökull’s clouds that could be transited with expectation of no or minimal risk of aircraft damage, under the condition of more frequent aircraft inspections and enhanced risk management by airlines. Preliminary data of the European Aviation Safety Agency indicate that transit through Eyjafjallajökull’s dilute ash clouds caused some wear (primarily abrasion) to a few aircraft, but not to the severity of degraded engine performance in flight; after inspections the aircraft were returned to service and continued to operate without problems. Following the crisis, recognizing that such a fundamental shift in risk management requires sound scientific and engineering bases, the International Civil Aviation Organization (ICAO) formed an International Volcanic Ash Task Force that, in conjunction with the World Meteorological Organization (WMO), will incorporate advice and recommendations from scientific, aviation, and engineering experts worldwide about ways to improve (1) situational awareness to aviation users of impending volcanic eruptions, (2) characterization of critical eruption source parameters for incorporation in forecast modeling, (3) detection and characterization of volcanic clouds, (4) accuracy of volcanic ash transport and dispersion models, and (5) airworthiness of engine, avionics, and airframes by manufacturers and airlines. Ground-based, airborne, and space-based methods are being evaluated in terms of the above items, and results of pertinent scientific investigations of the eruption and volcanic cloud are being compiled. Key topical issues being addressed include the need to depict uncertainty in quantitative modeling of ash concentration and capabilities to visualize and compare geospatial data from different sources. The timeline for this work extends over the next 3 years. More information about the ICAO and WMO scientific advisory process for volcanic ash hazards is at http://www2.icao.int/en/anb/met-aim/met/ivatf/Lists/Meetings/AllItems.aspx/. This process is still being refined, but participation from the broader scientific community within the IVATF framework is crucial to its success.

10-year record of atmospheric composition in the high Himalayas: source, transport and impact

NASA Astrophysics Data System (ADS)

Bonasoni, Paolo; Laj, Paolo; Marinoni, Angela; Cristofanelli, Paolo; Maione, Michela; Putero, Davide; Calzolari, Francescopiero; Decesari, Stefano; Facchini, Maria Cristina; Fuzzi, Sandro; Gobbi, Gianpaolo; Sellegri, Karine; Verza, Gianpietro; Vuillermoz, Elisa; Arduini, Jgor

2016-04-01

South Asia represents a global "hot-spot" for air-quality and climate impacts. Since the end of the 20th Century, field experiments and satellite observations identified a thick layer of atmospheric pollutants extending from the Indian Ocean up to the atmosphere of the Himalayas. Since large amount of short-lived climate pollutants (SLCPs) - like atmospheric aerosol (in particular, the light-absorbing aerosol) and ozone - characterize this region, severe implications were recognized for population health, ecosystem integrity as well as regional climate impacts, especially for what concerns hydrological cycle, monsoon regimes and cryosphere. Since 2006, the Nepal Climate Observatory - Pyramid (NCO-P, 27.95N, 86.82 E, 5079 m a.s.l.), a global station of the WMO/GAW programme has been active in the eastern Nepal Himalaya, not far from the Mt. Everest. NCO-P is located away from large direct anthropogenic pollution sources. The closest major urban area is Kathmandu (200 km south-west from the measurement site). As being located along the Khumbu valley, the observations are representative of synoptic-scale and mountain thermal circulation, providing direct information about the vertical transport of pollutants/climate-altering compounds to the Himalayas and to the free troposphere. In the framework of international programmes (GAW/WMO, UNEP-ABC, AERONET) the following continuous measurement programmes have been carried out at NCO-P: surface ozone, aerosol size distribution (from 10 nm to 25 micron), total particle number, aerosol scattering and absorption coefficients, equivalent BC, PM1-PM10, AOD by sun-photometry, global solar radiation (SW and LW), meteorology. Long-term sampling programmes for the off-line determination of halogenated gases and aerosol chemistry have been also activated. The atmospheric observation records at NCO-P, now representing the longest time series available for the high Himalayas, provided the first direct evidences about the systematic occurrence of pollution transport and high rate of new particle formation events in this region. Here we provide an overview of the main scientific results obtained during these ten years of research. In particular, we will discuss the impact of atmospheric transport and monsoon variability on atmospheric composition by disentangling the role played by mountain breeze system and synoptic-scale transport. We will provide specific information about the role of stratospheric intrusions, long-range mineral dust transport and open biomass burning emissions in determining the variability of ozone, aerosol and equivalent black carbon concentrations. The effect of particle nucleation processes on aerosol number concentrations will be shown. Finally, we discuss the climatic impact of aerosols observed at NCO-P both in terms of direct atmospheric radiative forcing and black carbon deposition on Himalayan snow.

Global Framework for Climate Services (GFCS): status of implementation

NASA Astrophysics Data System (ADS)

Lucio, Filipe

2015-04-01

The World Climate Conference-3 (Geneva 2009) unanimously decided to establish the Global Framework for Climate Services (GFCS), a UN-led initiative spearheaded by WMO to guide the development and application of science-based climate information and services in support of decision-making in climate sensitive sectors. By promoting science-based decision-making, the GFCS is empowering governments, communities and companies to build climate resilience, reduce vulnerabilities and adapt to impacts. The initial priority areas of GFCS are Agriculture and Food Security; Disaster Risk Reduction; Health; and Water Resources. The implementation of GFCS is well underway with a governance structure now fully established. The governance structure of GFCS includes the Partner Advisory Committee (PAC), which is GFCS's stakeholder engagement mechanism. The membership of the PAC allows for a broad participation of stakeholders. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Commission (EC), the Food and Agriculture Organization of the UN (FAO), the Global Water Partnership (GWP), the International Federation of Red Cross and Red Crescent Societies (IFRC), the International Union of Geodesy and Geophysics (IUGG), United Nations Environment Programme (UNEP), the United Nations Institute for Training and Research (UNITAR), the World Business Council for Sustainable Development (WBCSD), the World Food Programme (WFP) and WMO have already joined the PAC. Activities are being implemented in various countries in Africa, the Caribbean, Asia and Pacific Small Islands Developing States through flagship projects and activities in the four priority areas of GFCS to enable the development of a Proof of Concept. The focus at national level is on strengthening institutional capacities needed for development of capacities for co-design and co-production of climate services and their application in support of decision-making in climate sensitive sectors. Establishment of regional capacities through climate centres to support national institutional capacities is a major focus. The Proof of Concept will be replicated in other parts of the world to ensure worldwide improvements in climate services for the four priority areas to facilitate the reduction of society's vulnerability to climate-related hazards and the advancement of the key global development goals. To streamline and harness climate research and knowledge in support of GFCS implementation, regional research plans or agendas are being shaped in different regions. For example, a Climate Research for Development Agenda for Africa (CR4D) is being developed under the leadership of the World Climate Research Programme (WCRP) and in cooperation with the African Union Commission and other partners. Similarly, regional climate research priorities are being developed for Latin America and the Caribbean, following the WCRP Conference for Latin America and the Caribbean (Montevideo, March 2014). Availability of regional research plans or agendas would ensure more effective research and involvement of national experts in climate research activities.

MELIFT - A new device for accurate measurements in a snow rich environment

NASA Astrophysics Data System (ADS)

Dorninger, M.

2012-04-01

A deep snow pack, remote locations, no external power supply and very low temperatures are often the main ingredients when it comes to the deployment of meteorological stations in mountainous terrain. The accurate position of the sensor related to the snow surface is normally not known. A new device called METLIFT overcomes the problems. WMO recommends a height between 1.2 m and 2 m above ground level for the measurement of air temperature and humidity. The height above ground level is specified to take care of the possible strong vertical temperature and humidity gradients at the lowest layers in the atmosphere. Especially in snow rich and remote locations it may be hardly possible to follow this advice. Therefore most of the meteorological stations in mountainous terrain are situated at mountain tops where strong winds will blow off the snow or in valleys where a daily inspection of the sensors is possible. In other unpopulated mountainous areas, e.g. basins, plateaus, the distance of the sensor to the snow surface is not known or the sensor will be snow-covered. A new device was developed to guarantee the sensor height above surface within the WMO limits in harsh and remote environments. An ultrasonic snow height sensor measures the distance to the snow surface. If it exceeds certain limits due to snow accumulation or snow melt the lift adapts its height accordingly. The prototype of METLIFT has been installed in Lower Austria at an altitude of 1000m. The lift is 6 m high and can pull out for another 4 m. Sensor arms are mounted every meter to allow the connection of additional sensors or to measure a profile of a certain parameter of the lowest 5 m above surface. Sensors can be added easily since cable wiring is provided to each sensor arm. Horizontal winds are measured at 7 m height above surface. METLIFT is independent of external power supply. Three lead gel accumulators recharged by three solar panels provide the energy necessary for the sensors, the data loggers, the data transmission components and for the electromotor to lift the system. METLIFT is energy optimised to keep the energy consumption at low levels. The components of the lift device consist of a 12V electromotor with a worm gear with a transmission rate of 2856:1. This means that the lift moves extremely slow. The data logger can be programmed via the GSM connection from remote locations, the data flow is also conducted via this connection. First results of the winter campaign 2011/2012 will be presented at the conference.

Service architecture challenges in building the KNMI Data Centre

NASA Astrophysics Data System (ADS)

Som de Cerff, Wim; van de Vegte, John; Plieger, Maarten; de Vreede, Ernst; Sluiter, Raymond; Willem Noteboom, Jan; van der Neut, Ian; Verhoef, Hans; van Versendaal, Robert; van Binnendijk, Martin; Kalle, Henk; Knopper, Arthur; Calis, Gijs; Ha, Siu Siu; van Moosel, WIm; Klein Ikkink, Henk-Jan; Tosun, Tuncay

2013-04-01

One of the objectives of KNMI is to act as a National Data centre for weather, climate and seismological data. KNMI has experience in curation of data for many years however important scientific data is not well accessible. New technologies also are available to improve the current infrastructure. Therefore a data curation program is initiated with two main goals: setup a Satellite Data Platform (SDP) and a KNMI data centre (KDC). KDC will provide, besides curation, data access, and storage and retrieval portal for KNMI data. In 2010 first requirements were gathered, in 2011 the main architecture was sketched, KDC was implemented in 2012 and is available on: http://data.knmi.nl KDC is built with the data providers involved with as key challenge: 'adding a dataset should be as simple as creating an HTML page'. This is enabled by a three step process, in which the data provider is responsible for two steps: 1. Provide dataset metadata: An easy to use web interface for providing metadata, with automated validation. Metadata consists of an ISO 19115 profile (matching INSPIRE and WMO requirements) and additional technical metadata regarding the data structure and access rights to the data. The interface hides certain metadata fields, which are filed by KDC automatically. 2. Provide data: after metadata has been entered, an upload location for uploading the dataset is provided. Also scripts for pushing large datasets are available. 3. Process and publish: once files are uploaded, they are processed for metadata (e.g., geolocation, time, version) and made available in KDC. The data is put into archive and made available using the in-house developed Virtual File System, which provides a persistent virtual path to the data. For the end-user of the data, KDC provides a web interface with search filters on key words, geolocation and time. Data can be downloaded using HTTP or FTP and can be scripted. Users can register to gain access to restricted datasets. The architecture combines Open Source software components (e.g. Geonetwork, Magnolia, MongoDB, MySQL) with in-house built software (ADAGUC, NADC) and newly developed software. Challenges faced and solved are: How to deal with the different file formats used at KNMI? (e.g. NetCDF, GRIB, BUFR, ASCII); How to deal with the different metadata profiles while hiding the complexity of this to the user? How to incorporate the existing archives? KDC is a node in several networks (WMO WIS, INSPIRE, Open Data): how to do this? In the presentation/poster we will describe what has been done for each of these challenges and how it is implemented in KDC.

Aggregation of Environmental Model Data for Decision Support

NASA Astrophysics Data System (ADS)

Alpert, J. C.

2013-12-01

Weather forecasts and warnings must be prepared and then delivered so as to reach their intended audience in good time to enable effective decision-making. An effort to mitigate these difficulties was studied at a Workshop, 'Sustaining National Meteorological Services - Strengthening WMO Regional and Global Centers' convened, June , 2013, by the World Bank, WMO and the US National Weather Service (NWS). The skill and accuracy of atmospheric forecasts from deterministic models have increased and there are now ensembles of such models that improve decisions to protect life, property and commerce. The NWS production of numerical weather prediction products result in model output from global and high resolution regional ensemble forecasts. Ensembles are constructed by changing the initial conditions to make a 'cloud' of forecasts that attempt to span the space of possible atmospheric realizations which can quantify not only the most likely forecast, but also the uncertainty. This has led to an unprecedented increase in data production and information content from higher resolution, multi-model output and secondary calculations. One difficulty is to obtain the needed subset of data required to estimate the probability of events, and report the information. The calibration required to reliably estimate the probability of events, and honing of threshold adjustments to reduce false alarms for decision makers is also needed. To meet the future needs of the ever-broadening user community and address these issues on a national and international basis, the weather service implemented the NOAA Operational Model Archive and Distribution System (NOMADS). NOMADS provides real-time and retrospective format independent access to climate, ocean and weather model data and delivers high availability content services as part of NOAA's official real time data dissemination at its new NCWCP web operations center. An important aspect of the server's abilities is to aggregate the matrix of model output offering access to probability and calibrating information for real time decision making. The aggregation content server reports over ensemble component and forecast time in addition to the other data dimensions of vertical layer and position for each variable. The unpacking, organization and reading of many binary packed files is accomplished most efficiently on the server while weather element event probability calculations, the thresholds for more accurate decision support, or display remain for the client. Our goal is to reduce uncertainty for variables of interest, e.g, agricultural importance. The weather service operational GFS model ensemble and short range ensemble forecasts can make skillful probability forecasts to alert users if and when their selected weather events will occur. A description of how this framework operates and how it can be implemented using existing NOMADS content services and applications is described.

Climate and Health Vulnerability to Vector-Borne Diseases: Increasing Resilience under Climate Change Conditions in Africa

NASA Astrophysics Data System (ADS)

Ceccato, P.

2015-12-01

The International Research Institute for Climate and Society (IRI), the City University of New York (CUNY) and NASA Jet Propulsion Laboratory (JPL) in collaboration with NASA SERVIR are developing tools to monitor climate variables (precipitation, temperature, vegetation, water bodies, inundation) that help projects in Africa to increase resilience to climate change for vector-borne diseases ( malaria, trypanosomiasis, leishmaniasis, and schistosomiasis). Through the development of new products to monitor precipitation, water bodies and inundation, IRI, CUNY and JPL provide tools and capacity building to research communities; ministries of health; the WMO Global Framework for Climate and Services; and World Health Organization in Africa to: 1) Develop research teams' ability to appropriately use climate data as part of their research 2) Enable research teams and ministries to integrate climate information into social and economic drivers of vulnerability and opportunities for adaptation to climate change 3) Inform better policies and programs for climate change adaptation. This oral presentation will demonstrate how IRI, CUNY, and JPL developed new products, tools and capacity building to achieve the three objectives mentioned above with examples in South Africa, Zimbabwe, Tanzania and Malawi.

Preliminary study of atmospheric carbon dioxide in a glacial area of the Qilian Mountains, west China

NASA Astrophysics Data System (ADS)

Li, Chuanjin; Zhou, Lingxi; Qin, Dahe; Liu, Lixin; Qin, Xiang; Wang, Zebin; Ren, Jiawen

2014-12-01

Carbon dioxide represents the most important contribution to increased radiative forcing. The preliminary results of the atmospheric carbon dioxide mole fraction from the glacial region in the Qilian Mountains area, in the northeast of the Qinghai-Xizang (Tibetan) Plateau during July, 2009 to October, 2012 are presented. The annual mean CO2 mole fractions in 2010 and 2011 were 388.4 ± 2.7 ppm and 392.7 ± 2.6 ppm, respectively. These values were consistent with the CO2 mole fractions from the WMO/GAW stations located at high altitudes. However, both the concentration and seasonal variation were significantly lower than stations located adjacent to megacities or economic centers at low latitudes in eastern China. Shorter durations of photosynthesis of the alpine vegetation system that exceeded respiration were detected at the Qilian Mountains glacial area. The annual mean increase during the sampling period was 2.9 ppm yr-1 and this value was higher than the global mean values. Anthropogenic activities in the cities adjacent to the Qilian Mountains may have important influences on the CO2 mole fractions, especially in summer, when north and north-north-west winds are typical.

Analysis of selected volatile organic compounds at background level in South Africa.

NASA Astrophysics Data System (ADS)

Ntsasa, Napo; Tshilongo, James; Lekoto, Goitsemang

2017-04-01

Volatile organic compounds (VOC) are measured globally at urban air pollution monitoring and background level at specific locations such as the Cape Point station. The urban pollution monitoring is legislated at government level; however, the background levels are scientific outputs of the World Meteorological Organisation Global Atmospheric Watch program (WMO/GAW). The Cape Point is a key station in the Southern Hemisphere which monitors greenhouse gases and halocarbons, with reported for over the past decade. The Cape Point station does not have the measurement capability VOC's currently. A joint research between the Cape Point station and the National Metrology Institute of South Africa (NMISA) objective is to perform qualitative and quantitative analysis of volatile organic compounds listed in the GAW program. NMISA is responsible for development, maintain and disseminate primary reference gas mixtures which are directly traceable to the International System of Units (SI) The results of some volatile organic compounds which where sampled in high pressure gas cylinders will be presented. The analysis of samples was performed on the gas chromatography with flame ionisation detector and mass selective detector (GC-FID/MSD) with a dedicate cryogenic pre-concentrator system. Keywords: volatile organic compounds, gas chromatography, pre-concentrator

Laboratory simulations of cumulus cloud flows explain the entrainment anomaly

NASA Astrophysics Data System (ADS)

Narasimha, Roddam; Diwan, Sourabh S.; Subrahmanyam, Duvvuri; Sreenivas, K. R.; Bhat, G. S.

2010-11-01

In the present laboratory experiments, cumulus cloud flows are simulated by starting plumes and jets subjected to off-source heat addition in amounts that are dynamically similar to latent heat release due to condensation in real clouds. The setup permits incorporation of features like atmospheric inversion layers and the active control of off-source heat addition. Herein we report, for the first time, simulation of five different cumulus cloud types (and many shapes), including three genera and three species (WMO Atlas 1987), which show striking resemblance to real clouds. It is known that the rate of entrainment in cumulus cloud flows is much less than that in classical plumes - the main reason for the failure of early entrainment models. Some of the previous studies on steady-state jets and plumes (done in a similar setup) have attributed this anomaly to the disruption of the large-scale turbulent structures upon the addition of off-source heat. We present estimates of entrainment coefficients from these measurements which show a qualitatively consistent variation with height. We propose that this explains the observed entrainment anomaly in cumulus clouds; further experiments are planned to address this question in the context of starting jets and plumes.

Changes of precipitation extremes indices in São Francisco River Basin, Brazil from 1947 to 2012

NASA Astrophysics Data System (ADS)

Bezerra, Bergson G.; Silva, Lindenberg L.; Santos e Silva, Claudio M.; de Carvalho, Gilvani Gomes

2018-02-01

The São Francisco River is strategically important due to its hydroelectric potential and for bringing the largest water body of Brazilian Semiarid region, supplying water for irrigation, urban, and industrial activities. Thereby, for the purpose of characterizing changes on the precipitation patterns over São Francisco River basin, 11 extremes precipitation indices as defined by the joint WMO/CCI/ETCCDMI/CLIVAR project were calculated using daily observation from the 59 rain gauges during 1947-2012 period. The extreme climatic indices were calculated with the RClimDex software, which performs an exhaustive data quality control, intending to identify spurious errors and dataset inconsistencies. Weak and significant regional changes were observed in both CDD and SDII indices. Most precipitation extremes indices decreased but without statistical significance. The spatial analysis of indices did not show clearly regional changes due to the complexity of hydrometeorology of the region. In some cases, two rainfall stations exhibited opposite trends with the same significance level although they are separated by a few kilometers. This has occurred more frequently in Lower-Middle São Francisco, probably associated with intense land cover change over the last decades in this region.

Analysis of the Diurnal Cycle and Cloud Effects on the Surface Radiation Budget of the SURFRAD Network

NASA Astrophysics Data System (ADS)

Long, C. N.; Augustine, J. A.; McComiskey, A. C.

2017-12-01

The NOAA Earth Systems Research Laboratory (ESRL) Global Monitoring Division (GMD) operates a network of seven surface radiation budget sites (SURFRAD) across the continental United States. The SURFRAD network was established in 1993 with the primary objective to support climate research with accurate, continuous, long-term measurements of the surface radiation budget over the United States and is a major contributor to the WMO international Baseline Surface Radiation Network. The data from the SURFRAD sites have been used in many studies including trend analyses of surface solar brightening (Long et al, 2009; Augustine and Dutton, 2013; Gan et al., 2015). These studies have focused mostly on long term aggregate trends. Here we will present results of studies that take a closer look across the years of the cloud influence on the surface radiation budget components partitioned by seasonal and diurnal analyses, and using derived quantities now available from the SURFRAD data archive produced by the Radiative Flux Analysis value added processing. The results show distinct differences between the sites surface radiative energy budgets and cloud radiative effects due to their differing climates and latitudinal locations.

Intercomparison of land-surface parameterizations launched

NASA Astrophysics Data System (ADS)

Henderson-Sellers, A.; Dickinson, R. E.

One of the crucial tasks for climatic and hydrological scientists over the next several years will be validating land surface process parameterizations used in climate models. There is not, necessarily, a unique set of parameters to be used. Different scientists will want to attempt to capture processes through various methods “for example, Avissar and Verstraete, 1990”. Validation of some aspects of the available (and proposed) schemes' performance is clearly required. It would also be valuable to compare the behavior of the existing schemes [for example, Dickinson et al., 1991; Henderson-Sellers, 1992a].The WMO-CAS Working Group on Numerical Experimentation (WGNE) and the Science Panel of the GEWEX Continental-Scale International Project (GCIP) [for example, Chahine, 1992] have agreed to launch the joint WGNE/GCIP Project for Intercomparison of Land-Surface Parameterization Schemes (PILPS). The principal goal of this project is to achieve greater understanding of the capabilities and potential applications of existing and new land-surface schemes in atmospheric models. It is not anticipated that a single “best” scheme will emerge. Rather, the aim is to explore alternative models in ways compatible with their authors' or exploiters' goals and to increase understanding of the characteristics of these models in the scientific community.

Methods to homogenize electrochemical concentration cell (ECC) ozonesonde measurements across changes in sensing solution concentration or ozonesonde manufacturer

NASA Astrophysics Data System (ADS)

Deshler, Terry; Stübi, Rene; Schmidlin, Francis J.; Mercer, Jennifer L.; Smit, Herman G. J.; Johnson, Bryan J.; Kivi, Rigel; Nardi, Bruno

2017-06-01

Ozone plays a significant role in the chemical and radiative state of the atmosphere. For this reason there are many instruments used to measure ozone from the ground, from space, and from balloons. Balloon-borne electrochemical cell ozonesondes provide some of the best measurements of the ozone profile up to the mid-stratosphere, providing high vertical resolution, high precision, and a wide geographic distribution. From the mid-1990s to the late 2000s the consistency of long-term records from balloon-borne ozonesondes has been compromised by differences in manufacturers, Science Pump (SP) and ENSCI (EN), and differences in recommended sensor solution concentrations, 1.0 % potassium iodide (KI) and the one-half dilution: 0.5 %. To investigate these differences, a number of organizations have independently undertaken comparisons of the various ozonesonde types and solution concentrations, resulting in 197 ozonesonde comparison profiles. The goal of this study is to derive transfer functions to allow measurements outside of standard recommendations, for sensor composition and ozonesonde type, to be converted to a standard measurement and thus homogenize the data to the expected accuracy of 5 % (10 %) in the stratosphere (troposphere). Subsets of these data have been analyzed previously and intermediate transfer functions derived. Here all the comparison data are analyzed to compare (1) differences in sensor solution composition for a single ozonesonde type, (2) differences in ozonesonde type for a single sensor solution composition, and (3) the World Meteorological Organization's (WMO) and manufacturers' recommendations of 1.0 % KI solution for Science Pump and 0.5 % KI for ENSCI. From the recommendations it is clear that ENSCI ozonesondes and 1.0 % KI solution result in higher amounts of ozone sensed. The results indicate that differences in solution composition and in ozonesonde type display little pressure dependence at pressures ≥ 30 hPa, and thus the transfer function can be characterized as a simple ratio of the less sensitive to the more sensitive method. This ratio is 0.96 for both solution concentration and ozonesonde type. The ratios differ at pressures < 30 hPa such that OZ0. 5%/OZ1. 0 % = 0. 90 + 0. 041 ṡ log10(p) and OZSciencePump/OZENSCI = 0. 764 + 0. 133 ṡ log10(p) for p in units of hPa. For the manufacturer-recommended solution concentrations the dispersion of the ratio (SP-1.0 / EN-0.5 %), while significant, is generally within 3 % and centered near 1.0, such that no changes are recommended. For stations which have used multiple ozonesonde types with solution concentrations different from the WMO's and manufacturer's recommendations, this work suggests that a reasonably homogeneous data set can be created if the quantitative relationships specified above are applied to the non-standard measurements. This result is illustrated here in an application to the Nairobi data set.

The use of seasonal forecasts in a crop failure early warning system for West Africa

NASA Astrophysics Data System (ADS)

Nicklin, K. J.; Challinor, A.; Tompkins, A.

2011-12-01

Seasonal rainfall in semi-arid West Africa is highly variable. Farming systems in the region are heavily dependent on the monsoon rains leading to large variability in crop yields and a population that is vulnerable to drought. The existing crop yield forecasting system uses observed weather to calculate a water satisfaction index, which is then related to expected crop yield (Traore et al, 2006). Seasonal climate forecasts may be able to increase the lead-time of yield forecasts and reduce the humanitarian impact of drought. This study assesses the potential for a crop failure early warning system, which uses dynamic seasonal forecasts and a process-based crop model. Two sets of simulations are presented. In the first, the crop model is driven with observed weather as a control run. Observed rainfall is provided by the GPCP 1DD data set, whilst observed temperature and solar radiation data are given by the ERA-Interim reanalysis. The crop model used is the groundnut version of the General Large Area Model for annual crops (GLAM), which has been designed to operate on the grids used by seasonal weather forecasts (Challinor et al, 2004). GLAM is modified for use in West Africa by allowing multiple planting dates each season, replanting failed crops and producing parameter sets for Spanish- and Virginia- type West African groundnut. Crop yields are simulated for three different assumptions concerning the distribution and relative abundance of Spanish- and Virginia- type groundnut. Model performance varies with location, but overall shows positive skill in reproducing observed crop failure. The results for the three assumptions are similar, suggesting that the performance of the system is limited by something other than information on the type of groundnut grown. In the second set of simulations the crop model is driven with observed weather up to the forecast date, followed by ECMWF system 3 seasonal forecasts until harvest. The variation of skill with forecast date is assessed along with the extent to which forecasts can be improved by bias correction of the rainfall data. Two forms of bias correction are applied: a novel method of spatially bias correcting daily data, and statistical bias correction of the frequency and intensity distribution. Results are presented using both observed yields and the control run as the reference for verification. The potential for current dynamic seasonal forecasts to form part of an operational system giving timely and accurate warnings of crop failure is discussed. Traore S.B. et al., 2006. A Review of Agrometeorological Monitoring Tools and Methods Used in the West African Sahel. In: Motha R.P. et al., Strengthening Operational Agrometeorological Services at the National Level. Technical Bulletin WAOB-2006-1 and AGM-9, WMO/TD No. 1277. Pages 209-220. www.wamis.org/agm/pubs/agm9/WMO-TD1277.pdf Challinor A.J. et al., 2004. Design and optimisation of a large-area process based model for annual crops. Agric. For. Meteorol. 124, 99-120.

Worldwide Weather Radar Imagery May Allow Substantial Increase in Meteorite Fall Recovery

NASA Technical Reports Server (NTRS)

Fries, Marc; Matson, Robert; Schaefer, Jacob; Fries, Jeffery; Hankey, Mike; Anderson, Lindsay

2014-01-01

Weather radar imagery is a valuable new technique for the rapid recovery of meteorite falls, to include falls which would not otherwise be recovered (e.g. Battle Mountain). Weather radar imagery reveals about one new meteorite fall per year (18 falls since 1998), using weather radars in the United States alone. However, an additional 75 other nations operate weather radar networks according to the UN World Meteorological Organization (WMO). If the imagery of those radars were analyzed, the current rate of meteorite falls could be improved considerably, to as much as 3.6 times the current recovery rate based on comparison of total radar areal coverage. Recently, the addition of weather radar imagery, seismometry and internet-based aggregation of eyewitness reports has improved the speed and accuracy of fresh meteorite fall recovery [e.g. 1,2]. This was demonstrated recently with the radar-enabled recovery of the Sutter's Mill fall [3]. Arguably, the meteorites recovered via these methods are of special scientific value as they are relatively unweathered, fresh falls. To illustrate this, a recent SAO/NASA ADS search using the keyword "meteorite" shows that all 50 of the top search results included at least one named meteorite recovered from a meteorite fall. This is true even though only 1260 named meteorite falls are recorded among the >49,000 individual falls recorded in the Meteoritical Society online database. The US NEXRAD system used thus far to locate meteorite falls covers most of the United States' surface area. Using a WMO map of the world's weather radars, we estimate that the total coverage of the other 75 national weather radar networks equals about 3.6x NEXRAD's coverage area. There are two findings to draw from this calculation: 1) For the past 16 years during which 18 falls are seen in US radar data, there should be an additional 65 meteorite falls recorded in worldwide radar imagery. Also: 2) if all of the world's radar data could be analyzed, the rate of recovery of fresh meteorite falls can increase by as much as 3.6x the current rate. The authors' experience to date indicates that the most effective course of action would be to have local meteorite research groups (outside of the US) form research consortia and develop a working relationship with their nation's weather bureau for access to data. These research consortia could utilize the same, proven methods used for US NEXRAD imagery, internet eyewitness report aggregation, seismometry analysis, etc. to locate meteorite falls. The consortia could then recover and analyze meteorite falls and enrich their own research efforts. It would be beneficial to conduct a global program to coordinate the development of methods and data tools, as well as to coordinate meteorite sample sharing and research. Perhaps an institution such as the Meteoritical Society could lead such an effort.

Homogenization of long instrumental temperature and precipitation series over the Spanish Northern Coast

NASA Astrophysics Data System (ADS)

Sigro, J.; Brunet, M.; Aguilar, E.; Stoll, H.; Jimenez, M.

2009-04-01

The Spanish-funded research project Rapid Climate Changes in the Iberian Peninsula (IP) Based on Proxy Calibration, Long Term Instrumental Series and High Resolution Analyses of Terrestrial and Marine Records (CALIBRE: ref. CGL2006-13327-C04/CLI) has as main objective to analyse climate dynamics during periods of rapid climate change by means of developing high-resolution paleoclimate proxy records from marine and terrestrial (lakes and caves) deposits over the IP and calibrating them with long-term and high-quality instrumental climate time series. Under CALIBRE, the coordinated project Developing and Enhancing a Climate Instrumental Dataset for Calibrating Climate Proxy Data and Analysing Low-Frequency Climate Variability over the Iberian Peninsula (CLICAL: CGL2006-13327-C04-03/CLI) is devoted to the development of homogenised climate records and sub-regional time series which can be confidently used in the calibration of the lacustrine, marine and speleothem time series generated under CALIBRE. Here we present the procedures followed in order to homogenise a dataset of maximum and minimum temperature and precipitation data on a monthly basis over the Spanish northern coast. The dataset is composed of thirty (twenty) precipitation (temperature) long monthly records. The data are quality controlled following the procedures recommended by Aguilar et al. (2003) and tested for homogeneity and adjusted by following the approach adopted by Brunet et al. (2008). Sub-regional time series of precipitation, maximum and minimum temperatures for the period 1853-2007 have been generated by averaging monthly anomalies and then adding back the base-period mean, according to the method of Jones and Hulme (1996). Also, a method to adjust the variance bias present in regional time series associated over time with varying sample size has been applied (Osborn et al., 1997). The results of this homogenisation exercise and the development of the associated sub-regional time series will be widely discussed. Initial comparisons with rapidly growing speleothems in two different caves indicate that speleothem trace element ratios like Ba/Ca are recording the decrease in littoral precipitation in the last several decades. References Aguilar, E., Auer, I., Brunet, M., Peterson, T. C. and Weringa, J. 2003. Guidelines on Climate Metadata and Homogenization, World Meteorological Organization (WMO)-TD no. 1186 / World Climate Data and Monitoring Program (WCDMP) no. 53, Geneva: 51 pp. Brunet M, Saladié O, Jones P, Sigró J, Aguilar E, Moberg A, Lister D, Walther A, Almarza C. 2008. A case-study/guidance on the development of long-term daily adjusted temperature datasets, WMO-TD-1425/WCDMP-66, Geneva: 43 pp. Jones, P D, and Hulme M, 1996, Calculating regional climatic time series for temperature and precipitation: Methods and illustrations, Int. J. Climatol., 16, 361- 377. Osborn, T. J., Briffa K. R., and Jones P. D., 1997, Adjusting variance for sample-size in tree-ring chronologies and other regional mean time series, Dendrochronologia, 15, 89- 99.

Tropical Ocean Global Atmosphere (TOGA) Meteorological and Oceanographic Data Sets for 1985 and 1986

NASA Technical Reports Server (NTRS)

Halpern, D.; Ashby, H.; Finch, C.; Smith, E.; Robles, J.

1990-01-01

The Tropical Ocean Global Atmosphere (TOGA) Program is a component of the World Meteorological Organization (WMO)/International Council of Scientific Unions (ICSU) World Climate Research Program (WCRP). One of the objectives of TOGA, which began in 1985, is to determine the limits of predictability of monthly mean sea surface temperature variations in tropical regions. The TOGA program created a raison d'etre for an explosive growth of the tropical ocean observing system and a substantial improvement in numerical simulations from atmospheric and oceanic general circulation models. Institutions located throughout the world are involved in the TOGA-distributed active data archive system. The diverse TOGA data sets for 1985 and 1986, including results from general circulation models, are included on a CD-ROM. Variables on the CD-ROM are barometric pressure, surface air temperature, dewpoint temperature Cartesian components of surface wind, surface sensible and latent heat fluxes,Cartesian components of surface wind stress and of an index of surface wind stress, sea level, sea surface temperature, and depth profiles of temperature and current in the upper ocean. Some data sets are global in extent, some are regional and cover portions of an ocean basin. Data on the CD-ROM can be extracted with an Apple Macintosh or an IBM PC.

Measuring precipitation with a geolysimeter

NASA Astrophysics Data System (ADS)

Smith, Craig D.; van der Kamp, Garth; Arnold, Lauren; Schmidt, Randy

2017-10-01

Using the relationship between measured groundwater pressures in deep observation wells and total surface loading, a geological weighing lysimeter (geolysimeter) has the capability of measuring precipitation event totals independently of conventional precipitation gauge observations. Correlations between groundwater pressure change and event precipitation were observed at a co-located site near Duck Lake, SK, over a multi-year and multi-season period. Correlation coefficients (r2) varied from 0.99 for rainfall to 0.94 for snowfall. The geolysimeter was shown to underestimate rainfall by 7 % while overestimating snowfall by 9 % as compared to the unadjusted gauge precipitation. It is speculated that the underestimation of rainfall is due to unmeasured run-off and evapotranspiration within the response area of the geolysimeter during larger rainfall events, while the overestimation of snow is at least partially due to the systematic undercatch common to most precipitation gauges due to wind. Using recently developed transfer functions from the World Meteorological Organization's (WMO) Solid Precipitation Intercomparison Experiment (SPICE), bias adjustments were applied to the Alter-shielded, Geonor T-200B precipitation gauge measurements of snowfall to mitigate wind-induced errors. The bias between the gauge and geolysimeter measurements was reduced to 3 %. This suggests that the geolysimeter is capable of accurately measuring solid precipitation and can be used as an independent and representative reference of true precipitation.

The Unidata LDM Data Distribution System

NASA Astrophysics Data System (ADS)

Emmerson, S.; Yoksas, T. C.; Weber, W. J.; Schmidt, M.

2010-12-01

The Unidata LDM is a near real-time, event-driven system for transmitting frequently-generated data-products, 24/7, from a producer to multiple subscribers using the Internet. Once received, a data-product is processed according to user specifications. A data-product can be anything up to 4 gigabytes in size. Downstream LDM-s register a regular expression based selection predicate with upstream LDM-s. Network topologies include point-to-point, star, and tree. Based on ONC RPC, the LDM system is extremely robust and efficient. Since its initial release in 1994, a network of LDM-s called the Internet Data Distribution (IDD) system has been the primary means by which many if not most Earth Sciences departments in the US obtain and process meteorological data (up to 20 GB/hour and 250k products/hour) with latencies measured in seconds or less. Data-products include numerical model output, radar data, WMO bulletins, and lightning data. Users of the LDM also include the international atmospheric science university community, NOAA, NASA, USGS, the US military, ECMWF, and the meteorological agencies of China, Australia, Brazil, South Korea, and Vietnam. The LDM is the highest volume advanced application on Internet-2 (currently averaging 27 terabytes per week). The LDM history and architecture is presented together with an analysis of its strengths and weaknesses.

The GEOS Chemistry Climate Model: Implications of Climate Feedbacks on Ozone Depletion and Recovery

NASA Technical Reports Server (NTRS)

Stolarski, Richard S.; Pawson, Steven; Douglass, Anne R.; Newman, Paul A.; Kawa, S. Randy; Nielsen, J. Eric; Rodriquez, Jose; Strahan, Susan; Oman, Luke; Waugh, Darryn

2008-01-01

The Goddard Earth Observing System Chemistry Climate Model (GEOS CCM) has been developed by combining the atmospheric chemistry and transport modules developed over the years at Goddard and the GEOS general circulation model, also developed at Goddard. The first version of the model was used in the CCMVal intercomparison exercises that contributed to the 2006 WMO/UNEP Ozone Assessment. The second version incorporates the updated version of the GCM (GEOS 5) and will be used for the next round of CCMVal evaluations and the 2010 Ozone Assessment. The third version, now under development, incorporates the combined stratosphere and troposphere chemistry package developed under the Global Modeling Initiative (GMI). We will show comparison to past observations that indicate that we represent the ozone trends over the past 30 years. We will also show the basic temperature, composition, and dynamical structure of the simulations. We will further show projections into the future. We will show results from an ensemble of transient and time-slice simulations, including simulations with fixed 1960 chlorine, simulations with a best guess scenario (Al), and simulations with extremely high chlorine loadings. We will discuss planned extensions of the model to include emission-based boundary conditions for both anthropogenic and biogenic compounds.

Impact of Flow-Dependent Error Correlations and Tropospheric Chemistry on Assimilated Ozone

NASA Technical Reports Server (NTRS)

Wargan, K.; Stajner, I.; Hayashi, H.; Pawson, S.; Jones, D. B. A.

2003-01-01

The presentation compares different versions of a global three-dimensional ozone data assimilation system developed at NASA's Data Assimilation Office. The Solar Backscatter Ultraviolet/2 (SBUV/2) total and partial ozone column retrievals are the sole data assimilated in all of the experiments presented. We study the impact of changing the forecast error covariance model from a version assuming static correlations with a one that captures a short-term Lagrangian evolution of those correlations. This is further combined with a study of the impact of neglecting the tropospheric ozone production, loss and dry deposition rates, which are obtained from the Harvard GEOS-CHEM model. We compare statistical characteristics of the assimilated data and the results of validation against independent observations, obtained from WMO balloon-borne sondes and the Polar Ozone and Aerosol Measurement (POAM) III instrument. Experiments show that allowing forecast error correlations to evolve with the flow results in positive impact on assimilated ozone within the regions where data were not assimilated, particularly at high latitudes in both hemispheres. On the other hand, the main sensitivity to tropospheric chemistry is in the Tropics and sub-Tropics. The best agreement between the assimilated ozone and the in-situ sonde data is in the experiment using both flow-dependent error covariances and tropospheric chemistry.

First results of tall tower based nitrous oxide flux monitoring over an agricultural region in Central Europe

NASA Astrophysics Data System (ADS)

Haszpra, László; Hidy, Dóra; Taligás, Tímea; Barcza, Zoltán

2018-03-01

Nitrous oxide is one of the atmospheric greenhouse gases whose amount is significantly influenced by human activity. Its major anthropogenic sources are the agricultural soils but the emission is known only with large uncertainty yet. The paper presents a tall tower based measuring system installed in Hungary, which is designed for the long-term monitoring of nitrous oxide emission of a regionally typical composition of agricultural fields by means of eddy covariance technique. Due to the careful calibration of the gas analyzer applied the measuring system is also suitable for the recording of the atmospheric concentration of nitrous oxide on the globally compatible scale (WMO X2006A). The paper reports the results of the first two years of the monitoring program, which is the first of its kind in Central Europe. For the period of July 2015-June 2017 the concentration measurements indicate an increasing trend of 0.91 nmol mol-1 year-1 with an average concentration of 330.64 nmol mol-1. During the two years of the project, the monitoring system recorded a total of 441 ± 195 mg N2O-N m-2 nitrous oxide emission with late spring/early summer maximum. The measurements also revealed the episodic nature of the emission typically triggered by major precipitation events.

Global Atmosphere Watch Workshop on Measurement-Model ...

EPA Pesticide Factsheets

The World Meteorological Organization’s (WMO) Global Atmosphere Watch (GAW) Programme coordinates high-quality observations of atmospheric composition from global to local scales with the aim to drive high-quality and high-impact science while co-producing a new generation of products and services. In line with this vision, GAW’s Scientific Advisory Group for Total Atmospheric Deposition (SAG-TAD) has a mandate to produce global maps of wet, dry and total atmospheric deposition for important atmospheric chemicals to enable research into biogeochemical cycles and assessments of ecosystem and human health effects. The most suitable scientific approach for this activity is the emerging technique of measurement-model fusion for total atmospheric deposition. This technique requires global-scale measurements of atmospheric trace gases, particles, precipitation composition and precipitation depth, as well as predictions of the same from global/regional chemical transport models. The fusion of measurement and model results requires data assimilation and mapping techniques. The objective of the GAW Workshop on Measurement-Model Fusion for Global Total Atmospheric Deposition (MMF-GTAD), an initiative of the SAG-TAD, was to review the state-of-the-science and explore the feasibility and methodology of producing, on a routine retrospective basis, global maps of atmospheric gas and aerosol concentrations as well as wet, dry and total deposition via measurement-model

Predicting summer monsoon of Bhutan based on SST and teleconnection indices

NASA Astrophysics Data System (ADS)

Dorji, Singay; Herath, Srikantha; Mishra, Binaya Kumar; Chophel, Ugyen

2018-02-01

The paper uses a statistical method of predicting summer monsoon over Bhutan using the ocean-atmospheric circulation variables of sea surface temperature (SST), mean sea-level pressure (MSLP), and selected teleconnection indices. The predictors are selected based on the correlation. They are the SST and MSLP of the Bay of Bengal and the Arabian Sea and the MSLP of Bangladesh and northeast India. The Northern Hemisphere teleconnections of East Atlantic Pattern (EA), West Pacific Pattern (WP), Pacific/North American Pattern, and East Atlantic/West Russia Pattern (EA/WR). The rainfall station data are grouped into two regions with principal components analysis and Ward's hierarchical clustering algorithm. A support vector machine for regression model is proposed to predict the monsoon. The model shows improved skills over traditional linear regression. The model was able to predict the summer monsoon for the test data from 2011 to 2015 with a total monthly root mean squared error of 112 mm for region A and 33 mm for region B. Model could also forecast the 2016 monsoon of the South Asia Monsoon Outlook of World Meteorological Organization (WMO) for Bhutan. The reliance on agriculture and hydropower economy makes the prediction of summer monsoon highly valuable information for farmers and various other sectors. The proposed method can predict summer monsoon for operational forecasting.

Spatio-Temporal Variability of Atmospheric CO2 as Observed from In-Situ Measurements over North America during NASA Field Campaigns (2004-2008)

NASA Technical Reports Server (NTRS)

Choi, Yonghoon; Vay, Stephanie A.; Woo, Jung-Hun; Choi, Kichul; Diskin, Glenn S.; Sachse, G. W.; Vadrevu, Krishna P.; Czech, E.

2009-01-01

Regional-scale measurements were made over the eastern United States (Intercontinental Chemical Transport Experiment - North America (INTEX-NA), summer 2004); Mexico (Megacity Initiative: Local and Global Research Observations (MILAGRO), March 2006); the eastern North Pacific and Alaska (INTEX-B May 2006); and the Canadian Arctic (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), spring and summer 2008). For these field campaigns, instrumentation for the in situ measurement of CO2 was integrated on the NASA DC-8 research aircraft providing high-resolution (1 second) data traceable to the WMO CO2 mole fraction scale. These observations provide unique and definitive data sets via their intermediate-scale coverage and frequent vertical profiles (0.1 - 12 km) for examining the variability CO2 exhibits above the Earth s surface. A bottom-up anthropogenic CO2 emissions inventory (1deg 1deg) and processing methodology has also been developed for North America in support of these airborne science missions. In this presentation, the spatio-temporal distributions of CO2 and CO column values derived from the campaign measurements will be examined in conjunction with the emissions inventory and transport histories to aid in the interpretation of the CO2 observations.

Atmospheric Carbon Dioxide Record from In Situ Measurements at Mt. Cimone (1979-1997)

DOE Data Explorer

Colombo, Tiziano [Italian Meteorological Service, Sestola (MO), Italy; Santaguida, Riccardo

1998-01-01

Continuous atmospheric CO2 measurements have been carried out at Mt. Cimone since 1979. Since December 1988, air samples have also been collected approximately once per week in a pair of 2-L, electropolished, stainless steel cylindrical flasks. From 1979 until December 1988, a Hartmann and Braun URAS-2T NDIR gas analyzer was used for CO2 determinations. Currently, CO2 determinations are made through the use of a Siemens Ultramat-5E NDIR gas analyzer. Water vapor is eliminated by passing the air through a U-tube placed in an alcohol bath at -600°C. Calibration of the Ultramat-5E is accomplished by using two CO2-in-air working standard gases. These working standard gas concentrations are checked 10 days apart against three CO2-in-air mixtures that serve as secondary standards. The secondary standards are checked every 6 months against five other CO2-in-air primary standards. Hourly CO2 values are routinely plotted together with wind data. Anomalous concentrations and those affected by instrument failures or local sources are rejected. Atmospheric CO2 concentrations from Mt. Cimone are reported in the 1993 WMO/Scripps mole fraction scale. For further details on the measurement apparatus and sampling techniques used at Mt. Cimone, see Cundari et al. (1990).

A humidity controlled Nephelometer system to study the hygroscopic properties of aerosols in the marine environment

NASA Astrophysics Data System (ADS)

Vaishya, Aditya; O'Dowd, Colin; Jennings, S. Gerard

2010-05-01

A Humidograph system has been designed to study the hygroscopic properties of aerosols for different air-masses and for different seasons in the marine environment. Since ambient marine aerosols are likely to be found in a metastable state, and in accordance with recommendations of WMO/GAW to sample dry aerosol, a drying unit (Nafion based) is placed just after the inlet to dry the aerosols to a relative humidity (RH) < 40% so as not to misinterpret the optical properties of hygroscopic aerosols if they are on the descending branch of the hysteresis curve. The flow after the dryer is split into two, one going to a 3-wavelength TSI-3563 Integrating Nephelometer, and the other to a Gore-Tex based humidifier followed by a single-wavelength TSI-3561 Integrating Nephelometer. The humidifier is used to vary the RH from 40% to 90%. While the TSI-3563 Integrating Nephelometer will operate at RH < 40%, the TSI-3561 Integrating Nephelometer will operate under varying RH conditions. Software developed in LabVIEW is used to control the hardware components and to log the data in a predefined format. Results of the performance of the Humidograph system in the laboratory and at the Mace Head Atmospheric Research Station are presented.

Real-time analysis of δ13C- and δD-CH4 by high precision laser spectroscopy

NASA Astrophysics Data System (ADS)

Eyer, Simon; Emmenegger, Lukas; Tuzson, Béla; Fischer, Hubertus; Mohn, Joachim

2014-05-01

Methane (CH4) is the most important non-CO2 greenhouse gas (GHG) contributing 18% to total radiative forcing. Anthropogenic sources (e.g. ruminants, landfills) contribute 60% to total emissions and led to an increase in its atmospheric mixing ratio from 700 ppb in pre-industrial times to 1819 ± 1 ppb in 2012 [1]. Analysis of the most abundant methane isotopologues 12CH4, 13CH4 and 12CH3D can be used to disentangle the various source/sink processes [2] and to develop target oriented reduction strategies. High precision isotopic analysis of CH4 can be accomplished by isotope-ratio mass-spectrometry (IRMS) [2] and more recently by mid-infrared laser-based spectroscopic techniques. For high precision measurements in ambient air, however, both techniques rely on preconcentration of the target gas [3]. In an on-going project, we developed a fully-automated, field-deployable CH4 preconcentration unit coupled to a dual quantum cascade laser absorption spectrometer (QCLAS) for real-time analysis of CH4 isotopologues. The core part of the rack-mounted (19 inch) device is a highly-efficient adsorbent trap attached to a motorized linear drive system and enclosed in a vacuum chamber. Thereby, the adsorbent trap can be decoupled from the Stirling cooler during desorption for fast desorption and optimal heat management. A wide variety of adsorbents, including: HayeSep D, molecular sieves as well as the novel metal-organic frameworks and carbon nanotubes were characterized regarding their surface area, isosteric enthalpy of adsorption and selectivity for methane over nitrogen. The most promising candidates were tested on the preconcentration device and a preconcentration by a factor > 500 was obtained. Furthermore analytical interferants (e.g. N2O, CO2) are separated by step-wise desorption of trace gases. A QCL absorption spectrometer previously described by Tuzson et al. (2010) for CH4 flux measurements was modified to obtain a platform for high precision and simultaneous analysis of CH4 isotopologues. The infrared radiation emitted by the two cw-QC laser sources are combined and coupled into a 0.5 L astigmatic multipass absorption cell with an optical path length of 76 m. An Allan variance minimum of the isotope ratio time-series of 0.1 o for δ13C-CH4 and 0.3 o for δD-CH4 has been achieved using 300 s integration time. First experiments of the developed analytical technique demonstrate its potential with respect to field-applicability and temporal resolving power. References: [1] WMO, Greenhouse Gas Bulletin No. 9, 2013, WMO GAW, pp. 4. [2] H. Fischer, M. Behrens, M. Bock, U. Richter, J. Schmitt, L. Loulergue, J. Chappellaz, R. Spahni, T. Blunier, M. Leuenberger and T. F. Stocker, Nature, 2008, 452, 864-867. [3] J. Mohn, B. Tuzson, A. Manninen, N. Yoshida, S. Toyoda, W. A. Brand, and L. Emmenegger, Atmos. Meas. Tech., 2012, 5, 1601-1609. [4] Tuzson, B., Hiller, R. V., Zeyer, K., Eugster, W., Neftel, A., Ammann, C., and L. Emmenegger, Atmos. Meas. Tech., 2010, 3,1519-1531.

WMO SDS-WAS NAMEE Regional Center: Towards continuous evaluation of dust models in Northern Africa

NASA Astrophysics Data System (ADS)

Basart, Sara; García-Castillo, Gerardo; Cuevas, Emilio; Terradellas, Enric

2016-04-01

One of the most important activities of the Regional Center for Northern Africa, Middle East and Europe of the World Meteorological Organization's Sand and Dust Storm Warning Advisory and Assessment System (WMO SDS-WAS, http://sds-was.aemet.es) is the dust model intercomparison and forecast evaluation, which is deemed an indispensable service to the users and an invaluable tool to assess model skills. Currently, the Regional Center collects daily dust forecasts from models run by nine partners (BSC, ECMWF, NASA, NCEP, SEEVCCC, EMA, CNR-ISAC, NOA and UK Met Office). A multi-model ensemble has also been set up in an effort to provide added-value products to the users. The first problem to address the dust model evaluation is the scarcity of suitable routine observations near the Sahara, the world's largest source of mineral dust. The present contribution presents preliminary results of dust model evaluation using new observational datasets. The current routine evaluation of dust predictions is focused on total-column dust optical depth (DOD) and uses remote-sensing retrievals from sun-photometric (AERONET) and satellite (MODIS) measurements. However, most users of dust forecasts are interested in the concentration near the surface (in the air we breathe) rather than in the total column content. Therefore, evaluation of the predicted surface concentration is also necessary. In this context, the initiative of the African Monsoon Interdisciplinary Analysis (AMMA) International Program to establish permanent measuring stations in the Sahel is extremely important. Tapered Element Oscillating Microbalance (TEOM) monitors continuously record PM10 in M'Bour (Senegal); Cinzana (Mali) and Banizoumbou (Niger). This surface model evaluation is complemented with the PM10 observation from the Air Quality Control and Monitoring Network (AQCMN) of the Canary Islands (Spain). The region, located in the sub-tropical Eastern Atlantic (roughly 100 km west of the Moroccan coast), is frequently affected by intrusions of Saharan dust. Regional Node are evaluated during two years (2013-2014) with observations recorded in the Sahelian region and Canary Islands. Additionally, since the data sets of weather records have an excellent spatial and temporal coverage, observations of horizontal visibility included in meteorological reports are used as an alternative way to monitor dust events in near-real-time (NRT). Recently, a new visibility product that includes more than 1,500 METAR stations has implemented in the SDS-WAS NAMEE Regional Center. The present contribution also will demonstrate how the visibility can complement the information provided by other observing systems (air quality monitoring stations, sun photometers, vertical profilers or satellite products) and numerical simulations presenting its application in tracking several dust episodes. Otherwise, the vertical distribution of aerosol also influences the radiative effect at the top of the atmosphere, especially when aerosols have strong absorption of shortwave radiation. The free troposphere contribution to aerosol optical depth (AOD) and the altitude of lofted layers are provided thanks to the vertical profiling capability of the lidar/ceilomenter technique. Currently, a lidar located in Dakar (Senegal) and a ceilometer in Santa Cruz de Tenerife (Canary Islands, Spain) provide near-real-time (NRT) vertical profiles of aerosols, which are compared with those simulated by models.

On the fall 2010 Enhancements of the Global Precipitation Climatology Centre's Data Sets

NASA Astrophysics Data System (ADS)

Becker, A. W.; Schneider, U.; Meyer-Christoffer, A.; Ziese, M.; Finger, P.; Rudolf, B.

2010-12-01

Precipitation is meanwhile a top listed parameter on the WMO GCOS list of 44 essential climate variables (ECV). This is easily justified by its crucial role to sustain any form of life on earth as major source of fresh water, its major impact on weather, climate, climate change and related issues of society’s adaption to the latter. Finally its occurrence is highly variable in space and time thus bearing the potential to trigger major flood and draught related disasters. Since its start in 1989 the Global precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth’s land-surface on the basis of in-situ measurements. The effort was inaugurated as part of the Global Precipitation Climatology Project of the WMO World Climate Research Program (WCRP). Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The number of stations involved in the related data base has approximately doubled in the past 8 years by trespassing the 40, 60 and 80k thresholds in 2002, 2006 and 2010. Core data source of the GPCC analyses are the data from station networks operated by the National Meteorological Services worldwide; data deliveries have been received from ca. 190 countries. The GPCC integrates also other global precipitation data collections (i.e. FAO, CRU and GHCN), as well as regional data sets. Currently the Africa data set from S. Nicholson (Univ. Tallahassee) is integrated. As a result of these efforts the GPCC holds the worldwide largest and most comprehensive collection of precipitation data, which is continuously updated and extended. Due to the high spatial-temporal variability of precipitation, even its global analysis requires this high number of stations to provide for a sufficient density of measurement data on almost any place on the globe. The acquired data sets are pre-checked, reformatted and then imported into a relational data base, where they are archived separately in source specific slots, thus allowing an inter-comparison of data from the different sources. Any time new data sets are imported to the data base the metadata in the input data set are compared to those already available in the data base. In case of discrepancies (e.g. deviating coordinates), external geographical sources of information are utilized to decide whether a correction of the metadata in the data base is required or not, thus resulting in a perpetual improvement of the station meta data. The presentation shall give an account on the four major products derived from the GPCC data base, which are two near real-time ones comprising the precipitation data retrieved from the GTS, and two offline products that allow for hydro-climatological assessments. The real-time products are used for example to calibrate Satellite based precipitation measurements. To illustrate the potential of the offline (Full Data) products we will present an asessment of the strong 2010 La Nina season that has apparently caused severe weather patterns world wide, including the flood disasters in Pakistan and Wuhan, China.

Emissions of Bromine and Iodine from the Marine Environment in New Zealand

NASA Astrophysics Data System (ADS)

Martinez-Aviles, M.; Kreher, K.; Johnston, P. V.; Hay, T.; Thomas, A.; Schofield, R.

2009-12-01

As noted in the WMO/UNEP Scientific Assessment of Ozone Depletion: 2006, halogenated very short-lived substances (VSLS) contribute to the atmospheric budget of halogens and thereby lead to substantial decreases in ozone and increases in surface UV radiation in the tropics and mid-latitudes. Halogenated VSLS are primarily of natural origin; oceanic emissions constitute the largest source providing 90-95% of the total global flux to the atmosphere. Macro algae in the ocean appear to be an important source of polyhalogenated VSLS. Oxidation of halogenated VSLS in the atmosphere (i.e. photolysis and reactions with OH) produces halogen oxide radicals (e.g. ClO, BrO, IO) which have been suggested as the main component of gas-phase halogens. Countries with long coastlines and little land suitable for forestation are investigating the possibility of industrial scale marine kelp farming as a means of carbon sequestration. This marine analogy of the Kyoto Protocol forest has been thought as a means to contribute to climate change mitigation. Knowledge of how natural emissions of VSLS will respond to both the drivers of climate change (e.g. changes in CO2 and land use) and to the consequences of climate change (e.g. changes in sea surface temperature and wind stress) is very limited. As a result, it is imperative that observational studies are performed to quantify the contributions of these natural VSLS to halogen loading in the troposphere and, subsequently, in the stratosphere. For this, transport and degradation processes of the source gases and product gases need to be studied and quantified. A key question surfacing from the WMO Assessment is to what extent halogenated VSLS contribute to atmospheric Bry and Iy. During a field campaign conducted during the spring of 2009, measurements of BrO and IO were made along the coastline of the South Island of New Zealand using a portable Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) spectrometer with the aim of determining coastal sites where high active halogen release could be observed. The selected sites had high biomass concentration of marine algae that would be exposed by low tides. Local macro algae type, tidal height, sunlight, temperature, and wind speed were recorded and correlated to the resulting data in order to better understand the environmental factors that modulate the emissions of halogen oxides from the marine environment to the troposphere. Results of this multi-disciplinary approach to studying brominated VSLS and their atmospheric implications are presented. As well, the chemical processes taking place and producing these halogen oxides are discussed in a thorough manner. This study contributes to a better understanding of the origin of bromine and iodine in the lowermost atmosphere (i.e. marine boundary layer). Particularly, the role that natural emissions of halogenated VSLS from the ocean may play in the halogen budget of the lower atmosphere is addressed by quantitatively understanding key links in this chain so that its potential future impacts on atmospheric chemistry, surface UV radiation, and the biosphere can be thoroughly assessed.

Searching for the Beginning of the Ozone Turnaround Using a 22-Year Merged Satellite Data Set

NASA Technical Reports Server (NTRS)

Stolarski, Richard S.; Meeson, Blanche W. (Technical Monitor)

2001-01-01

We have used the data from six satellite instruments that measure the total column amount of ozone to construct a consistent merged data set extending from late 1978 into 2000. The keys to constructing a merged data set are to minimize potential drift of individual instruments and to accurately establish instrument-to-instrument offsets. We have used the short-wavelength D-pair measurements (306nm-313nm) of the SBUV and SBUV/2 instruments near the equator to establish a relatively drift-free record for these instruments. We have then used their overlap with the Nimbus 7 and EP TOMS instruments to establish the relative calibration of the various instruments. We have evaluated the drift uncertainty in our merged ozone data (MOD) set by examining both the individual instrument drift uncertainty and the uncertainty in establishing the instrument- to-instrument differences. We conclude that the instrumental drift uncertainty over the 22-year data record is 0.9 %/decade (2-sigma). We have compared our MOD record with 37 ground stations that have a continuous record over that time period. We have a mean drift with respect to the stations of +0.3 %/decade which is within 1-sigma of our uncertainty estimate. Using the satellite record as a transfer standard, we can estimate the capability of the ground instruments to establish satellite calibration. Adding the statistical variability of the station drifts with respect to the satellite to an estimate of the overall drift uncertainty of the world standard instrument, we conclude that the stations should be able to be used to establish the drift of the satellite data record to within and uncertainty of 0.6 %/decade (2-sigma). Adding to this an uncertainty due to the-incomplete global coverage of the stations, we conclude that the station data should be able to establish the global trend with an uncertainty of about 0.7 %/decade, slightly better than for the satellite record. We conclude that merging the two records together gives only a slight improvement in the uncertainty. Keeping them separate gives the greater confidence of two independent measures of the ozone trend and potential recovery. We fit the trend in our MOD record through May of 1991 and then extrapolated forward to see if the data at the end of the record was above the statistical model as a measure of ozone recovery as was done in the last WMO/UNEP assessment report. Because our data set drifts with respect to the ground-stations through May of 1991, we calculated a smaller global trend (-1.1 %/decade) than in the WMO/UNEP report. Our data in 1998 and 1999 was, on average 2 DU above the extrapolated statistical model with a 2-sigma uncertainty of 6 DU. For the combined mid-latitudes of the northern and southern hemispheres, the data was 5 DU above the extrapolated statistical model with a 2-sigma uncertainty of 10 DU. These may be signs of recovery, but they are still statistically insignificant.

An assessment of two automated snow water equivalent instruments during the WMO Solid Precipitation Intercomparison Experiment

NASA Astrophysics Data System (ADS)

Smith, Craig D.; Kontu, Anna; Laffin, Richard; Pomeroy, John W.

2017-01-01

During the World Meteorological Organization (WMO) Solid Precipitation Intercomparison Experiment (SPICE), automated measurements of snow water equivalent (SWE) were made at the Sodankylä (Finland), Weissfluhjoch (Switzerland) and Caribou Creek (Canada) SPICE sites during the northern hemispheric winters of 2013/14 and 2014/15. Supplementary intercomparison measurements were made at Fortress Mountain (Kananaskis, Canada) during the 2013/14 winter. The objectives of this analysis are to compare automated SWE measurements with a reference, comment on their performance and, where possible, to make recommendations on how to best use the instruments and interpret their measurements. Sodankylä, Caribou Creek and Fortress Mountain hosted a Campbell Scientific CS725 passive gamma radiation SWE sensor. Sodankylä and Weissfluhjoch hosted a Sommer Messtechnik SSG1000 snow scale. The CS725 operating principle is based on measuring the attenuation of soil emitted gamma radiation by the snowpack and relating the attenuation to SWE. The SSG1000 measures the mass of the overlying snowpack directly by using a weighing platform and load cell. Manual SWE measurements were obtained at the intercomparison sites on a bi-weekly basis over the accumulation-ablation periods using bulk density samplers. These manual measurements are considered to be the reference for the intercomparison. Results from Sodankylä and Caribou Creek showed that the CS725 generally overestimates SWE as compared to manual measurements by roughly 30-35 % with correlations (r2) as high as 0.99 for Sodankylä and 0.90 for Caribou Creek. The RMSE varied from 30 to 43 mm water equivalent (mm w.e.) and from 18 to 25 mm w.e. at Sodankylä and Caribou Creek, which had respective SWE maximums of approximately 200 and 120 mm w.e. The correlation at Fortress Mountain was 0.94 (RMSE of 48 mm w.e. with a maximum SWE of approximately 650 mm w.e.) with no systematic overestimation. The SSG1000 snow scale, having a different measurement principle, agreed quite closely with the manual measurements at Sodankylä and Weissfluhjoch throughout the periods when data were available (r2 as high as 0.99 and RMSE from 8 to 24 mm w.e. at Sodankylä and from 56 to 59 mm w.e. at Weissfluhjoch, where maximum SWE was approximately 850 mm w.e.). When the SSG1000 was compared to the CS725 at Sodankylä, the agreement was linear until the start of ablation when the positive bias in the CS725 increases substantially relative to the SSG1000. Since both Caribou Creek and Sodankylä have sandy soil, water from the snowpack readily infiltrates into the soil during melt, even if the soil is frozen. However, the CS725 does not differentiate this water from the unmelted snow. This issue can be identified, at least during the late spring ablation period, with soil moisture and temperature observations like those measured at Caribou Creek. With a less permeable soil and surface runoff, the increase in the instrument bias during ablation is not as significant, as shown by the Fortress Mountain intercomparison.

The Network for the Detection of Stratospheric Change: Investigating the Ozone Layer and Its Links to Global Climate

NASA Astrophysics Data System (ADS)

Kurylo, M. J.

2002-05-01

The international Network for the Detection of Stratospheric Change (NDSC) was formed to provide a consistent standardized set of long-term measurements of atmospheric trace gases, particles, and physical parameters via a suite of globally distributed sites. Officially operational since 1991, the NDSC was incepted and formalized during the late 1980s in response to the need to document and understand worldwide stratospheric perturbations resulting from increased anthropogenic emissions into the atmosphere of long-lived halogenated source gases with strong ozone depletion and global warming potentials. The main objective of the NDSC is to monitor, from pole to pole, the temporal evolution of the stratosphere, including its protective ozone layer, and to understand the causes (i.e., natural versus anthropogenic, chemical versus dynamical) of the observed changes and their impacts on the troposphere and at the ground. This dual goal of long-term global measurement and understanding has led to the implementation of a ground-based network of "primary" NDSC stations equipped with a suite of remote instruments (such as UV/Visible monochromators, various types of lidars, Fourier transform infrared spectrometers, microwave radiometers, in situ radiosondes, etc.), allowing the quasi-simultaneous study of a large number of chemical compounds and physical parameters of the middle atmosphere identified as priority targets for the Network. Over forty "complementary" sites, equipped with a subset of such instruments and/or operating less regularly than the primary stations, contribute to the global coverage of the Network and provide substantial support during coordinated campaigns targeted at special process studies, at calibration/validation phases of space-based sensors, and at more regional subtle atmospheric characteristics. During the past decade, the NDSC has contributed to the understanding of stratospheric ozone depletion in the polar regions and at mid-latitudes, and documented the increase and leveling-off of ozone-depleting chemicals in the atmosphere and the continued growth of greenhouse gases. Because of its worldwide dimension, the NDSC has been recognized as a major component of the international upper atmosphere research program. As such, it has been endorsed by national and international scientific agencies, including the United Nations Environmental Programme (UNEP) and the International Ozone Commission (IOC) of the International Association of Meteorology and Atmospheric Physics (IAMAP). It has also been recognized by the World Meteorological Organization (WMO) as a major contributor to WMO's Global Ozone Observing System (GO3OS) within the frame of its Global Atmosphere Watch (GAW) Programme. While the NDSC remains committed to monitoring changes in the stratosphere, with an emphasis on the long-term evolution of the ozone layer (its decay, likely stabilization and expected recovery), it has recently broadened its interest and objectives to encompass new and emerging challenges including interactions between the stratosphere and the troposphere, as well as related links to global climate. Additional examples of NDCS measurement and analysis accomplishments as well as details about the NDSC-SC implementation, structure and operation, data archiving, and related protocols and publications can be found at the NDSC home page http://www.ndsc.ws.

Volcanic-Ash Hazards to Aviation—Changes and Challenges since the 2010 Eruption of Eyjafjallajökull, Iceland

NASA Astrophysics Data System (ADS)

Guffanti, M.; Tupper, A.; Mastin, L. G.; Lechner, P.

2012-12-01

In response to the severe disruptions to civil aviation that resulted from atmospheric transport of ash from the eruption of Eyjafjallajökull volcano in Iceland in April and May 2010, the International Civil Aviation Organization (ICAO) quickly formed the International Volcanic Ash Task Force (IVATF), charging it to support the accelerated development of a global risk-management framework for volcanic-ash hazards to aviation. Recognizing the need for scientifically based advice on best methods to detect ash in the atmosphere and depict zones of hazardous airspace, the IVATF sought input from the global scientific community, primarily by means of the Volcanic Ash Scientific Advisory Group which was established in May 2010 by the World Meteorological Organization (WMO) and International Union of Geodesy and Geophysics to serve as a scientific resource for ICAO. The IVATF finished its work in June 2012 (see http://www.icao.int/safety/meteorology/ivatf/Pages/default.aspx for a record of its results). A major science-based outcome is that production of charts depicting areas of airspace expected to have specific ash-concentration values (e.g. <0.2, 0.2-2, 2-4, >4 mg/cu. m) will not be required of the world's nine Volcanic Ash Advisory Centers (VAACs). The VAACs are responsible for issuing warning information to the aviation sector regarding ash-cloud position and expected movement. Forecast concentrations in these charts are based primarily on dispersion models that have at least an order of magnitude in uncertainty in their output and therefore do not delineate hazardous airspace with the level of confidence needed by the aviation sector. The recommended approach to improving model-forecast accuracy is to assimilate diverse observations (e.g., satellite thermal-infrared measurements, lidar, radar, direct airborne sampling, visual sightings, etc.) into model simulations; doing that during an eruption in the demanding environment of aviation operations is a substantial challenge. A significant post-Eyjafjallajökull change has been renewed interest of the airline sector in the issue of ash hazards to aviation. Whereas it is accepted that flight into young, dense ash clouds is dangerous, many equipment manufacturers and airline operators view that dilute ash clouds (ash concentrations < ~2 mg/cu. m) can be transited without immediate safety impacts. This calls into question the long-standing mitigation strategy of complete ash avoidance. Consequently, entities under the ICAO and WMO banners, including the VAACs, are being challenged to provide more than qualitative "ash/no ash" depictions of affected airspace, while the aviation industry is being challenged to more fully specify what ash exposures cause economic as well as safety-related damage to aircraft. In the aftermath of the Eyjafjallajökull eruption, ICAO's global aviation-warning system of eruption reporting, ash cloud detecting and forecasting, and specialized messaging, implemented after highly damaging encounters of aircraft with ash clouds in the 1980's and 1990's, is still in place, but with renewed focus among all stakeholders on improving how hazardous airspace is defined and communicated.

Use of wind data in global modelling

NASA Technical Reports Server (NTRS)

Pailleux, J.

1985-01-01

The European Centre for Medium Range Weather Forecasts (ECMWF) is producing operational global analyses every 6 hours and operational global forecasts every day from the 12Z analysis. How the wind data are used in the ECMWF golbal analysis is described. For each current wind observing system, its ability to provide initial conditions for the forecast model is discussed as well as its weaknesses. An assessment of the impact of each individual system on the quality of the analysis and the forecast is given each time it is possible. Sometimes the deficiencies which are pointed out are related not only to the observing system itself but also to the optimum interpolation (OI) analysis scheme; then some improvements are generally possible through ad hoc modifications of the analysis scheme and especially tunings of the structure functions. Examples are given. The future observing network over the North Atlantic is examined. Several countries, coordinated by WMO, are working to set up an 'Operational WWW System Evaluation' (OWSE), in order to evaluate the operational aspects of the deployment of new systems (ASDAR, ASAP). Most of the new systems are expected to be deployed before January 1987, and in order to make the best use of the available resources during the deployment phase, some network studies are carried out at the present time, by using simulated data for ASDAR and ASAP systems. They are summarized.

High black carbon and ozone concentrations during pollution transport in the Himalayas: five years of continuous observations at NCO-P global GAW station.

PubMed

Marinoni, A; Cristofanelli, P; Laj, P; Duchi, R; Putero, D; Calzolari, F; Landi, T C; Vuillermoz, E; Maione, M; Bonasoni, P

2013-08-01

To study the influence of polluted air-mass transport carrying ozone (O3) and black carbon (BC) in the high Himalayas, since March 2006 the Nepal Climate Observatory at Pyramid (NCO-P) GAW-WMO global station (Nepal, 5079 m a.s.l.) is operative. During the first 5-year measurements, the O3 and BC concentrations have shown a mean value of 48 +/- 12 ppb (+/- standard deviation) and 208 +/- 374 ng/m3, respectively. Both O3 and BC showed well defined seasonal cycles with maxima during pre-monsoon (O3: 61.3 +/- 7.7 ppbV; BC: 444 +/- 433 ng/m3) and minima during the summer monsoon (O3: 40.1 +/- 12.4 ppbV; BC: 64 +/- 101 ng/m3). The analysis of the days characterised by the presence of a significant BC increase with respect to the typical seasonal cycle identified 156 days affected by "acute" pollution events, corresponding to 9.1% of the entire data-set. Such events mostly occur in the pre-monsoon period, when the O3 diurnal variability is strongly related to the transport of polluted air-mass rich on BC. On average, these "acute" pollution events were characterised by dramatic increases of BC (352%) and O3 (29%) levels compared with the remaining days.

Stratospheric ozone depletion due to nitrous oxide: influences of other gases

PubMed Central

Portmann, R. W.; Daniel, J. S.; Ravishankara, A. R.

2012-01-01

The effects of anthropogenic emissions of nitrous oxide (N2O), carbon dioxide (CO2), methane (CH4) and the halocarbons on stratospheric ozone (O3) over the twentieth and twenty-first centuries are isolated using a chemical model of the stratosphere. The future evolution of ozone will depend on each of these gases, with N2O and CO2 probably playing the dominant roles as halocarbons return towards pre-industrial levels. There are nonlinear interactions between these gases that preclude unambiguously separating their effect on ozone. For example, the CH4 increase during the twentieth century reduced the ozone losses owing to halocarbon increases, and the N2O chemical destruction of O3 is buffered by CO2 thermal effects in the middle stratosphere (by approx. 20% for the IPCC A1B/WMO A1 scenario over the time period 1900–2100). Nonetheless, N2O is expected to continue to be the largest anthropogenic emission of an O3-destroying compound in the foreseeable future. Reductions in anthropogenic N2O emissions provide a larger opportunity for reduction in future O3 depletion than any of the remaining uncontrolled halocarbon emissions. It is also shown that 1980 levels of O3 were affected by halocarbons, N2O, CO2 and CH4, and thus may not be a good choice of a benchmark of O3 recovery. PMID:22451111

[Gas chromatography with a Pulsed discharge helium ionization detector for measurement of molecular hydrogen(H2) in the atmosphere].

PubMed

Luan, Tian; Fang, Shuang-xi; Zhou, Ling-xi; Wang, Hong-yang; Zhang, Gen

2015-01-01

A high precision GC system with a pulsed discharge helium ionization detector was set up based on the commercial Agilent 7890A gas chromatography. The gas is identified by retention time and the concentration is calculated through the peak height. Detection limit of the system is about 1 x 10(-9) (mole fraction, the same as below). The standard deviation of 140 continuous injections with a standard cylinder( concentration is roughly 600 x 10(-9)) is better than 0.3 x 10(-9). Between 409.30 x 10(-9) and 867.74 x 10(-9) molecular hydrogen mole fractions and peak height have good linear response. By using two standards to quantify the air sample, the precision meets the background molecular hydrogen compatibility goal within the World Meteorological Organization/Global Atmosphere Watch (WMO/GAW) program. Atmospheric molecular hydrogen concentration at Guangzhou urban area was preliminarily measured by this method from January to November 2013. The results show that the atmospheric molecular hydrogen mole fraction varies from 450 x 10(-9) to 700 x 10(-9) during the observation period, with the lowest value at 14:00 (Beijing time, the same as below) and the peak value at 20:00. The seasonal variation of atmospheric hydrogen at Guangzhou area was similar with that of the same latitude stations in northern hemisphere.

Crowdsourcing urban air temperatures through smartphone battery temperatures in São Paulo, Brazil

NASA Astrophysics Data System (ADS)

Droste, Arjan; Pape, Jan-Jaap; Overeem, Aart; Leijnse, Hidde; Steeneveld, Gert-Jan; Van Delden, Aarnout; Uijlenhoet, Remko

2017-04-01

Crowdsourcing as a method to obtain and apply vast datasets is rapidly becoming prominent in meteorology, especially for urban areas where traditional measurements are scarce. Earlier studies showed that smartphone battery temperature readings allow for estimating the daily and city-wide air temperature via a straightforward heat transfer model. This study advances these model estimations by studying spatially and temporally smaller scales. The accuracy of temperature retrievals as a function of the number of battery readings is also studied. An extensive dataset of over 10 million battery temperature readings is available for São Paulo (Brazil), for estimating hourly and daily air temperatures. The air temperature estimates are validated with air temperature measurements from a WMO station, an Urban Fluxnet site, and crowdsourced data from 7 hobby meteorologists' private weather stations. On a daily basis temperature estimates are good, and we show they improve by optimizing model parameters for neighbourhood scales as categorized in Local Climate Zones. Temperature differences between Local Climate Zones can be distinguished from smartphone battery temperatures. When validating the model for hourly temperature estimates, initial results are poor, but are vastly improved by using a diurnally varying parameter function in the heat transfer model rather than one fixed value for the entire day. The obtained results show the potential of large crowdsourced datasets in meteorological studies, and the value of smartphones as a measuring platform when routine observations are lacking.

Implementation of a global-scale operational data assimilation system for satellite-based soil moisture retrievals

NASA Astrophysics Data System (ADS)

Bolten, J.; Crow, W.; Zhan, X.; Reynolds, C.

2008-08-01

Timely and accurate monitoring of global weather anomalies and drought conditions is essential for assessing global crop conditions. Soil moisture observations are particularly important for crop yield fluctuations provided by the US Department of Agriculture (USDA) Production Estimation and Crop Assessment Division (PECAD). The current system utilized by PECAD estimates soil moisture from a 2-layer water balance model based on precipitation and temperature data from World Meteorological Organization (WMO) and US Air Force Weather Agency (AFWA). The accuracy of this system is highly dependent on the data sources used; particularly the accuracy, consistency, and spatial and temporal coverage of the land and climatic data input into the models. However, many regions of the globe lack observations at the temporal and spatial resolutions required by PECAD. This study incorporates NASA's soil moisture remote sensing product provided by the EOS Advanced Microwave Scanning Radiometer (AMSR-E) into the U.S. Department of Agriculture Crop Assessment and Data Retrieval (CADRE) decision support system. A quasi-global-scale operational data assimilation system has been designed and implemented to provide CADRE a daily product of integrated AMSR-E soil moisture observations with the PECAD two-layer soil moisture model forecasts. A methodology of the system design and a brief evaluation of the system performance over the Conterminous United States (CONUS) is presented.

Comparison of Sunphotometric Measurements During the Fall 1997 ARM Intensive Observation Period

NASA Technical Reports Server (NTRS)

Michalsky, J. J.; Schmid, B.; Halthore, R. N.; Pavloski, C. F.; Ackerman, T. P.; Beauharnois, M. C.; Harrison, L. C.; Livingston, J. M.; Russell, P. B.

2000-01-01

In the Fall of 1997 the Atmospheric Radiation Measurement (ARM) program held an intensive observation period (IOP) to study atmospheric aerosols using in situ and remote sensing techniques at its Southern Great Plains (SGP) site near Lamont, Oklahoma. As part of this experiment five automated, tracking sunphotometers were present to measure total column aerosol optical depth over the three-week period. which included many clear days or parts of days that were clear. The World Meteorological Organization (WMO 1993) has recommended a comparison of tracking sunphotometers to assess the ability of different instruments to arrive at similar aerosol optical depths. It was further recommended that the comparison be staged at a clean mountain site. In fact, this comparison has not occurred, but the comparison that we describe in this paper is representative of what contemporary instruments may accomplish in an environment more typical of sites where aerosols measurements will be required. The measurements were made over the period 15 September to 5 October 1997. The aerosol loading varied from extremely clean to moderately turbid conditions. In the next section the instruments will be described along with a brief explanation of the calibration techniques. The third section contains the results compared graphically on moderately turbid and fairly clean days and in a table representing the whole period. The paper ends with a section of discussion and a summary of the results.

From up to date climate and ocean evidence with updated UN emissions projections, the time is now to recommend an immediate massive effort on CO2.

NASA Astrophysics Data System (ADS)

Carter, Peter

2017-04-01

This paper provides further compelling evidence for 'an immediate, massive effort to control CO2 emissions, stopped by mid-century' (Cai, Lenton & Lontzek, 2016). Atmospheric CO2 which is above 405 ppm (actual and trend) still accelerating, despite flat emissions since 2014, with a 2015 >3ppm unprecedented spike in Earth history (A. Glikson),is on the worst case IPCC scenario. Atmospheric methane is increasing faster than its past 20-year rate, almost on the worst-case IPCC AR5 scenario (Global Carbon Project, 2016). Observed effects of atmospheric greenhouse gas (GHG) pollution are increasing faster. This includes long-lived atmospheric GHG concentrations, radiative forcing, surface average warming, Greenland ice sheet melting, Arctic daily sea ice anomaly, ocean heat (and rate of going deeper), ocean acidification, and ocean de-oxygenation. The atmospheric GHG concentration of 485 ppm CO2 eq (WMO, 2015) commits us to 'about 2°C' equilibrium (AR5). 2°C by 2100 would require 'substantial emissions reductions over the next few decades' (AR5). Instead, the May 2016 UN update on 'intended' national emissions targets under the Paris Agreement projects global emissions will be 16% higher by 2030 and the November 2016 International Energy Agency update projects energy-related CO2 eq emissions will be 30% higher by 2030, leading to 'around 2.7°C by 2100 and above 3°C thereafter'. Climate change feedback will be positive this century and multiple large vulnerable sources of amplifying feedback exist (AR5). 'Extensive tree mortality and widespread forest die-back linked to drought and temperature stress have been documented on all vegetated continents' (AR5). 'Recent studies suggest a weakening of the land sink, further amplifying atmospheric growth of CO2' (WMO, 2016). Under all but the best-case IPCC AR5 scenario, surface temperature is projected to increase above 2°C by 2100, which is above 3°C (equilibrium) after 2100, with ocean acidification still increasing at 2100. Ocean heat is increasing under all scenarios at 2100. For all producing regions 'With or without adaptation, negative impacts on average crop yields become likely from the 2030s' (AR5). Crop models do not capture all adverse effects. The climate change of 2030 is practically locked in. NASA NEX downscaled daily maximum temperature projections at 1.5°C are incompatible with today's crop yields in major agricultural regions. Climate-change-related impacts from extreme events are high at 1.5°C (AR5) and add to modeled crop declines. 'Some unique and threatened systems are already at risk from climate change (high confidence)' with 'risk of severe consequences' higher with warming of around 1.5°C (AR5). At today's surface temperature increase, 'risks associated with tipping points become moderate' and 'increase disproportionately' as temperature increases above 1.5°C (AR5). According to mitigation projections, global emissions would decline forthwith for a better than 66% chance of a 2°C limit by 2100 (over 3°C after 2100). Failure to do so would risk the future sustainability of civilization and the human population. The IPCC does not make recommendations so this falls on scientists. By recommending immediate (emergency) massive action on CO2, the science community would make a momentous contribution to the future of humanity.

Faster from the Depths to Decision: Collecting, Distributing, and Applying Data from NOAA`s Deep-Sea Tsunameters

NASA Astrophysics Data System (ADS)

Bouchard, R. H.; Wang, D.; Branski, F.

2008-05-01

The National Oceanic and Atmospheric Administration (NOAA) operates two tsunami warning centers (TWCs): the West Coast/Alaska Tsunami Warning Center (ATWC) and Pacific Tsunami Warning Center (PTWC). ATWC provides tsunami alerts to Canadian coastal regions, Virgin Islands, Puerto Rico, and the coasts of continental US and Alaska. PTWC provides local/regional tsunami alerts/advisories to the state of Hawaii. An operational center of the Tsunami Warning System of the Pacific, it provides tsunami alerts to most countries of the Pacific Rim. PTWC also provides tsunami alerts for the Caribbean and Indian Ocean countries on an interim basis. The TWCs aim to issue first tsunami bulletins within 10-15 minutes of the earthquake for tele-tsunamis and within a few minutes for local tsunamis. The TWCs have a requirement for offshore tsunami detection in real-time with a data latency of 1 minute or less. Offshore detection of tsunamis is the purpose of NOAA`s recently completed 39-station array of deep-sea tsunameters. The tsunameters, employing the second-generation DART (Deep-ocean Assessment and Reporting of Tsunamis) technology, can speed tsunami detection information to the TWCs in less than 3 minutes from depths of 6000 meters in the Pacific and Western Atlantic oceans. The tsunameters consist of a Bottom Pressure Recorder (BPR) and a surface buoy. Communication from the BPR to the buoy is via underwater acoustic transmissions. Satellite communications carry the data from the buoy to NOAA`s National Data Buoy Center (NDBC), which operates the tsunameters. The BPRs make pressure measurements, converts them to an equivalent water-column height, and passes them through a tsunami detection algorithm. If the algorithm detects a sufficient change in the height, the tsunameter goes into a rapid reporting mode or Event Mode. The acoustic modem-satellite telecommunications path takes approximately 50 seconds to reach the NDBC server. In a few seconds, NDBC reformats the data and pushes them as messages to the National Weather Service Telecommunications Gateway also known as World Meteorological Organization (WMO) Regional Telecommunication Hub (RTH) Washington. RTH Washington can route more than 50 routine messages per second with reliability for all dissemination to all of its users of 99.9 percent. It provides a latency for high priority traffic of 10 seconds or less and routinely handles 1.2 TB of information per day. Its switching centers are on the Main Trunk Network of the WMO`s Global Telecommunication System (GTS), which provides international distribution of the tsunameter data. The GTS is required to deliver tsunami data and warnings to any connected center within two minutes anywhere in the world. TWCs receive the tsunameter data from RTH Washington via GTS circuits, or download the data from servers at the RTH, in the event the GTS circuits fails. TWCs display the data in real-time in their operations. When a tsunameter goes into Event Mode, the TWCs receive alerts. After subtracting the tide, tsunameter signals can measure tsunamis as small as a few millimeters. The usefulness of the tsunameter data at TWCs was demonstrated in some of the recent events in the Pacific Ocean (Kuril Tsunamis of November 2006 and January 2007, Peru Tsunamis of August 2007 and September 2007) and the Indian Ocean (Southern Sumatra Tsunami of September 2007).

Increasing severity of damage caused by floods in the Spanish Mediterranean coast (1960-2014), climate change or vulnerability?

NASA Astrophysics Data System (ADS)

Perez, Alfredo; Gil, Salvador; Lopez, Francisco; Barriendos, Mariano

2016-04-01

In recent decades, there has been an increase in physical and economic losses (WMO, CRED and UCL, 2014) that raises serious concerns in society. Climate change projections may explain the rise in flood losses; however, these shouldn't be considered yet (Bouwer, 2011). According to IPCC (2014), there is low confidence in anthropogenic climate change affecting the frequency and magnitude of fluvial floods on a global scale. In other words, this increase in flood events is not completely related to the higher frequency of heavy rainfall. To illustrate the aforementioned, a spatial example can be seen in the study area. In the Spanish Mediterranean coast, we see an increase in economic losses within the last 50 years due to flood events (Gil et al., 2014). It seems that the socio-economic growth and the rise of housing construction (Gaja, 2008) have led to an increase in vulnerability and exposure which are mainly responsible for those losses and the increase in severity of flood events (Pérez et al., 2015). Furthermore, this situation will probably become more precarious if some climate forecasts are met [IPCC, 2014; AEMET, 2015], and if the economic model fails to adopt efficient adaptive measures. Therefore, it is interesting to focus attention on social factors either within the present or future scenario in order to minimise the potential consequences and improve the adaptation. The main objective of this work focuses on the study of the evolution of the severity of the floods in the Spanish Mediterranean coast for the period (1960-2015). To do that, a statistical analysis of the data base [Gil et al., 2014; extended to the entire Spanish Mediterranean coast (MEDIFLOOD)] and a multiscale mapping (local, provincial and regional level) of the frequency of these events will take place in order to make comparisons and show spatiotemporal patterns according to the severity events evolution. Preliminary results show some interesting statistically significant relationships between severity and the increase of population and buildings mentioned above. Bibliography: AEMET (Agencia Estatal de Meteorología) (2015). Proyecciones Climáticas para el siglo XXI en España. www.aemet.es/es/serviciosclimaticos/cambio_climat Bouwer L.M. (2011). Have disaster losses increased due to anthropogenic climate change? Bull Am Meteorol Soc, 92. Gaja F. (2008). El 'tsunami urbanizador' en el litoral mediterráneo. El ciclo de hiperproducción inmobiliaria 1996-2006. Scripta Nova, 12. Gil S., Pérez A. & Barriendos M. (2014). Increasing vulnerability to flooding in the southern spanish mediterranean coast (1960-2013). In: Hydrological extreme events in historic and prehistoric times. Bonn (Germany). IPCC. (2014) Synthesis report. Contribution of working groups I, II and III to the fifth assessment report of the intergovernmental panel on climate change. Core Writing Team, R.K. Pachauri & L.A. Meyer, eds. Geneva, Switzerland. Pérez-Morales, A., Gil-Guirado, S., & Olcina-Cantos, J. (2015). Housing bubbles and the increase of flood exposure. Failures in flood risk management on the Spanish south-eastern coast (1975-2013). Journal of Flood Risk Management. WMO, CRED and UCL (2014). Atlas of mortality and economic losses from weather, climate and water extremes 1970-2012. Geneva, Switzerland.

A review of national and international activities on modeling the effects of increased CO/sub 2/ concentrations on the simulation of regional crop production: (A report on linkage between climate and crop models): Progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Decker, W.L.; Achutuni, R.

1987-01-01

General circulation models have been used to estimate the probable changes in climate due to increased levels of carbon dioxide. These models, generally, project increases in the mean surface temperatures; but changes in precipitation due to CO/sub 2/ enrichment are not as clear. It appears that some process models, which utilize a minimum amount of empiricism, can be adopted for use in studying the impacts of both climate change scenarios and the direct effects of CO/sub 2/ fertilization. The CERES-Maize, CERES-Wheat, SORGF, GLYCIM, and SOYGRO are among those classified for this use. There is a great deal of effort beingmore » directed toward these developments. A WMO/UNEP/ICSU focus has sponsored at least two European meetings but with only limited success for testing production models. A similar effort has been conducted by the Commission of European Communities. An attempt has been made to modify the CERES models, which have been used in climate studies, for use in simulation of the direct effects. Initial simulations involving this modification, show that doubling CO/sub 2/ will increase corn production 12 to 30% at locations in northern Illinois for the four-year period 1982 to 1985. The increase in yield due to higher photosynthesis showed a greater effect than the impact of decreased transpiration.« less

Integrated Information Systems Across the Weather-Climate Continuum

NASA Astrophysics Data System (ADS)

Pulwarty, R. S.; Higgins, W.; Nierenberg, C.; Trtanj, J.

2015-12-01

The increasing demand for well-organized (integrated) end-to-end research-based information has been highlighted in several National Academy studies, in IPCC Reports (such as the SREX and Fifth Assessment) and by public and private constituents. Such information constitutes a significant component of the "environmental intelligence" needed to address myriad societal needs for early warning and resilience across the weather-climate continuum. The next generation of climate research in service to the nation requires an even more visible, authoritative and robust commitment to scientific integration in support of adaptive information systems that address emergent risks and inform longer-term resilience strategies. A proven mechanism for resourcing such requirements is to demonstrate vision, purpose, support, connection to constituencies, and prototypes of desired capabilities. In this presentation we will discuss efforts at NOAA, and elsewhere, that: Improve information on how changes in extremes in key phenomena such as drought, floods, and heat stress impact management decisions for resource planning and disaster risk reduction Develop regional integrated information systems to address these emergent challenges, that integrate observations, monitoring and prediction, impacts assessments and scenarios, preparedness and adaptation, and coordination and capacity-building. Such systems, as illustrated through efforts such as NIDIS, have strengthened the integration across the foundational research enterprise (through for instance, RISAs, Modeling Analysis Predictions and Projections) by increasing agility for responding to emergent risks. The recently- initiated Climate Services Information System, in support of the WMO Global Framework for Climate Services draws on the above models and will be introduced during the presentation.

Effective Utilization of Satellite Observations for Assessing Transnational Impact of Disasters

NASA Astrophysics Data System (ADS)

Alozie, J. E.; Anuforom, A. C.

2014-12-01

General meteorological observations sources for the surface, upper air and outer space are conducted using different technological equipment and instruments that meet international standards prescribed and approved by the United Nations organizations such as the International Civil Aviation Organization (ICAO) and the World Meteorological Organization (WMO). Satellite weather observations are critical for effective monitoring of the developments, propagations and disseminations of cold clouds and their expected adverse weather conditions as they move across national and transnational boundaries. The Nigerian Meteorological Agency (NiMet) which is the national weather service provider for Nigeria, utilizes an array of satellite products obtained from mainly the European Meteorological Satellite (EUMETSAT) for its routine weather and climate monitoring and forecasts. Overtime, NiMet has used weather workstations such as MSG, SYNERGIE and now PUMA for accessing satellite products such as RGB, Infra-red, Water vapour and the Multi-sensor Precipitation Estimate (MPE) obtained at near real-time periods. The satellite imageries find extensive applications in the delivery of early warning of raising of severe weather conditions such as dust storm and dust haze during the harmattan season (November - February); and thunderstorm accompanied by severe lightning and destructive strong winds. The paper will showcase some special cases of the tracking of squall lines and issuance of weather alerts through the media. The good result is that there was limited damage to infrastructure and no loss of life from the flash floods caused by the heavy rainfall from the squally thunderstorm.

Raman lidar water vapor profiling over Warsaw, Poland

NASA Astrophysics Data System (ADS)

Stachlewska, Iwona S.; Costa-Surós, Montserrat; Althausen, Dietrich

2017-09-01

Water vapor mixing ratio and relative humidity profiles were derived from the multi-wavelength Raman PollyXT lidar at the EARLINET site in Warsaw, using the Rayleigh molecular extinction calculation based on atmospheric temperature and pressure from three different sources: i) the standard atmosphere US 62, ii) the Global Data Assimilation System (GDAS) model output, and iii) the WMO 12374 radiosoundings launched at Legionowo. With each method, 136 midnight relative humidity profiles were obtained for lidar observations from July 2013 to August 2015. Comparisons of these profiles showed in favor of the latter method (iii), but it also indicated that the other two data sources could replace it, if necessary. Such use was demonstrated for an automated retrieval of water vapor mixing ratio from dusk until dawn on 19/20 March 2015; a case study related to an advection of biomass burning aerosol from forest fires over Ukraine. Additionally, an algorithm that applies thresholds to the radiosounding relative humidity profiles to estimate macro-physical cloud vertical structure was used for the first time on the Raman lidar relative humidity profiles. The results, based on a subset of 66 profiles, indicate that below 6 km cloud bases/tops can be successfully obtained in 53% and 76% cases from lidar and radiosounding profiles, respectively. Finally, a contribution of the lidar derived mean relative humidity to cloudy conditions within the range of 0.8 to 6.2 km, in comparison to clear-sky conditions, was estimated.

Molybdenum Incorporation in Tungsten Aldehyde Oxidoreductase Enzymes from Pyrococcus furiosus▿ †

PubMed Central

Sevcenco, Ana-Maria; Bevers, Loes E.; Pinkse, Martijn W. H.; Krijger, Gerard C.; Wolterbeek, Hubert T.; Verhaert, Peter D. E. M.; Hagen, Wilfred R.; Hagedoorn, Peter-Leon

2010-01-01

The hyperthermophilic archaeon Pyrococcus furiosus expresses five aldehyde oxidoreductase (AOR) enzymes, all containing a tungsto-bispterin cofactor. The growth of this organism is fully dependent on the presence of tungsten in the growth medium. Previous studies have suggested that molybdenum is not incorporated in the active site of these enzymes. Application of the radioisotope 99Mo in metal isotope native radioautography in gel electrophoresis (MIRAGE) technology to P. furiosus shows that molybdenum can in fact be incorporated in all five AOR enzymes. Mo(V) signals characteristic for molybdopterin were observed in formaldehyde oxidoreductase (FOR) in electron paramagnetic resonance (EPR)-monitored redox titrations. Our finding that the aldehyde oxidation activity of FOR and WOR5 (W-containing oxidoreductase 5) correlates only with the residual tungsten content suggests that the Mo-containing AORs are most likely inactive. An observed W/Mo antagonism is indicative of tungstate-dependent negative feedback of the expression of the tungstate/molybdate ABC transporter. An intracellular selection mechanism for tungstate and molybdate processing has to be present, since tungsten was found to be preferentially incorporated into the AORs even under conditions with comparable intracellular concentrations of tungstate and molybdate. Under the employed growth conditions of starch as the main carbon source in a rich medium, no tungsten- and/or molybdenum-associated proteins are detected in P. furiosus other than the high-affinity transporter, the proteins of the metallopterin insertion machinery, and the five W-AORs. PMID:20562313

Atmospheric CO2 Records from Sites Operated by the Fraunhofer Institute for Atmospheric Environment Research (1978 - 1992)

DOE Data Explorer

Sladkovic, R. [Fraunhofer Institute for Atmospheric Environmental Research (IFU), Garmisch-Partenkirchen, Germany; Scheel, H. E. [Fraunhofer Institute for Atmospheric Environmental Research (IFU), Garmisch-Partenkirchen, Germany; Seiler, W. [Fraunhofer Institute for Atmospheric Environmental Research (IFU), Garmisch-Partenkirchen, Germany

1997-01-01

The monitoring site at Garmisch-Partenkirchen is considered a grassland valley site. Because of strong local influence (vegetation and meteorology), the CO2 concentrations at Garmisch-Partenkirchen are higher and show greater seasonal amplitudes than the concentrations measured at Wank or Zugspitze. According to the filtered data, the annual atmospheric CO2 concentrations at Garmisch-Partenkirchen increased from 330.2 ppmv in 1978 to 345.1 ppmv in 1986 and from 347.6 ppmv in 1988 to 354.7 ppmv in 1992. The monitoring site at Wank Peak (WMO-BAPMoN station) is located on the grass-covered, rounded top of the mountain, just above the timberline. The mean annual CO2 concentrations at Wank Peak increased from 334.2 ppmv in 1980 to 348.6 ppmv in 1992. The station at Zugspitze is located near the summit of the highest mountain of the German Alps. In 1990, the site of CO2 sampling was changed from a location 250 m below the summit to a new monitoring station (2937 m above MSL) close to the mountain top. Compatibility of the results was seen from measurements conducted in parallel at the two sites for several months. Because of the high elevation of the mountain station, the CO2 measurements at Zugspitze can be considered free of regional contamination most of the time. The mean annual CO2 concentrations at Zugspitze increased from 333.7 ppmv in 1981 to 349.4 ppmv in 1992.

Deriving meteorological variables across Africa for the study and control of vector-borne disease: a comparison of remote sensing and spatial interpolation of climate

PubMed Central

Hay, S. I.; Lennon, J. J.

2012-01-01

Summary This paper presents the results of an investigation into the utility of remote sensing (RS) using meteorological satellites sensors and spatial interpolation (SI) of data from meteorological stations, for the prediction of spatial variation in monthly climate across continental Africa in 1990. Information from the Advanced Very High Resolution Radiometer (AVHRR) of the National Oceanic and Atmospheric Administration’s (NOAA) polar-orbiting meteorological satellites was used to estimate land surface temperature (LST) and atmospheric moisture. Cold cloud duration (CCD) data derived from the High Resolution Radiometer (HRR) on-board the European Meteorological Satellite programme’s (EUMETSAT) Meteosat satellite series were also used as a RS proxy measurement of rainfall. Temperature, atmospheric moisture and rainfall surfaces were independently derived from SI of measurements from the World Meteorological Organization (WMO) member stations of Africa. These meteorological station data were then used to test the accuracy of each methodology, so that the appropriateness of the two techniques for epidemiological research could be compared. SI was a more accurate predictor of temperature, whereas RS provided a better surrogate for rainfall; both were equally accurate at predicting atmospheric moisture. The implications of these results for mapping short and long-term climate change and hence their potential for the study and control of disease vectors are considered. Taking into account logistic and analytical problems, there were no clear conclusions regarding the optimality of either technique, but there was considerable potential for synergy. PMID:10203175

Deriving meteorological variables across Africa for the study and control of vector-borne disease: a comparison of remote sensing and spatial interpolation of climate.

PubMed

Hay, S I; Lennon, J J

1999-01-01

This paper presents the results of an investigation into the utility of remote sensing (RS) using meteorological satellites sensors and spatial interpolation (SI) of data from meteorological stations, for the prediction of spatial variation in monthly climate across continental Africa in 1990. Information from the Advanced Very High Resolution Radiometer (AVHRR) of the National Oceanic and Atmospheric Administration's (NOAA) polar-orbiting meteorological satellites was used to estimate land surface temperature (LST) and atmospheric moisture. Cold cloud duration (CCD) data derived from the High Resolution Radiometer (HRR) on-board the European Meteorological Satellite programme's (EUMETSAT) Meteosat satellite series were also used as a RS proxy measurement of rainfall. Temperature, atmospheric moisture and rainfall surfaces were independently derived from SI of measurements from the World Meteorological Organization (WMO) member stations of Africa. These meteorological station data were then used to test the accuracy of each methodology, so that the appropriateness of the two techniques for epidemiological research could be compared. SI was a more accurate predictor of temperature, whereas RS provided a better surrogate for rainfall; both were equally accurate at predicting atmospheric moisture. The implications of these results for mapping short and long-term climate change and hence their potential for the study and control of disease vectors are considered. Taking into account logistic and analytical problems, there were no clear conclusions regarding the optimality of either technique, but there was considerable potential for synergy.

Water Isotopes in Precipitation: Data/Model Comparison for Present-Day and Past Climates

NASA Technical Reports Server (NTRS)

Jouzel, J.; Hoffmann, G.; Masson, V.

1998-01-01

Variations of HDO and H2O-18 concentrations are observed in precipitation both on a geographical and on a temporal basis. These variations, resulting from successive isotopic fractionation processes at each phase change of water during its atmospheric cycle, are well documented through the IAEA/WMO network and other sources. Isotope concentrations are, in middle and high latitudes, linearly related to the annual mean temperature at the precipitation site. Paleoclimatologists have used this relationship to infer paleotemperatures from isotope paleodata extractable from ice cores, deep groundwater and other such sources. For this application to be valid, however, the spatial relationship must also hold in time at a given location as the location undergoes a series of climatic changes. Progress in water isotope modeling aimed at examining and evaluating this assumption has been recently reviewed with a focus on polar regions and, more specifically, on Greenland. This article was largely based on the results obtained using the isotopic version of the NASA/GISS Atmospheric General Circulation Model (AGCM) fitted with isotope tracer diagnostics. We extend this review in comparing the results of two different isotopic AGCMs (NASA/GISS and ECHAM) and in examining, with a more global perspective, the validity of the above assumption, i.e. the equivalence of the spatial and temporal isotope-temperature relationship. We also examine recent progress made in modeling the relationship between the conditions prevailing in moisture source regions for precipitation and the deuterium-excess of that precipitation.

Impact of climate change on European weather extremes

NASA Astrophysics Data System (ADS)

Duchez, Aurelie; Forryan, Alex; Hirschi, Joel; Sinha, Bablu; New, Adrian; Freychet, Nicolas; Scaife, Adam; Graham, Tim

2015-04-01

An emerging science consensus is that global climate change will result in more extreme weather events with concomitant increasing financial losses. Key questions that arise are: Can an upward trend in natural extreme events be recognised and predicted at the European scale? What are the key drivers within the climate system that are changing and making extreme weather events more frequent, more intense, or both? Using state-of-the-art coupled climate simulations from the UK Met Office (HadGEM3-GC2, historical and future scenario runs) as well as reanalysis data, we highlight the potential of the currently most advanced forecasting systems to progress understanding of the causative drivers of European weather extremes, and assess future frequency and intensity of extreme weather under various climate change scenarios. We characterize European extremes in these simulations using a subset of the 27 core indices for temperature and precipitation from The Expert Team on Climate Change Detection and Indices (Tank et al., 2009). We focus on temperature and precipitation extremes (e.g. extremes in daily and monthly precipitation and temperatures) and relate them to the atmospheric modes of variability over Europe in order to establish the large-scale atmospheric circulation patterns that are conducive to the occurrence of extreme precipitation and temperature events. Klein Tank, Albert M.G., and Francis W. Zwiers. Guidelines on Analysis of Extremes in a Changing Climate in Support of Informed Decisions for Adaptation. WMO-TD No. 1500. Climate Data and Monitoring. World Meteorological Organization, 2009.

The GAW Aerosol Lidar Observation Network (GALION) as a source of near-real time aerosol profile data for model evaluation and assimilation

NASA Astrophysics Data System (ADS)

Hoff, R. M.; Pappalardo, G.

2010-12-01

In 2007, the WMO Global Atmospheric Watch’s Science Advisory Group on Aerosols described a global network of lidar networks called GAW Aerosol Lidar Observation Network (GALION). GALION has a purpose of providing expanded coverage of aerosol observations for climate and air quality use. Comprised of networks in Asia (AD-NET), Europe (EARLINET and CIS-LINET), North America (CREST and CORALNET), South America (ALINE) and with contribution from global networks such as MPLNET and NDACC, the collaboration provides a unique capability to define aerosol profiles in the vertical. GALION is designed to supplement existing ground-based and column profiling (AERONET, PHOTONS, SKYNET, GAWPFR) stations. In September 2010, GALION held its second workshop and one component of discussion focussed how the network would integrate into model needs. GALION partners have contributed to the Sand and Dust Storm Warning and Analysis System (SDS-WAS) and to assimilation in models such as DREAM. This paper will present the conclusions of those discussions and how these observations can fit into a global model analysis framework. Questions of availability, latency, and aerosol parameters that might be ingested into models will be discussed. An example of where EARLINET and GALION have contributed in near-real time observations was the suite of measurements during the Eyjafjallajokull eruption in Iceland and its impact on European air travel. Lessons learned from this experience will be discussed.

CEOS Land Surface Imaging Constellation Mid-Resolution Optical Guidelines

NASA Technical Reports Server (NTRS)

Keyes, Jennifer P.; Killough, B.

2011-01-01

The LSI community of users is large and varied. To reach all these users as well as potential instrument contributors this document has been organized by measurement parameters of interest such as Leaf Area Index and Land Surface Temperature. These measurement parameters and the data presented in this document are drawn from multiple sources, listed at the end of the document, although the two primary ones are "The Space-Based Global Observing System in 2010 (GOS-2010)" that was compiled for the World Meteorological Organization (WMO) by Bizzarro Bizzarri, and the CEOS Missions, Instruments, and Measurements online database (CEOS MIM). For each measurement parameter the following topics will be discussed: (1) measurement description, (2) applications, (3) measurement spectral bands, and (4) example instruments and mission information. The description of each measurement parameter starts with a definition and includes a graphic displaying the relationships to four general land surface imaging user communities: vegetation, water, earth, and geo-hazards, since the LSI community of users is large and varied. The vegetation community uses LSI data to assess factors related to topics such as agriculture, forest management, crop type, chlorophyll, vegetation land cover, and leaf or canopy differences. The water community analyzes snow and lake cover, water properties such as clarity, and body of water delineation. The earth community focuses on minerals, soils, and sediments. The geo-hazards community is designed to address and aid in emergencies such as volcanic eruptions, forest fires, and large-scale damaging weather-related events.

Radiative forcing perturbation due to observed increases in tropospheric ozone at Hohenpeissenberg

NASA Technical Reports Server (NTRS)

Wang, Wei-Chyung; Bojkov, Rumen D.; Zhuang, Yi-Cheng

1994-01-01

The effect on surface temperature due to changes in atmospheric O3 depends highly on the latitude where the change occurs. Previous sensitivity calculations indicate that ozone changes in the upper troposphere and lower stratosphere are more effective in causing surface temperature change (Wang et al., 1980). Long term ground-based observations show that tropospheric ozone, especially at the tropopause region, has been increasing at middle and high latitudes in the Northern Hemisphere (NATO, 1988; Quadrennial Ozone Symposium, 1992). These increases will enhance the greenhouse effect and increase the radiative forcing to the troposphere-surface system, which is opposite to the negative radiative forcing calculated from the observed stratospheric ozone depletion recently reported in WMO (1992). We used more than two thousands regularly measured ozonesondes providing reliable vertical O3 distribution at Hohenpeissenberg (47N; 11E) for the 1967-1990 to study the instantaneous solar and longwave radiative forcing the two decades 1971-1990 and compare the forcing with those caused by increasing CO2, CH4, N2O, and CFCs. Calculations are also made to compare the O3 radiative forcing between stratospheric depletion and tropospheric increase. Results indicate that the O3 changes will induce a positive radiative forcing dominated by tropospheric O3 increase and the magnitude of the forcing is comparable to that due to CO2 increases during the two decades. The significant implications of the tropospheric O3 increase to the global climate are discussed.

Statistical and dynamical forecast of regional precipitation after mature phase of ENSO

NASA Astrophysics Data System (ADS)

Sohn, S.; Min, Y.; Lee, J.; Tam, C.; Ahn, J.

2010-12-01

While the seasonal predictability of general circulation models (GCMs) has been improved, the current model atmosphere in the mid-latitude does not respond correctly to external forcing such as tropical sea surface temperature (SST), particularly over the East Asia and western North Pacific summer monsoon regions. In addition, the time-scale of prediction scope is considerably limited and the model forecast skill still is very poor beyond two weeks. Although recent studies indicate that coupled model based multi-model ensemble (MME) forecasts show the better performance, the long-lead forecasts exceeding 9 months still show a dramatic decrease of the seasonal predictability. This study aims at diagnosing the dynamical MME forecasts comprised of the state of art 1-tier models as well as comparing them with the statistical model forecasts, focusing on the East Asian summer precipitation predictions after mature phase of ENSO. The lagged impact of El Nino as major climate contributor on the summer monsoon in model environments is also evaluated, in the sense of the conditional probabilities. To evaluate the probability forecast skills, the reliability (attributes) diagram and the relative operating characteristics following the recommendations of the World Meteorological Organization (WMO) Standardized Verification System for Long-Range Forecasts are used in this study. The results should shed light on the prediction skill for dynamical model and also for the statistical model, in forecasting the East Asian summer monsoon rainfall with a long-lead time.

Multi-decadal and seasonal variability of dust observations in West Greenland.

NASA Astrophysics Data System (ADS)

Bullard, Joanna E.; Mockford, Tom

2017-04-01

Since the early 1900s expedition records from west Greenland have reported local dust storms. The Kangerlussuaq region, near the inland ice, is dry (mean annual precipitation <160 mm) with, on average, 150 snow-free days per year. The main local dust sources are active, proglacial outwash plains although reworking of loess deposits may also be important. This paper presents an analysis of 70-years of dust storm observations (1945-2015) based on WMO weather codes 6 (dust haze), 7 (raised dust or sand) and 9 (distant or past dust storm) and associated wind data. The 70-year average number of dust observations days is 5 per year but variable ranging from 0 observations to 23 observations in 1985. Over the past 7 decades the number of dust days has increased from <30 in 1945-54 to >75 in 1995-2004 and 2005-2015. The seasonality of dust observations has remained consistent throughout most of the period. Dust days occur all year round but are most frequent in May-June and September-October and are associated with minimum snow cover and glacial meltwater-driven sediment supply to the outwash plains during spring and fall flood events. Wind regime is bimodal dominated by katabatic winds from the northeast, which are strongest and most frequent during winter months (Nov-Jan), with less frequent, southwesterly winds generated by Atlantic storms mostly confined to spring (May, June). The southwesterly winds are those most likely to transport dust onto the Greenland ice sheet.

Evaporation from weighing precipitation gauges: impacts on automated gauge measurements and quality assurance methods

NASA Astrophysics Data System (ADS)

Leeper, R. D.; Kochendorfer, J.

2014-12-01

The effects of evaporation on precipitation measurements have been understood to bias total precipitation lower. For automated weighing-bucket gauges, the World Meteorological Organization (WMO) suggests the use of evaporative suppressants with frequent observations. However, the use of evaporation suppressants is not always feasible due to environmental hazards and the added cost of maintenance, transport, and disposal of the gauge additive. In addition, research has suggested that evaporation prior to precipitation may affect precipitation measurements from auto-recording gauges operating at sub-hourly frequencies. For further evaluation, a field campaign was conducted to monitor evaporation and its impacts on the quality of precipitation measurements from gauges used at US Climate Reference Network (USCRN) stations. Collocated Geonor gauges with (nonEvap) and without (evap) an evaporative suppressant were compared to evaluate evaporative losses and evaporation biases on precipitation measurements. From June to August, evaporative losses from the evap gauge exceeded accumulated precipitation, with an average loss of 0.12 mm h-1. However, the impact of evaporation on precipitation measurements was sensitive to calculation methods. In general, methods that utilized a longer time series to smooth out sensor noise were more sensitive to gauge (-4.6% bias with respect to control) evaporation than methods computing depth change without smoothing (< +1% bias). These results indicate that while climate and gauge design affect gauge evaporation rates computational methods can influence the magnitude of evaporation bias on precipitation measurements. It is hoped this study will advance QA techniques that mitigate the impact of evaporation biases on precipitation measurements from other automated networks.

Thermally evaporated mechanically hard tin oxide thin films for opto-electronic apllications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathy, Sumanta K.; Rajeswari, V. P.

2014-01-28

Tungsten doped tin oxide (WTO) and Molybdenum doped tin oxide (MoTO) thin film were deposited on corn glass by thermal evaporation method. The films were annealed at 350°C for one hour. Structural analysis using Xray diffraction data shows both the films are polycrystalline in nature with monoclinic structure of tin oxide, Sn{sub 3}O{sub 4}, corresponding to JCPDS card number 01-078-6064. SEM photograph showed that both the films have spherical grains with size in the range of 20–30 nm. Compositional analysis was carried out using EDS which reveals the presence of Sn, O and the dopant Mo/W only thereby indicating themore » absence of any secondary phase in the films. The films are found to contain nearly 6 wt% of Mo, 8 wt% of W as dopants respectively. The transmission pattern for both the films in the spectral range 200 – 2000 nm shows that W doping gives a transparency of nearly 80% from 380 nm onwards while Mo doping has less transparency of 39% at 380nm. Film hardness measurement using Triboscope shows a film hardness of about 9–10 GPa for both the films. It indicates that W or M doping in tin oxide provides the films the added advantage of withstanding the mechanical wear and tear due to environmental fluctuations By optimizing the optical and electrical properties, W/Mo doped tin oxide films may be explored as window layers in opto-electronic applications such as solar cells.« less

Comparison of Flow-Dependent and Static Error Correlation Models in the DAO Ozone Data Assimilation System

NASA Technical Reports Server (NTRS)

Wargan, K.; Stajner, I.; Pawson, S.

2003-01-01

In a data assimilation system the forecast error covariance matrix governs the way in which the data information is spread throughout the model grid. Implementation of a correct method of assigning covariances is expected to have an impact on the analysis results. The simplest models assume that correlations are constant in time and isotropic or nearly isotropic. In such models the analysis depends on the dynamics only through assumed error standard deviations. In applications to atmospheric tracer data assimilation this may lead to inaccuracies, especially in regions with strong wind shears or high gradient of potential vorticity, as well as in areas where no data are available. In order to overcome this problem we have developed a flow-dependent covariance model that is based on short term evolution of error correlations. The presentation compares performance of a static and a flow-dependent model applied to a global three- dimensional ozone data assimilation system developed at NASA s Data Assimilation Office. We will present some results of validation against WMO balloon-borne sondes and the Polar Ozone and Aerosol Measurement (POAM) III instrument. Experiments show that allowing forecast error correlations to evolve with the flow results in positive impact on assimilated ozone within the regions where data were not assimilated, particularly at high latitudes in both hemispheres and in the troposphere. We will also discuss statistical characteristics of both models; in particular we will argue that including evolution of error correlations leads to stronger internal consistency of a data assimilation ,

Integrated design of multivariable hydrometric networks using entropy theory with a multiobjective optimization approach

NASA Astrophysics Data System (ADS)

Kim, Y.; Hwang, T.; Vose, J. M.; Martin, K. L.; Band, L. E.

2016-12-01

Obtaining quality hydrologic observations is the first step towards a successful water resources management. While remote sensing techniques have enabled to convert satellite images of the Earth's surface to hydrologic data, the importance of ground-based observations has never been diminished because in-situ data are often highly accurate and can be used to validate remote measurements. The existence of efficient hydrometric networks is becoming more important to obtain as much as information with minimum redundancy. The World Meteorological Organization (WMO) has recommended a guideline for the minimum hydrometric network density based on physiography; however, this guideline is not for the optimum network design but for avoiding serious deficiency from a network. Moreover, all hydrologic variables are interconnected within the hydrologic cycle, while monitoring networks have been designed individually. This study proposes an integrated network design method using entropy theory with a multiobjective optimization approach. In specific, a precipitation and a streamflow networks in a semi-urban watershed in Ontario, Canada were designed simultaneously by maximizing joint entropy, minimizing total correlation, and maximizing conditional entropy of streamflow network given precipitation network. After comparing with the typical individual network designs, the proposed design method would be able to determine more efficient optimal networks by avoiding the redundant stations, in which hydrologic information is transferable. Additionally, four quantization cases were applied in entropy calculations to assess their implications on the station rankings and the optimal networks. The results showed that the selection of quantization method should be considered carefully because the rankings and optimal networks are subject to change accordingly.

Measurement accuracy of weighing and tipping-bucket rainfall intensity gauges under dynamic laboratory testing

NASA Astrophysics Data System (ADS)

Colli, M.; Lanza, L. G.; La Barbera, P.; Chan, P. W.

2014-07-01

The contribution of any single uncertainty factor in the resulting performance of infield rain gauge measurements still has to be comprehensively assessed due to the high number of real world error sources involved, such as the intrinsic variability of rainfall intensity (RI), wind effects, wetting losses, the ambient temperature, etc. In recent years the World Meteorological Organization (WMO) addressed these issues by fostering dedicated investigations, which revealed further difficulties in assessing the actual reference rainfall intensity in the field. This work reports on an extensive assessment of the OTT Pluvio2 weighing gauge accuracy when measuring rainfall intensity under laboratory dynamic conditions (time varying reference flow rates). The results obtained from the weighing rain gauge (WG) were also compared with a MTX tipping-bucket rain gauge (TBR) under the same test conditions. Tests were carried out by simulating various artificial precipitation events, with unsteady rainfall intensity, using a suitable dynamic rainfall generator. Real world rainfall data measured by an Ogawa catching-type drop counter at a field test site located within the Hong Kong International Airport (HKIA) were used as a reference for the artificial rain generation system. Results demonstrate that the differences observed between the laboratory and field performance of catching-type gauges are only partially attributable to the weather and operational conditions in the field. The dynamics of real world precipitation events is responsible for a large part of the measurement errors, which can be accurately assessed in the laboratory under controlled environmental conditions. This allows for new testing methodologies and the development of instruments with enhanced performance in the field.

Technical Report Series on Global Modeling and Data Assimilation, Volume 41 : GDIS Workshop Report

NASA Technical Reports Server (NTRS)

Koster, Randal D. (Editor); Schubert, Siegfried; Pozzi, Will; Mo, Kingtse; Wood, Eric F.; Stahl, Kerstin; Hayes, Mike; Vogt, Juergen; Seneviratne, Sonia; Stewart, Ron;

The cloud imaging and particle size experiment on the aeronomy of ice in the mesosphere mission: Cloud morphology for the northern 2007 season

NASA Astrophysics Data System (ADS)

Rusch, D. W.; Thomas, G. E.; McClintock, W.; Merkel, A. W.; Bailey, S. M.; Russell, J. M., III; Randall, C. E.; Jeppesen, C.; Callan, M.

2009-03-01

The Aeronomy of Ice in the Mesosphere (AIM) mission was launched from Vandenberg Air Force Base in California at 4:26:03 EDT on April 25, 2007, becoming the first satellite mission dedicated to the study of noctilucent clouds (NLCs), also known as polar mesospheric clouds (PMC) when viewed from space. We present the first results from one of the three instruments on board the satellite, the Cloud Imaging and Particle Size (CIPS) instrument. CIPS has produced detailed morphology of the Northern 2007 PMC and Southern 2007/2008 seasons with 5 km horizontal spatial resolution. CIPS, with its very large angular field of view, images cloud structures at multiple scattering angles within a narrow spectral bandpass centered at 265 nm. Spatial coverage is 100% above about 70° latitude, where camera views overlap from orbit to orbit, and terminates at about 82°. Spatial coverage decreases to about 50% at the lowest latitudes where data are collected (35°). Cloud structures have for the first time been mapped out over nearly the entire summertime polar region. These structures include [`]ice rings', spatially small but bright clouds, and large regions ([`]ice-free regions') in the heart of the cloud season essentially devoid of ice particles. The ice rings bear a close resemblance to tropospheric convective outflow events, suggesting a point source of mesospheric convection. These rings (often circular arcs) are most likely Type IV NLC ([`]whirls' in the standard World Meteorological Organization (WMO) nomenclature).

Pollution Monitoring: An Engineering Challenge

NASA Technical Reports Server (NTRS)

Snodgrass, J. M.

1971-01-01

One purpose in presenting this material is to bring to the attention of engineers background material which they would not normally encounter in the course of routine development work. An excellent and timely reference is as follows: Seminar on Methods of Detection, Measurement and Monitoring of Pollutants in the Marine Environment. The international seminar was organized by FAO with the support of UNESCO, IAEA, SCOR and WMO, and was held in Rome, Italy, 4-10 December 1970. The final report, the title of which was given, is a very thoroughgoing document and certainly a must reference for anyone seriously considering the development of sensors for pollution measurement. Perhaps it would be appropriate to present some exact quotations selected from the referenced document. The quotations follow: 1) "The pressures to develop sensitive and reliable methods come about when those responsible for the management of our environment need an objective evaluation of existing or potential perils." 2) "Nearly all of the Panels concerned with the contaminants identified specific examples of man's waste products which may be leaking to the environment in substantial quantities and for which as yet there are no analytical techniques available ". 3) "Very few analyses for organochlorine pesticides appear to have been carried out on sea water and the panel considered that the present methodology was not capable of detecting, on a routine basis, the quantities of these compounds in open sea waters." and 4) "This corresponds essentially to the ratio of useful data produced to the labour expended, since instrumentation costs in the long run become negligible."

Global Framework for Climate Services (GFCS): status of implementation

NASA Astrophysics Data System (ADS)

Lucio, Filipe

2014-05-01

The GFCS is a global partnership of governments and UN and international agencies that produce and use climate information and services. WMO, which is leading the initiative in collaboration with UN ISDR, WHO, WFP, FAO, UNESCO, UNDP and other UN and international partners are pooling their expertise and resources in order to co-design and co-produce knowledge, information and services to support effective decision making in response to climate variability and change in four priority areas (agriculture and fod security, water, health and disaster risk reduction). To address the entire value chain for the effective production and application of climate services the GFCS main components or pillars are being implemented, namely: • User Interface Platform — to provide ways for climate service users and providers to interact to identify needs and capacities and improve the effectiveness of the Framework and its climate services; • Climate Services Information System — to produce and distribute climate data, products and information according to the needs of users and to agreed standards; • Observations and Monitoring - to generate the necessary data for climate services according to agreed standards; • Research, Modelling and Prediction — to harness science capabilities and results and develop appropriate tools to meet the needs of climate services; • Capacity Building — to support the systematic development of the institutions, infrastructure and human resources needed for effective climate services. Activities are being implemented in various countries in Africa, the Caribbean and South pacific Islands. This paper will provide details on the status of implementation of the GFCS worldwider.

High Concentrations of Ozone Air Pollution on Mount Everest: Health Implications for Sherpa Communities and Mountaineers.

PubMed

Semple, John L; Moore, G W Kent; Koutrakis, Petros; Wolfson, Jack M; Cristofanelli, Paolo; Bonasoni, Paolo

2016-12-01

Semple, John L., G.W. Kent Moore, Petros Koutrakis, Jack M. Wolfson, Paolo Cristofanelli, and Paolo Bonasoni. High concentrations of ozone air pollution on Mount Everest: health implications for Sherpa communities and mountaineers. High Alt Med Biol. 17:365-369, 2016.-Introduction: Populations in remote mountain regions are increasingly vulnerable to multiple climate mechanisms that influence levels of air pollution. Few studies have reported on climate-sensitive health outcomes unique to high altitude ecosystems. In this study, we report on the discovery of high-surface ozone concentrations and the potential impact on health outcomes on Mount Everest and the high Himalaya. Surface ozone measurements were collected during ascending transects in the Mount Everest region of Nepal with passive nitrite-coated Ogawa filter samplers to obtain 8-hour personal exposures (2860-5364 m asl). In addition, the Nepal Climate Observatory-Pyramid, a GAW-WMO Global Station sited in the Khumbu Valley (5079 m asl), collected ozone mixing ratios with photometric gas analyzer. Surface ozone measurements increased with altitude with concentrations that exceed 100 ppb (8-hour exposure). Highest values were during the spring season and the result of diverse contributions: hemispheric background values, the descent of ozone-rich stratospheric air, and the transport of tropospheric pollutants occurring at different spatial scales. Multiple climate factors, including descending stratospheric ozone and imported anthropogenic air masses from the Indo-Gangetic Plain, contribute to ambient ozone exposure levels in the vicinity of Mount Everest that are similar to if not higher than those reported in industrialized cities.

Monitoring stratospheric chlorine activation from time series of OClO DSCDs above Kiruna using ground-based zenith sky DOAS observations

NASA Astrophysics Data System (ADS)

Gu, Myojeong; Enell, Carl-Fredrik; Pukite, Janis; Platt, Ulrich; Raffalski, Uwe; Wagner, Thomas

2017-04-01

After to the Montreal protocol and amendments, the production of CFCs was strongly reduced. Since then scientists have steadily made efforts to monitor the amount of chlorine compounds which are responsible for the destruction of ozone in the stratosphere. Although very recent research of stratospheric ozone indicates an ozone recovery, ozone depletion is still observed in the polar spring and is expected to last for about another 70 years according to the WMO. Therefore, continuous observation and analysis of the stratospheric ozone as well as other stratospheric trace gases are highly demanded. Several previous studies have investigated OClO which is an indicator for stratospheric chlorine activation using satellite, ground-based, and balloon remote sensing measurements. In this work, we investigate long-term time series of OClO DSCDs (Differential Slant Column densities) above Kiruna, Sweden (67.84°N, 20.41°E) which is located inside the Arctic Circle by using the ground-based zenith sky DOAS measurements. Since our measurements are performed at the fixed site, for the interpretation also the relative position of the polar vortex has to be considered. Our long-term data obtained during about 15 years allows us to classify the dependence of the OClO amount on the various meteorological conditions. Our data show a large variability with high OClO SCDs in cold, and low OClO SCDs in warm winters. Our measurements also allow to investigate the effect of the chlorine activation and its duration on the strength of the ozone destruction.

Have we underestimated the role of short-lived chlorine compounds in ozone depletion?

NASA Astrophysics Data System (ADS)

Oram, David; Laube, Johannes; Sturges, Bill; Gooch, Lauren; Leedham, Emma; Ashfold, Matthew; Pyle, John; Abu Samah, Azizan; Moi Phang, Siew; Ou-Yang, Chang-Feng; Lin, Neng-Huei; Wang, Jia-Lin; Brenninkmeijer, Carl

2015-04-01

In recent years much attention has been focussed on the potential of bromine-containing VSLS (very short lived substances) to contribute to stratospheric ozone depletion. This is primarily due to the large observed discrepancy between the measured inorganic bromine in the stratosphere and the amount of bromine available from known, longer lived sources gases (halons and CH3Br). In contrast, the role of very short-lived chlorine compounds (VSLS-CL) has been considered trivial because they contribute only a few percent to the total organic chlorine in the troposphere, the majority of which is supplied by long-lived compounds such as the CFCs, HCFCs, methyl chloroform and carbon tetrachloride. However recent evidence shows that one VSLS-Cl, dichloromethane (CH2Cl2) has increased by 60% over the past decade (WMO, 2014) and has already begun to offset the long-term decline in stratospheric chlorine loading caused by the reduction in emissions of substances controlled by the Montreal Protocol. We will present new VSLS-Cl measurements from recent ground-based and aircraft campaigns in SE Asia where we have observed dramatic enhancements in a number of VSLS-Cl, including CH2Cl2. Furthermore we will demonstrate how pollution from China and the surrounding region can rapidly, and regularly, be transported across the South China Sea and subsequently uplifted to altitudes of 11-12 km, the region close to the lower TTL. This process occurs frequently during the winter monsoon season and could represent a fast and efficient mechanism for transporting short-lived compounds, and other pollutants, to the lower stratosphere.

Inorganic nanotubes and fullerene-like nanoparticles at the crossroad between materials science and nanotechnology

NASA Astrophysics Data System (ADS)

Tenne, Reshef

2014-03-01

This presentation is aimed at underlying the principles, synthesis, characterization and applications of inorganic nanotubes (INT) and fullerne-like (IF) nanoparticles (NP) from 2-D layered compounds. While the high temperature synthesis and study of IF materials and INT from layered metal dichalcogenides, like WS2 and MoS2 remain a major challenge, progress with the synthesis of IF and INT structures from various other compounds has been realized, as well. Intercalation and doping of these nanostructures, which lends itself to interesting electronic properties, has been realized, too. Core-shell nanotubular structures, like PbI2@WS2 and SnS/SnS2 and PbS/NbS2 nanotubes from ``misfit'' compounds have been recently reported. Re doping of the IF and INT endow them with interesting electrical and other physio-chemical properties. Major progress has been achieved in elucidating the structure of INT and IF using advanced microscopy techniques, like aberration corrected TEM and electron tomography. Also recently, scaling up efforts in collaboration with ``NanoMaterials'' resulted in multikilogram production of (almost) pure multiwall WS2 nanotubes phases. Extensive experimental and theoretical analysis of the mechanical properties of individual INT and more recently IF NP was performed casting light on their behavior in the macroscopic world. IF-MS2 (M =W,Mo, etc) were shown to be superior solid lubricants in variety of forms, including an additive to various lubricating fluids/greases and for various self-lubricating coating. Full commercialization of products based on this technology is taking place now.

Enhancing the USDA Global Crop Assessment Decision Support System Using SMAP Soil Moisture Data

NASA Astrophysics Data System (ADS)

Bolten, J. D.; Mladenova, I. E.; Crow, W. T.; Reynolds, C. A.

2016-12-01

The Foreign Agricultural Services (FAS) is a subdivision of U.S. Department of Agriculture (USDA) that is in charge with providing information on current and expected crop supply and demand estimates. Knowledge of the amount of water in the root zone is an essential source of information for the crop analysts as it governs the crop development and crop growth, which in turn determine the end-of-season yields. USDA FAS currently relies on root zone soil moisture (RZSM) estimates generated using the modified two-layer Palmer Model (PM). PM is a simple water-balance hydrologic model that is driven by daily precipitation observations and minimum and maximum temperature data. These forcing data are based on ground meteorological station measurements from the World Meteorological Organization (WMO), and gridded weather data from the former U.S. Air Force Weather Agency (AFWA), currently called U.S. Air Force 557th Weather Wing. The PM was extended by adding a data assimilation (DA) unit that provides the opportunity to routinely ingest satellite-based soil moisture observations. This allows us to adjust for precipitation-related inaccuracies and enhance the quality of the PM soil moisture estimates. The current operational DA system is based on a 1-D Ensample Kalman Filter approach and relies on observations obtained from the Soil Moisture Ocean Salinity Mission (SMOS). Our talk will demonstrate the value of assimilating two satellite products (i.e. a passive and active) and discuss work that is done in preparation for ingesting soil moisture observations from the Soil Moisture Active Passive (SMAP) mission.

Ground-based intercomparisons of SBUV/2 flight instruments the world standard Dobson spectrophotometer 83 and overpass observations from Nimbus-7 TOMS and NOAA-11 SBUV/2

NASA Technical Reports Server (NTRS)

Heath, D. F.; Ahmad, Z.; Torres, O.; Evans, R. D.; Grass, R. D.; Komhyr, W. A.; Nelson, W.

1994-01-01

Total ozone data obtained during summers at Mauna Loa Observatory, Hawaii, with Dobson Spectrophotometer 83 are routinely compared with overpass total ozone data from the Total Ozone Mapping Spectrometer (TOMS) and the Solar Backscatter Ultraviolet (SBUV) spectrometer launched aboard the Nimbus 7 satellite in 1978. Results from the TOMS/Dobson instrument comparisons through 1990 have been presented by McPeters and Komhyr (1991). Dobson spectrophotometer 83 was established as the standard instrument for the U.S.A. Dobson instrument station network in 1962. In 1980, the instrument was designated by the World Meteorological Organization (WMO) as the Standard Dobson Spectrophotometer for the World. Long-term ozone measurement precision of the instrument has been maintained at plus or minus 0.5 percent (Komhyr et al., 1989). On an absolute scale, the ozone measurement accuracy of the instrument is estimated to plus or minus 3 percent. In early April, 1990, comparison of total ozone and vertical distribution (Umkehr) observations were made for the first time with Dobson spectrophotometer 8.3. The work was conducted at the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) in Boulder, Colorado, and at the research and instrument manufacturing facility of the Ball Aerospace System Division located about 2 km east of Boulder. (The SBUV-2 S/N-2 instrument, built by Ball Aerospace Systems Division, is scheduled for launch aboard the NOAA-13 satellite). We present results of the comparisons which include ozone vertical distribution data obtained with a balloon-borne electrochemical concentration cell (ECC) ozonesonde (Komhyr, 1969).

Integrated design of multivariable hydrometric networks using entropy theory with a multiobjective optimization approach

NASA Astrophysics Data System (ADS)

Keum, J.; Coulibaly, P. D.

2017-12-01

Obtaining quality hydrologic observations is the first step towards a successful water resources management. While remote sensing techniques have enabled to convert satellite images of the Earth's surface to hydrologic data, the importance of ground-based observations has never been diminished because in-situ data are often highly accurate and can be used to validate remote measurements. The existence of efficient hydrometric networks is becoming more important to obtain as much as information with minimum redundancy. The World Meteorological Organization (WMO) has recommended a guideline for the minimum hydrometric network density based on physiography; however, this guideline is not for the optimum network design but for avoiding serious deficiency from a network. Moreover, all hydrologic variables are interconnected within the hydrologic cycle, while monitoring networks have been designed individually. This study proposes an integrated network design method using entropy theory with a multiobjective optimization approach. In specific, a precipitation and a streamflow networks in a semi-urban watershed in Ontario, Canada were designed simultaneously by maximizing joint entropy, minimizing total correlation, and maximizing conditional entropy of streamflow network given precipitation network. After comparing with the typical individual network designs, the proposed design method would be able to determine more efficient optimal networks by avoiding the redundant stations, in which hydrologic information is transferable. Additionally, four quantization cases were applied in entropy calculations to assess their implications on the station rankings and the optimal networks. The results showed that the selection of quantization method should be considered carefully because the rankings and optimal networks are subject to change accordingly.

Effects of anthropogenic heat release upon the urban climate in a Japanese megacity.

PubMed

Narumi, Daisuke; Kondo, Akira; Shimoda, Yoshiyuki

2009-05-01

This report presents results of investigations of the influence of anthropogenic heat release in Japanese megacity (Keihanshin district) upon the urban climate, using the energy database [Shimoda et al., 1999. Estimation and evaluation of artificial waste heat in urban area. Selected Papers from the Conference ICB-ICUC'99 WCASP-50 WMO/TD no. 1026] as a part of the land-surface boundary conditions of a mesoscale meteorological simulation model. The calculated results related to atmospheric temperature distribution were similar to observed values not only for daily averages but also for amplitudes and phases of diurnal change. To reproduce accurately, it is essential to reproduce urban characteristics such as an urban canopy and anthropogenic heat release in a fine resolution mesh. We attempted an analysis using current data for anthropogenic heat and under uniform heat release conditions, to investigate temporal and spatial characteristics in relation to the influence of anthropogenic heat release on the urban climate. The results of investigation into the influence of anthropogenic heat release on atmospheric temperature using current data indicate that the amount of heat released is lower at night than during the day, but the temperature rise is nearly 3 times greater. Results of investigation into the influence of anthropogenic heat release on wind systems using current data indicate that the onset of land breezes is delayed, particularly in a coastal area. Investigation into the temporal characteristics related to the influence of anthropogenic heat release under uniform heat release conditions showed a maximum influence on temperature during the predawn period.

Comparison of nitrous oxide (N2O) analyzers for high-precision measurements of atmospheric mole fractions

NASA Astrophysics Data System (ADS)

Lebegue, B.; Schmidt, M.; Ramonet, M.; Wastine, B.; Yver Kwok, C.; Laurent, O.; Belviso, S.; Guemri, A.; Philippon, C.; Smith, J.; Conil, S.; Jost, H. J.; Crosson, E. R.

2015-10-01

Over the last few decades, in-situ measurements of atmospheric N2O mole fractions have been performed using gas chromatographs (GCs) equipped with electron capture detectors (ECDs). When trying to meet the World Meteorological Organization's (WMO) quality goal, this technique becomes very challenging as the detectors are highly non-linear and the GCs at remote stations require a considerable amount of maintenance by qualified technicians to maintain good short-term and long-term repeatability. With more robust optical spectrometers being now available for N2O measurements, we aim to identify a robust and stable analyzer that can be integrated into atmospheric monitoring networks, such as the Integrated Carbon Observation System (ICOS). In this study, we tested seven analyzers that were developed and commercialized from five different companies and compared the results with established techniques. Each instrument was characterized during a time period of approximately eight weeks. The test protocols included the characterization of the short-term and long-term repeatability, drift, temperature dependence, linearity and sensitivity to water vapor. During the test period, ambient air measurements were compared under field conditions at the Gif-sur-Yvette station. All of the analyzers showed a standard deviation better than 0.1 ppb for the 10 min averages. Some analyzers would benefit from improvements in temperature stability to reduce the instrument drift, which could then help in reducing the frequency of calibrations. For most instruments, the water vapor correction algorithms applied by companies are not sufficient for high-precision atmospheric measurements, which results in the need to dry the ambient air prior to analysis.

Long Term Measurement of the Earth's Radiation Budget using a constellation of Broadband Radiometers hosted on Iridium NEXT

NASA Astrophysics Data System (ADS)

Gupta, Om Prakash; Thoma, Donald; Chaloner, Chris; Russell, Jacqueline; Simpson, Bill; Spilling, David; Morris, Nigel; Caldwell, Martin; Oneill, Alan

The WMO called for "bringing new missions to operational status" and that "ERB should be measured through a constellation of sensors". A unique opportu-nity exists to host a set of Earth Radiation Budget (ERB) sensors on the Iridium NEXT (NEXT) LEO constellation in a cost effective manner that can deliver these requirements. The NEXT constellation, with 66 interconnected satellites in 6 near polar orbiting planes, provides a unique platform for hosting a variety of Earth observation missions including ERB. Launches are planned to begin in 2014 through 2016. The ERB both drives and responds to global climate and monitoring it can provide much insight into the climate system and how it might be changing. A climate quality measurement of the ERB requires high absolute accuracy and excellent stability and a long-term (decades) data record in order to inform the debate about global warming. Measurement of the ERB in terms of the broadband reflected solar (0.3 to 4 µm) and emitted thermal (4 to 200 µm) components have been identified as high priority by the WMO for climate observations. High temporal resolution is the key advantage offered by the NEXT platform and can provide a great step forward in accurately monitoring the energy balance of the planet. The sensor we propose will consist of a broad band instrument and associated imager for scene identification and cloud classification. There is the chance to place two such sensors in each of six different orbital planes this will improve the product refresh time from currently 12 hours to 3 hours. The increased temporal resolution will allow direct measure-ment of the changes to the broadband radiances that result from rapidly varying components of the climate such as cloud and aerosol, and avoid the need of relying on narrow band sensors to infer such changes. Considering that the prediction of cloud response to climate change is still a major source of uncertainty; improved measurement of the cloud effect and possible changes in this quantity are of particular interest. This proposed configuration of twelve ERB sensors on NEXT has been analyzed in a detailed study by this team and demonstrated to have compatibility with proposed NEXT satellites. This study has also demonstrated the following: 1. Full globe coverage, including the poles, and 3 hourly temporal resolution even at the equator 2. Spatial coverage with a swath of each sensor of 1000 km and resolution of 10 km at nadir 3. LEO orbits which are not sun-synchronous so aliasing effects, which are always a concern with single sensors in sun-synchronous orbits, are no longer of concern 4. Twelve sensors in orbit simultaneously, with frequent near-coincidences at high latitudes, so cross-calibration will become a normal part of the system operation. Cross-calibration will also be possible against current sensors such as CERES in LEO and GERB in GEO and offers the possibly of combined products with the sensors. 5. The data stream will be in real-time via the NEXT communications network 6. System robustness is assured since loss of a sensor or satellite is not mission critical 7. Low risk and short lead times because heritage sensors are to be deployed 8. Low chance of launch delays or mission creep, since timing is crucial to the Iridium's business 9. Planned long constellation design life reduces long term cost and continuity problems 10. Near-certain continuity missions as follow-on constellations are part of the host's business plans 11. A move to truly operational observations using real, rather than virtual, constellation 12. A significantly lower cost alternative to traditional methods for collecting this data.

Past Changes in the Vertical Distribution of Ozone Part 1: Measurement Techniques, Uncertainties and Availability

NASA Technical Reports Server (NTRS)

Hassler, B.; Petropavlovskikh, I.; Staehelin, J.; August, T.; Bhartia, P. K.; Clerbaux, C.; Degenstein, D.; Maziere, M. De; Dinelli, B. M.; Dudhia, A.;

Using Transport Diagnostics to Understand Chemistry Climate Model Ozone Simulations

NASA Technical Reports Server (NTRS)

Strahan, S. E.; Douglass, A. R.; Stolarski, R. S.; Akiyoshi, H.; Bekki, S.; Braesicke, P.; Butchart, N.; Chipperfield, M. P.; Cugnet, D.; Dhomse, S.;

Evaporation from weighing precipitation gauges: impacts on automated gauge measurements and quality assurance methods

NASA Astrophysics Data System (ADS)

Leeper, R. D.; Kochendorfer, J.

2015-06-01

Evaporation from a precipitation gauge can cause errors in the amount of measured precipitation. For automated weighing-bucket gauges, the World Meteorological Organization (WMO) suggests the use of evaporative suppressants and frequent observations to limit these biases. However, the use of evaporation suppressants is not always feasible due to environmental hazards and the added cost of maintenance, transport, and disposal of the gauge additive. In addition, research has suggested that evaporation prior to precipitation may affect precipitation measurements from auto-recording gauges operating at sub-hourly frequencies. For further evaluation, a field campaign was conducted to monitor evaporation and its impacts on the quality of precipitation measurements from gauges used at U.S. Climate Reference Network (USCRN) stations. Two Geonor gauges were collocated, with one gauge using an evaporative suppressant (referred to as Geonor-NonEvap) and the other with no suppressant (referred to as Geonor-Evap) to evaluate evaporative losses and evaporation biases on precipitation measurements. From June to August, evaporative losses from the Geonor-Evap gauge exceeded accumulated precipitation, with an average loss of 0.12 mm h-1. The impact of evaporation on precipitation measurements was sensitive to the choice of calculation method. In general, the pairwise method that utilized a longer time series to smooth out sensor noise was more sensitive to gauge evaporation (-4.6% bias with respect to control) than the weighted-average method that calculated depth change over a smaller window (<+1% bias). These results indicate that while climate and gauge design affect gauge evaporation rates, computational methods also influence the magnitude of evaporation biases on precipitation measurements. This study can be used to advance quality insurance (QA) techniques used in other automated networks to mitigate the impact of evaporation biases on precipitation measurements.

Using smartphone batteries as an urban thermometer

NASA Astrophysics Data System (ADS)

Droste, Arjan; Pape, Jan-Jaap; Overeem, Aart; Leijnse, Hidde; Steeneveld, Gert-Jan; Van Delden, Aarnout; Uijlenhoet, Remko

2017-04-01

Taking meteorological measurements in the urban environment is notoriously difficult due to the complex geometry at street and neighbourhood level. Traditional weather stations are absent in cities because of WMO regulations, so urban data has to come from typically expensive measurement-networks, or short intensive campaigns. While traditional measurements are scarce, there is an abundance of smart devices in cities: the well-known Internet of Things. It is for these reasons that crowdsourcing data has an enormous potential in cities, to deliver vast quantities of data without the maintenance costs of a measurement network. A promising source of potentially valuable data is the smartphone, because of its ubiquity and the many sensors most newer phone models now possess. Since most people nowadays have a smartphone, and carry it around wherever they go, data logged by the phone can be used to estimate the urban air temperature. A persistent log taken by nearly all smartphone models, even those without air temperature sensors, is the smartphone's battery temperature. The free OpenSignal smartphone application logs this battery temperature (among many other variables) and the position of the smartphone, which makes it possible to estimate the urban air temperature through a straightforward heat transfer model relating battery temperature to air and body temperature. The obtained urban temperatures are accurate within 1 to 2 degrees of certified measurement stations, proving the huge potential of this innovative method. This poster focuses on describing how thousands of daily smartphone battery temperature measurements can be translated to a relatively robust estimation of an urban air temperature, using 2 years of data from São Paulo in Brazil. Analysis of the results is presented in a separate session.

How Certain are We of the Uncertainties in Recent Ozone Profile Trend Assessments of Merged Limbo Ccultation Records? Challenges and Possible Ways Forward

NASA Technical Reports Server (NTRS)

Hubert, Daan; Lambert, Jean-Christopher; Verhoelst, Tijl; Granville, Jose; Keppens, Arno; Baray, Jean-Luc; Cortesi, Ugo; Degenstein, D. A.; Froidevaux, Lucien; Godin-Beekmann, Sophie;

Integrating Multi-Sensor Remote Sensing and In-situ Measurements for Africa Drought Monitoring and Food Security Assessment

NASA Astrophysics Data System (ADS)

Hao, X.; Qu, J. J.; Motha, R. P.; Stefanski, R.; Malherbe, J.

2014-12-01

Drought is one of the most complicated natural hazards, and causes serious environmental, economic and social consequences. Agricultural production systems, which are highly susceptible to weather and climate extremes, are often the first and most vulnerable sector to be affected by drought events. In Africa, crop yield potential and grazing quality are already nearing their limit of temperature sensitivity, and, rapid population growth and frequent drought episodes pose serious complications for food security. It is critical to promote sustainable agriculture development in Africa under conditions of climate extremes. Soil moisture is one of the most important indicators for agriculture drought, and is a fundamentally critical parameter for decision support in crop management, including planting, water use efficiency and irrigation. While very significant technological advances have been introduced for remote sensing of surface soil moisture from space, in-situ measurements are still critical for calibration and validation of soil moisture estimation algorithms. For operational applications, synergistic collaboration is needed to integrate measurements from different sensors at different spatial and temporal scales. In this presentation, a collaborative effort is demonstrated for drought monitoring in Africa, supported and coordinated by WMO, including surface soil moisture and crop status monitoring. In-situ measurements of soil moisture, precipitation and temperature at selected sites are provided by local partners in Africa. Measurements from the Soil Moisture and Ocean Salinity (SMOS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) are integrated with in-situ observations to derive surface soil moisture at high spatial resolution. Crop status is estimated through temporal analysis of current and historical MODIS measurements. Integrated analysis of soil moisture data and crop status provides both in-depth understanding of drought conditions and potential impacts on crop yield. This information is extremely useful in local decision support for agricultural management.

Integrating Multi-Sensor Remote Sensing and In-situ Measurements for Africa Drought Monitoring and Food Security Assessment

NASA Astrophysics Data System (ADS)

Hao, X.; Qu, J. J.; Motha, R. P.; Stefanski, R.; Malherbe, J.

2015-12-01

Drought is one of the most complicated natural hazards, and causes serious environmental, economic and social consequences. Agricultural production systems, which are highly susceptible to weather and climate extremes, are often the first and most vulnerable sector to be affected by drought events. In Africa, crop yield potential and grazing quality are already nearing their limit of temperature sensitivity, and, rapid population growth and frequent drought episodes pose serious complications for food security. It is critical to promote sustainable agriculture development in Africa under conditions of climate extremes. Soil moisture is one of the most important indicators for agriculture drought, and is a fundamentally critical parameter for decision support in crop management, including planting, water use efficiency and irrigation. While very significant technological advances have been introduced for remote sensing of surface soil moisture from space, in-situ measurements are still critical for calibration and validation of soil moisture estimation algorithms. For operational applications, synergistic collaboration is needed to integrate measurements from different sensors at different spatial and temporal scales. In this presentation, a collaborative effort is demonstrated for drought monitoring in Africa, supported and coordinated by WMO, including surface soil moisture and crop status monitoring. In-situ measurements of soil moisture, precipitation and temperature at selected sites are provided by local partners in Africa. Measurements from the Soil Moisture and Ocean Salinity (SMOS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) are integrated with in-situ observations to derive surface soil moisture at high spatial resolution. Crop status is estimated through temporal analysis of current and historical MODIS measurements. Integrated analysis of soil moisture data and crop status provides both in-depth understanding of drought conditions and potential impacts on crop yield. This information is extremely useful in local decision support for agricultural management.

Analysis of the variation of the 0°C isothermal altitude during rainfall events

NASA Astrophysics Data System (ADS)

Zeimetz, Fränz; Garcìa, Javier; Schaefli, Bettina; Schleiss, Anton J.

2016-04-01

In numerous countries of the world (USA, Canada, Sweden, Switzerland,…), the dam safety verifications for extreme floods are realized by referring to the so called Probable Maximum Flood (PMF). According to the World Meteorological Organization (WMO), this PMF is determined based on the PMP (Probable Maximum Precipitation). The PMF estimation is performed with a hydrological simulation model by routing the PMP. The PMP-PMF simulation is normally event based; therefore, if no further information is known, the simulation needs assumptions concerning the initial soil conditions such as saturation or snow cover. In addition, temperature series are also of interest for the PMP-PMF simulations. Temperature values can not only be deduced from temperature measurement but also using the temperature gradient method, the 0°C isothermal altitude can lead to temperature estimations on the ground. For practitioners, the usage of the isothermal altitude for referring to temperature is convenient and simpler because one value can give information over a large region under the assumption of a certain temperature gradient. The analysis of the evolution of the 0°C isothermal altitude during rainfall events is aimed here and based on meteorological soundings from the two sounding stations Payerne (CH) and Milan (I). Furthermore, hourly rainfall and temperature data are available from 110 pluviometers spread over the Swiss territory. The analysis of the evolution of the 0°C isothermal altitude is undertaken for different precipitation durations based on the meteorological measurements mentioned above. The results show that on average, the isothermal altitude tends to decrease during the rainfall events and that a correlation between the duration of the altitude loss and the duration of the rainfall exists. A significant difference in altitude loss is appearing when the soundings from Payerne and Milan are compared.

Precipitation chemistry of Lhasa and other remote towns, Tibet

NASA Astrophysics Data System (ADS)

Zhang, David D.; Peart, Mervyn; Jim, C. Y.; He, Y. Q.; Li, B. S.; Chen, J. A.

Precipitation event samples during 1987-1988 field expedition periods and 1997, 1998, 1999 and 2000 have been collected at Lhasa, Dingri, Dangxiong and Amdo, Tibet. The sampling and analysis were based on WMO recommendations for a background network with some modifications according to local conditions and environmental characteristics. The following precipitation constituents and related parameters were measured: pH, conductivity, CO 2 partial pressure, total suspended particles, and the content of K +, Na +, Ca 2+, Mg 2+, Fe, Mn, NH 4+, Cl -, NO 2-, NO 3-, SO42- Br-, HCO 3- and HPO 42-. Some atmospheric dust samples have also been collected. Over 300 precipitation events have been measured for pH and conductivity. Among these, 60 have been analysed for their chemical components. The results show that Lhasa's precipitation events were constantly alkaline with weighted averages of pH 8.36 in the 1987-1988 period, and 7.5 for 1997 to 1999. Only one event was weakly acidic during 1997-1999. Although CO 2 partial pressure, a major producer of acidity in natural water on the Plateau, falls with increasing elevation, the lowest measured CO 2 partial pressure can only raise pH value by 0.1 units in the sampling areas. Chemical analysis indicates that the major contributor to alkaline precipitation is the continental dust, which is rich in calcium. The analysis also shows that Tibet is still one of the cleanest areas in the world with little air pollution. However, the decline of pH from the 1980s to 1990s, which was reflected by an increase of NO 3- and SO 42- in precipitation, alerts us to the urgency of environmental protection in this fragile paradise.

An Overview of the Upcoming International Polar Year

NASA Astrophysics Data System (ADS)

Carlson, D.

2006-05-01

The ICSU - WMO International Polar Year 2007 - 2008 has drawn extraordinary interest from scientists of many specialties and many nationalities. A cautious assessment prior to the IPY start shows more than 200 projects, each with at least10 and often 50 or more scientists from at least three different nations, addressing a wide range of physical, biological and social research topics in both polar regions. Adding students, engineers, technicians and all manner of talented support crew so essential to polar research, and accepting some limitations due to logistics and funding, it seems likely that IPY will involve several 10's of thousands of individuals from at least 60 nations. Much of the IPY research will represent redirection and new collaboration on the basis of existing funds, but several nations will implement substantial new research funding and enhanced logistical support during IPY. One of IPY's strongest scientific contributions will arise from a substantial effort to understand geophysical, biological, and even social linkages between northern and southern polar regions - these linkages will highlight the importance of polar science to global processes and issues. IPY will offer unprecedented data management and communication challenges and opportunities, internally among so broad a range of scientific disciplines and externally to science education systems at all levels and to the general public. Against a background of prominent and largely commercial events, including films, television series, museum exhibitions, and regular broadcast coverage, many polar institutions and individuals will consider local events, new educational materials, and new engagement strategies that can have an enormous impact on public perception of science. In its total science and outreach effort, IPY will provide a large step forward that AGU and other pre-eminent science organizations can use and should plan to sustain.

International cooperation in water resources

USGS Publications Warehouse

Jones, J.R.; Beall, R.M.; Giusti, E.V.

1979-01-01

Advancements in hydrology proceeded slowly until the late 1800's when new ventures created a surge of interest and accomplishment. Progress waned again until the middle 20th century when an International Hydrological Decade was conceived, eventually receiving wide multinational support from governmental agencies and nongovernmental institutions. Organized by UNESCO, the Decade program was launched January 1, 1965. Participation included 107 nations, six United Nations agencies, and more than a dozen international scientific organizations. The initial program emphasized scientific research, and international cooperation; the second half of the Decade, emphasized technical assistance and technology transfer, largerly through education, training and demonstration. The success of the Decade led to the establishment of the International Hydrological Program, again under the aegis of UNESCO, to continue the work of the Decade indefinitely. The five major program activities, now involving about 90 countries and several international organizations, include: the scientific program, the promotion of education and training, the enhancement of information exchange, support of technical assistance, and the enlargement of regional cooperation. A significant amount of activity related to hydrological data networks and forecasting is carried on in an Operational Hydrology Programme by the WMO, chiefly through its Commission for Hydrology. Other international governmental organizations with a strong interest in water include the UN, the UN Development Programme, the FAO, the WHO, the International Atomic Energy Agency, the UN Environment Programme, the International Standardization Organization, and developmental institutions such as the World Bank. The specialized interests of researchers outside of the governmental structure, are met through association in various scientific and technical organizations which are world wide in scope and membership. Notwithstanding a sometimes bewildering variety of organizations, there certainly exists, for any nation, group, or individual, a demonstrated mechanism for almost any conceivable form of international cooperation in hydrology and water resources. ?? 1979 Akademische Verlagsgesellschaft.

Climatology and Characteristics of Aerosol Optical Properties in the Arctic

NASA Astrophysics Data System (ADS)

Schmeisser, Lauren; Ogren, John; Backman, John; Asmi, Eija; Andrews, Elisabeth; Jefferson, Anne; Bergin, Michael; Tunved, Peter; Sharma, Sangeeta; Starkweather, Sandra

2016-04-01

Within the Arctic, climate forcers like atmospheric aerosols are important contributors to the observed warming and environmental changes in the region. Quantifying the forcing by aerosols in the Arctic is especially difficult, given short aerosol lifetimes, annual variability in illumination and surface albedo, stratified atmospheric conditions, complex feedbacks, and long-range aerosol transport. However, in-situ surface measurements of Arctic aerosol optical properties can be used to constrain variability of light scattering and absorption, identify potential particle sources, and help evaluate the resulting forcing. Data from six WMO Global Atmosphere Watch stations are presented: Alert, Canada (ALT); Barrow, Alaska (BRW); Pallas, Finland (PAL); Summit, Greenland (SUM); Tiksi, Russia (TIK); and Zeppelin Mountain, Norway (ZEP). These sites contribute to the International Arctic System for Observing the Atmosphere (IASOA), which facilitates Arctic-wide data collection and analysis. Climatologies of aerosol optical properties from each station show differences in magnitude and variability of observed parameters. For example, most stations (ALT, BRW, SUM, TIK, ZEP) experience maximum scattering in winter/spring, while PAL exhibits maximum scattering in the summer. The observed range in scattering across these sites is large (almost an order of magnitude) - SUM has the lowest annual median scattering at 0.82 Mm-1 while BRW has the highest at 6.9 Mm-1. A closer look at systematic variability between optical properties at each station, as well as site back trajectories, suggest differences in aerosol processes, sources and transport. The development of consistent climatologies and additional analyses like the ones presented here can help provide a better understanding of trans-Arctic aerosol variability, which can be an asset for improving aerosol models in this unique and remote region.

Ambient dose equivalent and effective dose from scattered x-ray spectra in mammography for Mo/Mo, Mo/Rh and W/Rh anode/filter combinations.

PubMed

Künzel, R; Herdade, S B; Costa, P R; Terini, R A; Levenhagen, R S

2006-04-21

In this study, scattered x-ray distributions were produced by irradiating a tissue equivalent phantom under clinical mammographic conditions by using Mo/Mo, Mo/Rh and W/Rh anode/filter combinations, for 25 and 30 kV tube voltages. Energy spectra of the scattered x-rays have been measured with a Cd(0.9)Zn(0.1)Te (CZT) detector for scattering angles between 30 degrees and 165 degrees . Measurement and correction processes have been evaluated through the comparison between the values of the half-value layer (HVL) and air kerma calculated from the corrected spectra and measured with an ionization chamber in a nonclinical x-ray system with a W/Mo anode/filter combination. The shape of the corrected x-ray spectra measured in the nonclinical system was also compared with those calculated using semi-empirical models published in the literature. Scattered x-ray spectra measured in the clinical x-ray system have been characterized through the calculation of HVL and mean photon energy. Values of the air kerma, ambient dose equivalent and effective dose have been evaluated through the corrected x-ray spectra. Mean conversion coefficients relating the air kerma to the ambient dose equivalent and to the effective dose from the scattered beams for Mo/Mo, Mo/Rh and W/Rh anode/filter combinations were also evaluated. Results show that for the scattered radiation beams the ambient dose equivalent provides an overestimate of the effective dose by a factor of about 5 in the mammography energy range. These results can be used in the control of the dose limits around a clinical unit and in the calculation of more realistic protective shielding barriers in mammography.

Variability of extreme weather events over the equatorial East Africa, a case study of rainfall in Kenya and Uganda

NASA Astrophysics Data System (ADS)

Ongoma, Victor; Chen, Haishan; Omony, George William

2018-01-01

This study investigates the variability of extreme rainfall events over East Africa (EA), using indices from the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices (ETCCDI). The analysis was based on observed daily rainfall from 23 weather stations, with length varying within 1961 and 2010. The indices considered are: wet days ( R ≥1 mm), annual total precipitation in wet days (PRCPTOT), simple daily intensity index (SDII), heavy precipitation days ( R ≥ 10 mm), very heavy precipitation days ( R ≥ 20 mm), and severe precipitation ( R ≥ 50 mm). The non-parametric Mann-Kendall statistical analysis was carried out to identify trends in the data. Temporal precipitation distribution was different from station to station. Almost all indices considered are decreasing with time. The analysis shows that the PRCPTOT, very heavy precipitation, and severe precipitation are generally declining insignificantly at 5 % significant level. The PRCPTOT is evidently decreasing over Arid and Semi-Arid Land (ASAL) as compared to other parts of EA. The number of days that recorded heavy rainfall is generally decreasing but starts to rise in the last decade although the changes are insignificant. Both PRCPTOT and heavy precipitation show a recovery in trend starting in the 1990s. The SDII shows a reduction in most areas, especially the in ASAL. The changes give a possible indication of the ongoing climate variability and change which modify the rainfall regime of EA. The results form a basis for further research, utilizing longer datasets over the entire region to reduce the generalizations made herein. Continuous monitoring of extreme events in EA is critical, given that rainfall is projected to increase in the twenty-first century.

T-FLAP improvement for VOS Program

NASA Astrophysics Data System (ADS)

Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Mainardi, Umberto; Manzella, Giuseppe M. R.

2010-05-01

The operational oceanography has been engaged in the development of new acquisition, transmission and assimilation systems in order to have the widest possible coverage of real time informations, reflecting the guidelines of the World Meteorological Organization (WMO) and of the Intergovernmental Oceanographic Commission (IOC). Physical and biological processes of marine ecosystems have a high spatial and temporal variability, whose study is possible only through high resolution and synoptic observations. More than for the physical variables, the biological ones have to be observed in situ. Especially in the mid-high latitudes, a deep observation of the water column is needed, because of the typical distribution of phytoplankton's biomass (Mann and Lazier, 1991). In the last times an extensive use of XBT was performed in order to provide near real time analysis of the ocean temperature, but there is still a lack in the biomass estimation. T-FLAP technology (Temperature and Fluorescence LAunchable Probe - Marcelli et al. 2007) was designed to answer to the claim of a cost effective temperature and fluorescence autonomous probe, to be used on ships of opportunity for the Voluntary Observing Ship Program (VOS). During the last three years the probe was upgraded and improved both in materials and in measure sensitivity. New LEDs were mounted to increase the radiant power of the excitation source.. In order to evaluate the red filter efficiency to detect fluorescence chlorophyll a emission wavelengths, transmittance of new available filters in the range 682-685 nm was calculated. In vivo fluorescence spectra of each filter were also performed on samples from Chlorella sp. cultures, to assess the percentage of the fluorescence emission peak transmitted by the filters. A multiple system was designed and realized for a high accuracy dynamic calibration of the probes.

New Radiosonde Temperature Bias Adjustments for Potential NWP Applications Based on GPS RO Data

NASA Astrophysics Data System (ADS)

Sun, B.; Reale, A.; Ballish, B.; Seidel, D. J.

2014-12-01

Conventional radiosonde observations (RAOBs), along with satellite and other in situ data, are assimilated in numerical weather prediction (NWP) models to generate a forecast. Radiosonde temperature observations, however, have solar and thermal radiation induced biases (typically a warm daytime bias from sunlight heating the sensor and a cold bias at night as the sensor emits longwave radiation). Radiation corrections made at stations based on algorithms provided by radiosonde manufacturers or national meteorological agencies may not be adequate, so biases remain. To adjust these biases, NWP centers may make additional adjustments to radiosonde data. However, the radiation correction (RADCOR) schemes used in the NOAA NCEP data assimilation and forecasting system is outdated and does not cover several widely-used contemporary radiosonde types. This study focuses on work whose objective is to improve these corrections and test their impacts on the NWP forecasting and analysis. GPS Radio Occultation (RO) dry temperature (Tdry) is considered to be highly accurate in the upper troposphere and low stratosphere where atmospheric water vapor is negligible. This study uses GPS RO Tdry from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) as the reference to quantify the radiation induced RAOB temperature errors by analyzing ~ 3-yr collocated RAOB and COSMIC GPS RO data compile by the NOAA Products Validation System (NPROVS). The new radiation adjustments are developed for different solar angle categories and for all common sonde types flown in the WMO global operational upper air network. Results for global and several commonly used sondes are presented in the context of NCEP Global Forecast System observation-minus-background analysis, indicating projected impacts in reducing forecast error. Dedicated NWP impact studies to quantify the impact of the new RADCOR schemes on the NCEP analyses and forecast are under consideration.

The Urgent Need for Improved Climate Models and Predictions

NASA Astrophysics Data System (ADS)

Goddard, Lisa; Baethgen, Walter; Kirtman, Ben; Meehl, Gerald

2009-09-01

An investment over the next 10 years of the order of US$2 billion for developing improved climate models was recommended in a report (http://wcrp.wmo.int/documents/WCRP_WorldModellingSummit_Jan2009.pdf) from the May 2008 World Modelling Summit for Climate Prediction, held in Reading, United Kingdom, and presented by the World Climate Research Programme. The report indicated that “climate models will, as in the past, play an important, and perhaps central, role in guiding the trillion dollar decisions that the peoples, governments and industries of the world will be making to cope with the consequences of changing climate.” If trillions of dollars are going to be invested in making decisions related to climate impacts, an investment of $2 billion, which is less than 0.1% of that amount, to provide better climate information seems prudent. One example of investment in adaptation is the World Bank's Climate Investment Fund, which has drawn contributions of more than $6 billion for work on clean technologies and adaptation efforts in nine pilot countries and two pilot regions. This is just the beginning of expenditures on adaptation efforts by the World Bank and other mechanisms, focusing on only a small fraction of the nations of the world and primarily aimed at anticipated anthropogenic climate change. Moreover, decisions are being made now, all around the world—by individuals, companies, and governments—that affect people and their livelihoods today, not just 50 or more years in the future. Climate risk management, whether related to projects of the scope of the World Bank's or to the planning and decisions of municipalities, will be best guided by meaningful climate information derived from observations of the past and model predictions of the future.

Ozonometer M-124 calibration for the Ukrainian network: method and results

NASA Astrophysics Data System (ADS)

Grytsai, A.; Milinevsky, G.; Evtushevsky, O.; Sosonkin, M.; Kravchenko, V.; Danylevsky, V.

2016-12-01

M-124 filter ozonometers are used for total ozone measuring in Ukraine since 1970s. Recently the need to calibrate several M-124 instruments of the Ukrainian filter ozonometer network is raised to continue ozone observations. The calibration became possible owing to the accurate ozone measurements by Dobson spectrophotometer started in 2010 at the Kyiv-Goloseyev WMO station located at the Main Astronomical Observatory of National Academy of Sciences of Ukraine. For calibration purposes the simultaneous M-124 and Dobson Direct Sun measurements were carried out during the 2013-2016 period by researchers from Taras Shevchenko National University of Kyiv and Main Astronomical Observatory. The M-124 instrument has two spectral channels: first is 305 nm and second is 325 nm. Outgoing signal from M-124 is determined by transparency of the terrestrial atmosphere and filter characteristics. Theoretical description of the solar radiation propagation through the atmosphere is determined by the Bouguer-Lambert-Beer law taking into account ozone absorption, Rayleigh and aerosol scattering. Parameters of the aerosol scattering have been determined from observations with the CIMEL sunphotometer of Aerosol Robotic Network which is also located at the Kyiv-Goloseyev station. The ozonometers optical characteristics were studied after M-124 refurbishment and modernization at the Central Geophysical Observatory of Ukraine that includes a significant part of the whole calibration work. Knowing the spectral dependence of each filter is necessary to calculate signal ratios in two channels. This information allowed solving the inverse problem of determining total ozone content in the terrestrial atmosphere. Comparison of these results with Dobson spectrophotometer data shows their good quality even without an additional correction. These results open a possibility to calibrate M-124 filter ozonometers for future ozone measurements at the observation sites of the Ukraine ozonometer network.

Long-term response of total ozone content at different latitudes of the Northern and Southern Hemispheres caused by solar activity during 1958-2006 (results of regression analysis)

NASA Astrophysics Data System (ADS)

Krivolutsky, Alexei A.; Nazarova, Margarita; Knyazeva, Galina

Solar activity influences on atmospheric photochemical system via its changebale electromag-netic flux with eleven-year period and also by energetic particles during solar proton event (SPE). Energetic particles penetrate mostly into polar regions and induce additional produc-tion of NOx and HOx chemical compounds, which can destroy ozone in photochemical catalytic cycles. Solar irradiance variations cause in-phase variability of ozone in accordance with photo-chemical theory. However, real ozone response caused by these two factors, which has different physical nature, is not so clear on long-term time scale. In order to understand the situation multiply linear regression statistical method was used. Three data series, which covered the period 1958-2006, have been used to realize such analysis: yearly averaged total ozone at dif-ferent latitudes (World Ozone Data Centre, Canada, WMO); yearly averaged proton fluxes with E¿ 10 MeV ( IMP, GOES, METEOR satellites); yearly averaged numbers of solar spots (Solar Data). Then, before the analysis, the data sets of ozone deviations from the mean values for whole period (1958-2006) at each latitudinal belt were prepared. The results of multiply regression analysis (two factors) revealed rather complicated time-dependent behavior of ozone response with clear negative peaks for the years of strong SPEs. The magnitudes of such peaks on annual mean basis are not greater than 10 DU. The unusual effect -positive response of ozone to solar proton activity near both poles-was discovered by statistical analysis. The pos-sible photochemical nature of found effect is discussed. This work was supported by Russian Science Foundation for Basic Research (grant 09-05-009949) and by the contract 1-6-08 under Russian Sub-Program "Research and Investigation of Antarctica".

Climate: Into the 21st Century

NASA Astrophysics Data System (ADS)

Burroughs, William

2003-08-01

Toward the end of the twentieth century, it became evident to professionals working within the meterological arena that the world's climate system was showing signs of change that could not be adequately explained in terms of natural variation. Since that time there has been an increasing recognition that the climate system is changing as a result of human industries and lifestyles, and that the outcomes may prove catastrophic to the world's escalating population. Compiled by an international team formed under the auspices of the World Meteorological Organization (WMO), Climate: Into the 21st Century features an unrivalled collection of essays by the world's leading meteorological experts. These fully integrated contributions provide a perspective of the global climate system across the twentieth century, and describe some of the most arresting and extreme climatic events and their effects that have occurred during that time. In addition, the book traces the development of our capabilities to observe and monitor the climate system, and outlines our understanding of the predictability of climate on time-scales of months and longer. It concludes with a summary of the prospects for applying the twentieth century climate experience in order to benefit society in the twenty-first century. Lavishly illustrated in color, Climate is an accessible acccount of the challenges that climate poses at the start of the twenty-first century. Filled with fascinating facts and diagrams, it is written for a wide audience and will captivate the general reader interested in climate issues, and will be a valuable teaching resource. William Burroughs is a successful science author of books on climate, including Weather (Time Life, 2000), and Climate Change: A Multidisciplinary Approach (2001), Does the Weather Really Matter? (1997) and The Climate Revealed (1999), all published by Cambridge University Press.

Measuring Snow Precipitation in New Zealand- Challenges and Opportunities.

NASA Astrophysics Data System (ADS)

Renwick, J. A.; Zammit, C.

2015-12-01

Monitoring plays a pivotal role in determining sustainable strategy for efficient overall management of the water resource. Though periodic monitoring provides some information, only long-term monitoring can provide data sufficient in quantity and quality to determine trends and develop predictive models. These can support informed decisions about sustainable and efficient use of water resources in New Zealand. However the development of such strategies is underpinned by our understanding and our ability to measure all inputs in headwaters catchments, where most of the precipitation is falling. Historically due to the harsh environment New Zealand has had little to no formal high elevation monitoring stations for all climate and snow related parameters outside of ski field climate and snow stations. This leads to sparse and incomplete archived datasets. Due to the importance of these catchments to the New Zealand economy (eg irrigation, hydro-electricity generation, tourism) NIWA has developed a climate-snow and ice monitoring network (SIN) since 2006. This network extends existing monitoring by electricity generator and ski stations and it is used by a number of stakeholders. In 2014 the network comprises 13 stations located at elevation above 700masl. As part of the WMO Solid Precipitation Intercomparison Experiment (SPICE), NIWA is carrying out an intercomparison of precipitation data over the period 2013-2015 at Mueller Hut. The site was commissioned on 11 July 2013, set up on the 17th September 2013 and comprises two Geonor weighing bucket raingauges, one shielded and the other un-shielded, in association with a conventional tipping bucket raingauge and conventional climate and snow measurements (temperature, wind, solar radiation, relative humidity, snow depth and snow pillow). The presentation aims to outline the state of the current monitoring network in New Zealand, as well as the challenge and opportunities for measurement of precipitation in alpine environment.

Prediction of skin cancer occurrence by ultraviolet solar index

PubMed Central

Rivas, Miguel; Rojas, Elisa; Calaf, Gloria M.

2012-01-01

An increase in the amount of solar ultraviolet light that reaches the Earth is considered to be responsible for the worldwide increase in skin cancer. It has been reported that exposure to excessive levels of solar ultraviolet light has multiple effects, which can be harmful to humans. Experimental ultraviolet light measurements were obtained in several locations in Chile between 2006 and 2009 using wide-band solar light Biometer YES, calibrated according to World Meteorological Organization (WMO) criteria and integrated into the National Meteorological Center of Chile ultraviolet network (DMC). The aim of this study was to determine skin cancer rates in relation to experimental data accumulated during one year of studying the solar ultraviolet index in Chile, in order to explain the possible effect of radiation on skin cancer. The rate of skin cancer per 100,000 persons was considered in Arica, Santiago, Concepción and Valdivia and extrapolated to other cities. Results of the present study showed that the incidence of skin cancer was markedly correlated with accumulative ultraviolet radiation, and rates of skin cancer could be extrapolated to other locations in Chile. There is a steady increase in the rate of skin cancer in cities located nearest to the equator (low latitude) that receive greater accumulated solar ultraviolet radiation, due to the accumulative effects of this type of radiation on the skin. It can be concluded that Arica is a city at sea level that receives higher levels of ultraviolet solar radiation than other locations, which may explain the higher prevalence of skin cancer in the population of this location, compared with other cities in Chile. PMID:22741013

Validation and Inter-comparison Against Observations of GODAE Ocean View Ocean Prediction Systems

NASA Astrophysics Data System (ADS)

Xu, J.; Davidson, F. J. M.; Smith, G. C.; Lu, Y.; Hernandez, F.; Regnier, C.; Drevillon, M.; Ryan, A.; Martin, M.; Spindler, T. D.; Brassington, G. B.; Oke, P. R.

2016-02-01

For weather forecasts, validation of forecast performance is done at the end user level as well as by the meteorological forecast centers. In the development of Ocean Prediction Capacity, the same level of care for ocean forecast performance and validation is needed. Herein we present results from a validation against observations of 6 Global Ocean Forecast Systems under the GODAE OceanView International Collaboration Network. These systems include the Global Ocean Ice Forecast System (GIOPS) developed by the Government of Canada, two systems PSY3 and PSY4 from the French Mercator-Ocean Ocean Forecasting Group, the FOAM system from UK met office, HYCOM-RTOFS from NOAA/NCEP/NWA of USA, and the Australian Bluelink-OceanMAPS system from the CSIRO, the Australian Meteorological Bureau and the Australian Navy.The observation data used in the comparison are sea surface temperature, sub-surface temperature, sub-surface salinity, sea level anomaly, and sea ice total concentration data. Results of the inter-comparison demonstrate forecast performance limits, strengths and weaknesses of each of the six systems. This work establishes validation protocols and routines by which all new prediction systems developed under the CONCEPTS Collaborative Network will be benchmarked prior to approval for operations. This includes anticipated delivery of CONCEPTS regional prediction systems over the next two years including a pan Canadian 1/12th degree resolution ice ocean prediction system and limited area 1/36th degree resolution prediction systems. The validation approach of comparing forecasts to observations at the time and location of the observation is called Class 4 metrics. It has been adopted by major international ocean prediction centers, and will be recommended to JCOMM-WMO as routine validation approach for operational oceanography worldwide.

On the Dome Effect of Flux Radiometers to Radiative Forcing

NASA Technical Reports Server (NTRS)

Tsay, S.-C.; Ji, Q.

1999-01-01

Since the introduction of thermopile, pyranometers (solar, e.g., 0.3-3.0 microns) and pyrgeometers (terrestrial, e.g., 4-50 microns) have become instruments commonly used for measuring the broadband hemispherical irradiances at the surface in a long-term, monitoring mode for decades. These commercially available radiometers have been manufactured in several countries such as from the United States, Asia, and Europe, and are generally reliable and economical. These worldwide distributions of surface measurements become even more important in the era of Earth remote sensing in studying climate forcing. However, recent studies from field campaigns have pointed out that erroneous factors (e.g., temperature gradients between the filter dome and detector, emissivity of the thermopile) are responsible for the unacceptable level of uncertainty (e.g., 10-20 W/square Meter). Using a newly developed instrument of Quantum Well Infrared Photodetector (QWIP), we have characterized the brightness temperature fields of pyranometers and pyrgeometers under various sky conditions. The QWIP is based on the superlattice (GaAs/AlGaAs) technology and has a noise equivalent temperature (NE delta T) less than 0.1 K. The quality of pyranometer and pyrgeometer measurements can be improved largely by applying proper knowledge of the thermal parameters affecting the operation of the thermopile systems. For example, we show a method to determine the "dome factor" (the longwave emission divided by the longwave transmission of a pyrgeometer dome) from field measurements. The results show, and are verified independently by the QWIP, that our dome factors of 0.59 and 0.90 are much smaller than the value of 4.0 assumed by the WMO. Data correction procedure and algorithm will be presented and discussed.

On the Dome Effect of Flux Radiometers to Radiative Forcing

NASA Technical Reports Server (NTRS)

Tsay, S.-C.; Ji, Q.

1999-01-01

Since the introduction of thermopile, pyranometers (solar, e.g., 0.3-3.0 micrometers) and pyrgeometers (terrestrial, e.g., 4-50 micrometers) have become instruments commonly used for measuring the broadband hemispherical irradiances at the surface in a long-term, monitoring mode for decades. These commercially available radiometers have been manufactured in several countries such as from the United States, Asia, and Europe, and are generally reliable and economical. These worldwide distributions of surface measurements become even more important in the era of Earth remote sensing in studying climate forcing. However, recent studies from field campaigns have pointed out that erroneous factors (e.g., temperature gradients between the filter dome and detector, emissivity of the thermopile) are responsible for the unacceptable level of uncertainty (e.g., 10-20 W m (exp -2)). Using a newly developed instrument of Quantum Well Infrared Photodetector (QWIP), we have characterized the brightness temperature fields of pyranometers and pyrgeometers under various sky conditions. The QWIP is based on the superlattice (GaAs/AlGaAs) technology and has a noise equivalent temperature (NE delta T) less than 0.1 K. The quality of pyranometer and pyrgeometer measurements can be improved largely by applying proper knowledge of the thermal parameters affecting the operation of the thermopile systems. For example, we show a method to determine the "dome factor" (the longwave emission divided by the longwave transmission of a pyrgeometer dome) from field measurements. The results show, and are verified independently by the QWIP, that our dome factors of 0.59 and 0.90 are much smaller than the value of 4.0 assumed by the WMO (World Meteorological Organization). Data correction procedure and algorithm will be presented and discussed.

Synoptic-scale dust transport events in the southern Himalaya

NASA Astrophysics Data System (ADS)

Duchi, R.; Cristofanelli, P.; Marinoni, A.; Bourcier, L.; Laj, P.; Calzolari, F.; Adhikary, B.; Verza, G. P.; Vuillermoz, E.; Bonasoni, P.

2014-06-01

The variability of long-range dust transport events observed in the southern Himalaya and its relation with source areas have been studied thanks to five years’ continuous measurements which were carried out at the “Nepal Climate Observatory-Pyramid” (NCO-P, 27°57‧N, 86°48‧E), the highest Northern Hemisphere GAW-WMO global station sited at 5079 m a.s.l. in the high Khumbu valley (Nepal) on the southern Himalaya. During the period March 2006-February 2011, the analyses of the aerosol particle concentrations and LAGRANTO three-dimensional backward trajectories indicated the occurrence of 275 days affected by synoptic-scale dust transport, which account for 22.2% of the investigated period. The frequency of dust transport days (DTDs) showed a clear seasonal cycle, with the highest seasonal value observed during pre-monsoon season (33.5% of the pre-monsoon’s days are DTDs). Large enhancements in coarse aerosol number concentration N1-10 (average: +689%) and mass PM1-10 (average: +1086%) were observed during the dust transport events as compared to the days without dust (dust-free days, DFDs). In addition, the single scattering albedo (SSA) also showed higher values, ranging from 0.87 to 0.90, during DTDs with respect to DFDs (0.80-0.87). The predominant source of mineral dust reaching the measurement site was identified in the arid regions of the north-western Indian subcontinent (Thar desert), which accounted for 41.6% of the trajectories points associated with DTDs. Seasonal analysis also indicated that the winter season was significantly influenced by far western desert regions, such as North Africa and the Arabic Peninsula.

Aerosol profiling using the ceilometer network of the German Meteorological Service

NASA Astrophysics Data System (ADS)

Flentje, H.; Heese, B.; Reichardt, J.; Thomas, W.

2010-08-01

The German Meteorological Service (DWD) operates about 52 lidar ceilometers within its synoptic observations network, covering Germany. These affordable low-power lidar systems provide spatially and temporally high resolved aerosol backscatter profiles which can operationally provide quasi 3-D distributions of particle backscatter intensity. Intentionally designed for cloud height detection, recent significant improvements allow following the development of the boundary layer and to detect denser particle plumes in the free tropospere like volcanic ash, Saharan dust or fire smoke. Thus the network builds a powerful aerosol plume alerting and tracking system. If auxiliary aerosol information is available, the particle backscatter coefficient, the extinction coefficient and even particle mass concentrations may be estimated, with however large uncertainties. Therefore, large synergistic benefit is achieved if the ceilometers are linked to existing lidar networks like EARLINET or integrated into WMO's envisioined Global Aerosol Lidar Observation Network GALION. To this end, we demonstrate the potential and limitations of ceilometer networks by means of three representative aerosol episodes over Europe, namely Sahara dust, Mediterranean fire smoke and, more detailed, the Icelandic Eyjafjoll volcano eruption from mid April 2010 onwards. The DWD (Jenoptik CHM15k) lidar ceilometer network tracked the Eyjafjoll ash layers over Germany and roughly estimated peak extinction coefficients and mass concentrations on 17 April of 4-6(± 2) 10-4 m-1 and 500-750(± 300) μg/m-3, respectively, based on co-located aerosol optical depth, nephelometer (scattering coefficient) and particle mass concentration measurements. Though large, the uncertainties are small enough to let the network suit for example as aviation advisory tool, indicating whether the legal flight ban threshold of presently 2 mg/m3 is imminent to be exceeded.

Evaluation of the airborne quantum cascade laser spectrometer (QCLS) measurements of the carbon and greenhouse gas suite - CO2, CH4, N2O, and CO - during the CalNex and HIPPO campaigns

NASA Astrophysics Data System (ADS)

Santoni, G. W.; Daube, B. C.; Kort, E. A.; Jiménez, R.; Park, S.; Pittman, J. V.; Gottlieb, E.; Xiang, B.; Zahniser, M. S.; Nelson, D. D.; McManus, J. B.; Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Andrews, A. E.; Sweeney, C.; Hall, B.; Hintsa, E. J.; Moore, F. L.; Elkins, J. W.; Hurst, D. F.; Stephens, B. B.; Bent, J.; Wofsy, S. C.

2014-06-01

We present an evaluation of aircraft observations of the carbon and greenhouse gases CO2, CH4, N2O, and CO using a direct-absorption pulsed quantum cascade laser spectrometer (QCLS) operated during the HIPPO and CalNex airborne experiments. The QCLS made continuous 1 Hz measurements with 1σ Allan precisions of 20, 0.5, 0.09, and 0.15 ppb for CO2, CH4, N2O, and CO, respectively, over > 500 flight hours on 79 research flights. The QCLS measurements are compared to two vacuum ultraviolet (VUV) CO instruments (CalNex and HIPPO), a cavity ring-down spectrometer (CRDS) measuring CO2 and CH4 (CalNex), two broadband non-dispersive infrared (NDIR) spectrometers measuring CO2 (HIPPO), two onboard gas chromatographs measuring a variety of chemical species including CH4, N2O, and CO (HIPPO), and various flask-based measurements of all four species. QCLS measurements are tied to NOAA and WMO standards using an in-flight calibration system, and mean differences when compared to NOAA CCG flask data over the 59 HIPPO research flights were 100, 1, 1, and 2 ppb for CO2, CH4, N2O, and CO, respectively. The details of the end-to-end calibration procedures and the data quality assurance and quality control (QA/QC) are presented. Specifically, we discuss our practices for the traceability of standards given uncertainties in calibration cylinders, isotopic and surface effects for the long-lived greenhouse gas tracers, interpolation techniques for in-flight calibrations, and the effects of instrument linearity on retrieved mole fractions.

Atmospheric Transport Modelling and Radionuclide Analysis for the NPE 2015 scenario

NASA Astrophysics Data System (ADS)

Ross, J. Ole; Bollhöfer, Andreas; Heidmann, Verena; Krais, Roman; Schlosser, Clemens; Gestermann, Nicolai; Ceranna, Lars

2017-04-01

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) prohibits all kinds of nuclear explosions. The International Monitoring System (IMS) is in place and at about 90% complete to verify compliance with the CTBT. The stations of the waveform technologies are capable to detect seismic, hydro-acoustic and infrasonic signals for detection, localization, and characterization of explosions. For practicing Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification procedures and interplay between the International Data Centre (IDC) and National Data Centres (NDC), prepardness exercises (NPE) are regularly performed with selected events of fictitious CTBT-violation. The German NDC's expertise for radionuclide analyses and operation of station RN33 is provided by the Federal Office for Radiation Protection (BfS) while Atmospheric Transport Modelling (ATM) for CTBT purposes is performed at the Federal Institute for Geosciences and Natural Resources (BGR) for the combination of the radionuclide findings with waveform evidence. The radionuclide part of the NPE 2015 scenario is tackled in a joint effort by BfS and BGR. First, the NPE 2015 spectra are analysed, fission products are identified, and respective activity concentrations are derived. Special focus is on isotopic ratios which allow for source characterization and event timing. For atmospheric backtracking the binary coincidence method is applied for both, SRS fields from IDC and WMO-RSMC, and for in-house backward simulations in higher resolution for the first affected samples. Results are compared with the WebGrape PSR and the spatio-temporal domain with high atmospheric release probability is determined. The ATM results together with the radionuclide fingerprint are used for identification of waveform candidate events. Comparative forward simulations of atmospheric dispersion for candidate events are performed. Finally the overall consistency of various source scenarios is assessed and a fictitious government briefing on the findings is given.

RECENT DEVELOPMENTS IN HYDROWEB DATABASE Water level time series on lakes and reservoirs (Invited)

NASA Astrophysics Data System (ADS)

Cretaux, J.; Arsen, A.; Calmant, S.

2013-12-01

We present the current state of the Hydroweb database as well as developments in progress. It provides offline water level time series on rivers, reservoirs and lakes based on altimetry data from several satellites (Topex/Poseidon, ERS, Jason-1&2, GFO and ENVISAT). The major developments in Hydroweb concerns the development of an operational data centre with automatic acquisition and processing of IGDR data for updating time series in near real time (both for lakes & rivers) and also use of additional remote sensing data, like satellite imagery allowing the calculation of lake's surfaces. A lake data centre is under development at the Legos in coordination with Hydrolare Project leaded by SHI (State Hydrological Institute of the Russian Academy of Science). It will provide the level-surface-volume variations of about 230 lakes and reservoirs, calculated through combination of various satellite images (Modis, Asar, Landsat, Cbers) and radar altimetry (Topex / Poseidon, Jason-1 & 2, GFO, Envisat, ERS2, AltiKa). The final objective is to propose a data centre fully based on remote sensing technique and controlled by in situ infrastructure for the Global Terrestrial Network for Lakes (GTN-L) under the supervision of WMO and GCOS. In a longer perspective, the Hydroweb database will integrate data from future missions (Jason-3, Jason-CS, Sentinel-3A/B) and finally will serve for the design of the SWOT mission. The products of hydroweb will be used as input data for simulation of the SWOT products (water height and surface variations of lakes and rivers). In the future, the SWOT mission will allow to monitor on a sub-monthly basis the worldwide lakes and reservoirs bigger than 250 * 250 m and Hydroweb will host water level and extent products from this

Metrology and ionospheric observation standards

NASA Astrophysics Data System (ADS)

Panshin, Evgeniy; Minligareev, Vladimir; Pronin, Anton

Accuracy and ionospheric observation validity are urgent trends nowadays. WMO, URSI and national metrological and standardisation services bring forward requirements and descriptions of the ionospheric observation means. Researches in the sphere of metrological and standardisation observation moved to the next level in the Russian Federation. Fedorov Institute of Applied Geophysics (IAG) is in charge of ionospheric observation in the Russian Federation and the National Technical Committee, TC-101 , which was set up on the base of IAG- of the standardisation in the sphere. TC-101 can be the platform for initiation of the core international committee in the network of ISO The new type of the ionosounde “Parus-A” is engineered, which is up to the national requirements. “Parus-A” calibration and test were conducted by National metrological Institute (NMI) -D.I. Mendeleyev Institute for Metrology (VNIIM), signed CIMP MRA in 1991. VNIIM is a basic NMI in the sphere of Space weather (including ionospheric observations), the founder of which was celebrated chemist and metrologist Dmitriy I. Mendeleyev. Tests and calibration were carried out for the 1st time throughout 50-year-history of ionosonde exploitation in Russia. The following metrological characteristics were tested: -measurement range of radiofrequency time delay 0.5-10 ms; -time measurement inaccuracy of radio- frequency pulse ±12mcs; -frequency range of radio impulse 1-20 MHz ; -measurement inaccuracy of radio impulse carrier frequency± 5KHz. For example, the sound impulse simulator that was built-in in the ionosounde was used for measurement range of radiofrequency time delay testing. The number of standards on different levels is developed. - “Ionospheric observation guidance”; - “The Earth ionosphere. Terms and definitions”.

The Joint Aerosol-Monsoon Experiment: A New Challenge to Monsoon Climate Research

NASA Technical Reports Server (NTRS)

Lau, William K. M.

2008-01-01

Aerosol and monsoon related droughts and floods are two of the most serious environmental hazards confronting more than 60% of the population of the world living in the Asian monsoon countries. In recent years, thanks to improved satellite and in-situ observations, and better models, great strides have been made in aerosol, and monsoon research respectively. There is now a growing body of evidence suggesting that interaction of aerosol forcing with water cycle dynamics in monsoon regions may substantially alter the redistribution of energy at the earth surface and in the atmosphere, and therefore significantly impact monsoon rainfall variability and long term trends. In this talk, I will describe issues related to societal needs, scientific background, and challenges in studies of aerosol-water cycle interaction in Asian monsoon regions. As a first step towards addressing these issues, the authors call for an integrated observation and modeling research approach aimed at the interactions between aerosol chemistry and radiative effects and monsoon dynamics of the coupled ocean-atmosphere-land system. A Joint Aerosol-Monsoon Experiment (JAMEX) is proposed for 2007-2011, with an enhanced observation period during 2008-09, encompassing diverse arrays of observations from surface, aircraft, unmanned aerial vehicles, and satellites of physical and chemical properties of aerosols, long range aerosol transport as well as meteorological and oceanographic parameters in the Indo-Pacific Asian monsoon region. JAMEX will leverage on coordination among many ongoing and planned national programs on aerosols and monsoon research in China, India, Japan, Nepal, Italy, US, as well as international research programs of the World Climate Research Program (WCRP) and the World Meteorological Organization (WMO).

Transport and Chemical Production of Ozone in the East Asian Pacific Rim Region: -Modeling Study Based on Observation-

NASA Astrophysics Data System (ADS)

Akimoto, H.; Li, J.; Wang, Z.; Yamaji, K.; Pochanart, P.; Ohara, T.; Uno, I.; Gao, C.; Wang, X.; Tanimoto, H.; Kurokawa, J.

2007-12-01

Form satellite observational data, east-central China covering the North China Plain (NCP) and Yanzi Delta (YZD) has been identified as the most widely spread source area of air pollutants in the East Asian Pacific region. In order to quantify transport and chemical production of ozone in this region, both of observational and modeling studies in both of source and outflow region are necessary. In the present study, we investigated the budgets of ozone over East Asia by using regional chemical transport models (NAQPMS and CMAQ) based on observations at newly founded three mountain sites (Mt. Tai, Hua and Huang) in east-central China, and several sites from EANET and regional WMO/GAW. The observations show that a striking pattern of two sharp high ozone peaks in May-June and September-October at the three mountain sites. The budget analysis by the model confirms that maximum of net photochemical ozone production reaches 31.8, 15.1 and 11.4 ppb/day at Mt. Tai, Hua and Huang, respectively. The net chemical production dominates the formation of ozone maximum at Mt. Tai and Hua in June, and the importing transport also plays a comparable importance at Mt. Huang. In the outflow region at Oki, Japan, transport of ozone produced by East Asian emissions accounts up to 21 ppb in summer but less than 3 ppb in winter agreeing with the model analysis. The contribution of ozone due to East Asian emission is the largest (53.6%) in July-August, and somewhat smaller in May-June (34.0%) and September-October (30.7%) on the transect between Japan and the Asian continent.

Four years (2011-2015) of total gaseous mercury measurements from the Cape Verde Atmospheric Observatory

NASA Astrophysics Data System (ADS)

Read, Katie A.; Neves, Luis M.; Carpenter, Lucy J.; Lewis, Alastair C.; Fleming, Zoe L.; Kentisbeer, John

2017-04-01

Mercury is a chemical with widespread anthropogenic emissions that is known to be highly toxic to humans, ecosystems and wildlife. Global anthropogenic emissions are around 20 % higher than natural emissions and the amount of mercury released into the atmosphere has increased since the industrial revolution. In 2005 the European Union and the United States adopted measures to reduce mercury use, in part to offset the impacts of increasing emissions in industrialising countries. The changing regional emissions of mercury have impacts on a range of spatial scales. Here we report 4 years (December 2011-December 2015) of total gaseous mercury (TGM) measurements at the Cape Verde Observatory (CVO), a global WMO-GAW station located in the subtropical remote marine boundary layer. Observed total gaseous mercury concentrations were between 1.03 and 1.33 ng m-3 (10th, 90th percentiles), close to expectations based on previous interhemispheric gradient measurements. We observe a decreasing trend in TGM (-0.05 ± 0.04 ng m-3 yr-1, -4.2 % ± 3.3 % yr-1) over the 4 years consistent with the reported decrease of mercury concentrations in North Atlantic surface waters and reductions in anthropogenic emissions. The decrease was more visible in the summer (July-September) than in the winter (December-February), when measurements were impacted by air from the African continent and Sahara/Sahel regions. African air masses were also associated with the highest and most variable TGM concentrations. We suggest that the less pronounced downward trend inclination in African air may be attributed to poorly controlled anthropogenic sources such as artisanal and small-scale gold mining (ASGM) in West Africa.

Sand/dust storm processes in Northeast Asia and associated large-scale circulations

NASA Astrophysics Data System (ADS)

Yang, Y. Q.; Hou, Q.; Zhou, C. H.; Liu, H. L.; Wang, Y. Q.; Niu, T.

2008-01-01

This paper introduces a definition of sand/dust storm process as a new standard and idea of sand/dust storm (SDS) groups a number of SDS-events in Northeast Asia. Based on the meteorological data from WMO/GOS network, 2456 Chinese surface stations and NCEP-NCAR reanalysis, the sand/dust storm processes in Northeast Asia in spring 2000-2006 are investigated. And the evolutions of anomalies of general circulation in the troposphere are analyzed by comparing the spring having most and least occurrences of SDS in year 2006 and 2003. Associated with the noticeably increased occurrence of SDS processes in spring 2006, the anomalies in 3-D structure of general circulation especially in the mid-and high latitudes of the Northen Hemisphere (NH) are revealed. The transition period from the winter of 2005 to spring 2006 has witnessed a fast-developed high center over the circumpolar vortex area in the upper troposphere, which pushes the polar vortex more southwards to mid-latitudes with a more extensive area over the east NH. In spring 2006, there are the significant circulation anomalies in the middle troposphere from the Baikal Lake to northern China with a stronger southward wind anomaly over Northeast Asia. Compared with a normal year, stronger meridional wind with a southward wind anomaly also in the lower troposphere prevail over the arid and semiarid regions in Mongolia and northern China during spring 2006. The positive anomalies of surface high pressure registered an abnormal high of 4-10 hPa in the Tamil Peninsular make a stronger cold air source for the repeated cold air outbreak across the desert areas in spring 2006 resulting in the most frequent SDS seasons in the last 10 years in Northeast Asia.

The World Meteorological Organization Focus on Urban Issues

NASA Astrophysics Data System (ADS)

Terblanche, D. E.

2015-12-01

Many of the milestones of human development can be traced back to people assembled in urban settings where economies of scale, competition and social interaction stimulated innovation. Considering that more than half the global pollution now lives in cities and towns and that most of the growth in the global pollution in the remainder of this century will continue to take place in the urban environment, the question could be asked whether humankind will continue to capitalize on the traditional benefits of city life to find solutions for growing environmental challenges? In the past cities developed organically. They evolved through trial and error into livable environments. Things have now changed. The global population is larger, urbanization is rapid, pressure on Earth's limited resources is constraining and we are faced with a changing climate. If cities are now allowed to develop in a haphazard manner, the fight for survival in the city will overshadow its entrepreneurial spirit. It is for this reason that the 11th Sustainable Development Goal will focus on: 'Making cities and human settlements inclusive, safe, resilient and sustainable'. There is now a window of opportunity for weather, climate, water and environmental scientists to contribute towards a more sustainable urban future by ensuring that science based services form an integrated part of urban planning, development and management. WMO recognizes that rapid urbanization will require new types of new and enhanced services. Such integrated urban weather, environment and climate services will assist cities to deal better with hazards such as storm surge, flooding, heat waves, and air pollution episodes, especially in a changing climate. From a research perspective the World Climate Research Programme, the World Weather Research Programme and the Global Atmosphere Watch Programme all have a unique contribution to make in this regard.

Progress in Developing an Integrated Global Greenhouse Gas Information System (IG3IS)

NASA Astrophysics Data System (ADS)

Decola, P.; Butler, J. H.

2015-12-01

Recent studies suggest that, if society can do no better than the commitments it's already made to reducing greenhouse gases, we will achieve a 2C threshold by 2030 and a 3C threshold by 2050 [e.g., Jackson et al., 2015]. Given that a global average of 2C or 3C translates to about three times that (6C, 9C) over continents, this portends a future of on-going climate change for generations to come, with all of its concomitant struggles in adapting. It also portends a global society looking increasingly at ways to mitigate the cause(s) of climate change. Recent events have propelled that to some extent already, but it is likely we will see more as time goes on. Nevertheless, there is a huge difference between making commitments and achieving them. Nations, states, cities, resource managers, energy interests, and other invested parties will be looking at ways to reduce emissions, driven either by markets, taxes, or other relevant policies. Anticipating this need, WMO has begun developing an implementation plan for an Integrated Global Greenhouse Gas Information System (IG3IS). To work effectively, an IG3IS must integrate high quality observations from multiple and varied platforms, incorporate observation-based information from transport models, and deliver useful information at sub-continental, policy-relevant scales. Existing surface-based networks, emerging networks in developing countries, and new aircraft-based measurements and satellite observations make a difference, but additional observations and improved transport modeling are critical. This presentation will look at what is available, what the gaps are, and how IG3IS intends to address them.

The Darwin TCCON Site - CO2 Calibration and First Data

NASA Astrophysics Data System (ADS)

Deutscher, N. M.; Griffith, D. W.; Keppel-Aleks, G.; Washenfelder, R. A.; Wennberg, P. O.; Toon, G. C.

2007-12-01

This paper presents the first measurements from the solar observatory deployed to Darwin, Australia in August 2005. The observatory is the second dedicated instrument in the Total Carbon Column Observing Network (TCCON). The first two years of column values are presented, as well as comparison to integrated in situ aircraft profiles obtained during the Tropical Warm Pool - International Cloud Experiment (TWP-ICE) in January - February 2006. Sites in TCCON will provide ground-based validation and calibration for upcoming space-based instruments, such as the Orbiting Carbon Observatory (OCO) and Greenhouse Gases Observing Satellite (GOSAT), which measure the same atmospheric quantities. The TCCON stations are calibrated against integrated columns measured from aircraft by instruments calibrated on the accepted WMO CO2 scale. Two CO2 microwindows are calibrated independently, and the correction factors are determined to be 1.0143 ± 0.0004 (fit ± 95% confidence interval) and 1.0152 ± 0.0003, respectively, for the 6228 cm-1 and 6348 cm-1 bands. These values are in good agreement with similar comparisons made at Park Falls, and show an improvement in the absolute calibration, due to improved CO2 line parameters. The first two years of CO2 data from the solar FTS are analysed for secular and seasonal trends in the column average mixing ratio. These are compared to some surface in situ data trends for the same period. The column data capture the secular trend as observed in surface in situ measurements, however, the seasonal cycle is dampened relative to the surface data illustrating the need for high precision measurements, but also the potential to remove rectifier effects.

The Urban melting pot: A recipe for sustainable living?

NASA Astrophysics Data System (ADS)

Terblanche, Deon

2015-04-01

Many of the milestones of human development can be traced back to people assembled in groups where economies of scale, competition and social interaction stimulated innovation. Considering that more than half the global pollution now lives in cities and towns and that most of the growth in the global pollution in the remainder of this century will continue to take place in the urban environment, the question could be asked whether humankind will continue to capitalize on the traditional benefits of city life to find solutions for growing environmental challenges? By ensuring that cities are planned and operated to make best use of the prevailing climate, resources and in a manner in which its inhabitants are safe from extreme weather and environmental events there is a good chance that cities will continue to contribute to solutions. However, if cities are allowed to developed in a haphazard manner with poorly managed infrastructure which expose citizens to the dangers of a changing climate and environmental degradation, the fight for survival will overshadow the entrepreneurial spirit. There is now a window of opportunity for weather, climate, water and environmental scientists to contribute towards a more sustainable urban future by ensuring that services based on these sciences from an integrated part of urban development and management. WMO recognizes that the rapid urbanization will require new types of services making best use of science and technology and considers this problem as one of the main priorities. Such Integrated Urban Weather, Environment and Climate Services should assist cities in facing hazards such as storm surge, flooding, heat waves, and air pollution episodes, especially in changing climates. The talk will highlight some of the opportunities that exist in this regard.

Oxygen isotope fractionation between bird bone phosphate and drinking water

NASA Astrophysics Data System (ADS)

Amiot, Romain; Angst, Delphine; Legendre, Serge; Buffetaut, Eric; Fourel, François; Adolfssen, Jan; André, Aurore; Bojar, Ana Voica; Canoville, Aurore; Barral, Abel; Goedert, Jean; Halas, Stanislaw; Kusuhashi, Nao; Pestchevitskaya, Ekaterina; Rey, Kevin; Royer, Aurélien; Saraiva, Antônio Álamo Feitosa; Savary-Sismondini, Bérengère; Siméon, Jean-Luc; Touzeau, Alexandra; Zhou, Zhonghe; Lécuyer, Christophe

2017-06-01

Oxygen isotope compositions of bone phosphate (δ18Op) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δ18Op values (from 9.8 to 22.5‰ V-SMOW) and the local rainfall δ18Ow values estimated from nearby IAEA/WMO stations (from -16.0 to -1.0‰ V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: δ18Ow = 1.119 (±0.040) δ18Op - 24.222 (±0.644); R 2 = 0.98. The δ18Op-δ18Ow couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher δ18Ow value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.

Intercomparison of Open-Path Trace Gas Measurements with Two Dual Frequency Comb Spectrometers

PubMed Central

Waxman, Eleanor M.; Cossel, Kevin C.; Truong, Gar-Wing; Giorgetta, Fabrizio R.; Swann, William C.; Coburn, Sean; Wright, Robert J.; Rieker, Gregory B.; Coddington, Ian; Newbury, Nathan R.

2017-01-01

We present the first quantitative intercomparison between two open-path dual comb spectroscopy (DCS) instruments which were operated across adjacent 2-km open-air paths over a two-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6021 to 6388 cm−1 (1565 to 1661 nm), corresponding to a 367 cm−1 bandwidth, at 0.0067 cm−1 sample spacing. The measured absorption spectra agree with each other to within 5×10−4 without any external calibration of either instrument. The absorption spectra are fit to retrieve concentrations for carbon dioxide (CO2), methane (CH4), water (H2O), and deuterated water (HDO). The retrieved dry mole fractions agree to 0.14% (0.57 ppm) for CO2, 0.35% (7 ppb) for CH4, and 0.40% (36 ppm) for H2O over the two-week measurement campaign, which included 23 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a WMO-calibrated cavity ringdown point sensor located along the path with good agreement. Short-term and long-term differences between the two systems are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the two-week measurement campaign yields diurnal cycles of CO2 and CH4 that are consistent with the presence of local sources of CO2 and absence of local sources of CH4. PMID:29276547

Advancing Solar Irradiance Measurement for Climate-Related Studies: Accurate Constraint on Direct Aerosol Radiative Effect (DARE)

NASA Technical Reports Server (NTRS)

Tsay, Si-Chee; Ji, Q. Jack

2011-01-01

Earth's climate is driven primarily by solar radiation. As summarized in various IPCC reports, the global average of radiative forcing for different agents and mechanisms, such as aerosols or CO2 doubling, is in the range of a few W/sq m. However, when solar irradiance is measured by broadband radiometers, such as the fleet of Eppley Precision Solar Pyranometers (PSP) and equivalent instrumentation employed worldwide, the measurement uncertainty is larger than 2% (e.g., WMO specification of pyranometer, 2008). Thus, out of the approx. 184 W/sq m (approx.263 W/sq m if cloud-free) surface solar insolation (Trenberth et al. 2009), the measurement uncertainty is greater than +/-3.6 W/sq m, overwhelming the climate change signals. To discern these signals, less than a 1 % measurement uncertainty is required and is currently achievable only by means of a newly developed methodology employing a modified PSP-like pyranometer and an updated calibration equation to account for its thermal effects (li and Tsay, 2010). In this talk, we will show that some auxiliary measurements, such as those from a collocated pyrgeometer or air temperature sensors, can help correct historical datasets. Additionally, we will also demonstrate that a pyrheliometer is not free of the thermal effect; therefore, comparing to a high cost yet still not thermal-effect-free "direct + diffuse" approach in measuring surface solar irradiance, our new method is more economical, and more likely to be suitable for correcting a wide variety of historical datasets. Modeling simulations will be presented that a corrected solar irradiance measurement has a significant impact on aerosol forcing, and thus plays an important role in climate studies.

Comparing the cloud vertical structure derived from several methods based on radiosonde profiles and ground-based remote sensing measurements

NASA Astrophysics Data System (ADS)

Costa-Surós, M.; Calbó, J.; González, J. A.; Long, C. N.

2014-08-01

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, are important characteristics in order to describe the impact of clouds on climate. In this work, several methods for estimating the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering the number and position of cloud layers, with a ground-based system that is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ in the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study, these methods are applied to 193 radiosonde profiles acquired at the Atmospheric Radiation Measurement (ARM) Southern Great Plains site during all seasons of the year 2009 and endorsed by Geostationary Operational Environmental Satellite (GOES) images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The perfect agreement (i.e., when the whole CVS is estimated correctly) for the methods ranges between 26 and 64%; the methods show additional approximate agreement (i.e., when at least one cloud layer is assessed correctly) from 15 to 41%. Further tests and improvements are applied to one of these methods. In addition, we attempt to make this method suitable for low-resolution vertical profiles, like those from the outputs of reanalysis methods or from the World Meteorological Organization's (WMO) Global Telecommunication System. The perfect agreement, even when using low-resolution profiles, can be improved by up to 67% (plus 25% of the approximate agreement) if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

Comparing the cloud vertical structure derived from several methods based on measured atmospheric profiles and active surface measurements

NASA Astrophysics Data System (ADS)

Costa-Surós, M.; Calbó, J.; González, J. A.; Long, C. N.

2014-04-01

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, is an important characteristic in order to describe the impact of clouds on climate. In this work several methods to estimate the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering number and position of cloud layers, with a ground based system which is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ on the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study these methods are applied to 193 radiosonde profiles acquired at the ARM Southern Great Plains site during all seasons of year 2009 and endorsed by GOES images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The perfect agreement (i.e. when the whole CVS is correctly estimated) for the methods ranges between 26-64%; the methods show additional approximate agreement (i.e. when at least one cloud layer is correctly assessed) from 15-41%. Further tests and improvements are applied on one of these methods. In addition, we attempt to make this method suitable for low resolution vertical profiles, like those from the outputs of reanalysis methods or from the WMO's Global Telecommunication System. The perfect agreement, even when using low resolution profiles, can be improved up to 67% (plus 25% of approximate agreement) if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

English/Russian terminology on radiometric calibration of space-borne optoelectronic sensors

NASA Astrophysics Data System (ADS)

Privalsky, V.; Zakharenkov, V.; Humpherys, T.; Sapritsky, V.; Datla, R.

The efficient use of data acquired through exo-atmospheric observations of the Earth within the framework of existing and newly planned programs requires a unique understanding of respective terms and definitions. Yet, the last large-scale document on the subject - The International Electrotechnical Vocabulary - had been published 18 years ago. This lack of a proper document, which would reflect the changes that had occurred in the area since that time, is especially detrimental to the developing international efforts aimed at global observations of the Earth from space such as the Global Earth Observations Program proposed by the U.S.A. at the 2003 WMO Congress. To cover this gap at least partially, a bi-lingual explanatory dictionary of terms and definitions in the area of radiometric calibration of space-borne IR sensors is developed. The objectives are to produce a uniform terminology for the global space-borne observations of the Earth, establish a unique understanding of terms and definitions by the radiometric communities, including a correspondence between the Russian and American terms and definitions, and to develop a formal English/Russian reference dictionary for use by scientists and engineers involved in radiometric observations of the Earth from space. The dictionary includes close to 400 items covering basic concepts of geometric, wave and corpuscular optics, remote sensing technologies, and ground-based calibration as well as more detailed treatment of terms and definitions in the areas of radiometric quantities, symbols and units, optical phenomena and optical properties of objects and media, and radiometric systems and their properties. The dictionary contains six chapters: Basic Concepts, Quantities, Symbols, and Units, Optical phenomena, Optical characteristics of surfaces and media, Components of Radiometric Systems, Characteristics of radiometric system components, plus English/Russian and Russian/Inglish indices.

On the unsteady decline of atmospheric CFC-11: Bumps in the road to ozone recovery or variations in atmospheric transport and/or loss?

NASA Astrophysics Data System (ADS)

Montzka, S. A.; Dutton, G. S.; Ray, E. A.; Moore, F. L.; Nance, J. D.; Hall, B. D.; Siso, C.; Miller, B.; Mondeel, D. J.; Hu, L.; Elkins, J. W.

2016-12-01

Atmospheric mole fractions of the ozone-depleting and greenhouse gas CFC-11 have declined since 1995 owing to global controls on production associated with the fully adjusted and amended Montreal Protocol on Substances that Deplete the Ozone Layer. From 2002 to 2012, CFC-11 mole fractions in both hemispheres decreased at a near-constant rate of 2.2 ± 0.2 ppt/yr. Despite the decreasing being consistent throughout that decade, this rate was consistently slower than projected in WMO scenarios. Since 2012, however, the atmospheric decline of CFC-11 slowed substantially: the 2013 to 2015 rate was -1.3 ± 0.1 ppt/yr and the slow-down was most prominent in the northern hemisphere. This change is consistent with an increase in the net flux of CFC-11 to the northern hemisphere, and has been observed by three quasi-independent global measurement programs within NOAA. Given that global production of CFC-11 has been essentially zero since 2007, it seems improbable that this anomaly is due to increased emissions. Here we will explore this possibility, as well as the possibility that variations in transport (or in loss rates as recorded by surface observations) might explain the slower decline. Preliminary analyses with an idealized model suggest that the mass flux of CFC-11 from the stratosphere to the troposphere was anomalously low during 2014. Does this transport-related anomaly explain the anomalous rates in 2014 and does it persist through 2015? Or do the observations imply a significant increase in global CFC-11 emissions since 2013?

Study of Extreme Hydrometeorological Events under Consideration of Climate Change in terms of Flood Protection Design Standard

NASA Astrophysics Data System (ADS)

Lin, B.-Z.

2012-04-01

A study of Trend and Shift on annual maximum daily data over 500 raingauges with data length of 80 years or longer in the Ohio River Basin U.S. demonstrated a significant increase in variance of the data over time. The area-average increase in standard deviation is 23% for the recent 40 years (1959 - 1998) in comparison with the earlier 40-60 years (1919 or earlier - 1958). This implies that more and more extreme hydrometeorological events such as extreme rainfalls and droughts could be observed in the future years. The centurial flood disaster of August 8-10 2009 in the mid-southern Taiwan caused by Morakot Typhoon and the extraordinary drought lasting from winter 2009 to early summer 2010 wreaking havoc of a vast area of south-west China mainland were two good examples of the extremes. This variation could attribute to climate change. It challenges the hydrologic frequency analysis. Thus, exploration of a robust and reliable approach to precipitation frequency analysis becomes an imminent issue in hydrologic design studies. This paper introduces a novel hydrometeorological approach, the Regional L-moments method (RLM), to rainfall frequency analysis. There are two fatal weaknesses in FA: 1) There is no analytical way to derive a theoretical distribution to best fit the data; 2) The theoretical true value of a frequency such as 50-y or 100-y is unknown forever. The RLM, which is developed based on the order statistics and the concept of hydrometeorological homogeneity, demonstrates unbiasedness of parameter estimates and robust to outliers, and reduces the uncertainties of frequency estimates as well via the real data in Ohio River Basin of the U.S. and in the Taihu Lake Basin of China. Further study indicated that the variation of the frequency estimates such as 10-year, 100-year, 500-year, etc. is not normal as suggested in current textbooks. Actually, the frequency estimates vary asymmetrically from positive skew to negative skew when estimates go through from common frequencies to rare frequencies. Probable Maximum Precipitation (PMP) is defined as the greatest depth of precipitation for a given duration meteorologically possible for a design watershed or a given storm area at a particular location at a particular time of year, with no allowance made for long-term climate trends (WMO, 2009). The PMP has been widely used by many hydrologists to determine the probable maximum flood (PMF) critical to the design of a variety of hydrological structures and other high profile infrastructures such as nuclear power-generation station with respect to flood-protection, for which a high level safety is required. What is the impact of climate change on PMP estimation? Actually, in the definition of PMP, there is "no allowance made for long-term climate trends" (WMO, 2009). However, when people are talking about impact of climate change on PMP estimation, two things may be taken into account practically: (1) To affect the precipitable water as a result of increase of SST; (2) Effect on the selection of the transposed storm because more extreme storms would occur due to climate change and more potential candidates to be used for storm transposition. The occurrence of a severe rainfall storm could alter the PMP estimates. A good example is the lashing of the Typhoon Morakot of 8 - 10 Aug. 2009 on Taiwan Island that set up new rainfall picture. What is the effect of topography on rainfall is another big issue in PMP estimation. Many observations of precipitation in mountainous areas show a general increase in precipitation with elevation. Practically, the effect of topography on rainfall should be taken into account in PMP estimation and implemented by the storm separation technique. The Step-Duration-Orographic-Intensification-Factor (SDOIF) Method, which was developed based on statistics analysis of extreme rainfalls in the storm area, can practically be used as storm separation technique to decouple the Morakot storm rainfalls into two components, convergence component and orographic component. Then, the convergence component can be transposed in a wider area for PMP estimation at a design location in the East Asia region. At last, this paper provides a clue for the first time on relationship between the frequency analysis and the PMP estimation in terms of hydrologic engineering design studies.

Measuring tropospheric wind with microwave sounders

NASA Astrophysics Data System (ADS)

Lambrigtsen, B.; Su, H.; Turk, J.; Hristova-Veleva, S. M.; Dang, V. T.

2017-12-01

In its 2007 "Decadal Survey" of earth science missions for NASA the U.S. National Research Council recommended that a Doppler wind lidar be developed for a three-dimensional tropospheric winds mission ("3D-Winds"). The technology required for such a mission has not yet been developed, and it is expected that the next Decadal Survey, planned to be released by the end of 2017, will put additional emphasis on the still pressing need for wind measurements from space. The first Decadal Survey also called for a geostationary microwave sounder (GMS) on a Precipitation and All-weather Temperature and Humidity (PATH) mission, which could be used to measure wind from space. Such a sounder, the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR), has been developed at the Jet Propulsion Laboratory (JPL). The PATH mission has not yet been funded by NASA, but a low-cost subset of PATH, GeoStorm has been proposed as a hosted payload on a commercial communications satellite. Both PATH and GeoStorm would obtain frequent (every 15 minutes of better) measurements of tropospheric water vapor profiles, and they can be used to derive atmospheric motion vector (AMV) wind profiles, even in the presence of clouds. Measurement of wind is particularly important in the tropics, where the atmosphere is largely not in thermal balance and wind estimates cannot generally be derived from temperature and pressure fields. We report on simulation studies of AMV wind vectors derived from a GMS and from a cluster of low-earth-orbiting (LEO) small satellites (e.g., CubeSats). The results of two separate simulation studies are very encouraging and show that a ±2 m/s wind speed precision is attainable, which would satisfy WMO requirements. A GMS observing system in particular, which can be implemented now, would enable significant progress in the study of atmospheric dynamics. Copyright 2017 California Institute of Technology. Government sponsorship acknowledged

An Update on Ozone Profile Trends for the Period 2000 to 2016

NASA Technical Reports Server (NTRS)

Steinbrecht, Wolfgang; Froidevaux, Lucien; Fuller, Ryan; Wang, Ray; Anderson, John; Roth, Chris; Bourassa, Adam; Degenstein, Doug; Damadeo, Robert; Zawodny, Joe;

Long-term observations of tropospheric ozone: GAW Measurement Guidelines

NASA Astrophysics Data System (ADS)

Tarasova, Oksana; Galbally, Ian E.; Schultz, Martin G.

2013-04-01

The Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) coordinates long-term observations of the chemical composition and physical properties of the atmosphere which are relevant for understanding of atmospheric chemistry and climate change. Atmospheric observations of reactive gases (tropospheric ozone, carbon monoxide, volatile organic compounds and nitrogen oxides) coordinated by the GAW Programme complement local and regional scale air quality monitoring efforts. As part of the GAW quality assurance (QA) system detailed measurement guidelines for atmospheric trace species are developed by international expert teams at irregular intervals. The most recent report focuses on continuous in-situ measurements of ozone in the troposphere, performed in particular at continental or island sites with altitudes ranging from sea level to mountain tops. Data Quality Objectives (DQOs) are defined for different applications of the data (e.g. trend analysis and verification of global model forecasts). These DQOs include a thorough discussion of the tolerable level of measurement uncertainty and data completeness. The guidelines present the best practices and practical arrangements adopted by the GAW Programme in order to enable the GAW station network to approach or achieve the defined tropospheric ozone DQOs. The document includes information on the selection of station and measurement locations, required skills and training of staff, recommendations on the measurement technique and the necessary equipment to perform highest quality measurements, rules for conducting the measurements, preparing the data and archiving them, and more. Much emphasis is given to discussions about how to ensure the quality of the data through tracing calibrations back to primary standards, proper calibration and data analysis, etc. In the GAW Programme the QA system is implemented through Central Facilities (Central Calibration Laboratories, World and Regional Calibration Centers and World Data Centers), Scientific Advisory Groups and GAW Training and Education Center. These bodies support primary standards, provide calibration and data archiving facilities, coordinate comparison campaigns, perform stations audit, provide documentation and training of personnel.

Substituting physicians with nurse practitioners, physician assistants or nurses in nursing homes: protocol for a realist evaluation case study

PubMed Central

Lovink, Marleen Hermien; Persoon, Anke; van Vught, Anneke JAH; Schoonhoven, Lisette; Koopmans, Raymond TCM; Laurant, Miranda GH

2017-01-01

Introduction In developed countries, substituting physicians with nurse practitioners, physician assistants and nurses (physician substitution) occurs in nursing homes as an answer to the challenges related to the ageing population and the shortage of staff, as well as to guarantee the quality of nursing home care. However, there is great diversity in how physician substitution in nursing homes is modelled and it is unknown how it can best contribute to the quality of healthcare. This study aims to gain insight into how physician substitution is modelled and whether it contributes to perceived quality of healthcare. Second, this study aims to provide insight into the elements of physician substitution that contribute to quality of healthcare. Methods and analysis This study will use a multiple-case study design that draws upon realist evaluation principles. The realist evaluation is based on four concepts for explaining and understanding interventions: context, mechanism, outcome and context–mechanism–outcome configuration. The following steps will be taken: (1) developing a theory, (2) conducting seven case studies, (3) analysing outcome patterns after each case and a cross-case analysis at the end and (4) revising the initial theory. Ethics and dissemination The research ethics committee of the region Arnhem Nijmegen in the Netherlands concluded that this study does not fall within the scope of the Dutch Medical Research Involving Human Subjects Act (WMO) (registration number 2015/1914). Before the start of the study, the Board of Directors of the nursing home organisations will be informed verbally and by letter and will also be asked for informed consent. In addition, all participants will be informed verbally and by letter and will be asked for informed consent. Findings will be disseminated by publication in a peer-reviewed journal, international and national conferences, national professional associations and policy partners in national government. PMID:28600370

NetCDF-CF-OPeNDAP: Standards for ocean data interoperability and object lessons for community data standards processes

USGS Publications Warehouse

Hankin, Steven C.; Blower, Jon D.; Carval, Thierry; Casey, Kenneth S.; Donlon, Craig; Lauret, Olivier; Loubrieu, Thomas; Srinivasan, Ashwanth; Trinanes, Joaquin; Godøy, Øystein; Mendelssohn, Roy; Signell, Richard P.; de La Beaujardiere, Jeff; Cornillon, Peter; Blanc, Frederique; Rew, Russ; Harlan, Jack; Hall, Julie; Harrison, D.E.; Stammer, Detlef

2010-01-01

It is generally recognized that meeting society's emerging environmental science and management needs will require the marine data community to provide simpler, more effective and more interoperable access to its data. There is broad agreement, as well, that data standards are the bedrock upon which interoperability will be built. The path that would bring the marine data community to agree upon and utilize such standards, however, is often elusive. In this paper we examine the trio of standards 1) netCDF files; 2) the Climate and Forecast (CF) metadata convention; and 3) the OPeNDAP data access protocol. These standards taken together have brought our community a high level of interoperability for "gridded" data such as model outputs, satellite products and climatological analyses, and they are gaining rapid acceptance for ocean observations. We will provide an overview of the scope of the contribution that has been made. We then step back from the information technology considerations to examine the community or "social" process by which the successes were achieved. We contrast the path by which the World Meteorological Organization (WMO) has advanced the Global Telecommunications System (GTS) - netCDF/CF/OPeNDAP exemplifying a "bottom up" standards process whereas GTS is "top down". Both of these standards are tales of success at achieving specific purposes, yet each is hampered by technical limitations. These limitations sometimes lead to controversy over whether alternative technological directions should be pursued. Finally we draw general conclusions regarding the factors that affect the success of a standards development effort - the likelihood that an IT standard will meet its design goals and will achieve community-wide acceptance. We believe that a higher level of thoughtful awareness by the scientists, program managers and technology experts of the vital role of standards and the merits of alternative standards processes can help us as a community to reach our interoperability goals faster.

GUMNET - A new long-term monitoring initiative in the Guadarrama Mountains, Madrid, Spain

NASA Astrophysics Data System (ADS)

Rath, Volker; Fidel González Rouco, J.; Yagüe Anguis, Carlos

2014-05-01

We are announcing a new monitoring network in the Guadarrama Mountains north of Madrid, which is planned to be operational in early 2015. This network integrates atmospheric measurements as well as subsurface observations. It aims at improving the characterization of atmosphere-ground interactions in mountainous terrain, the hydrometeorology of the region, climatic change, and related research lines. It will also provide the meteorological and climate data which form the necessary background information for biological, agricultural and hydrological investigations in this area. Currently, the initiative is supported by research groups from the Complutense and Polytechnical Universities of Madrid (UCM and UPM), the Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), the Spanish National Meteorological Agency (AEMET), and finally the Parque Nacional de la Sierra de Guadarrama (PNSG). This infrastructure forms part of the Campus of Excellence Moncloa, and is supposed to become a focus of local as well as of international research. However, it is not associated with a particular project: data will in principle be available to the scientific and public communities. Also, the integration of new instruments (long or short term) will be welcome. The starting setup is as following: A group of WMO-compatible meteorological station in the central area of the massif will be installed, which include also a subsurface component of boreholes (≡20 m depth), where temperature and moisture will be measured. This core group is complemented by a reference site near El Escorial (including a fixed and a mobile tower for micrometeorological investigations). This setup is embedded in a network of meteorological stations run partly by AEMET and partly by the PNSG, which will provide the information necessary for the characterization of regional meteorology and climate. Finally, part of the data will be made available quasi-online on a central web server in Madrid. (temporary web page: http://tifon.fis.ucm.es/~gumnet/)

Oxygen isotope fractionation between bird bone phosphate and drinking water.

PubMed

Amiot, Romain; Angst, Delphine; Legendre, Serge; Buffetaut, Eric; Fourel, François; Adolfssen, Jan; André, Aurore; Bojar, Ana Voica; Canoville, Aurore; Barral, Abel; Goedert, Jean; Halas, Stanislaw; Kusuhashi, Nao; Pestchevitskaya, Ekaterina; Rey, Kevin; Royer, Aurélien; Saraiva, Antônio Álamo Feitosa; Savary-Sismondini, Bérengère; Siméon, Jean-Luc; Touzeau, Alexandra; Zhou, Zhonghe; Lécuyer, Christophe

2017-06-01

Oxygen isotope compositions of bone phosphate (δ 18 O p ) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δ 18 O p values (from 9.8 to 22.5‰ V-SMOW) and the local rainfall δ 18 O w values estimated from nearby IAEA/WMO stations (from -16.0 to -1.0‰ V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: δ 18 O w  = 1.119 (±0.040) δ 18 O p  - 24.222 (±0.644); R 2  = 0.98. The δ 18 O p -δ 18 O w couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher δ 18 O w value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.

Comparative estimation and assessment of initial soil moisture conditions for Flash Flood warning in Saxony

NASA Astrophysics Data System (ADS)

Luong, Thanh Thi; Kronenberg, Rico; Bernhofer, Christian; Janabi, Firas Al; Schütze, Niels

2017-04-01

Flash Floods are known as highly destructive natural hazards due to their sudden appearance and severe consequences. In Saxony/Germany flash floods occur in small and medium catchments of low mountain ranges which are typically ungauged. Besides rainfall and orography, pre-event moisture is decisive, as it determines the available natural retention in the catchment. The Flash Flood Guidance concept according to WMO and Prof. Marco Borga (University of Padua) will be adapted to incorporate pre-event moisture in real-time flood forecast within the ESF EXTRUSO project (SAB-Nr. 100270097). To arrive at pre-event moisture for the complete area of the low mountain range with flash flood potential, a widely applicable, accurate but yet simple approach is needed. Here, we use radar precipitation as input time series, detailed orographic, land-use and soil information and a lumped parameter model to estimate the overall catchment soil moisture and potential retention. When combined with rainfall forecast and its intrinsic uncertainty, the approach allows to find the point in time when precipitation exceeds the retention potential of the catchment. Then, spatially distributed and complex hydrological modeling and additional measurements can be initiated. Assuming reasonable rainfall forecasts of 24 to 48hrs, this part can start up to two days in advance of the actual event. The lumped-parameter model BROOK90 is used and tested for well observed catchments. First, physical meaningful parameters (like albedo or soil porosity) a set according to standards and second, "free" parameters (like percentage of lateral flow) were calibrated objectively by PEST (Model-Independent Parameter Estimation and Uncertainty Analysis) with the target on evapotranspiration and soil moisture which both have been measured at the study site Anchor Station Tharandt in Saxony/Germany. Finally, first results are presented for the Wernersbach catchment in Tharandt forest for main flood events in the 50-year gauging period since 1968.

Globalizing Lessons Learned from Regional-scale Observatories

NASA Astrophysics Data System (ADS)

Glenn, S. M.

2016-02-01

The Mid Atlantic Regional Association Coastal Ocean Observing System (MARACOOS) has accumulated a decade of experience designing, building and operating a Regional Coastal Ocean Observing System for the U.S. Integrated Ocean Observing System (IOOS). MARACOOS serves societal goals and supports scientific discovery at the scale of a Large Marine Ecosystem (LME). Societal themes include maritime safety, ecosystem decision support, coastal inundation, water quality and offshore energy. Scientific results that feed back on societal goals with better products include improved understanding of seasonal transport pathways and their impact on phytoplankton blooms and hypoxia, seasonal evolution of the subsurface Mid Atlantic Cold Pool and its impact on fisheries, biogeochemical transformations in coastal plumes, coastal ocean evolution and impact on hurricane intensities, and storm sediment transport pathways. As the global ocean observing requirements grow to support additional societal needs for information on fisheries and aquaculture, ocean acidification and deoxygenation, water quality and offshore development, global observing will necessarily evolve to include more coastal observations and forecast models at the scale of the world's many LMEs. Here we describe our efforts to share lessons learned between the observatory operators at the regional-scale of the LMEs. Current collaborators are spread across Europe, and also include Korea, Indonesia, Australia, Brazil and South Africa. Specific examples include the development of a world standard QA/QC approach for HF Radar data that will foster the sharing of data between countries, basin-scale underwater glider missions between internationally-distributed glider ports to developed a shared understanding of operations and an ongoing evaluation of the global ocean models in which the regional models for the LME will be nested, and joint training programs to develop the distributed teams of scientists and technicians required to support the global network. Globalization includes the development of international networks to coordinate activities, such as the Global HF Radar network supported by GEO, the global Everyone's Glider Organization supported by WMO and IOC, and the need for professional training supported by MTS.

Duloxetine in OsteoArthritis (DOA) study: study protocol of a pragmatic open-label randomised controlled trial assessing the effect of preoperative pain treatment on postoperative outcome after total hip or knee arthroplasty

PubMed Central

Blikman, T; Rienstra, W; van Raaij, T M; ten Hagen, A J; Dijkstra, B; Zijlstra, W P; Bulstra, S K; van den Akker-Scheek, I; Stevens, M

2016-01-01

Introduction Residual pain is a major factor in patient dissatisfaction following total hip arthroplasty or total knee arthroplasty (THA/TKA). The proportion of patients with unfavourable long-term residual pain is high, ranging from 7% to 34%. There are studies indicating that a preoperative degree of central sensitisation (CS) is associated with poorer postoperative outcomes and residual pain. It is thus hypothesised that preoperative treatment of CS could enhance postoperative outcomes. Duloxetine has been shown to be effective for several chronic pain syndromes, including knee osteoarthritis (OA), in which CS is most likely one of the underlying pain mechanisms. This study aims to evaluate the postoperative effects of preoperative screening and targeted duloxetine treatment of CS on residual pain compared with care-as-usual. Methods and analysis This multicentre, pragmatic, prospective, open-label, randomised controlled trial includes patients with idiopathic hip/knee OA who are on a waiting list for primary THA/TKA. Patients at risk for CS will be randomly allocated to the preoperative duloxetine treatment programme group or the care-as-usual control group. The primary end point is the degree of postoperative pain 6 months after THA/TKA. Secondary end points at multiple time points up to 12 months postoperatively are: pain, neuropathic pain-like symptoms, (pain) sensitisation, pain catastrophising, joint-associated problems, physical activity, health-related quality of life, depressive and anxiety symptoms, and perceived improvement. Data will be analysed on an intention-to-treat basis. Ethics and dissemination The study is approved by the local Medical Ethics Committee (METc 2014/087) and will be conducted according to the principles of the Declaration of Helsinki (64th, 2013) and the Good Clinical Practice standard (GCP), and in compliance with the Medical Research Involving Human Subjects Act (WMO). Trial registration number 2013-004313-41; Pre-results. PMID:26932142

Substituting physicians with nurse practitioners, physician assistants or nurses in nursing homes: protocol for a realist evaluation case study.

PubMed

Lovink, Marleen Hermien; Persoon, Anke; van Vught, Anneke J A H; Schoonhoven, Lisette; Koopmans, Raymond T C M; Laurant, Miranda G H

2017-06-08

In developed countries, substituting physicians with nurse practitioners, physician assistants and nurses (physician substitution) occurs in nursing homes as an answer to the challenges related to the ageing population and the shortage of staff, as well as to guarantee the quality of nursing home care. However, there is great diversity in how physician substitution in nursing homes is modelled and it is unknown how it can best contribute to the quality of healthcare. This study aims to gain insight into how physician substitution is modelled and whether it contributes to perceived quality of healthcare. Second, this study aims to provide insight into the elements of physician substitution that contribute to quality of healthcare. This study will use a multiple-case study design that draws upon realist evaluation principles. The realist evaluation is based on four concepts for explaining and understanding interventions: context, mechanism, outcome and context-mechanism-outcome configuration. The following steps will be taken: (1) developing a theory, (2) conducting seven case studies, (3) analysing outcome patterns after each case and a cross-case analysis at the end and (4) revising the initial theory. The research ethics committee of the region Arnhem Nijmegen in the Netherlands concluded that this study does not fall within the scope of the Dutch Medical Research Involving Human Subjects Act (WMO) (registration number 2015/1914). Before the start of the study, the Board of Directors of the nursing home organisations will be informed verbally and by letter and will also be asked for informed consent. In addition, all participants will be informed verbally and by letter and will be asked for informed consent. Findings will be disseminated by publication in a peer-reviewed journal, international and national conferences, national professional associations and policy partners in national government. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Progress toward an Integrated Global Greenhouse Gas Information System (IG3IS)

NASA Astrophysics Data System (ADS)

DeCola, P.; Butler, J. H.; Stanitski, D.; Tarasova, O. A.; Terblanche, D. E.; Duren, R. M.; Gurney, K. R.; Manning, A.; Reimann, S.; Ciais, P.; Arnold, T.; Burston, J.; Rayner, P. J.; Wofsy, S. C.; Hamburg, S.; Zavala-Araiza, D.; Miller, J. B.; Gerbig, C.; Vogel, F. R.; Canadell, J.

2016-12-01

Accurate and precise atmospheric long-term measurements of greenhouse gas (GHG) concentrations have revealed the rapid and unceasing rise of global GHG concentrations due to human socioeconomic activity. Long-term observations also show a resulting rise in global temperatures and evidence of negative impacts on society. In response to this mounting evidence, nations, sub-national governments, private enterprises and individuals are establishing and accelerating efforts to reduce GHG emissions while meeting the needs for global development and increasing energy access. With this motivation, WMO and its partners have called for an Integrated Global Greenhouse Information System (IG3IS). The IG3IS will serve as an international coordinating mechanism to establish and propagate consistent methods and standards to help assess emission-reduction actions. For the IG3IS initiative to succeed the end users must understand, trust, and recognize the value of the information they receive, and act more effectively in response. Over time, the IG3IS framework will be capable of promoting and accepting advancing technical capabilities (e.g., new satellite observations), continually improving the quality of and confidence in such information. By combining accurate atmospheric measurements with enhanced socioeconomic activity data and model analyses we can meet the overarching goals of IG3IS to: Reduce uncertainty of emission inventory reporting, Locate, quantify and prioritize previously unknown emission reduction opportunities, and Provide national and sub-national governments with timely and quantified information to support their assessment of progress towards their mitigation goals. An effective IG3IS will provide on-going, observation-based information on the relative success of GHG management efforts on policy-relevant scales and the response of the global carbon cycle to a warming world. The presentation will cover the principles and objectives of IG3IS, as well as progress toward answering the questions: What research capabilities are ready and able to deliver useful information and for whom? What decisions will be informed? What valuable and additional outcomes will result?

Evaluation of a Soil Moisture Data Assimilation System Over the Conterminous United States

NASA Astrophysics Data System (ADS)

Bolten, J. D.; Crow, W. T.; Zhan, X.; Reynolds, C. A.; Jackson, T. J.

2008-12-01

A data assimilation system has been designed to integrate surface soil moisture estimates from the EOS Advanced Microwave Scanning Radiometer (AMSR-E) with an online soil moisture model used by the USDA Foreign Agriculture Service for global crop estimation. USDA's International Production Assessment Division (IPAD) of the Office of Global Analysis (OGA) ingests global soil moisture within a Crop Assessment Data Retrieval and Evaluation (CADRE) Decision Support System (DSS) to provide nowcasts of crop conditions and agricultural-drought. This information is primarily used to derive mid-season crop yield estimates for the improvement of foreign market access for U.S. agricultural products. The CADRE is forced by daily meteorological observations (precipitation and temperature) provided by the Air Force Weather Agency (AFWA) and World Meteorological Organization (WMO). The integration of AMSR-E observations into the two-layer soil moisture model employed by IPAD can potentially enhance the reliability of the CADRE soil moisture estimates due to AMSR-E's improved repeat time and greater spatial coverage. Assimilation of the AMSR-E soil moisture estimates is accomplished using a 1-D Ensemble Kalman filter (EnKF) at daily time steps. A diagnostic calibration of the filter is performed using innovation statistics by accurately weighting the filter observation and modeling errors for three ranges of vegetation biomass density estimated using historical data from the Advanced Very High Resolution Radiometer (AVHRR). Assessment of the AMSR-E assimilation has been completed for a five year duration over the conterminous United States. To evaluate the ability of the filter to compensate for incorrect precipitation forcing into the model, a data denial approach is employed by comparing soil moisture results obtained from separate model simulations forced with precipitation products of varying uncertainty. An analysis of surface and root-zone anomalies is presented for each model simulation over the conterminous United States, as well as statistical assessments for each simulation over various land cover types.

The impact of a windshield in a tipping bucket rain gauge on the reduction of losses in precipitation measurements during snowfall events

NASA Astrophysics Data System (ADS)

Buisan, Samuel T.; Collado, Jose Luis; Alastrue, Javier

2016-04-01

The amount of snow available controls the ecology and hydrological response of mountainous areas and cold regions and affects economic activities including winter tourism, hydropower generation, floods and water supply. An accurate measurement of snowfall accumulation amount is critical and source of error for a better evaluation and verification of numerical weather forecast, hydrological and climate models. It is well known that the undercatch of solid precipitation resulting from wind-induced updrafts at the gauge orifice is the main factor affecting the quality and accuracy of the amount of snowfall precipitation. This effect can be reduced by the use of different windshields. Overall, Tipping Bucket Rain Gauges (TPBRG) provide a large percentage of the precipitation amount measurements, in all climate regimes, estimated at about 80% of the total of observations by automatic instruments. In the frame of the WMO-SPICE project, we compared at the Formigal-Sarrios station (Spanish Pyrenees, 1800 m a.s.l.) the measured precipitation in two heated TPBRGs, one of them protected with a single alter windshield in order to reduce the wind bias. Results were contrasted with measured precipitation using the SPICE reference gauge (Pluvio2 OTT) in a Double Fence Intercomparison Reference (DFIR). Results reported that shielded reduces undercatch up to 40% when wind speed exceeds 6 m/s. The differences when compared with the reference gauge reached values higher than 70%. The inaccuracy of these measurements showed a significant impact in nowcasting operations and climatology in Spain, especially during some heavy snowfall episodes. Also, hydrological models showed a better agreement with the observed rivers flow when including the precipitation not accounted during these snowfall events. The conclusions of this experiment will be used to take decisions on the suitability of the installation of windshields in stations characterized by a large quantity of snowfalls during the winter season and which are mainly located in Northern Spain

Emerging Subsea Networks: SMART Cable Systems for Science and Society

NASA Astrophysics Data System (ADS)

Howe, B. M.; Butler, R.; Joint Task Force, U.

2016-02-01

The subsea telecommunications cable industry is approaching a prospective new era: deploying SMART subsea cable systems (SMART = Science Monitoring And Reliable Telecommunication). The current global, commercial cable infrastructure consists of 1 Gm of cable, being refreshed now and expanding in the future. The SMART concept is to add a small external sensor package along the cable system at its optical repeaters to transmit important real-time environmental data via a dedicated wavelength or overhead channel in the transmission system, avoiding any impact on the commercial traffic. These small, reliable, existing sensors would precisely measure temperature, pressure and three-axis acceleration across the world's ocean floor over an extended period of time, being deployed using standard cable-laying procedures on new or refurbished cables, but not requiring maintenance through the 2-3 decade life of the cable systems. The game-changing factor is the urgent international need for ocean environmental data related to mitigating climate and sea-level change and improving tsunami and slope failure hazard warnings. Societal costs incurred by these are reaching billions of dollars and hundreds of thousands of deaths. Pressures for new and urgent public policies are evident from the 5th IPCC Assessment, USA-China agreement on limiting greenhouse gas emissions, clear evidence for rapid global warming, 21st Session of the Conference of the Parties to the UNFCCC (December 2015, Paris), and the scale of the costs of inaction. To support revised public policies and actions, decision-makers, industry leaders, and the public are seeking key scientific data, which will necessitate new sources of funding. Hence, the emergence of new SMART cable systems offered by the subsea telecommunications industry will provide new market opportunities, engage additional non-traditional users, and make profound societal contributions. The Joint Task Force (JTF) on SMART Subsea Cable Systems established by three UN agencies (ITU, WMO, and UNESCO IOC) is helping facilitate this transformation. http://www.itu.int/en/ITU-T/climatechange/task-force-sc/Pages/default.aspx or google 'jtf cable'

Jena Reference Air Set (JRAS): a multi-point scale anchor for isotope measurements of CO2 in air

NASA Astrophysics Data System (ADS)

Wendeberg, M.; Richter, J. M.; Rothe, M.; Brand, W. A.

2013-03-01

The need for a unifying scale anchor for isotopes of CO2 in air was brought to light at the 11th WMO/IAEA Meeting of Experts on Carbon Dioxide in Tokyo 2001. During discussions about persistent discrepancies in isotope measurements between the worlds leading laboratories, it was concluded that a unifying scale anchor for Vienna Pee Dee Belemnite (VPDB) of CO2 in air was desperately needed. Ten years later, at the 2011 Meeting of Experts on Carbon Dioxide in Wellington, it was recommended that the Jena Reference Air Set (JRAS) become the official scale anchor for isotope measurements of CO2 in air (Brailsford, 2012). The source of CO2 used for JRAS is two calcites. After releasing CO2 by reaction with phosphoric acid, the gases are mixed into CO2-free air. This procedure ensures both isotopic stability and longevity of the CO2. That the reference CO2 is generated from calcites and supplied as an air mixture is unique to JRAS. This is made to ensure that any measurement bias arising from the extraction procedure is eliminated. As every laboratory has its own procedure for extracting the CO2, this is of paramount importance if the local scales are to be unified with a common anchor. For a period of four years, JRAS has been evaluated through the IMECC1 program, which made it possible to distribute sets of JRAS gases to 13 laboratories worldwide. A summary of data from the six laboratories that have reported the full set of results is given here along with a description of the production and maintenance of the JRAS scale anchors. 1 IMECC refers to the EU project "Infrastructure for Measurements of the European Carbon Cycle" (http://imecc.ipsl.jussieu.fr/).

Heterogeneous processes: Laboratory, field, and modeling studies

NASA Technical Reports Server (NTRS)

Poole, Lamont R.; Kurylo, Michael J.; Jones, Rod L.; Wahner, Andreas; Calvert, Jack G.; Leu, M.-T.; Fried, A.; Molina, Mario J.; Hampson, Robert F.; Pitts, M. C.

1991-01-01

The efficiencies of chemical families such as ClO(x) and NO(x) for altering the total abundance and distribution of stratospheric ozone are controlled by a partitioning between reactive (active) and nonreactive (reservoir) compounds within each family. Gas phase thermodynamics, photochemistry, and kinetics would dictate, for example, that only about 1 percent of the chlorine resident in the lower stratosphere would be in the form of active Cl or ClO, the remainder existing in the reservoir compounds HCl and ClONO2. The consistency of this picture was recently challenged by the recognition that important chemical transformations take place on polar regions: the Airborne Antarctic Ozone Experiment (AAOE) and the Airborne Arctic Stratospheric Expedition (AASA). Following the discovery of the Antarctic ozone hole, Solomon et al. suggested that the heterogeneous chemical reaction: ClONO2(g)+HCl(s) yields Cl2(g)+HNO3(s) could play a key role in converting chlorine from inactive forms into a species (Cl2) that would rapidly dissociate in sunlight to liberate atomic chlorine and initiate ozone depletion. The symbols (s) and (g) denote solid phase, or adsorbed onto a solid surface, and gas phase, respectively, and represent the approach by which such a reaction is modeled rather than the microscopic details of the reaction. The reaction was expected to be most important at altitudes where PSC's were most prevalent (10 to 25 km), thereby extending the altitude range over which chlorine compounds can efficiently destroy ozone from the 35 to 45 km region (where concentrations of active chlorine are usually highest) to lower altitudes where the ozone concentration is at its peak. This chapter will briefly review the current state of knowledge of heterogeneous processes in the stratosphere, emphasizing those results obtained since the World Meteorological Organization (WMO) conference. Sections are included on laboratory investigations of heterogeneous reactions, the characteristics and climatology of PSC's, stratospheric sulfate aerosols, and evidence of heterogeneous chemical processing.

New mechanism under International Flood Initiative toward robustness for flood management in the Asia Pacific region

NASA Astrophysics Data System (ADS)

Murase, M.; Yoshitani, J.; Takeuchi, K.; Koike, T.

2015-12-01

Climate change is likely to result in increases in the frequency or intensity of extreme weather events. It is imperative that a good understanding is developed of how climate change affects the events that are reflected in hydrological extremes such as floods and how practitioners in water resources management deal with them. Since there is still major uncertainty as to how the impact of climate change affect actual water resources management, it is important to build robustness into management schemes and communities. Flood management under such variety of uncertainty favors the flexible and adaptive implementation both in top-down and bottom-up approaches. The former uses projections of global or spatially downscaled models to drive resource models and project resource impacts. The latter utilizes policy or planning tools to identify what changes in climate would be most threatening to their long-range operations. Especially for the bottom-up approaches, it is essential to identify the gap between what should be done and what has not been achieved for disaster risks. Indicators or index are appropriate tools to measure such gaps, but they are still in progress to cover the whole world. The International Flood Initiative (IFI), initiated in January 2005 by UNESCO and WMO in close cooperation with UNU and ISDR, IAHS and IAHR, has promoted an integrated approach to flood management to take advantage of floods and use of flood plains while reducing the social, environmental and economic risks. Its secretariat is located in ICHARM. The initiative objective is to support national platforms to practice evidence-based disaster risk reduction through mobilizing scientific and research networks at national, regional and international levels. The initiative is now preparing for a new mechanism to facilitate the integrated approach for flood management on the ground regionally in the Asia Pacific (IFI-AP) through monitoring, assessment and capacity building.

Gridded sunshine duration climate data record for Germany based on combined satellite and in situ observations

NASA Astrophysics Data System (ADS)

Walawender, Jakub; Kothe, Steffen; Trentmann, Jörg; Pfeifroth, Uwe; Cremer, Roswitha

2017-04-01

The purpose of this study is to create a 1 km2 gridded daily sunshine duration data record for Germany covering the period from 1983 to 2015 (33 years) based on satellite estimates of direct normalised surface solar radiation and in situ sunshine duration observations using a geostatistical approach. The CM SAF SARAH direct normalized irradiance (DNI) satellite climate data record and in situ observations of sunshine duration from 121 weather stations operated by DWD are used as input datasets. The selected period of 33 years is associated with the availability of satellite data. The number of ground stations is limited to 121 as there are only time series with less than 10% of missing observations over the selected period included to keep the long-term consistency of the output sunshine duration data record. In the first step, DNI data record is used to derive sunshine hours by applying WMO threshold of 120 W/m2 (SDU = DNI ≥ 120 W/m2) and weighting of sunny slots to correct the sunshine length between two instantaneous image data due to cloud movement. In the second step, linear regression between SDU and in situ sunshine duration is calculated to adjust the satellite product to the ground observations and the output regression coefficients are applied to create a regression grid. In the last step regression residuals are interpolated with ordinary kriging and added to the regression grid. A comprehensive accuracy assessment of the gridded sunshine duration data record is performed by calculating prediction errors (cross-validation routine). "R" is used for data processing. A short analysis of the spatial distribution and temporal variability of sunshine duration over Germany based on the created dataset will be presented. The gridded sunshine duration data are useful for applications in various climate-related studies, agriculture and solar energy potential calculations.

Innovations and Lessons Learned Developing the USDA Long-Term Agroecosystem Research Network Common Observatory Data Repository

NASA Astrophysics Data System (ADS)

Campbell, J. D.; Heilman, P.; Goodrich, D. C.; Sadler, J.

2015-12-01

The objective for the USDA Long-Term Agroecosystem Research (LTAR) network Common Observatory Repository (CORe) is to provide data management services including archive, discovery, and access for consistently observed data across all 18 nodes. LTAR members have an average of 56 years of diverse historic data. Each LTAR has designated a representative 'permanent' site as the location's common meteorological observatory. CORe implementation is phased, starting with meteorology, then adding hydrology, eddy flux, soil, and biology data. A design goal was to adopt existing best practices while minimizing the additional data management duties for the researchers. LTAR is providing support for data management specialists at the locations and the National Agricultural Library is providing central data management services. Maintaining continuity with historical observations is essential, so observations from both the legacy and new common methods are included in CORe. International standards are used to store robust descriptive metadata (ISO 19115) for the observation station and surrounding locale (WMO), sensors (Sensor ML), and activity (e.g., re-calibration, locale changes) to provide sufficient detail for novel data re-use for the next 50 years. To facilitate data submission a simple text format was designed. Datasets in CORe will receive DOIs to encourage citations giving fair credit for data providers. Data and metadata access are designed to support multiple formats and naming conventions. An automated QC process is being developed to enhance comparability among LTAR locations and to generate QC process metadata. Data provenance is maintained with a permanent record of changes including those by local scientists reviewing the automated QC results. Lessons learned so far include increase in site acceptance of CORe with the decision to store data from both legacy and new common methods. A larger than anticipated variety of currently used methods with potentially significant differences for future data use was found. Cooperative peer support among locations with the same sensors coupled with central support has reduced redundancy in procedural and data documentation.

Global Drought Services: Collaborations Toward an Information System for Early Warning

NASA Astrophysics Data System (ADS)

Hayes, M. J.; Pulwarty, R. S.; Svoboda, M.

2014-12-01

Drought is a hazard that lends itself well to diligent, sustained monitoring and early warning. However, unlike most hazards, the fact that droughts typically evolve slowly, can last for months or years and cover vast areas spanning multiple political boundaries/jurisdictions and economic sectors can make it a daunting task to monitor, develop plans for, and identify appropriate, proactive mitigation strategies. The National Drought Mitigation Center (NDMC) and National Integrated Drought Information System (NIDIS) have been working together to reduce societal vulnerability to drought by helping decision makers at all levels to: 1) implement drought early warning/forecasting and decision support systems; 2) support and advocate for better collection of, and understanding of drought impacts; and 3) increase long-term resilience to drought through proactive planning. The NDMC and NIDIS risk management approach has been the basis from which many partners around the world are developing a collaboration and coordination nexus with an ultimate goal of building comprehensive global drought early warning information systems (GDEWIS). The core emphasis of this model is on developing and applying useful and usable information that can be integrated and transferred freely to other regions around the globe. The High-Level Ministerial Declaration on Drought, the Integrated Drought Management Programme (IDMP) co-led by the WMO and the Global Water Partnership (GWP), and the Global Framework for Climate Services are drawing extensively from the integrated NDMC-NIDIS risk management framework. This presentation will describe, in detail, the various drought resources, tools, services, and collaborations already being provided and undertaken at the national and regional scales by the NDMC, NIDIS, and their partners. The presentation will be forward-looking, identifying improvements in existing and proposed mechanisms to help strengthen national and international drought early warning information systems to support preparedness and adaptation decisions in a changing climate.

New generation nuclear fuel structures: Dense particles in selectively soluble matrix

NASA Astrophysics Data System (ADS)

Devlin, Dave; Jarvinen, Gordon; Patterson, Brian; Pattillo, Steve; Valdez, James; Liu, X.-Y.; Phillips, Jonathan

2009-11-01

We have developed a technology for dispersing sub-millimeter sized fuel particles within a bulk matrix that can be selectively dissolved. This may enable the generation of advanced nuclear fuels with easy separation of actinides and fission products. The large kinetic energy of the fission products results in most of them escaping from the sub-millimeter sized fuel particles and depositing in the matrix during burning of the fuel in the reactor. After the fuel is used and allowed to cool for a period of time, the matrix can be dissolved and the fission products removed for disposal while the fuel particles are collected by filtration for recycle. The success of such an approach would meet a major goal of the GNEP program to provide advanced recycle technology for nuclear energy production. The benefits of such an approach include (1) greatly reduced cost of the actinide/fission product separation process, (2) ease of recycle of the fuel particles, and (3) a radiation barrier to prevent theft or diversion of the recycled fuel particles during the time they are re-fabricated into new fuel. In this study we describe a method to make surrogate nuclear fuels of micrometer scale W (shell)/Mo (core) or HfO 2 particles embedded in an MgO matrix that allows easy separation of the fission products and their embedded particles. In brief, the method consists of physically mixing W-Mo or hafnia particles with an MgO precursor. Heating the mixture, in air or argon, without agitation, to a temperature is required for complete decomposition of the precursor. The resulting material was examined using chemical analysis, scanning electron microscopy, X-ray diffraction and micro X-ray computed tomography and found to consist of evenly dispersed particles in an MgO + matrix. We believe this methodology can be extended to actinides and other matrix materials.

Incorporating Quality Control Information in the Sensor Web

NASA Astrophysics Data System (ADS)

Devaraju, Anusuriya; Kunkel, Ralf; Bogena, Heye

2013-04-01

The rapid development of sensing technologies had led to the creation of large amounts of heterogeneous environmental observations. The Sensor Web provides a wider access to sensors and observations via common protocols and specifications. Observations typically go through several levels of quality control, and aggregation before they are made available to end-users. Raw data are usually inspected, and related quality flags are assigned. Data are gap-filled, and errors are removed. New data series may also be derived from one or more corrected data sets. Until now, it is unclear how these kinds of information can be captured in the Sensor Web Enablement (SWE) framework. Apart from the quality measures (e.g., accuracy, precision, tolerance, or confidence), the levels of observational series, the changes applied, and the methods involved must be specified. It is important that this kind of quality control information is well described and communicated to end-users to allow for a better usage and interpretation of data products. In this paper, we describe how quality control information can be incorporated into the SWE framework. Concerning this, first, we introduce the TERENO (TERrestrial ENvironmental Observatories), an initiative funded by the large research infrastructure program of the Helmholtz Association in Germany. The main goal of the initiative is to facilitate the study of long-term effects of climate and land use changes. The TERENO Online Data RepOsitORry (TEODOOR) is a software infrastructure that supports acquisition, provision, and management of observations within TERENO via SWE specifications and several other OGC web services. Next, we specify changes made to the existing observational data model to incorporate quality control information. Here, we describe the underlying TERENO data policy in terms of provision and maintenance issues. We present data levels, and their implementation within TEODOOR. The data levels are adapted from those used by other similar systems such as CUAHSI, EarthScope and WMO. Finally, we outline recommendations for future work.

Transport of nitrogen oxides, carbon monoxide and ozone to the Alpine Global Atmosphere Watch stations Jungfraujoch (Switzerland), Zugspitze and Hohenpeissenberg (Germany), Sonnblick (Austria) and Mt. Krvavec (Slovenia)

NASA Astrophysics Data System (ADS)

Kaiser, August; Scheifinger, Helfried; Spangl, Wolfgang; Weiss, Andrea; Gilge, Stefan; Fricke, Wolfgang; Ries, Ludwig; Cemas, Danijel; Jesenovec, Brigita

The Alpine stations Zugspitze, Hohenpeissenberg, Sonnblick, Jungfraujoch and Mt. Krvavec contribute to the Global Atmosphere Watch Programme (GAW) of the World Meteorological Organization (WMO). The aim of GAW is the surveillance of the large-scale chemical composition of the atmosphere. Thus, the detection of air pollutant transport from regional sources is of particular interest. In this paper, the origin of NO x (measured with a photo-converter), CO and O 3 at the four Alpine GAW stations is studied by trajectory residence time statistics. Although these methods originated during the early 1980s, no comprehensive study of different atmospheric trace gases measured simultaneously at several background observatories in the Alps was conducted up to present. The main NO x source regions detected by the trajectory statistics are the northwest of Europe and the region covering East Germany, Czech Republic and southeast Poland, whereas the main CO source areas are the central, north eastern and eastern parts of Europe with some gradient from low to high latitudes. Subsiding air masses from west and southwest are relatively poor in NO x and CO. The statistics for ozone show strong seasonal effects. Near ground air masses are poor in ozone in winter but rich in ozone in summer. The main source for high ozone concentration in winter is air masses that subside from higher elevations, often enhanced by foehn effects at Hohenpeissenberg. During summer, the Mediterranean constitutes an important additional source for high ozone concentrations. Especially during winter, large differences between Hohenpeissenberg and the higher elevated stations are found. Hohenpeissenberg is frequently within the inversion, whereas the higher elevated stations are above the inversion. Jungfraujoch is the only station where the statistics detect an influence of air rich in CO and NO x from the Po Basin.

Wave and Current Measurements From the Coastal Storms Program (CSP) Buoy 41012 off St. Augustine, FL

NASA Astrophysics Data System (ADS)

Crout, R. L.

2008-05-01

The Coastal Storms Program (CSP) is a NOAA program that involves several different branches within NOAA. Components of the National Ocean Service, the National Weather Service, the National Marine Fisheries Service, and the Office of Oceanic and Atmospheric Research participate in CSP, which is administered by the Coastal Services Center. CSP selects an area where an impact in support of the NOAA Societal Goals can be made. The first area selected was the northeast coast of Florida in 2002. In addition to coastal water level stations and modeling efforts, a 3-meter discuss buoy (WMO 41012) was deployed off the coast of St. Augustine, FL in approximately 38 meters of water. In addition to the normal complement of meteorological sensors, Buoy 41012 contained a sensor to measure directional waves at hourly intervals, a temperature-conductivity sensor to measure near-surface temperature and salinity, and a current profiler to obtain near-surface to near-bottom currents at hourly intervals. These data on the continental shelf provide a view of the oceanography on the inner margin of the Gulf Stream. The data are served over the National Data Buoy Center's web page and over the Global Telecommunications System. The waves and currents during the period from September 2005 through December 2007 are related to coastal storms, hurricanes, tides, and Gulf Stream intrusions. During several late fall and winter periods the waves exceeded 4.5 meters. The on-offshore component of the currents appears to be tidally driven, however, predominant on- and off-shore flows are observed in response to storms and Gulf Stream intrusions. The primary component of the flow is aligned alongshore and although the tidal influence is obvious, extended periods of northward and southward currents are observed. Currents approaching 2 knots are observed at various times during the period that the buoy has been active. The high currents appear to be in response to strong wind events (atmospheric frontal passages) and Gulf Stream intrusions.

Sampling, storage, and analysis of C2-C7 non-methane hydrocarbons from the US National Oceanic and Atmospheric Administration Cooperative Air Sampling Network glass flasks.

PubMed

Pollmann, Jan; Helmig, Detlev; Hueber, Jacques; Plass-Dülmer, Christian; Tans, Pieter

2008-04-25

An analytical technique was developed to analyze light non-methane hydrocarbons (NMHC), including ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, n-hexane, isoprene, benzene and toluene from whole air samples collected in 2.5l-glass flasks used by the National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Global Monitoring Division (NOAA ESRL GMD, Boulder, CO, USA) Cooperative Air Sampling Network. This method relies on utilizing the remaining air in these flasks (which is at below-ambient pressure at this stage) after the completion of all routine greenhouse gas measurements from these samples. NMHC in sample aliquots extracted from the flasks were preconcentrated with a custom-made, cryogen-free inlet system and analyzed by gas chromatography (GC) with flame ionization detection (FID). C2-C7 NMHC, depending on their ambient air mixing ratios, could be measured with accuracy and repeatability errors of generally < or =10-20%. Larger deviations were found for ethene and propene. Hexane was systematically overestimated due to a chromatographic co-elution problem. Saturated NMHC showed less than 5% changes in their mixing ratios in glass flask samples that were stored for up to 1 year. In the same experiment ethene and propene increased at approximately 30% yr(-1). A series of blank experiments showed negligible contamination from the sampling process and from storage (<10 pptv yr(-1)) of samples in these glass flasks. Results from flask NMHC analyses were compared to in-situ NMHC measurements at the Global Atmospheric Watch station in Hohenpeissenberg, Germany. This 9-months side-by-side comparison showed good agreement between both methods. More than 94% of all data comparisons for C2-C5 alkanes, isoprene, benzene and toluene fell within the combined accuracy and precision objectives of the World Meteorological Organization Global Atmosphere Watch (WMO-GAW) for NMHC measurements.

Flood Induced Disasters and Stakeholder Involvement to Implement Integrated Food Management in Nepal

NASA Astrophysics Data System (ADS)

Gautam, N. P.

2016-12-01

Nepal, a landlocked country in South Asia covers an area of 147, 181 square kilometers. Its elevation ranges from 61m as the lowest to 8848m, the highest peak Everest in the world. More than 80% of the annual rainfall occurs in the monsoon season from June to September. Thus, due to the intense rainfall that occurs within a short period, monsoon acts as the biggest cause for the occurrence of different disastrous events including flood. Beyond it, Nepal lies at the center and southern edge of Hindu-Kush Himalayan (HKH) region, which is the youngest geological formation in the world. Hence, floods and landslides are common in this region. In Nepal, from the records of 1971-2010, floods and landslides are the second biggest cause for casualties after epidemics. Hawaii based Center of Excellence in disaster management and humanitarian assistance in 2015 has declared Nepal as 30th vulnerable country from the aspect of floods. According to WMO definition, integrated flood management (IFM) is a process of promoting an integrated rather than a fragmented approach to flood management, integrating land and water resource development in a river basin within the context of integrated water resources management (IWRM), with the aim of maximizing the net benefits from flood plains while minimizing loss of life from flooding. That is the reason why the IFM is one of the important countermeasures to be implemented in Nepal to reduce the adverse effects of floods. This study emphasizes on the existing conditions along with the challenges of IFM with respect to stakeholder involvement in the context of Nepal. It can be assured that all the highlighted issues coming out from this study will be highly valuable to policy makers, implementing agencies along with scientific and local communities to enhance IFM works in the nation for the benefits of societies.

Operational Use of the AIRS Total Column Ozone Retrievals Along with the RGB Air Mass Product as Part of the GOES-R Proving Ground

NASA Technical Reports Server (NTRS)

Folmer, Michael; Zavodsky, Bradley; Molthan, Andrew

2012-01-01

The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) Hydrometeorological Prediction Center (HPC) and Ocean Prediction Center (OPC) provide short-term and medium-range forecast guidance of heavy precipitation, strong winds, and other features often associated with mid-latitude cyclones over both land and ocean. As a result, detection of factors that lead to rapid cyclogenesis and high wind events is key to improving forecast skill. One phenomenon that has been identified with these events is the stratospheric intrusion that occurs near tropopause folds. This allows for deep mixing near the top of the atmosphere where dry air high in ozone concentrations and potential vorticity descends (sometimes rapidly) deep into the mid-troposphere. Observations from satellites can aid in detection of these stratospheric air intrusions (SAI) regions. Specifically, multispectral composite imagery assign a variety of satellite spectral bands to the red, green, and blue (RGB) color components of imagery pixels and result in color combinations that can assist in the detection of dry stratospheric air associated with PV advection, which in turn may alert forecasters to the possibility of a rapidly strengthening storm system. Single channel or RGB satellite imagery lacks quantitative information about atmospheric moisture unless the sampled brightness temperatures or other data are converted to estimates of moisture via a retrieval process. Thus, complementary satellite observations are needed to capture a complete picture of a developing storm system. Here, total column ozone retrievals derived from a hyperspectral sounder are used to confirm the extent and magnitude of SAIs. Total ozone is a good proxy for defining locations and intensity of SAIs and has been used in studies evaluating that phenomenon (e.g. Tian et al. 2007, Knox and Schmidt 2005). Steep gradients in values of total ozone seen by satellites have been linked to stratosphere-troposphere exchange (WMO, 1985).

A Study of Subseasonal Predictability of the Atmospheric Circulation Low-frequency Modes based on SL-AV forecasts

NASA Astrophysics Data System (ADS)

Kruglova, Ekaterina; Kulikova, Irina; Khan, Valentina; Tischenko, Vladimir

2017-04-01

The subseasonal predictability of low-frequency modes and the atmospheric circulation regimes is investigated based on the using of outputs from global Semi-Lagrangian (SL-AV) model of the Hydrometcentre of Russia and Institute of Numerical Mathematics of Russian Academy of Science. Teleconnection indices (AO, WA, EA, NAO, EU, WP, PNA) are used as the quantitative characteristics of low-frequency variability to identify zonal and meridional flow regimes with focus on control distribution of high impact weather patterns in the Northern Eurasia. The predictability of weekly and monthly averaged indices is estimated by the methods of diagnostic verification of forecast and reanalysis data covering the hindcast period, and also with the use of the recommended WMO quantitative criteria. Characteristics of the low frequency variability have been discussed. Particularly, it is revealed that the meridional flow regimes are reproduced by SL-AV for summer season better comparing to winter period. It is shown that the model's deterministic forecast (ensemble mean) skill at week 1 (days 1-7) is noticeably better than that of climatic forecasts. The decrease of skill scores at week 2 (days 8-14) and week 3( days 15-21) is explained by deficiencies in the modeling system and inaccurate initial conditions. It was noticed the slightly improvement of the skill of model at week 4 (days 22-28), when the condition of atmosphere is more determined by the flow of energy from the outside. The reliability of forecasts of monthly (days 1-30) averaged indices is comparable to that at week 1 (days 1-7). Numerical experiments demonstrated that the forecast accuracy can be improved (thus the limit of practical predictability can be extended) through the using of probabilistic approach based on ensemble forecasts. It is shown that the quality of forecasts of the regimes of circulation like blocking is higher, than that of zonal flow.

Web-Based Tools for Data Visualization and Decision Support for South Asia

NASA Astrophysics Data System (ADS)

Jones, N.; Nelson, J.; Pulla, S. T.; Ames, D. P.; Souffront, M.; David, C. H.; Zaitchik, B. F.; Gatlin, P. N.; Matin, M. A.

2017-12-01

The objective of the NASA SERVIR project is to assist developing countries in using information provided by Earth observing satellites to assess and manage climate risks, land use, and water resources. We present a collection of web apps that integrate earth observations and in situ data to facilitate deployment of data and water resources models as decision-making tools in support of this effort. The interactive nature of web apps makes this an excellent medium for creating decision support tools that harness cutting edge modeling techniques. Thin client apps hosted in a cloud portal eliminates the need for the decision makers to procure and maintain the high performance hardware required by the models, deal with issues related to software installation and platform incompatibilities, or monitor and install software updates, a problem that is exacerbated for many of the regional SERVIR hubs where both financial and technical capacity may be limited. All that is needed to use the system is an Internet connection and a web browser. We take advantage of these technologies to develop tools which can be centrally maintained but openly accessible. Advanced mapping and visualization make results intuitive and information derived actionable. We also take advantage of the emerging standards for sharing water information across the web using the OGC and WMO approved WaterML standards. This makes our tools interoperable and extensible via application programming interfaces (APIs) so that tools and data from other projects can both consume and share the tools developed in our project. Our approach enables the integration of multiple types of data and models, thus facilitating collaboration between science teams in SERVIR. The apps developed thus far by our team process time-varying netCDF files from Earth observations and large-scale computer simulations and allow visualization and exploration via raster animation and extraction of time series at selected points and/or regions.

Observational and modeling studies of heat, moisture, precipitation and global-scale circulation patterns

NASA Technical Reports Server (NTRS)

Vincent, Dayton G.

1994-01-01

This research grant was a revised version of an original proposal. The period of the grant was for three years with a six-month no-cost extension; thus, it was from 20 July 1990 to 19 January 1994. The objectives of the grant were to identify periods and locations of active convection centers, primarily over the Southern Hemisphere tropical Indian and Pacific Oceans; determine reasons for any periodic behavior found in the first objective; identify cases where subtropical jets over the South Pacific persisted for several days and examine the influences of tropical versus extra-tropical mechanisms in maintaining them; obtain estimates of precipitation by Q(sub 1) and Q(sub 2) budgets, including the importance of terms in each of the respective budgets, and compare these estimates to those obtained by other methods; and diagnose the distributions of moisture and precipitable water over the North Atlantic Ocean using routine analyses and satellite microwave data. To accomplish these objectives, we used grant funds to purchase several data sets, including the Global Precipitation Climate Project (GPCP) observations of station precipitation, ECMWF WCRP/TOGA archive two analyses for January 1985 - December 1990, ECMWF WMO analyses for January 1980 - December 1987, and OLR data for July 1974 - December 1991. We already had some SSM/I data and GLA analyses from a previous grant. In addition, to improve our computing power, we also used grant funds to purchase an IBM PS/2 with accessories, a NEC laser jet printer, and a microcomputer system for word processing. This report is organized as follows. Our research team is listed first. Section two contains a summary of our significant accomplishments; however, a detailed discussion of research results is not included since this information can be found in the accompanying reprints and preprints. Section three offers some concluding remarks, and a complete bibliographic summary is given in Section four.

Toward Probabilistic Risk Analyses - Development of a Probabilistic Tsunami Hazard Assessment of Crescent City, CA

NASA Astrophysics Data System (ADS)

González, F. I.; Leveque, R. J.; Hatheway, D.; Metzger, N.

2011-12-01

Risk is defined in many ways, but most are consistent with Crichton's [1999] definition based on the ''risk triangle'' concept and the explicit identification of three risk elements: ''Risk is the probability of a loss, and this depends on three elements: hazard, vulnerability, and exposure. If any of these three elements in risk increases or decreases, then the risk increases or decreases respectively." The World Meteorological Organization, for example, cites Crichton [1999] and then defines risk as [WMO, 2008] Risk = function (Hazard x Vulnerability x Exposure) while the Asian Disaster Reduction Center adopts the more general expression [ADRC, 2005] Risk = function (Hazard, Vulnerability, Exposure) In practice, probabilistic concepts are invariably invoked, and at least one of the three factors are specified as probabilistic in nature. The Vulnerability and Exposure factors are defined in multiple ways in the relevant literature; but the Hazard factor, which is the focus of our presentation, is generally understood to deal only with the physical aspects of the phenomena and, in particular, the ability of the phenomena to inflict harm [Thywissen, 2006]. A Hazard factor can be estimated by a methodology known as Probabilistic Tsunami Hazard Assessment (PTHA) [González, et al., 2009]. We will describe the PTHA methodology and provide an example -- the results of a previous application to Seaside, OR. We will also present preliminary results for a PTHA of Crescent City, CA -- a pilot project and coastal modeling/mapping effort funded by the Federal Emergency Management Agency (FEMA) Region IX office as part of the new California Coastal Analysis and Mapping Project (CCAMP). CCAMP and the PTHA in Crescent City are being conducted under the nationwide FEMA Risk Mapping, Assessment, and Planning (Risk MAP) Program which focuses on providing communities with flood information and tools they can use to enhance their mitigation plans and better protect their citizens.

Downscaling, 2-way Nesting, and Data Assimilative Modeling in Coastal and Shelf Waters of the U.S. Mid-Atlantic Bight and Gulf of Maine

NASA Astrophysics Data System (ADS)

Wilkin, J.; Levin, J.; Lopez, A.; Arango, H.

2016-02-01

Coastal ocean models that downscale output from basin and global scale models are widely used to study regional circulation at enhanced resolution and locally important ecosystem, biogeochemical, and geomorphologic processes. When operated as now-cast or forecast systems, these models offer predictions that assist decision-making for numerous maritime applications. We describe such a system for shelf waters of the Mid-Atlantic Bight (MAB) and Gulf of Maine (GoM) where the MARACOOS and NERACOOS associations of U.S. IOOS operate coastal ocean observing systems that deliver a dense observation set using CODAR HF-radar, autonomous underwater glider vehicles (AUGV), telemetering moorings, and drifting buoys. Other U.S. national and global observing systems deliver further sustained observations from moorings, ships, profiling floats, and a constellation of satellites. Our MAB and GoM re-analysis and forecast system uses the Regional Ocean Modeling System (ROMS; myroms.org) with 4-dimensional Variational (4D-Var) data assimilation to adjust initial conditions, boundary conditions, and surface forcing in each analysis cycle. Data routinely assimilated include CODAR velocities, altimeter satellite sea surface height (with coastal corrections), satellite temperature, in situ CTD data from AUGV and ships (NMFS Ecosystem Monitoring voyages), and all in situ data reported via the WMO GTS network. A climatological data assimilative analysis of hydrographic and long-term mean velocity observations specifies the regional Mean Dynamic Topography that augments altimeter sea level anomaly data and is also used to adjust boundary condition biases that would otherwise be introduced in the process of downscaling from global models. System performance is described with respect to the impact of satellite, CODAR and in situ observations on analysis skill. Results from a 2-way nested modeling system that adds enhanced resolution over the NSF OOI Pioneer Array in the central MAB are also shown.

Competence Center for Earth & Environmental Data (KomFor)

NASA Astrophysics Data System (ADS)

Diepenbroek, M.; Bernonville, S.; Bertelmann, R.; Bittner, M.; Brase, J.; Grobe, H.; Hoeck, H.; Klump, J.; Lautenschlager, M.; Schindler, U.; Sens, I.; Peters, S.; Toussaint, F.; Ulbricht, D.; Ziedorn, F.

2012-04-01

The Competence Center is planned as link between Geoscientific facilities and an existing archive network for earth and environmental data in Germany. KomFor generally aims at improving the overall availability and quality of data in a sustainable way. Practically from the users view the project will create a unique instance which accompanies scientific facilities, projects, and groups in all questions of data management - from the planning phase via data production, QA/QC, registration and long term storage to publication of data; the latter also including science publishers. In addition KomFor will supply systems and interfaces for accessing data comprising a data portal, services which allow downloading data for analysis and visualization tools (added value services), components for cross-referencing data and science articles as well as a broker function into superior global networks. KomFor is based on ICSU World Data Centers and Services located in Germany, which are collaborating in a national cluster since 2003 - the WDC Climate (WDC-C, DKRZ), WDC for Remote Sensing (WDC-RSAT, DLR), the German Research Centre for Geosciences (GfZ), and the Data Publisher for Earth & Environmental Science (PANGAEA, AWI/Marum). The cluster is complemented by the German National Library of Science and Technology (TIB). The consortium is well embedded into the international environment (WDS, IPCC, ESA, NASA, CEOS, GMES, GEOSS, INSPIRE, ESFRI, WMO, IODP, ICDP, IOC etc.) and is engaged since years in the development of standards as well as organizational structures and infrastructures for research data. Amongst others the consortium has implemented a registry service for scientific data which meanwhile is supported by an international association of libraries and is used worldwide (DataCite). A milestone was also the implementation of a web service for dynamically cross-referencing science articles with related data, initially used by Elsevier and now increasingly used by further publishers.

Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: method development and first intercomparison results

NASA Astrophysics Data System (ADS)

Eyer, S.; Tuzson, B.; Popa, M. E.; van der Veen, C.; Röckmann, T.; Rothe, M.; Brand, W. A.; Fisher, R.; Lowry, D.; Nisbet, E. G.; Brennwald, M. S.; Harris, E.; Zellweger, C.; Emmenegger, L.; Fischer, H.; Mohn, J.

2015-08-01

In situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, μmole/mole) methane is 0.1 and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to isotope-ratio mass-spectrometry (IRMS) based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers. Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX-QCLAS data and bag/flask sampling-IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and δD-CH4, respectively. Thus, the intercomparison also reveals the need for reference air samples with accurately determined isotopic composition of CH4 to further improve the interlaboratory compatibility.

Test tools and test data for the future EUMETSAT EPS-SG platform

NASA Astrophysics Data System (ADS)

Khlystova, Iryna; Sunda, Michela

2017-04-01

The EUMETSAT Polar System - Second Generation (EPS-SG) represents Europe's contribution to the future Joint Polar System (JPS), which is planned to be established together with the National Oceanic and Atmospheric Administration (NOAA) of the United States, following on from the Initial Joint Polar System (IJPS). Due to its global coverage and the variety of passive and active sensors on the EPS-SG platform, a significant positive impact on Numerical Weather Prediction (NWP) can be expected for all forecasts based on NWP in the 2020-2040 time frame. It will increase direct socio-economic benefits to Member States and leverage additional benefits through its integration into the JPS and cooperation in the context of CGMS and WMO. For the EUMETSAT will develop the EPS-SG overall system of satellites and the Overall Ground Segment (OGS) and be responsible for the Payload Data Acquisition and Processing (PDAP) system. This will include all the functionality dedicated to the L0, L1 and L2 Operational Processor, for generation of the near-real time L1 and L2 mission central products. Also the European Space Agency will develop the EPS-SG satellites and a number of instruments, with CNES and DLR playing a key role. The general processing chain should be in place and be extensively tested before the first data set is sent from the space platform to the ground. For this, numerous test tools, such as satellite data simulators (IDS) and processors prototypes (GPPs and IPPs) need to be developed and operated before the launch of the satellites. EUMETSAT cooperated with several European agencies in order to provide all the testing items in time. Here, we present the insight into the EPS-SG the logic of the test tools for the generation of the test data and provide insights into the modern space-based mission planning and preparation activities.

Towards a Novel Integrated Approach for Estimating Greenhouse Gas Emissions in Support of International Agreements

NASA Astrophysics Data System (ADS)

Reimann, S.; Vollmer, M. K.; Henne, S.; Brunner, D.; Emmenegger, L.; Manning, A.; Fraser, P. J.; Krummel, P. B.; Dunse, B. L.; DeCola, P.; Tarasova, O. A.

2016-12-01

In the recently adopted Paris Agreement the community of signatory states has agreed to limit the future global temperature increase between +1.5 °C and +2.0 °C, compared to pre-industrial times. To achieve this goal, emission reduction targets have been submitted by individual nations (called Intended Nationally Determined Contributions, INDCs). Inventories will be used for checking progress towards these envisaged goals. These inventories are calculated by combining information on specific activities (e.g. passenger cars, agriculture) with activity-related, typically IPCC-sanctioned, emission factors - the so-called bottom-up method. These calculated emissions are reported on an annual basis and are checked by external bodies by using the same method. A second independent method estimates emissions by translating greenhouse gas measurements made at regionally representative stations into regional/global emissions using meteorologically-based transport models. In recent years this so-called top-down approach has been substantially advanced into a powerful tool and emission estimates at the national/regional level have become possible. This method is already used in Switzerland, in the United Kingdom and in Australia to estimate greenhouse gas emissions and independently support the national bottom-up emission inventories within the UNFCCC framework. Examples of the comparison of the two independent methods will be presented and the added-value will be discussed. The World Meteorological Organization (WMO) and partner organizations are currently developing a plan to expand this top-down approach and to expand the globally representative GAW network of ground-based stations and remote-sensing platforms and integrate their information with atmospheric transport models. This Integrated Global Greenhouse Gas Information System (IG3IS) initiative will help nations to improve the accuracy of their country-based emissions inventories and their ability to evaluate the success of emission reductions strategies. This could foster trans-national collaboration on methodologies for estimation of emissions. Furthermore, more accurate emission knowledge will clarify the value of emission reduction efforts and could encourage countries to strengthen their reduction pledges.

RCOF in European region: current status and future perspective

NASA Astrophysics Data System (ADS)

Hovsepyan, A.

2010-09-01

Regional Climate Outlook Forums are a key component of WMO WCASP/CLIPS activities. The RCOF process pioneered in Africa in late 1990s, since then it spread worldwide, and at present climate outlook forums are being conducted nearly in all regions all over the world. The RCOF brings together experts from a climatologically homogeneous region and provides consensus based climate prediction and information, which has critical socio-economic significance. This information has been applied to reducing climate-related risks and supporting sustainable development. The RCOF process has facilitated a better understanding of the links between the past, current and future evolution of the climate system and its consequences for Members' socio-economic activities. RCOFs have greatly enhanced interactions and exchange of information between providers and users of climate information. In addition, RCOFs contribute substantially to training and capacity building in the regions targeted at. In RA VI the RCOF process was launched in 2008. The South-East European Climate Outlook Forum (SEECOF) mechanism covers mainly countries of South East Europe and Caucasus. Two SEECOFs have been successfully conducted in 2008 and 2009: SEECOF-I took place in Zagreb/Croatia in June 2008 and SEECOF-II was hosted by Hungary, Budapest, in November 2009. SEECOF-III was held as an online COF. Nevertheless, the RCOF mechanism in RA VI still needs substantial support in order to strengthen the process, to better involve the participating countries and users, to sharpen the communication of the consensus forecasts to build trust amongst the user communities, and most importantly to achieve sustainability, which is one of the priority tasks of the RAVI Working Group on Climate and Hydrology (WG CH). Through the Task Team on Regional Climate Outlook Forums (TT RCOF) the WG CH has taken responsibility for the co-ordination of the RCOF process in RA VI, in order to extend it to other parts of RA VI region, strengthen climate change section in the SEECOF, to better involve the participating countries and users, to sharpen the communication of the consensus forecasts in order to build trust amongst the user communities, and most importantly to achieve sustainability of RCOF in Europe.

Influence of biomass burning emissions on black carbon and ozone variability in the Southern Himalayas (NCO-P, 5079 m a.s.l.)

NASA Astrophysics Data System (ADS)

Putero, Davide; Landi, Tony Christian; Cristofanelli, Paolo; Marinoni, Angela; Laj, Paolo; Duchi, Rocco; Adhikary, Bhupesh; Calzolari, Francescopiero; Bonafè, Ubaldo; Stocchi, Paolo; Vuillermoz, Elisa; Bonasoni, Paolo

2013-04-01

Black carbon (BC) and tropospheric ozone (O3) play a key role in the climate system, since they are short-lived climate forcers (SLCF) that contribute to climate change. BC and O3 precursors are emitted from several natural and anthropogenic sources; one of the most important is biomass burning, i.e. the combustion of organic matter from natural or man-made activities. Studying BC and O3 variations in connection to biomass burning is critical, mainly because of the effects that these SLCF have on the ecosystems, agriculture and human health. The issue appears urgent in several regions of the world, such as South Asia, where a vast region extending from the Indian Ocean to the Himalayas is characterized by large amounts of aerosols and pollutant gases. Here we present the variability of BC and O3 concentrations observed at the Nepal Climate Observatory-Pyramid (NCO-P, 5079 m a.s.l.), the highest WMO-GAW global station, installed in the high Khumbu valley (Nepal, Everest region) since March 2006. Considering over 5 years of continuous measurements, the BC and O3 concentrations have shown an average value of 48.7 ± 12.6 ppbv and 208.1 ± 364.1 ng m-3, respectively. The possible contribution of open biomass burning to the average BC and O3 levels is investigated, using various satellite observations, such as MODIS fire products, the USGS Land Use Cover Characterization and TRMM rainfall measurements, linking these products to the air-mass back-trajectories reaching the sampling site (computed using LAGRANTO model). On 162 days (9% of the entire dataset), characterized by acute pollution events at NCO-P, 90 days (56%) were characterized by the transport of pollutants originated by agricultural and forest fires located in regions very close to the Himalayan sampling site. These analyses have shown that biomass burning emissions, especially at regional scale, are likely to play a key role in BC and O3 variations at NCO-P, particularly concerning the development of acute pollution events.

NREL Pyrheliometer Comparisons: September 25-October 6, 2017 (NPC-2017)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reda, Ibrahim M.; Dooraghi, Michael R.; Andreas, Afshin M.

Accurate measurements of direct normal (beam) solar irradiance from pyrheliometers are important for developing and deploying solar energy conversion systems, improving our understanding of the Earth's energy budget for climate change studies, and for other science and technology applications involving solar flux. Providing these measurements places many demands on the quality system used by the operator of commercially available radiometers. Maintaining accurate radiometer calibrations that are traceable to an international standard is the first step in producing research-quality solar irradiance measurements. In 1977, the World Meteorological Organization (WMO) established the World Radiometric Reference (WRR) as the international standard for themore » measurement of direct normal solar irradiance (Frohlich 1991). The WRR is an internationally recognized, detector-based measurement standard determined by the collective performance of six electrically self-calibrated absolute cavity radiometers comprising the World Standard Group (WSG). Various countries, including the United States, have contributed these specialized radiometers to the Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center (PMOD/WRC) to establish the WSG. As with all measurement systems, Absolute Cavity Radiometers (ASR) are subject to performance changes over time. Therefore, every five years the PMOD/WRC in Davos, Switzerland, hosts an International Pyrheliometer Comparison (IPC) for transferring the WRR to participating radiometers. NREL has represented the U.S. Department of Energy (DOE) in each IPC since 1980. As a result, NREL has developed and maintained a select group of absolute cavity radiometers with direct calibration traceability to the WRR, and uses these reference instruments to calibrate pyrheliometers and pyranometers using the International Organization for Standardization (ISO) 17025 accredited Broadband Outdoor Radiometer Calibration (BORCAL) process (Reda et al. 2008). National Renewable Energy Laboratory (NREL) pyrheliometer comparisons (NPCs) are held annually at the Solar Radiation Research Laboratory (SRRL) in Golden, Colorado. Open to all ACR owners and operators, each NPC provides an opportunity to determine the unique WRR transfer factor (WRR-TF) for each participating pyrheliometer. By adjusting all subsequent pyrheliometer measurements by the appropriate WRR-TF, the solar irradiance data are traceable to the WRR.« less

Long-term prognosis of young breast cancer patients (≤40 years) who did not receive adjuvant systemic treatment: protocol for the PARADIGM initiative cohort study

PubMed Central

Dackus, Gwen MHE; ter Hoeve, Natalie D; Opdam, Mark; Vreuls, Willem; Varga, Zsuzsanna; Koop, Esther; Willems, Stefan M; Van Deurzen, Carolien HM; Groen, Emilie J; Cordoba, Alicia; Bart, Jos; Mooyaart, Antien L; van den Tweel, Jan G; Zolota, Vicky; Wesseling, Jelle; Sapino, Anna; Chmielik, Ewa; Ryska, Ales; Amant, Frederic; Broeks, Annegien; Kerkhoven, Ron; Stathonikos, Nikolas; Veta, Mitko; Voogd, Adri; Jozwiak, Katarzyna; Hauptmann, Michael; Hoogstraat, Marlous; Schmidt, Marjanka K; Sonke, Gabe; van der Wall, Elsken; Siesling, Sabine; van Diest, Paul J; Linn, Sabine C

2017-01-01

Introduction Currently used tools for breast cancer prognostication and prediction may not adequately reflect a young patient’s prognosis or likely treatment benefit because they were not adequately validated in young patients. Since breast cancers diagnosed at a young age are considered prognostically unfavourable, many treatment guidelines recommend adjuvant systemic treatment for all young patients. Patients cured by locoregional treatment alone are, therefore, overtreated. Lack of prognosticators for young breast cancer patients represents an unmet medical need and has led to the initiation of the PAtients with bReAst cancer DIaGnosed preMenopausally (PARADIGM) initiative. Our aim is to reduce overtreatment of women diagnosed with breast cancer aged ≤40 years. Methods and analysis All young, adjuvant systemic treatment naive breast cancer patients, who had no prior malignancy and were diagnosed between 1989 and 2000, were identified using the population based Netherlands Cancer Registry (n=3525). Archival tumour tissues were retrieved through linkage with the Dutch nationwide pathology registry. Tissue slides will be digitalised and placed on an online image database platform for clinicopathological revision by an international team of breast pathologists. Immunohistochemical subtype will be assessed using tissue microarrays. Tumour RNA will be isolated and subjected to next-generation sequencing. Differences in gene expression found between patients with a favourable and those with a less favourable prognosis will be used to establish a prognostic classifier, using the triple negative patients as proof of principle. Ethics and dissemination Observational data from the Netherlands Cancer Registry and left over archival patient material are used. Therefore, the Dutch law on Research Involving Human Subjects Act (WMO) is not applicable. The PARADIGM study received a ‘non-WMO’ declaration from the Medical Ethics Committee of the Netherlands Cancer Institute - Antoni van Leeuwenhoek hospital, waiving individual patient consent. All data and material used are stored in a coded way. Study results will be presented at international (breast cancer) conferences and published in peer-reviewed, open-access journals. PMID:29138205

Nowcasting in the FROST-2014 Sochi Olympic project

NASA Astrophysics Data System (ADS)

Bica, Benedikt; Wang, Yong; Joe, Paul; Isaac, George; Kiktev, Dmitry; Bocharnikov, Nikolai

2013-04-01

FROST (Forecast and Research: the Olympic Sochi Testbed) 2014 is a WMO WWRP international project aimed at development, implementation, and demonstration of capabilities of short-range numerical weather prediction and nowcasting technologies for mountainous terrain in winter season. Sharp weather contrasts and high spatial and temporal variability are typical for the region of the Sochi-2014 Olympics. Steep mountainous terrain and an intricate mixture of maritime sub-tropical and Alpine environments make weather forecasting in this region extremely challenging. Goals of the FROST-2014 project: • To develop a comprehensive information resource of Alpine winter weather observations; • To improve and exploit: o Nowcasting systems of high impact weather phenomena (precipitation type and intensity, snow levels, visibility, wind speed, direction and gusts) in complex terrain; o High-resolution deterministic and ensemble mesoscale forecasts in winter complex terrain environment; • To improve the understanding of physics of high impact weather phenomena in the region; • To deliver forecasts (Nowcasts) to Olympic weather forecasters and decision makers and assess benefits of forecast improvement. 46 Automatic Meteorological Stations (AMS) were installed in the Olympic region by Roshydromet, by owners of sport venues and by the Megafon corporation, provider of mobile communication services. The time resolution of AMS observations does not exceed 10 minutes. For a subset of the stations it is even equal to 1 min. Data flow from the new dual polarization Doppler weather radar WRM200 in Sochi was organized at the end of 2012. Temperature/humidity and wind profilers and two Micro Rain Radars (MRR) will supplement the network. Nowcasting potential of NWP models participating in the project (COSMO, GEM, WRF, AROME, HARMONIE) is to be assessed for direct and post-processed (e.g. Kalman filter, 1-D model, MOS) model forecasts. Besides the meso-scale models, the specialized nowcasting systems are expected to be used in the project - ABOM, CARDS, INCA, INTW, STEPS, MeteoExpert. FROST-2014 is intended as an 'end-to-end' project. Its products will be used by local forecasters for meteorological support of the Olympics and preceding test sport events. The project is open for new interested participants. Additional information is available at http://frost2014.meteoinfo.ru.

Greenland ice sheet surface mass-balance modeling in a 131-year perspective, 1950-2080

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mernild, Sebastian Haugard; Liston, Glen; Hiemstra, Christopher

2009-01-01

Fluctuations in the Greenland Ice Sheet (GrIS) surface mass-balance (SMB) and freshwater influx to the surrounding oceans closely follow climate fluctuations and are of considerable importance to the global eustatic sea level rise. SnowModel, a state-of-the-art snow-evolution modeling system, was used to simulate variations in the GrIS melt extent, surface water balance components, changes in SMB, and freshwater influx to the ocean. The simulations are based on the IPCC scenario AlB modeled by the HIRHAM4 RCM (using boundary conditions from ECHAM5 AOGCM) from 1950 through 2080. In-situ meteorological station (GC-Net and WMO DMI) observations from inside and outside the GrISmore » were used to validate and correct RCM output data before it was used as input for SnowModel. Satellite observations and independent SMB studies were used to validate the SnowModel output and confirm the model's robustness. We simulated a {approx}90% increase in end-of-summer surface melt extent (0.483 x 10{sup 6} km{sup 2}) from 1950 to 2080, and a melt index (above 2,000-m elevation) increase of 138% (1.96 x 10{sup 6} km{sup 2} x days). The greatest difference in melt extent occured in the southern part of the GrIS, and the greatest changes in the number of melt days was seen in the eastern part of the GrIS ({approx}50-70%) and was lowest in the west ({approx}20-30%). The rate of SMB loss, largely tied to changes in ablation processes, lead to an enhanced average loss of 331 km{sup 3} from 1950 to 2080, an average 5MB level of -99 km{sup 3} for the period 2070-2080. GrIS surface freshwater runoff yielded an eustatic rise in sea level from 0.8 {+-} 0.1 (1950-1959) to 1.9 {+-} 0.1 mm (2070-2080) sea level equivalent (SLE) y{sup -1}. The accumulated GrIS freshwater runoff contribution from surface melting equaled 160 mm SLE from 1950 through 2080.« less

Components for Maintaining and Publishing Earth Science Vocabularies

NASA Astrophysics Data System (ADS)

Cox, S. J. D.; Yu, J.

2014-12-01

Shared vocabularies are an important aid to geoscience data interoperability. Many organizations maintain useful vocabularies, with Geologic Surveys having a particularly long history of vocabulary and lexicon development. However, the mode of publication is heterogeneous, ranging from PDFs and HTML web pages, spreadsheets and CSV, through various user-interfaces and APIs. Update and maintenance ranges from tightly-governed and externally opaque, through various community processes, all the way to crowd-sourcing ('folksonomies'). A general expectation, however, is for greater harmonization and vocabulary re-use. In order to be successful this requires (a) standardized content formalization and APIs (b) transparent content maintenance and versioning. We have been trialling a combination of software dealing with registration, search and linking. SKOS is designed for formalizing multi-lingual, hierarchical vocabularies, and has been widely adopted in earth and environmental sciences. SKOS is an RDF vocabulary, for which SPARQL is the standard low-level API. However, for interoperability between SKOS vocabulary sources, a SKOS-based API (i.e. based on the SKOS predicates prefLabel, broader, narrower, etc) is required. We have developed SISSvoc for this purpose, and used it to deploy a number of vocabularies on behalf of the IUGS, ICS, NERC, OGC, the Australian Government, and CSIRO projects. SISSvoc Search provides simple search UI on top of one or more SISSvoc sources. Content maintenance is composed of many elements, including content-formalization, definition-update, and mappings to related vocabularies. Typically there is a degree of expert judgement required. In order to provide confidence in users, two requirements are paramount: (i) once published, a URI that denotes a vocabulary item must remain dereferenceable; (ii) the history and status of the content denoted by a URI must be available. These requirements match the standard 'registration' paradigm which is implemented in the Linked Data Registry, which is currently used by WMO and the UK Environment Agency for publication of vocabularies. Together, these components provide a powerful and flexible system for providing earth science vocabularies for the community, consistent with semantic web and linked-data principles.

The Global Heat Health Information Network (GHHIN): Putting the Pieces Together

NASA Astrophysics Data System (ADS)

Jones, H.; Shumake, J.; Trtanj, J.

2017-12-01

Human exposure to extreme heat is one of the principal and most manageable impacts of climate on human health. Yet, every year worldwide, tens of thousands of people die as a result of avoidable heat-induced health consequences and countless others experience reduced labor productivity, physiological stress and ill health. The IPCC predicts with high confidence, that the observed trend of longer lasting, more frequent, more intense, and earlier onset heat waves will continue into the future. This situation requires the global health community to aggressively confront this recognized risk. Many countries and cities worldwide have developed heat action plans or heat health early warning systems, but these efforts are only connected in an ad-hoc fashion, use a broad range of non-standardized tools, methods, and approaches, and lack a clear mechanism to learn from each other in order to more rapidly advance health protection. To address this gap and accelerate heat health protection, the Global Heat Health Information Network (GHHIN) was launched in June 2016, by the WMO/WHO joint office for Climate and Health and the NOAA Climate Program Office. GHHIN is envisioned to be an independent, voluntary, member driven forum of scientists, professionals, and policymakers focused on enhancing and multiplying the global and local learning and resilience-building for heat health that is already occurring. GHHIN seeks to serve as a catalyst, knowledge broker, disseminator of good practices, and a forum for facilitating exchange and identifying needs. GHHIN will promote evidence-driven interventions, shared-learning, co-production of information, synthesis of priorities and capacity building to empower actors to take more effective and informed life-saving preparedness and planning measures. GHHIN is working toward several activities in 2018. The first Global Heat Health Synthesis report will be published to synthesize the state of science and practice to monitor, predict, and address extreme heat risks to human health, and the first GHHIN Global Forum will be held to bring together the community of experts and practitioners to share experience, inform a global common agenda, strengthen the network, and formally launch GHHIN. This presentation serves as an overview, status update, and invitation to become involved in GHHIN.

Duloxetine in OsteoArthritis (DOA) study: study protocol of a pragmatic open-label randomised controlled trial assessing the effect of preoperative pain treatment on postoperative outcome after total hip or knee arthroplasty.

PubMed

Blikman, T; Rienstra, W; van Raaij, T M; ten Hagen, A J; Dijkstra, B; Zijlstra, W P; Bulstra, S K; van den Akker-Scheek, I; Stevens, M

2016-03-01

Residual pain is a major factor in patient dissatisfaction following total hip arthroplasty or total knee arthroplasty (THA/TKA). The proportion of patients with unfavourable long-term residual pain is high, ranging from 7% to 34%. There are studies indicating that a preoperative degree of central sensitisation (CS) is associated with poorer postoperative outcomes and residual pain. It is thus hypothesised that preoperative treatment of CS could enhance postoperative outcomes. Duloxetine has been shown to be effective for several chronic pain syndromes, including knee osteoarthritis (OA), in which CS is most likely one of the underlying pain mechanisms. This study aims to evaluate the postoperative effects of preoperative screening and targeted duloxetine treatment of CS on residual pain compared with care-as-usual. This multicentre, pragmatic, prospective, open-label, randomised controlled trial includes patients with idiopathic hip/knee OA who are on a waiting list for primary THA/TKA. Patients at risk for CS will be randomly allocated to the preoperative duloxetine treatment programme group or the care-as-usual control group. The primary end point is the degree of postoperative pain 6 months after THA/TKA. Secondary end points at multiple time points up to 12 months postoperatively are: pain, neuropathic pain-like symptoms, (pain) sensitisation, pain catastrophising, joint-associated problems, physical activity, health-related quality of life, depressive and anxiety symptoms, and perceived improvement. Data will be analysed on an intention-to-treat basis. The study is approved by the local Medical Ethics Committee (METc 2014/087) and will be conducted according to the principles of the Declaration of Helsinki (64th, 2013) and the Good Clinical Practice standard (GCP), and in compliance with the Medical Research Involving Human Subjects Act (WMO). 2013-004313-41; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Geoinformation web-system for processing and visualization of large archives of geo-referenced data

NASA Astrophysics Data System (ADS)

Gordov, E. P.; Okladnikov, I. G.; Titov, A. G.; Shulgina, T. M.

2010-12-01

Developed working model of information-computational system aimed at scientific research in area of climate change is presented. The system will allow processing and analysis of large archives of geophysical data obtained both from observations and modeling. Accumulated experience of developing information-computational web-systems providing computational processing and visualization of large archives of geo-referenced data was used during the implementation (Gordov et al, 2007; Okladnikov et al, 2008; Titov et al, 2009). Functional capabilities of the system comprise a set of procedures for mathematical and statistical analysis, processing and visualization of data. At present five archives of data are available for processing: 1st and 2nd editions of NCEP/NCAR Reanalysis, ECMWF ERA-40 Reanalysis, JMA/CRIEPI JRA-25 Reanalysis, and NOAA-CIRES XX Century Global Reanalysis Version I. To provide data processing functionality a computational modular kernel and class library providing data access for computational modules were developed. Currently a set of computational modules for climate change indices approved by WMO is available. Also a special module providing visualization of results and writing to Encapsulated Postscript, GeoTIFF and ESRI shape files was developed. As a technological basis for representation of cartographical information in Internet the GeoServer software conforming to OpenGIS standards is used. Integration of GIS-functionality with web-portal software to provide a basis for web-portal’s development as a part of geoinformation web-system is performed. Such geoinformation web-system is a next step in development of applied information-telecommunication systems offering to specialists from various scientific fields unique opportunities of performing reliable analysis of heterogeneous geophysical data using approved computational algorithms. It will allow a wide range of researchers to work with geophysical data without specific programming knowledge and to concentrate on solving their specific tasks. The system would be of special importance for education in climate change domain. This work is partially supported by RFBR grant #10-07-00547, SB RAS Basic Program Projects 4.31.1.5 and 4.31.2.7, SB RAS Integration Projects 4 and 9.

Comparative analysis of atmosphere temperature variability for Northern Eurasia based on the Reanalysis and in-situ observed data

NASA Astrophysics Data System (ADS)

Shulgina, T.; Genina, E.; Gordov, E.; Nikitchuk, K.

2009-04-01

At present numerous data archives which include meteorological observations as well as climate processes modeling data are available for Earth Science specialists. Methods of mathematical statistics are widely used for their processing and analysis. In many cases they represent the only way of quantitative assessment of the meteorological and climatic information. Unified set of analysis methods allows us to compare climatic characteristics calculated on the basis of different datasets with the purpose of performing more detailed analysis of climate dynamics for both regional and global levels. The report presents the results of comparative analysis of atmosphere temperature behavior for the Northern Eurasia territory for the period from 1979 to 2004 based on the NCEP/NCAR Reanalysis, NCEP/DOE Reanalysis AMIP II, JMA/CRIEPI JRA-25 Reanalysis, ECMWF ERA-40 Reanalysis data and observation data obtained from meteorological stations of the former Soviet Union. Statistical processing of atmosphere temperature data included analysis of time series homogeneity of climate indices approved by WMO, such as "Number of frost days", "Number of summer days", "Number of icing days", "Number of tropical nights", etc. by means of parametric methods of mathematical statistics (Fisher and Student tests). That allowed conducting comprehensive research of spatio-temporal features of the atmosphere temperature. Analysis of the atmosphere temperature dynamics revealed inhomogeneity of the data obtained for large observation intervals. Particularly, analysis performed for the period 1979 - 2004 showed the significant increase of the number of frost and icing days approximately by 1 day for every 2 years and decrease roughly by 1 day for 2 years for the number of summer days. Also it should be mentioned that the growth period mean temperature have increased by 1.5 - 2° C for the time period being considered. The usage of different Reanalysis datasets in conjunction with in-situ observed data allowed comparing of climate indices values calculated on the basis of different datasets that improves the reliability of the results obtained. Partial support of SB RAS Basic Research Program 4.5.2 (Project 2) is acknowledged.

Water isotope systematics: Improving our palaeoclimate interpretations

USGS Publications Warehouse

Jones, M. D.; Dee, S.; Anderson, L.; Baker, A.; Bowen, G.; Noone, D.

2016-01-01

The stable isotopes of oxygen and hydrogen, measured in a variety of archives, are widely used proxies in Quaternary Science. Understanding the processes that control δ18O change have long been a focus of research (e.g. Shackleton and Opdyke, 1973; Talbot, 1990 ; Leng, 2006). Both the dynamics of water isotope cycling and the appropriate interpretation of geological water-isotope proxy time series remain subjects of active research and debate. It is clear that achieving a complete understanding of the isotope systematics for any given archive type, and ideally each individual archive, is vital if these palaeo-data are to be used to their full potential, including comparison with climate model experiments of the past. Combining information from modern monitoring and process studies, climate models, and proxy data is crucial for improving our statistical constraints on reconstructions of past climate variability.As climate models increasingly incorporate stable water isotope physics, this common language should aid quantitative comparisons between proxy data and climate model output. Water-isotope palaeoclimate data provide crucial metrics for validating GCMs, whereas GCMs provide a tool for exploring the climate variability dominating signals in the proxy data. Several of the studies in this set of papers highlight how collaborations between palaeoclimate experimentalists and modelers may serve to expand the usefulness of palaeoclimate data for climate prediction in future work.This collection of papers follows the session on Water Isotope Systematics held at the 2013 AGU Fall Meeting in San Francisco. Papers in that session, the breadth of which are represented here, discussed such issues as; understanding sub-GNIP scale (Global Network for Isotopes in Precipitation, (IAEA/WMO, 2006)) variability in isotopes in precipitation from different regions, detailed examination of the transfer of isotope signals from precipitation to geological archives, and the implications of advances in understanding in these areas for the interpretation of palaeo records and proxy data – climate model comparison.Here, we briefly review these areas of research, and discuss challenges for the water isotope community in improving our ability to partition climate vs. auxiliary signals in palaeoclimate data.

Intercomparison of open-path trace gas measurements with two dual-frequency-comb spectrometers

DOE PAGES

Waxman, Eleanor M.; Cossel, Kevin C.; Truong, Gar-Wing; ...

2017-09-11

We present the first quantitative intercomparison between two open-path dual-comb spectroscopy (DCS) instruments which were operated across adjacent 2 km open-air paths over a 2-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6023 to 6376 cm −1 (1568 to 1660 nm), corresponding to a 355 cm −1 bandwidth, at 0.0067 cm −1 sample spacing. The measured absorption spectra agree with each other to within 5 × 10 −4 in absorbance without any external calibration of either instrument. The absorption spectra are fit to retrieve path-integrated concentrations for carbon dioxide (CO 2), methane (CH 4), water (H 2O), and deuteratedmore » water (HDO). The retrieved dry mole fractions agree to 0.14 % (0.57 ppm) for CO 2, 0.35 % (7 ppb) for CH 4, and 0.40 % (36 ppm) for H 2O at  ∼  30 s integration time over the 2-week measurement campaign, which included 24 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a World Meteorological Organization (WMO)-calibrated cavity ring-down point sensor located along the path with good agreement. Short-term and long-term differences between the open-path DCS and point sensor are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the 2-week measurement campaign yields diurnal cycles of CO 2 and CH 4 that are consistent with the presence of local sources of CO 2 and absence of local sources of CH 4.« less

A Preliminary Assessment of Orbiting Carbon Observatory-2 (OCO-2) Measurements Using TCCON Data

NASA Astrophysics Data System (ADS)

Wennberg, P. O.; Fisher, B.; Roehl, C. M.; Wunch, D.; Osterman, G. B.; Eldering, A.; Naylor, B. J.; Nguyen, H.; Mandrake, L.; O'Dell, C.; Frankenberg, C.; Natraj, V.; Taylor, T.; Smyth, M.; Crisp, D.; Pollock, H. R.; Payne, V.; Gunson, M. R.; Salawitch, R. J.

2014-12-01

The NASA Orbiting Carbon Observatory-2 (OCO-2) successfully launched from Vandenberg Air Force Base in California on July 2, 2014. The mission provides remotely-sensed measurements of the column-averaged dry air mole fraction of carbon dioxide from space. In order to insure the quality of the space-based observations, a detailed validation program was developed for the original OCO mission. During the time period between the original OCO launch failure and the successful launch of OCO-2, that validation methodology was tested and refined using data from the Japanese Greenhouse gases Observing SATellite (GOSAT) as part of the NASA Atmospheric CO2 Observations from Space (ACOS) project. At the core of the OCO-2 validation plan are comparisons of the satellite data to observations from Total Carbon Column Observation Network (TCCON), a network of ground based Fourier Transform Spectrometers. The TCCON instruments provide "ground truth", allowing for determination of bias in the space-based observations. The TCCON observations are, in turn, traceable to the World Meteorological Organization (WMO) standards through aircraft and balloon-borne profile observations at the TCCON locations. OCO-2 is capable of making measurements in three observation modes: nadir; glint; and target. The initial operational mode for OCO-2 alternates between nadir and glint mode every 16 days with target mode observations initiated by commanding the spacecraft to point to specific surface location. Of the 19 locations that can be observed by OCO-2 in target mode, 18 are TCCON sites. The decision to target a specific TCCON site is based on a variety of criteria, including the local weather forecast, the operational status of the station, and the time since previous observation of that site. In addition, the coincidence criteria to utilize in comparison between the satellite and TCCON measurements have been refined during the ACOS project and will be utilized to compare OCO-2 nadir and glint observations with TCCON data. In this presentation, we will show preliminary comparisons between OCO-2 and TCCON, using data from all satellite observing modes.

Towards the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC)

NASA Astrophysics Data System (ADS)

Fuglestvedt, J. S.; Masson-Delmotte, V.; Zhai, P.; Pirani, A.

2016-12-01

The IPCC, set up in 1988 by WMO and UNEP, is the international body for assessing the science related to climate change. The reports of the IPCC include Assessments, Synthesis and Special Reports (and their Summaries for Policymakers), as well as Methodological Reports, providing policymakers with regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation. These assessments are policy-relevant, but not policy-prescriptive, and based on the assessment of the published literature. The assessments of the IPCC follow precise procedures to ensure that they provide a rigorous and balanced scientific information. Particularly critical is the volunteer involvment of tens of scientists involved in the scoping of each report, as well as the work of hundreds of Coordinating Lead Authors and Lead Authors of reports, with the complementary expertise of hundreds of sollicited Contributing Authors. The review process plays a key role in the open and transparent process underlying the IPCC reports. It is organized in multiple rounds and mobilizes thousands of other experts, a process monitored by Review Editors. The author teams develop rigorous methodologies to report the degree of confidence associated with each finding and report information with uncertainty. As a result, successive IPCC reports provide regular steps to determine matured climate science, through robust findings, but also emerging research pathways, and facilitate science maturation through analyses of multiple perspectives provided by the scientific literature in a comprehensive approach. While the IPCC does not conduct its own scientific research, the timeline of the IPCC reports acts as a stimulation for the research community, especially for internationally coordinated research programmes associated with global climate projections. These aspects will be developed in this presentation, with a focus on Working Group I (the physical science basis), and the 6th Assessment Report (AR6). For more information, see : www.ipcc.ch For new special reports planned in 2018-2019 : http://www.ipcc.ch/activities/activities.shtml For the strategic planning schedule for the AR6 : http://www.ipcc.ch/activities/pdf/ar6_WSPSchedule_07072016.pdf

Proposed School of Earth And Space Sciences, Hyderabad, India

NASA Astrophysics Data System (ADS)

Aswathanarayana, U.

2004-05-01

The hallmarks of the proposed school in the University of Hyderabad, Hyderabad,India, would be synergy, inclusivity and globalism. The School will use the synergy between the earth (including oceanic and atmospheric realms), space and information sciences to bridge the digital divide, and promote knowledge-driven and job-led economic development of the country. It will endeavour to (i) provide the basic science underpinnings for Space and Information Technologies, (ii) develop new methodologies for the utilization of natural resources (water, soils, sediments, minerals, biota, etc.)in ecologically-sustainable, employment-generating and economically-viable ways, (iii) mitigate the adverse consequences of natural hazards through preparedness systems,etc. The School will undertake research in the inter-disciplinary areas of earth and space sciences (e.g. climate predictability, satellite remote sensing of soil moisture) and linking integrative science with the needs of the decision makers. It will offer a two-year M.Tech. (four semesters, devoted to Theory, Tools, Applications and Dissertation, respectively ) course in Earth and Space Sciences. The Applications will initially cover eight course clusters devoted to Water Resources Management, Agriculture, Ocean studies, Energy Resources, Urban studies, Environment, Natural Hazards and Mineral Resources Management. The School will also offer a number of highly focused short-term refresher courses / supplementary courses to enable cadres to update their knowledge and skills. The graduates of the School would be able to find employment in macro-projects, such as inter-basin water transfers, and Operational crop condition assessment over large areas, etc. as well as in micro-projects, such as rainwater harvesting, and marketing of remote sensing products to stake-holders (e.g. precision agricultural advice to the farmers, using the large bandwidth of thousands of kilometres of unlit optical fibres). As the School is highly interdisciplinary, it will seek to cooperate not only with national public institutions, such as NRSA, NGRI, AMD, IMD, NIO, and national industrial houses, such as Reliance, but also with international institutions such as WMO, Geneva, CIRES and NOAA in Boulder, Colorado, USA, and University of Paris, Paris, France, etc.

An Evaluation of C1-C3 Hydrochlorofluorocarbon (HCFC) Metrics: Lifetimes, Ozone Depletion Potentials, Radiative Efficiencies, Global Warming and Global Temperature Potentials

NASA Astrophysics Data System (ADS)

Burkholder, J. B.; Papanastasiou, D. K.; Marshall, P.

2017-12-01

Hydrochlorofluorocarbons (HCFCs) have been used as chlorofluorocarbon (CFC) substitutes in a number of applications, e.g. refrigerator and air-conditioning systems. Although HCFCs have lower ozone-depletion potentials (ODPs) compared to CFCs, they are potent greenhouse gases. The twenty-eighth meeting of the parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (Kigali, 2016) included a list of 274 HCFCs to be controlled under the Montreal Protocol. However, from this list, only 15 of the HCFCs have values for their atmospheric lifetime, ODP, global warming potential (GWP), and global temperature potential (GTP) that are based on fundamental experimental studies, while 48 are registered compounds. In this work, we present a comprehensive evaluation of the atmospheric lifetimes, ODPs, radiative efficiencies (REs), GWPs, and GTPs for all 274 HCFCs to be included in the Montreal Protocol. Atmospheric lifetimes were estimated based on HCFC reactivity with OH radicals and O(1D), as well as their removal by UV photolysis using structure activity relationships and reactivity trends. ODP values are based on the semi-empirical approach described in the WMO/UNEP ozone assessment. Radiative efficiencies were estimated, based on infrared spectra calculated using theoretical electronic structure methods (Gaussian 09). GWPs and GTPs were calculated relative to CO2 using our estimated atmospheric lifetimes and REs. The details of the methodology will be discussed as well as the associated uncertainties. This study has provided a consistent set of atmospheric metrics for a wide range of HCFCs that support future policy decisions. More accurate metrics for a specific HCFC, if desired, would require fundamental laboratory studies to better define the OH reactivity and infrared absorption spectrum of the compound of interest. Overall, HCFCs within the same family (isomers) show a large ODP, GWP, GTP dependence on the molecular geometry of the isomers. The atmospheric lifetime of HCFCs is predominantly determined by reaction with the OH radical, with photolysis making only a minor contribution for long-lived highly chlorinated compounds. RE values are within the 0.05 and 0.3 W m-2 ppb-1 range with highly fluorinated HCFCs having the largest RE values.

Validation of crowdsourced automatic rain gauge measurements in Amsterdam

NASA Astrophysics Data System (ADS)

de Vos, Lotte; Leijnse, Hidde; Overeem, Aart; Uijlenhoet, Remko

2016-04-01

The increasing number of privately owned weather stations and the facilitating role the internet to make this data publicly available, has led to several online platforms that collect and visualize crowdsourced weather data. This has resulted in ever increasing freely available datasets of weather measurements generated by amateur weather enthusiasts. Because of the lack of quality control and the frequent absence of metadata, these measurements are often considered as unreliable. Given the often large variability of weather variables in space and time, and the generally low number of official weather stations, this growing quantity of crowdsourced data may become an important additional source of information. Amateur weather observations have become more frequent over the past decade due to weather stations becoming more user-friendly and affordable. The variables measured by these weather stations are temperature, pressure and dew point, and in some cases wind and rainfall. Meteorological data from crowdsourced automatic weather stations in cities have primarily been used to examine the urban heat island effect. Thus far, these studies have focused on the comparison of the crowdsourced station temperature measurements with a nearby WMO-standard weather station, which is often located in a rural area or the outskirts of a city, generally not being representative of the city center. Instead of temperature, the rainfall measurements by the stations are examined. This research focuses on the combined ability of a large number of privately owned weather stations in an urban setting to correctly monitor rainfall. A set of 64 automatic weather stations distributed over Amsterdam (The Netherlands) that have at least 3 months of precipitation measurement during one year are evaluated. Precipitation measurements from stations are compared to a merged radar-gauge precipitation product. Disregarding sudden jumps in station measured precipitation, the accumulative rainfall over time in most stations showed an underestimation of rainfall compared to the accumulative values found in the corresponding radar pixel of the reference. Special consideration is given to the identification of faulty measurements without the need to obtain additional meta-data, such as setup and surroundings. This validation will show the potential of crowdsourced automatic weather stations for future urban rainfall monitoring.

Direct normal irradiance related definitions and applications: The circumsolar issue

DOE PAGES

Blanc, P.; Espinar, B.; Geuder, N.; ...

2014-10-21

The direct irradiance received on a plane normal to the sun, called direct normal irradiance (DNI), is of particular relevance to concentrated solar technologies, including concentrating solar thermal plants and concentrated photovoltaic systems. Following various standards from the International Organization for Standardization (ISO), the DNI definition is related to the irradiance from a small solid angle of the sky, centered on the position of the sun. Half-angle apertures of pyrheliometers measuring DNI have varied over time, up to ≈10°. The current recommendation of the World Meteorological Organization (WMO) for this half-angle is 2.5°. Solar concentrating collectors have an angular acceptancemore » function that can be significantly narrower, especially for technologies with high concentration ratios. The disagreement between the various interpretations of DNI, from the theoretical definition used in atmospheric physics and radiative transfer modeling to practical definitions corresponding to specific measurements or conversion technologies is significant, especially in the presence of cirrus clouds or large concentration of aerosols. Under such sky conditions, the circumsolar radiation—i.e. the diffuse radiation coming from the vicinity of the sun—contributes significantly to the DNI ground measurement, although some concentrating collectors cannot utilize the bulk of it. These issues have been identified in the EU-funded projects MACC-II (Monitoring Atmospheric Composition and Climate-Interim Implementation) and SFERA (Solar Facilities for the European Research Area), and have been discussed within a panel of international experts in the framework of the Solar Heating and Cooling (SHC) program of the International Energy Agency’s (IEA’s) Task 46 “ Solar Resource Assessment and Forecasting”. In accordance with these discussions, the terms of reference related to DNI are specified here. The important role of circumsolar radiation is evidenced, and its potential contribution is evaluated for typical atmospheric conditions. Thus, thorough analysis of performance of concentrating solar systems, it is recommended that, in addition to the conventional DNI related to 2.5° half-angle of today’s pyrheliometers, solar resource data sets also report the sunshape, the circumsolar contribution or the circumsolar ratio (CSR).« less

UTCI—Why another thermal index?

NASA Astrophysics Data System (ADS)

Jendritzky, Gerd; de Dear, Richard; Havenith, George

2012-05-01

Existing procedures for the assessment of the thermal environment in the fields of public weather services, public health systems, precautionary planning, urban design, tourism and recreation and climate impact research exhibit significant shortcomings. This is most evident for simple (mostly two-parameter) indices, when comparing them to complete heat budget models developed since the 1960s. ISB Commission 6 took up the idea of developing a Universal Thermal Climate Index (UTCI) based on the most advanced multi-node model of thermoregulation representing progress in science within the last three to four decades, both in thermo-physiological and heat exchange theory. Creating the essential research synergies for the development of UTCI required pooling the resources of multidisciplinary experts in the fields of thermal physiology, mathematical modelling, occupational medicine, meteorological data handling (in particular radiation modelling) and application development in a network. It was possible to extend the expertise of ISB Commission 6 substantially by COST (a European programme promoting Cooperation in Science and Technology) Action 730 so that finally over 45 scientists from 23 countries (Australia, Canada, Israel, several Europe countries, New Zealand, and the United States) worked together. The work was performed under the umbrella of the WMO Commission on Climatology (CCl). After extensive evaluations, Fiala's multi-node human physiology and thermal comfort model (FPC) was adopted for this study. The model was validated extensively, applying as yet unused data from other research groups, and extended for the purposes of the project. This model was coupled with a state-of-the-art clothing model taking into consideration behavioural adaptation of clothing insulation by the general urban population in response to actual environmental temperature. UTCI was then derived conceptually as an equivalent temperature (ET). Thus, for any combination of air temperature, wind, radiation, and humidity (stress), UTCI is defined as the isothermal air temperature of the reference condition that would elicit the same dynamic response (strain) of the physiological model. As UTCI is based on contemporary science its use will standardise applications in the major fields of human biometeorology, thus making research results comparable and physiologically relevant.

The future for the Global Sea Level Observing System (GLOSS) Sea Level Data Rescue

NASA Astrophysics Data System (ADS)

Bradshaw, Elizabeth; Matthews, Andrew; Rickards, Lesley; Aarup, Thorkild

2016-04-01

Historical sea level data are rare and unrepeatable measurements with a number of applications in climate studies (sea level rise), oceanography (ocean currents, tides, surges), geodesy (national datum), geophysics and geology (coastal land movements) and other disciplines. However, long-term time series are concentrated in the northern hemisphere and there are no records at the Permanent Service for Mean Sea Level (PSMSL) global data bank longer than 100 years in the Arctic, Africa, South America or Antarctica. Data archaeology activities will help fill in the gaps in the global dataset and improve global sea level reconstruction. The Global Sea Level Observing System (GLOSS) is an international programme conducted under the auspices of the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology. It was set up in 1985 to collect long-term tide gauge observations and to develop systems and standards "for ocean monitoring and flood warning purposes". At the GLOSS-GE-XIV Meeting in 2015, GLOSS agreed on a number of action items to be developed in the next two years. These were: 1. To explore mareogram digitisation applications, including NUNIEAU (more information available at: http://www.mediterranee.cerema.fr/logiciel-de-numerisation-des-enregistrements-r57.html) and other recent developments in scanning/digitisation software, such as IEDRO's Weather Wizards program, to see if they could be used via a browser. 2. To publicise sea level data archaeology and rescue by: • maintaining and regularly updating the Sea Level Data Archaeology page on the GLOSS website • strengthening links to the GLOSS data centres and data rescue organisations e.g. linking to IEDRO, ACRE, RDA • restarting the sea level data rescue blog with monthly posts. 3. Investigate sources of funding for data archaeology and rescue projects. 4. Propose "Guidelines" for rescuing sea level data. These action items will aid the discovery, scanning, digitising and quality control of analogue tide gauge charts and sea level ledgers and improve the quality, quantity and availability of long-term sea level data series.

Intercomparison of open-path trace gas measurements with two dual-frequency-comb spectrometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waxman, Eleanor M.; Cossel, Kevin C.; Truong, Gar-Wing

We present the first quantitative intercomparison between two open-path dual-comb spectroscopy (DCS) instruments which were operated across adjacent 2 km open-air paths over a 2-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6023 to 6376 cm −1 (1568 to 1660 nm), corresponding to a 355 cm −1 bandwidth, at 0.0067 cm −1 sample spacing. The measured absorption spectra agree with each other to within 5 × 10 −4 in absorbance without any external calibration of either instrument. The absorption spectra are fit to retrieve path-integrated concentrations for carbon dioxide (CO 2), methane (CH 4), water (H 2O), and deuteratedmore » water (HDO). The retrieved dry mole fractions agree to 0.14 % (0.57 ppm) for CO 2, 0.35 % (7 ppb) for CH 4, and 0.40 % (36 ppm) for H 2O at  ∼  30 s integration time over the 2-week measurement campaign, which included 24 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a World Meteorological Organization (WMO)-calibrated cavity ring-down point sensor located along the path with good agreement. Short-term and long-term differences between the open-path DCS and point sensor are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the 2-week measurement campaign yields diurnal cycles of CO 2 and CH 4 that are consistent with the presence of local sources of CO 2 and absence of local sources of CH 4.« less

Stream Flow Prediction and Flood Mapping in the Hindu Kush-Himalaya with the ICIMOD Water Resources App Portal (IWRAP)

NASA Astrophysics Data System (ADS)

Nelson, J.; Ames, D. P.; Jones, N.; Souffront, M.

2016-12-01

Earth observations of precipitation, temperature, moisture, and other atmospheric and land surface conditions form the foundation of global hydrologic forecasts that are increasingly available in native as well as other derived products. The European Centre for Medium Range Weather Forecasts (ECMWF) have developed such products for global flood awareness which can be downscaled to smaller regions and used for stream flow prediction in underserved areas such as the Hindu Kush-Himalaya. Combined with digital elevation data, now available at 30 meters through the Shuttle Radar Topography Mission (SRTM) reconnaissance-level flood maps can be generated across wide regions that would otherwise not be possible and where increased information to drive higher resolution models are available the same forecasts can be used to provide forcing inflows for improved flood maps. Advances in cloud computing offer a unique opportunity to facilitate deployment of water resources models as decision-making tools in the cloud-based ICIMOD Water Resources App Portal or IWRAP. The interactive nature of web apps makes this an excellent medium for creating decision support tools that harness cutting edge modeling techniques. Thin client apps hosted in a cloud portal eliminates the need for the decision makers to procure and maintain the high performance hardware required by the models, deal with issues related to software installation and platform incompatibilities, or monitor and install software updates, a problem that is exacerbated in the Hindu Kush-Himalaya where both financial and technical capacity are limited. All that is needed to use the system is an Internet connection and a web browser. We will take advantage of these technologies to develop tools which can be centrally maintained but openly accessible. Advanced mapping and visualization will make results intuitive and information derived actionable. We will also take advantage of the emerging standards for sharing water information across the web using the OGC and WMO approved WaterML standards. This will make our tools interoperable and we will help train those we work with so that tools and data from other projects can both consume and share with the tools developed in our project.

ACTRIS non-methane hydrocarbon intercomparison experiment in Europe to support WMO-GAW and EMEP observation networks

NASA Astrophysics Data System (ADS)

Hoerger, C. C.; Werner, A.; Plass-Duelmer, C.; Reimann, S.; Eckart, E.; Steinbrecher, R.; Aalto, J.; Arduini, J.; Bonnaire, N.; Cape, J. N.; Colomb, A.; Connolly, R.; Diskova, J.; Dumitrean, P.; Ehlers, C.; Gros, V.; Hakola, H.; Hill, M.; Hopkins, J. R.; Jäger, J.; Junek, R.; Kajos, M. K.; Klemp, D.; Leuchner, M.; Lewis, A. C.; Locoge, N.; Maione, M.; Martin, D.; Michl, K.; Nemitz, E.; O'Doherty, S.; Pérez Ballesta, P.; Ruuskanen, T. M.; Sauvage, S.; Schmidbauer, N.; Spain, T. G.; Straube, E.; Vana, M.; Vollmer, M. K.; Wegener, R.; Wenger, A.

2014-10-01

The performance of 20 European laboratories involved in long-term non-methane hydrocarbon (NMHC) measurements within the framework of Global Atmosphere Watch (GAW) and European Monitoring and Evaluation Programme (EMEP) was assessed with respect to the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) and GAW data quality objectives (DQOs). Compared to previous intercomparisons the DQOs of ACTRIS are much more demanding with deviations to a reference value of less than 5% and repeatability of better than 2% for mole fractions above 0.1 nmol mol-1. The participants were asked to measure both a 30 component NMHC mixture in nitrogen (NMHC_N2) at approximately 1 nmol mol-1 and whole air (NMHC_air), following a standardised operation procedure including zero- and calibration gas measurements. Furthermore, they had to report details on their instruments and they were asked to assess measurement uncertainties. The NMHCs were analysed either by gas chromatography-flame ionisation detection or gas chromatography-mass spectrometer methods. Most systems performed well for the NMHC_N2 measurements (88% of the reported values were within the GAW DQOs and even 58% within the ACTRIS DQOs). For NMHC_air generally more frequent and larger deviations to the assigned values were observed compared to NMHC_N2 (77% of the reported values were within the GAW DQOs, but only 48% within the ACTRIS DQOs). Important contributors to the poorer performance in NMHC_air compared to NMHC_N2 were a more complex matrix and a larger span of NMHC mole fractions (0.03-2.5 nmol mol-1). Issues, which affected both NMHC mixtures, are the usage of direct vs. two-step calibration, breakthrough of C2-C3 hydrocarbons, blank values in zero-gas measurements (especially for those systems using a Nafion® Dryer), adsorptive losses of aromatic compounds, and insufficient chromatographic resolution. Essential for high-quality results are experienced operators, a comprehensive quality assurance and quality control, well characterised systems, and sufficient man-power to operate the systems and evaluate the data.

The Continuation of Cloud Statistics for NASA Climate Change Studies

NASA Technical Reports Server (NTRS)

Wylie, Donald P.

2001-01-01

The weather systems, cyclones, and anticyclones, along with air trajectories and cloud forms, are compared to past studies of the Arctic to assess compatibility of the four month study of the Arctic Cloud Experiment flights of the First ISCCP Regional Experiment (FIRE/ACE) with past climatologies. The frequency and movement of cyclones (lows) and anticyclones (highs) followed the general eastward and northeastward directions indicated by past studies. Most cyclones (lows) came from eastern Siberia and the Bering Sea to the south and moved north across the Bering Straight or Alaska into the Arctic Ocean. They generally weakened in central pressure as they moved poleward. Anticyclones (highs) were most common in the eastern Beaufort Sea near Canada in June and July as predicted from previous studies. However, many cyclones and anticyclones moved in westward directions which is rare in other latitudes. Erratic changes in shape and intensity on a daily basis also were observed. The National Center for Environmental Prediction (NCEP) analysis generally reflected the Surface Heat Budget in the Arctic (SHEBA) Ship World Meteorological Organization (WMO) observations which it used. However, NCEP temperatures were biased warm by 1.0 to 1.5 C in April and early May. In July when the surface temperature were at the freezing/thawing point, the NCEP analysis changed to a cold bias of -1.0 C. Dew points had smaller biases except for July where they were biased cold by -1.4 C. Wind speeds had a -2 m/s low bias for the six windiest days. Surface barometric pressures had consistently low biases from -1.2 to -2.8 hPa in all four months. Air parcel historical trajectories were mainly from the south or from local anticyclonic gyres in the Beaufort Sea. Most air came to the SHEBA Ship from the north Pacific Ocean or from Alaska and Canada and occasionally from eastern Siberia. Very few trajectories traced back across the pole to Europe and Central Asia. Cloud cover was high, as expected, from 69-86% of the time. Satellite data also indicate frequent stratus, altostratus, and cirrus clouds (occurring 61% of the time) above the expected boundary layer fog and Arctic stratus clouds.

Total Ozone Trends from 1979 to 2016 Derived from Five Merged Observational Datasets - The Emergence into Ozone Recovery

NASA Technical Reports Server (NTRS)

Weber, Mark; Coldewey-Egbers, Melanie; Fioletov, Vitali E.; Frith, Stacey M.; Wild, Jeannette D.; Burrows, John P.; Loyola, Diego

2018-01-01

We report on updated trends using different merged datasets from satellite and ground-based observations for the period from 1979 to 2016. Trends were determined by applying a multiple linear regression (MLR) to annual mean zonal mean data. Merged datasets used here include NASA MOD v8.6 and National Oceanic and Atmospheric Administration (NOAA) merge v8.6, both based on data from the series of Solar Backscatter UltraViolet (SBUV) and SBUV-2 satellite instruments (1978–present) as well as the Global Ozone Monitoring Experiment (GOME)-type Total Ozone (GTO) and GOME-SCIAMACHY-GOME-2 (GSG) merged datasets (1995-present), mainly comprising satellite data from GOME, the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and GOME-2A. The fifth dataset consists of the monthly mean zonal mean data from ground-based measurements collected at World Ozone and UV Data Center (WOUDC). The addition of four more years of data since the last World Meteorological Organization (WMO) ozone assessment (2013-2016) shows that for most datasets and regions the trends since the stratospheric halogen reached its maximum (approximately 1996 globally and approximately 2000 in polar regions) are mostly not significantly different from zero. However, for some latitudes, in particular the Southern Hemisphere extratropics and Northern Hemisphere subtropics, several datasets show small positive trends of slightly below +1 percent decade(exp. -1) that are barely statistically significant at the 2 Sigma uncertainty level. In the tropics, only two datasets show significant trends of +0.5 to +0.8 percent(exp.-1), while the others show near-zero trends. Positive trends since 2000 have been observed over Antarctica in September, but near-zero trends are found in October as well as in March over the Arctic. Uncertainties due to possible drifts between the datasets, from the merging procedure used to combine satellite datasets and related to the low sampling of ground-based data, are not accounted for in the trend analysis. Consequently, the retrieved trends can be only considered to be at the brink of becoming significant, but there are indications that we are about to emerge into the expected recovery phase. However, the recent trends are still considerably masked by the observed large year-to-year dynamical variability in total ozone.

Model calculations for the airborne Fast Ice Nuclei CHamber FINCH-HALO

NASA Astrophysics Data System (ADS)

Nillius, B.; Bingemer, H.; Bundke, U.; Jaenicke, R.; Reimann, B.; Wetter, T.

2009-04-01

Ice nuclei (IN) initiate the formation of primary ice in tropospheric clouds. In mixed phase clouds the primary ice crystals can grow very fast by the Bergeron-Findeisen process (Findeisen, 1938) at the expense of evaporating water droplets, and form precipitation. Thus, IN are essential for the development of precipitation in mixed phase clouds in the middle latitude. However, the role of IN in the development of clouds is still poorly understood and needs to be studied (Levin and Cotton, 2007). A Fast Ice Nuclei CHamber (FINCH-HALO) for airborne operation on the High And LOng Range research aircraft (HALO) is under development at the Institute for Atmosphere and Environment University Frankfurt. IN particles are activated within the chamber at certain ice super-saturation and temperature by mixing three gas flows, a warm moist, a cold dry, and an aerosol flow. After activation the particles will grow within a processing chamber. In an optical depolarisation detector droplets and ice crystals are detected separately. The setup of the new FINCH-HALO instrument is based on the ground based IN counter FINCH (Bundke, 2008). In FINCH-HALO a new cooling unit is used. Thus, measurements down to -40°C are possible. Furthermore minor changes of the inlet section where the mixing occurs were done. The contribution will present 3D model calculations with FLUENT of the flow conditions in the new inlet section for different pressure levels during a flight typical for HALO. Growth rates of ice crystals in the chamber at different temperature and super-saturation will be shown. References: Bundke U., B. Nillius, R. Jaenicke, T. Wetter, H. Klein, H. Bingemer, (2008). The Fast Ice Nucleus Chamber FINCH, Atmospheric Research, doi:10.1016/j.atmosres.2008.02.008 Findeisen, R., (1938). Meteorologisch-physikalische Begebenheiten der Vereisung in der Atmosphäre. Hauptversammlung 1938 der Lilienthal-Gesellschaft. Levin, Z., W. Cotton, (2007). Aerosol pollution impact on precipitation: a scientific review. The WMO/IUGG International Aerosol Precipitation Science Assessment Group (IAPSAG). World Meteorological Organization, Geneva. Acknowledgements: This work was supported by the German Research Foundation, SFB 641 "Tropospheric Ice Phase" TP A1, SPP 1294, BU 1432/3-1, JA 344/12-1, by the Helmholtz Association, VI-233 "Aerosol Cloud Interactions" and by the EU FP6 Infrastructure Project EUSAAR.

Volcanic-plutonic connections and metal fertility of highly evolved magma systems: A case study from the Herberton Sn-W-Mo Mineral Field, Queensland, Australia

NASA Astrophysics Data System (ADS)

Cheng, Yanbo; Spandler, Carl; Chang, Zhaoshan; Clarke, Gavin

2018-03-01

Understanding the connection between the highly evolved intrusive and extrusive systems is essential to explore the evolution of high silicic magma systems, which plays an important role in discussions of planetary differentiation, the growth of continents, crustal evolution, and the formation of highly evolved magma associated Sn-W-Mo mineral systems. To discern differences between "fertile" and "non-fertile" igneous rocks associated with Sn-W-Mo mineralization and reveal the genetic links between coeval intrusive and extrusive rocks, we integrate whole rock geochemistry, geochronology and Hf isotope signatures of igneous zircons from contemporaneous plutonic and volcanic rocks from the world-class Herberton Mineral Field of Queensland, Australia. The 310-300 Ma intrusive rocks and associated intra-plutonic W-Mo mineralization formed from relatively oxidized magmas after moderate degrees of crystal fractionation. The geochemical and isotopic features of the coeval volcanic succession are best reconciled utilizing the widely-accepted volcanic-plutonic connection model, whereby the volcanic rocks represent fractionated derivatives of the intrusive rocks. Older intrusions emplaced at 335-315 Ma formed from relatively low fO2 magmas that fractionated extensively to produce highly evolved granites that host Sn mineralization. Coeval volcanic rocks of this suite are compositionally less evolved than the intrusive rocks, thereby requiring a different model to link these plutonic-volcanic sequences. In this case, we propose that the most fractionated magmas were not lost to volcanism, but instead were effectively retained at the plutonic level, which allowed further localized build-up of volatiles and lithophile metals in the plutonic environment. This disconnection to the volcanism and degassing may be a crucial step for forming granite-hosted Sn mineralization. The transition between these two igneous regimes in Herberton region over a ∼30 m.y. period is attributed to a change from an early compressive tectonic environment with a thickened crust, to conditions of crustal thinning and lithospheric extension due to progressive slab rollback. Such tectonic transitions may provide favorable conditions for intrusion-related mineralization. Given the common occurrence of volcanic and plutonic rocks associated with Sn-W-Mo mineralization worldwide, we suggest that a combined understanding of temporal tectonic evolution and plutonic-volcanic connections can assist in assessment of regional-scale mineralization potential, which in turn can aid strategies for future ore deposit exploration.

User-tailored seasonal forecasts for agriculture - creating socio-economic benefit through climate services in the Andes

NASA Astrophysics Data System (ADS)

De Ventura, Sara; Avalos, Grinia; Rossa, Andrea; Flubacher, Moritz; Gubler, Stefanie; Sedlmeier, Katrin; Dapozzo, Marlene; Garcia, Teresa; Quevedo, Karim; Liniger, Mark; Spirig, Christoph; Rosas, Gabriela; Schwierz, Cornelia

2017-04-01

The project Climandes is a twinning project between the Peruvian National Meteorological and Hydrological Service (SENAMHI) and the Federal Office of Meteorology and Climatology of Switzerland (MeteoSwiss) aiming at improving climate services for the Andean Region. It was launched in 2012 as a pilot project of the Global Framework for Climate Services (GFCS) of WMO. In 2016 a second phase of the project has started. Until now, Peru as all the Andean countries has had only a limited access to climate services, and the few instruments already in place have mostly not been developed in concordance with the user needs. Due to this mismatch, the opportunity to achieve veritable socio-economic benefits (SEB) has been overlooked so far. An additional difficulty is the lack of trained and experienced climatology and meteorology professionals able to develop and provide high quality climate services. Furthermore, the importance of climate information and its far-reaching benefits has not yet been fully acknowledged and embraced by the political decision-makers. The overall goals of the Climandes project are the following:. • Provision of user-tailored climate services for the Andean Region to improve socio- economic benefits for the agricultural sector and for society at large. • Improvement of the capacities of the meteorological service of Peru to generate user-tailored climate services in the agricultural sector. These goals are elaborated within three mutually dependent modules: The first one comprises user-tailored climate products for the agricultural sector in the Peruvian Andes. This includes drought and precipitation monitoring as well as the development of a prototype seasonal prediction system for the region including indices tailored to the agricultural sector. The second module focuses on capacity building, enabling climatology-related professionals and students to develop high-quality climate services for Peru and the Andean Region. Training courses as well as E-learning tools covering the knowledge needed for the elaboration and use of climate services (e.g. monitoring, seasonal prediction of precipitation) are developed and implemented. The third module aims at raising the awareness of political stakeholders of the SEB of SENAMHI's sector-specific climate services underpinned by a case study to quantify the SEB of drought and precipitation information platform for selected crops. This contribution will give an overview of the project and highlights some of the results of the first year of Climandes 2.

Observing Arctic Sea Ice from Bow to Screen: Introducing Ice Watch, the Data Network of Near Real-Time and Historic Observations from the Arctic Shipborne Sea Ice Standardization Tool (ASSIST)

NASA Astrophysics Data System (ADS)

Orlich, A.; Hutchings, J. K.; Green, T. M.

2013-12-01

The Ice Watch Program is an open source forum to access in situ Arctic sea ice conditions. It provides the research community and additional stakeholders a convenient resource to monitor sea ice and its role in understanding the Arctic as a system by implementing a standardized observation protocol and hosting a multi-service data portal. International vessels use the Arctic Shipborne Sea Ice Standardization Tool (ASSIST) software to report near-real time sea ice conditions while underway. Essential observations of total ice concentration, distribution of multi-year ice and other ice types, as well as their respective stage of melt are reported. These current and historic sea ice conditions are visualized on interactive maps and in a variety of statistical analyses, and with all data sets available to download for further investigation. The summer of 2012 was the debut of the ASSIST software and the Ice Watch campaign, with research vessels from six nations reporting from a wide spatio-temporal scale spanning from the Beaufort Sea, across the North Pole and Arctic Basin, the coast of Greenland and into the Kara and Barents Seas during mid-season melt and into the first stages of freeze-up. The 2013 summer field season sustained the observation and data archiving record, with participation from some of the same cruises as well as other geographic and seasonal realms covered by new users. These results are presented to illustrate the evolution of the program, increased participation and critical statistics of ice regime change and record of melt and freeze processes revealed by the data. As an ongoing effort, Ice Watch/ASSIST aims to standardize observations of Arctic-specific sea ice features and conditions while utilizing nomenclature and coding based on the World Meteorological Organization (WMO) standards and the Antarctic Sea Ice and Processes & Climate (ASPeCt) protocol. Instigated by members of the CliC Sea Ice Working Group, the program has evolved with coordination from the International Arctic Research Center, software development by the Geographic Information Network of Alaska, and funding support from the Japanese Aerospace Exploration Agency (JAXA), the Japan Agency for Marine-Earth Science & Technology (JAMSTEC), and the National Science Foundation (NSF).

Historic AVHRR Processing in the Eumetsat Climate Monitoring Satellite Application Facility (cmsaf) (Invited)

NASA Astrophysics Data System (ADS)

Karlsson, K.

2010-12-01

The EUMETSAT CMSAF project (www.cmsaf.eu) compiles climatological datasets from various satellite sources with emphasis on the use of EUMETSAT-operated satellites. However, since climate monitoring primarily has a global scope, also datasets merging data from various satellites and satellite operators are prepared. One such dataset is the CMSAF historic GAC (Global Area Coverage) dataset which is based on AVHRR data from the full historic series of NOAA-satellites and the European METOP satellite in mid-morning orbit launched in October 2006. The CMSAF GAC dataset consists of three groups of products: Macroscopical cloud products (cloud amount, cloud type and cloud top), cloud physical products (cloud phase, cloud optical thickness and cloud liquid water path) and surface radiation products (including surface albedo). Results will be presented and discussed for all product groups, including some preliminary inter-comparisons with other datasets (e.g., PATMOS-X, MODIS and CloudSat/CALIPSO datasets). A background will also be given describing the basic methodology behind the derivation of all products. This will include a short historical review of AVHRR cloud processing and resulting AVHRR applications at SMHI. Historic GAC processing is one of five pilot projects selected by the SCOPE-CM (Sustained Co-Ordinated Processing of Environmental Satellite data for Climate Monitoring) project organised by the WMO Space programme. The pilot project is carried out jointly between CMSAF and NOAA with the purpose of finding an optimal GAC processing approach. The initial activity is to inter-compare results of the CMSAF GAC dataset and the NOAA PATMOS-X dataset for the case when both datasets have been derived using the same inter-calibrated AVHRR radiance dataset. The aim is to get further knowledge of e.g. most useful multispectral methods and the impact of ancillary datasets (for example from meteorological reanalysis datasets from NCEP and ECMWF). The CMSAF project is currently defining plans for another five years (2012-2017) of operations and development. New GAC reprocessing efforts are planned and new methodologies will be tested. Central questions here will be how to increase the quantitative use of the products through improving error and uncertainty estimates and how to compile the information in a way to allow meaningful and efficient ways of using the data for e.g. validation of climate model information.

Pan-European comparison of candidate distributions for climatological drought indices, SPI and SPEI

NASA Astrophysics Data System (ADS)

Stagge, James; Tallaksen, Lena; Gudmundsson, Lukas; Van Loon, Anne; Stahl, Kerstin

2013-04-01

Drought indices are vital to objectively quantify and compare drought severity, duration, and extent across regions with varied climatic and hydrologic regimes. The Standardized Precipitation Index (SPI), a well-reviewed meterological drought index recommended by the WMO, and its more recent water balance variant, the Standardized Precipitation-Evapotranspiration Index (SPEI) both rely on selection of univariate probability distributions to normalize the index, allowing for comparisons across climates. The SPI, considered a universal meteorological drought index, measures anomalies in precipitation, whereas the SPEI measures anomalies in climatic water balance (precipitation minus potential evapotranspiration), a more comprehensive measure of water availability that incorporates temperature. Many reviewers recommend use of the gamma (Pearson Type III) distribution for SPI normalization, while developers of the SPEI recommend use of the three parameter log-logistic distribution, based on point observation validation. Before the SPEI can be implemented at the pan-European scale, it is necessary to further validate the index using a range of candidate distributions to determine sensitivity to distribution selection, identify recommended distributions, and highlight those instances where a given distribution may not be valid. This study rigorously compares a suite of candidate probability distributions using WATCH Forcing Data, a global, historical (1958-2001) climate dataset based on ERA40 reanalysis with 0.5 x 0.5 degree resolution and bias-correction based on CRU-TS2.1 observations. Using maximum likelihood estimation, alternative candidate distributions are fit for the SPI and SPEI across the range of European climate zones. When evaluated at this scale, the gamma distribution for the SPI results in negatively skewed values, exaggerating the index severity of extreme dry conditions, while decreasing the index severity of extreme high precipitation. This bias is particularly notable for shorter aggregation periods (1-6 months) during the summer months in southern Europe (below 45° latitude), and can partially be attributed to distribution fitting difficulties in semi-arid regions where monthly precipitation totals cluster near zero. By contrast, the SPEI has potential for avoiding this fitting difficulty because it is not bounded by zero. However, the recommended log-logistic distribution produces index values with less variation than the standard normal distribution. Among the alternative candidate distributions, the best fit distribution and the distribution parameters vary in space and time, suggesting regional commonalities within hydroclimatic regimes, as discussed further in the presentation.

Total ozone trends from 1979 to 2016 derived from five merged observational datasets - the emergence into ozone recovery

NASA Astrophysics Data System (ADS)

Weber, Mark; Coldewey-Egbers, Melanie; Fioletov, Vitali E.; Frith, Stacey M.; Wild, Jeannette D.; Burrows, John P.; Long, Craig S.; Loyola, Diego

2018-02-01

We report on updated trends using different merged datasets from satellite and ground-based observations for the period from 1979 to 2016. Trends were determined by applying a multiple linear regression (MLR) to annual mean zonal mean data. Merged datasets used here include NASA MOD v8.6 and National Oceanic and Atmospheric Administration (NOAA) merge v8.6, both based on data from the series of Solar Backscatter UltraViolet (SBUV) and SBUV-2 satellite instruments (1978-present) as well as the Global Ozone Monitoring Experiment (GOME)-type Total Ozone (GTO) and GOME-SCIAMACHY-GOME-2 (GSG) merged datasets (1995-present), mainly comprising satellite data from GOME, the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and GOME-2A. The fifth dataset consists of the monthly mean zonal mean data from ground-based measurements collected at World Ozone and UV Data Center (WOUDC). The addition of four more years of data since the last World Meteorological Organization (WMO) ozone assessment (2013-2016) shows that for most datasets and regions the trends since the stratospheric halogen reached its maximum (˜ 1996 globally and ˜ 2000 in polar regions) are mostly not significantly different from zero. However, for some latitudes, in particular the Southern Hemisphere extratropics and Northern Hemisphere subtropics, several datasets show small positive trends of slightly below +1 % decade-1 that are barely statistically significant at the 2σ uncertainty level. In the tropics, only two datasets show significant trends of +0.5 to +0.8 % decade-1, while the others show near-zero trends. Positive trends since 2000 have been observed over Antarctica in September, but near-zero trends are found in October as well as in March over the Arctic. Uncertainties due to possible drifts between the datasets, from the merging procedure used to combine satellite datasets and related to the low sampling of ground-based data, are not accounted for in the trend analysis. Consequently, the retrieved trends can be only considered to be at the brink of becoming significant, but there are indications that we are about to emerge into the expected recovery phase. However, the recent trends are still considerably masked by the observed large year-to-year dynamical variability in total ozone.

The Copernicus S5P Mission Performance Centre / Validation Data Analysis Facility for TROPOMI operational atmospheric data products

NASA Astrophysics Data System (ADS)

Compernolle, Steven; Lambert, Jean-Christopher; Langerock, Bavo; Granville, José; Hubert, Daan; Keppens, Arno; Rasson, Olivier; De Mazière, Martine; Fjæraa, Ann Mari; Niemeijer, Sander

2017-04-01

Sentinel-5 Precursor (S5P), to be launched in 2017 as the first atmospheric composition satellite of the Copernicus programme, carries as payload the TROPOspheric Monitoring Instrument (TROPOMI) developed by The Netherlands in close cooperation with ESA. Designed to measure Earth radiance and solar irradiance in the ultraviolet, visible and near infrared, TROPOMI will provide Copernicus with observational data on atmospheric composition at unprecedented geographical resolution. The S5P Mission Performance Center (MPC) provides an operational service-based solution for various QA/QC tasks, including the validation of S5P Level-2 data products and the support to algorithm evolution. Those two tasks are to be accomplished by the MPC Validation Data Analysis Facility (VDAF), one MPC component developed and operated at BIRA-IASB with support from S[&]T and NILU. The routine validation to be ensured by VDAF is complemented by a list of validation AO projects carried out by ESA's S5P Validation Team (S5PVT), with whom interaction is essential. Here we will introduce the general architecture of VDAF, its relation to the other MPC components, the generic and specific validation strategies applied for each of the official TROPOMI data products, and the expected output of the system. The S5P data products to be validated by VDAF are diverse: O3 (vertical profile, total column, tropospheric column), NO2 (total and tropospheric column), HCHO (tropospheric column), SO2 (column), CO (column), CH4 (column), aerosol layer height and clouds (fractional cover, cloud-top pressure and optical thickness). Starting from a generic validation protocol meeting community-agreed standards, a set of specific validation settings is associated with each data product, as well as the appropriate set of Fiducial Reference Measurements (FRM) to which it will be compared. VDAF collects FRMs from ESA's Validation Data Centre (EVDC) and from other sources (e.g., WMO's GAW, NDACC and TCCON). Data manipulations on satellite and FRM data (format conversion, filtering, co-location, regridding and vertical smoothing) are performed by the open source software HARP, while more specific manipulations apply in-house routines. The paper concludes with a short description of expected outputs of the system.

A laboratory assessment of the measurement accuracy of weighing type rainfall intensity gauges

NASA Astrophysics Data System (ADS)

Colli, M.; Chan, P. W.; Lanza, L. G.; La Barbera, P.

2012-04-01

In recent years the WMO Commission for Instruments and Methods of Observation (CIMO) fostered noticeable advancements in the accuracy of precipitation measurement issue by providing recommendations on the standardization of equipment and exposure, instrument calibration and data correction as a consequence of various comparative campaigns involving manufacturers and national meteorological services from the participating countries (Lanza et al., 2005; Vuerich et al., 2009). Extreme events analysis is proven to be highly affected by the on-site RI measurement accuracy (see e.g. Molini et al., 2004) and the time resolution of the available RI series certainly constitutes another key-factor in constructing hyetographs that are representative of real rain events. The OTT Pluvio2 weighing gauge (WG) and the GEONOR T-200 vibrating-wire precipitation gauge demonstrated very good performance under previous constant flow rate calibration efforts (Lanza et al., 2005). Although WGs do provide better performance than more traditional Tipping Bucket Rain gauges (TBR) under continuous and constant reference intensity, dynamic effects seem to affect the accuracy of WG measurements under real world/time varying rainfall conditions (Vuerich et al., 2009). The most relevant is due to the response time of the acquisition system and the derived systematic delay of the instrument in assessing the exact weight of the bin containing cumulated precipitation. This delay assumes a relevant role in case high resolution rain intensity time series are sought from the instrument, as is the case of many hydrologic and meteo-climatic applications. This work reports the laboratory evaluation of Pluvio2 and T-200 rainfall intensity measurements accuracy. Tests are carried out by simulating different artificial precipitation events, namely non-stationary rainfall intensity, using a highly accurate dynamic rainfall generator. Time series measured by an Ogawa drop counter (DC) at a field test site located within the Hong Kong International Airport (HKIA) were aggregated at a 1-minute scale and used as reference for the artificial rain generation (Colli et al., 2012). The preliminary development and validation of the rainfall simulator for the generation of variable time steps reference intensities is also shown. The generator is characterized by a sufficiently short time response with respect to the expected weighing gauges behavior in order to ensure effective comparison of the measured/reference intensity at very high resolution in time.

Comparison of continuous in-situ CO2 observations at Jungfraujoch using two different measurement techniques

NASA Astrophysics Data System (ADS)

Schibig, M. F.; Steinbacher, M.; Buchmann, B.; van der Laan-Luijkx, I. T.; van der Laan, S.; Ranjan, S.; Leuenberger, M. C.

2014-07-01

Since 2004, atmospheric carbon dioxide (CO2) is measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP) using a nondispersive infrared gas analyzer (NDIR) in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring down spectroscopy (CRDS) as part of the Swiss National Air Pollution Monitoring Network have been added by the Swiss Federal Laboratories for Materials Science and Technology (Empa). To ensure a smooth transition - a prerequisite when merging two datasets e.g. for trend determinations - the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows identifying potential offsets between the two datasets and getting information about the compatibility of the two systems on different time scales. A good agreement of the seasonality as well as for the short-term variations was observed and to a lesser extent for trend calculations mainly due to the short common period. However, the comparison revealed some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It was possible to adapt an improved calibration strategy based on standard gas determinations, which lead to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS - NDIR) of the two systems is -0.03 ppm ± 0.25 ppm. Although the difference of the two datasets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO), the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min) for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additionally for signal stabilization after switching the sample, an effective data coverage of only 1/6 for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates between the two systems may affect observed differences.

Comparison of continuous in situ CO2 observations at Jungfraujoch using two different measurement techniques

NASA Astrophysics Data System (ADS)

Schibig, M. F.; Steinbacher, M.; Buchmann, B.; van der Laan-Luijkx, I. T.; van der Laan, S.; Ranjan, S.; Leuenberger, M. C.

2015-01-01

Since 2004, atmospheric carbon dioxide (CO2) is being measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP) using a nondispersive infrared gas analyzer (NDIR) in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring-down spectroscopy (CRDS) as part of the Swiss National Air Pollution Monitoring Network were added by the Swiss Federal Laboratories for Materials Science and Technology (Empa). To ensure a smooth transition - a prerequisite when merging two data sets, e.g., for trend determinations - the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows the identification of potential offsets between the two data sets and the collection of information about the compatibility of the two systems on different time scales. A good agreement of the seasonality, short-term variations and, to a lesser extent mainly due to the short common period, trend calculations is observed. However, the comparison reveals some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It is possible to adapt an improved calibration strategy based on standard gas determinations, which leads to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS - NDIR) of the two systems is -0.03 ppm ± 0.25 ppm. Although the difference of the two data sets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO), the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min) for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additional time for signal stabilization after switching the sample, an effective data coverage of only one-sixth for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates may affect observed differences.

Lake Surface Water Temperature of European Lakes retrieved from AVHRR Data - Time Series and Quality Assessment

NASA Astrophysics Data System (ADS)

Wunderle, S.; Lieberherr, G.; Riffler, M.

2016-12-01

Data analysis of the recent years showed an increase of lake surface water temperature for many lakes around the world. But due to sparse in-situ measurements, which are often not well documented, only satellite data can provide the needed information of the last decades. The importance of lakes for climate research was also highlighted by the Global Climate Observing System (GCOS) defining lakes as Essential Climate Variables (ECVs). Within the frame of a research project funded by the Swiss National Science Foundation a procedure was developed to retrieve lake surface water temperature with high accuracy based on our archived AVHRR data at the University of Bern, Switzerland. The data archive starts in 1985 and is continuously filled with NOAA-/MetOp-AVHRR data received by our antenna resulting in a time series of more than 30 years (WMO definition of a climate period). The data set covering Europe is also used by other teams for climate related studies resulting in improved pre-processing to guarantee precise calibration and geocoding. The first part of our presentation will be dedicated to the quality of the LSWT retrieval comparing various in-situ measurements from lakes in Switzerland with varying sizes (150km2 - 9km2). The quality of the used split-window approach is sensitive to the derived split-window coefficients. The influence of water vapor, view angle, temporal and spatial validity and day vs. night data will be shown. In addition, some information will be presented about the influence of topography and climatic regions (e.g. Scandinavia vs. Greece) on the quality of the LSWT product. Based on these findings compiling time series for different lakes in Europe will be the focus of the second part of our presentation with details of the applied quality assessment to avoid erroneous signals. Hence, some information is given about hierarchical quality checks which are needed to guarantee a dataset without artefacts. Finally, some results of time series are presented to show the reaction of different lakes (size, depth) on climate forcing. The lakes are selected to be representative for different climatic regions in Europe (northern - southern Europe, etc.). At the end of the project the data set will be accessible for the public.

A UK portrait of wind-induced undercatch in rainfall measurement

NASA Astrophysics Data System (ADS)

Pollock, Michael; Quinn, Paul; O'Donnell, Greg; Colli, Matteo; Dutton, Mark; Black, Andrew; Wilkinson, Mark; Kilsby, Chris; Stagnaro, Mattia; Lanza, Luca; O'Connell, Enda

2017-04-01

Rainfall is vital to life; civilisation depends upon it. Changing local and regional rainfall regimes toward more intense storm events (e.g. in the UK), increases the existing challenge of accurately measuring and modelling rainfall. Data from rain gauges, often considered to provide the most accurate practicable measure of precipitation at a point in space in time, play a critical role. They are used for, inter alia, flood forecasting and flood risk management; radar calibration and numerical weather prediction models; urban planning and drainage; and water resource management and hydrological modelling. Despite the key importance of these measurements, they remain susceptible to fundamental sources of systematic error which are often not considered when rainfall data are used. Inaccuracies in measurements are compounded in modelling applications by producing potentially misleading or incorrect results; it is therefore of great importance to understand and present uncertainty in observations. Standard practice is to mount rain gauges above the ground surface. This configuration obstructs the prevailing wind which causes an acceleration of airflow above the orifice. Precipitation is deflected away from the orifice and lands 'downstream' of the area represented by the gauge measurement, reducing its collection efficiency (CE). This phenomenon is commonly referred to as 'wind-induced undercatch'. The physical shape of a gauge bears a significant impact on its CE. Computational Fluid Dynamics (CFD) simulations are used to investigate how different shapes of precipitation gauge are affected by the wind. CFD modelling is supported by high-resolution field measurements at several exposed 'Hydro-Met' research stations in the UK. These sites are occupied by rain gauges which are scrutinised in the CFD analyses. The reference measurements at all sites are made within a WMO reference pit, where the rain gauge is mounted with its orifice at ground level and surrounded by an appropriate grid structure. 'Undercatch' exhibited within UK storms, not captured by operational gauge networks in the UK, is quantified and presented in this study. Results from CFD modelling and the field studies show that gauge shape and mounting height significantly affect the extent of the undercatch. 'Aerodynamic' gauges following a 'champagne flute' or a 'funnel' profile were demonstrated by both to have significant advantages over conventional gauge shapes, in terms of improving the CE. This study presents the latest analyses, and proposes the possible extent of rainfall underestimation within the UK, with particular reference to its hydrology.

The role of sea surface salinity in ENSO related water cycle anomaly

NASA Astrophysics Data System (ADS)

Tang, Wenqing; Yueh, Simon

2017-04-01

This study investigates the role of sea surface salinity (SSS) in the water cycle anomaly associated with El Niño Southern Oscillation (ENSO). The 2015-16 El Niño, one of the strongest ENSO events observed in centuries, coincident with unprecedented coverage of spacebased remote sensing of SSS over global oceans. We analyze three SSS data sets: from the NASA's missions of SMAP and Aquarius, and the ESA's Soil Moisture and Ocean Salinity (SMOS). One typical characteristics of an ENSO event is the zonal displacement of the Western equatorial Pacific Fresh Pool (WPFP). The edge of the pool extends eastward during El Niño, retreats westward during La Niña. For super El Niño, the eastern edge of WPFP extends much more east across the equatorial Pacific. Indeed, SSS from SMAP reveals much stronger eastward migration of WPFP starting in April 2015. The eastern edge of WPFP reached 140°W in March 2016, about 40° more eastward extension than Aquarius observed in previous years. In the following months from March to June 2016, WPFP retreated westward, coincident with the ending of this strong El Niño event [WMO, El Nino/La Nina update, 2016]. SMOS data shows similar feature, confirming that there is no systematic biases between SMAP and Aquarius retrievals. We examine the linkage between the observed SSS variation and ENSO related water cycle anomaly by integrated analysis of SSS data sets in conjunction with other satellite and in situ measurements on rain, wind, evaporation and ocean currents. Based on the governing equation of the mixed layer salt budget, the freshwater exchange between air-sea interfaces is estimated as residual of the mixed-layer salinity (MLS) temporal change and advection (Focean), as an alternative to evaporation minus precipitation (FE-P). We analyzed the spatial and temporal variation of Focean and FE-P to explore the anomalous signature in the oceanic and atmospheric branches of the water cycle associated with 2015/16 ENSO. The maximum anomalous along the Equator shown in Focean occurred a few weeks ahead of FE-P, suggesting that salinity is not only a passive tracer but also plays an active role in the onset and evolvement of an ENSO event.

Multiplatform observations enabling albedo retrievals with high temporal resolution

NASA Astrophysics Data System (ADS)

Riihelä, Aku; Manninen, Terhikki; Key, Jeffrey; Sun, Qingsong; Sütterlin, Melanie; Lattanzio, Alessio; Schaaf, Crystal

2017-04-01

In this paper we show that combining observations from different polar orbiting satellite families (such as AVHRR and MODIS) is physically justifiable and technically feasible. Our proposed approach will lead to surface albedo retrievals at higher temporal resolution than the state of the art, with comparable or better accuracy. This study is carried out in the World Meteorological Organization (WMO) Sustained and coordinated processing of Environmental Satellite data for Climate Monitoring (SCOPE-CM) project SCM-02 (http://www.scope-cm.org/projects/scm-02/). Following a spectral homogenization of the Top-of-Atmosphere reflectances of bands 1 & 2 from AVHRR and MODIS, both observation datasets are atmospherically corrected with a coherent atmospheric profile and algorithm. The resulting surface reflectances are then fed into an inversion of the RossThick-LiSparse-Reciprocal surface bidirectional reflectance distribution function (BRDF) model. The results of the inversion (BRDF kernels) may then be integrated to estimate various surface albedo quantities. A key principle here is that the larger number of valid surface observations with multiple satellites allows us to invert the BRDF coefficients within a shorter time span, enabling the monitoring of relatively rapid surface phenomena such as snowmelt. The proposed multiplatform approach is expected to bring benefits in particular to the observation of the albedo of the polar regions, where persistent cloudiness and long atmospheric path lengths present challenges to satellite-based retrievals. Following a similar logic, the retrievals over tropical regions with high cloudiness should also benefit from the method. We present results from a demonstrator dataset of a global combined AVHRR-GAC and MODIS dataset covering the year 2010. The retrieved surface albedo is compared against quality-monitored in situ albedo observations from the Baseline Surface Radiation Network (BSRN). Additionally, the combined retrieval dataset is compared against MODIS C6 albedo/BRDF datasets to assess the quality of the multiplatform approach against current state of the art. This approach is not limited to AHVRR and MODIS observations. Provided that the spectral homogenization produces an acceptably good match, any instrument observing the Earth's surface in the visible and near-infrared wavelengths could, in principal, be included to further enhance the temporal resolution and accuracy of the retrievals. The SCOPE-CM initiative provides a potential framework for such expansion in the future.

Continuity of Earth Radiation Budget Observations

NASA Astrophysics Data System (ADS)

Loeb, N. G.; Su, W.; Wong, T.; Priestley, K.

2017-12-01

Earth's climate is determined by the exchange of radiant energy between the Sun, Earth and space. The absorbed solar radiation at the top-of-atmosphere (TOA) fuels the climate system, providing the energy required for atmospheric and oceanic motions. Earth's radiation budget (ERB) involves a balance between how much solar energy Earth absorbs and how much terrestrial thermal infrared radiation is emitted to space. Because of its critical role in climate, continuous monitoring of the ERB is necessary for improved understanding and prediction of climate variability and change. NASA's long history in observing the TOA ERB is acknowledged in the 2007 and 2013 reports of the IPCC (IPCC 2007, 2013), the 2007 NRC Decadal Survey (NRC 2007), and the GCOS implementation plan of the WMO (GCOS 2016). A key reason for NASA's success in this area is due to its support of the CERES Project and its predecessor, ERBE. During ERBE, the TOA ERB was observed using both scanner and nonscanner broadband instruments. The CERES project consists of six scanner instruments flying alongside high-resolution spectral imagers (MODIS, VIIRS) in morning and afternoon sun-synchronous orbits. In addition to extending the ERBE TOA radiation budget record, CERES also provides observations of Earth's surface radiation budget with unprecedented accuracy. Here we assess the likelihood of a measurement gap in the ERB record. We show that unless a follow-on ERB instrument to the last available CERES copy (FM6) is built and launched, there is a significant risk of a measurement gap in the ERB record by the mid-2020s. A gap is of concern not only because the ERB would not be monitored during the gap period but also because it would be exceedingly difficult to tie the records before and after the gap together with sufficient accuracy for climate analyses. While ERB instruments are highly stable temporally, they lack the absolute accuracy needed to bridge a gap. Consequently, there is a requirement that successive satellite missions flying ERB instruments must overlap with one another for at least one year. We also discuss the tremendous challenges associated with alternate observing systems to CERES-like scanner instruments proposed recently to extend the ERB record (e.g., nonscanner broadband instruments on small satellites).

The International Permafrost Association: current initiatives for cryospheric research

NASA Astrophysics Data System (ADS)

Schollaen, Karina; Lewkowicz, Antoni G.; Christiansen, Hanne H.; Romanovsky, Vladimir E.; Lantuit, Hugues; Schrott, Lothar; Sergeev, Dimitry; Wei, Ma

2015-04-01

The International Permafrost Association (IPA), founded in 1983, has as its objectives to foster the dissemination of knowledge concerning permafrost and to promote cooperation among persons and national or international organizations engaged in scientific investigation and engineering work on permafrost. The IPA's primary responsibilities are convening International Permafrost Conferences, undertaking special projects such as preparing databases, maps, bibliographies, and glossaries, and coordinating international field programs and networks. Membership is through adhering national or multinational organizations or as individuals in countries where no Adhering Body exists. The IPA is governed by its Executive Committee and a Council consisting of representatives from 26 Adhering Bodies having interests in some aspect of theoretical, basic and applied frozen ground research, including permafrost, seasonal frost, artificial freezing and periglacial phenomena. This presentation details the IPA core products, achievements and activities as well as current projects in cryospheric research. One of the most important core products is the circumpolar permafrost map. The IPA also fosters and supports the activities of the Global Terrestrial Network on Permafrost (GTN-P) sponsored by the Global Terrestrial Observing System, GTOS, and the Global Climate Observing System, GCOS, whose long-term goal is to obtain a comprehensive view of the spatial structure, trends, and variability of changes in the active layer thickness and permafrost temperature. A further important initiative of the IPA are the biannually competitively-funded Action Groups which work towards the production of well-defined products over a period of two years. Current IPA Action Groups are working on highly topical and interdisciplinary issues, such as the development of a regional Palaeo-map of Permafrost in Eurasia, the integration of multidisciplinary knowledge about the use of thermokarst and permafrost landscapes, and defining permafrost research priorities - a roadmap for the future. The latter project is a joint effort with the Climate and Cryosphere initiative (CliC) and a contribution to the upcoming International Conference on Arctic Research Planning III (ICARP III). The product stemming from the effort will consist of a journal publication listing permafrost research priorities and putting them into context. In all of these activities, the IPA emphasizes the involvement of young researchers (especially through the Permafrost Young Researchers Network and APECS) as well as its collaboration with international partner organizations such as IASC, SCAR, CliC, IACS, IUGS and WMO.

Re-Os, Sm-Nd, U-Pb, and stepwise lead leaching isotope systematics in shear-zone hosted gold mineralization: genetic tracing and age constraints of crustal hydrothermal activity

NASA Astrophysics Data System (ADS)

Frei, R.; Nägler, Th. F.; Schönberg, R.; Kramers, J. D.

1998-06-01

A combined Re-Os, Sm-Nd, U-Pb, and stepwise Pb leaching (PbSL) isotope study of hydrothermal (Mo-W)-bearing minerals and base metal sulfides from two adjacent shear zone hosted gold deposits (RAN, Kimberley) in the Harare-Shamva greenstone belt (Zimbabwe) constrain the timing of the mineralizing events to two periods. During an initial Late Archean event (2.60 Ga) a first molybdenite-scheelite bearing paragenesis was deposited in both shear zone systems, followed by a local reactivation of the shear systems during an Early Proterozoic (1.96 Ga) tectono-thermal overprint, during which base metal sulfides and most of the gold was (re-)deposited. While PbSL has revealed an open-system behavior of the U-Pb systematics in molybdenite and wolframite from the RAN mine, initial Archean Re-Os ages are still preserved implying that this system in these minerals was more resistant to the overprint. A similar retentivity could be shown for the Sm-Nd system in scheelite and powellite associated with the above ore minerals. Re-Os isotopic data from the Proterozoic mineralization in the Kimberley mine point to a recent gain of Re, most pronouncedly affecting Fe-rich sulfides such as pyrrhotite. A significant Re-loss in powellitic scheelite (an alteration phase of molybdenite-bearing scheelite), coupled with a marked loss of U in W-Mo ore minerals, complements the observation of a major Re uptake in Fe-sulfides during oxidizing conditions in a weathering environment. Pyrrhotite under these conditions behaves as an efficient Re-sink. Lead isotope signatures from PbSL residues of molybdenite, powellite, and quartz indicate a continental crustal source and/or contamination for the mineralizing fluid by interaction of the fluids with older sedimentary material as represented by the direct host country rocks. Our investigation reveals the potential of the Re-Os isotopic system applied to crustal hydrothermal ore minerals for genetic tracing and dating purposes. The simplified chemical separation of Re and Os from geological material used in this study, together with improvements of chemical yields, will enable high precision data to be collected rapidly on crustal material with low Os concentrations in the future.

A global, space-based stratospheric aerosol climatology: 1979 to 2014

NASA Astrophysics Data System (ADS)

Thomason, L. W.; Vernier, J. P.; Bourassa, A. E.; Millan, L.; Manney, G. L.

2016-12-01

Herein, we report on a global space-based stratospheric aerosol climatology (GloSSAC) that has been developed to support Coupled Model Intercomparison Project Phase 6 (CMIP6) (REF to CMIP6 and ETH work). GloSSAC is most closely related to the ASAP[SPARC, 2006] and CCMI data sets and follows a similar approach used to produce those data sets. It is primarily built using space-based measurements by a number of instruments including the SAGE series, OSIRIS, CALIPSO, CLAES and HALOE. The data set is presented as monthly depictions for 80S to 80N and from at least the tropopause to 40 km. The data set consists primarily of measurements by the instruments at their native wavelength and measurement type (e.g., extinction coefficient). However, every bin in these monthly grids receives measured or indirectly inferred values for aerosol extinction coefficient at 525 and 1020 nm. Generally, bins where no data are available are filled via simple linear interpolation in time only. The exceptions are in the SAGE I/II gap from 1982 to 1984 where data from SAM II and ground-based and airborne lidar data sets are used to span the 3 years between the end of the SAGE I mission in November 1981 and the beginning of the SAGE II mission in October 1984. Ground-based lidar also supplements space-based data in the months following the Pinatubo eruption when much of the lower stratosphere is too optically opaque for occultation measurements. This data set includes total aerosol surface area density and volume estimates based on Thomason et al.[2008] though these should be interpreted as bounding values (low and high) rather than functional aerosol parameters that are generally produced from this and predecessor data sets by other parties. Unlike previous versions of this data set, GloSSAC has been permanently archived at NASA's Atmospheric Science Data Center and a digital object identifier (doi) for GloSSAC is available. SPARC (2006), Assessment of Stratospheric Aerosol Properties (ASAP), 348 pp., WCRP-124, WMO/TD No. 1295, SPARC Report No. 4. Thomason, L. W., S. P. Burton, B. P. Luo, and T. Peter (2008), SAGE II measurements of stratospheric aerosol properties at non-volcanic levels, Atmospheric Chemistry and Physics, 8(4), 983-995, doi:10.5194/acp-8-983-2008.

Reexamination of the State of the Art Cloud Modeling Shows Real Improvements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muehlbauer, Andreas D.; Grabowski, Wojciech W.; Malinowski, S. P.

Following up on an almost thirty year long history of International Cloud Modeling Workshops, that started out with a meeting in Irsee, Germany in 1985, the 8th International Cloud Modeling Workshop was held in July 2012 in Warsaw, Poland. The workshop, hosted by the Institute of Geophysics at the University of Warsaw, was organized by Szymon Malinowski and his local team of students and co-chaired by Wojciech Grabowski (NCAR/MMM) and Andreas Muhlbauer (University of Washington). International Cloud Modeling Workshops have been held traditionally every four years typically during the week before the International Conference on Clouds and Precipitation (ICCP) .more » Rooted in the World Meteorological Organization’s (WMO) weather modification program, the core objectives of the Cloud Modeling Workshop have been centered at the numerical modeling of clouds, cloud microphysics, and the interactions between cloud microphysics and cloud dynamics. In particular, the goal of the workshop is to provide insight into the pertinent problems of today’s state-of-the-art of cloud modeling and to identify key deficiencies in the microphysical representation of clouds in numerical models and cloud parameterizations. In recent years, the workshop has increasingly shifted the focus toward modeling the interactions between aerosols and clouds and provided case studies to investigate both the effects of aerosols on clouds and precipitation as well as the impact of cloud and precipitation processes on aerosols. This time, about 60 (?) scientists from about 10 (?) different countries participated in the workshop and contributed with discussions, oral and poster presentations to the workshop’s plenary and breakout sessions. Several case leaders contributed to the workshop by setting up five observationally-based case studies covering a wide range of cloud types, namely, marine stratocumulus, mid-latitude squall lines, mid-latitude cirrus clouds, Arctic stratus and winter-time orographic clouds and precipitation. Interested readers are encouraged to visit the workshop website at http://www.atmos.washington.edu/~andreasm/workshop2012/ and browse through the list of case studies. The web page also provides a detailed list of participants and the workshop agenda. Aside from contributed oral and poster presentations during the workshop’s plenary sessions, parallel breakout sessions focused on presentations and discussions of the individual cases. A short summary and science highlights from each of the cases is presented below.« less

Examining Environmental Gradients with Remotely Sensed Data - the ESA GlobPermafrost project

NASA Astrophysics Data System (ADS)

Bartsch, Annett; Grosse, Guido; Kääb, Andreas; Westermann, Sebastian; Strozzi, Tazio; Wiesmann, Andreas; Duguay, Claude; Seifert, Frank Martin; Obu, Jaroslav; Nitze, Ingmar; Heim, Birgit; Haas, Antoni; Widhalm, Barbara

2017-04-01

Permafrost cannot be directly detected from space, but many surface features of permafrost terrains and typical periglacial landforms are observable with a variety of EO sensors ranging from very high to medium resolution at various wavelengths. In addition, landscape dynamics associated with permafrost changes and geophysical variables relevant for characterizing the state of permafrost, such as land surface temperature or freeze-thaw state can be observed with space-based Earth Observation. Suitable regions to examine environmental gradients across the Arctic have been defined in a community white paper (Bartsch et al. 2014). These transects have been updated within the ESA DUE GlobPermafrost project. The ESA DUE GlobPermafrost project develops, validates and implements Earth Observation (EO) products to support research communities and international organisations in their work on better understanding permafrost characteristics and dynamics. Prototype product cases will cover different aspects of permafrost by integrating in situ measurements of subsurface properties and surface properties, Earth Observation, and modelling to provide a better understanding of permafrost today. The project will extend local process and permafrost monitoring to broader spatial domains, support permafrost distribution modelling, and help to implement permafrost landscape and feature mapping in a GIS framework. It will also complement active layer and thermal observing networks. Both lowland (latitudinal) and mountain (altitudinal) permafrost issues are addressed. The selected transects and first results will be presented. This includes identified needs from the user requirements survey, a review of existing land surface products available for the Arctic as well as prototypes of GlobPermafrost datasets, and the permafrost information system through which they can be accessed. Bartsch, Annett; Allard, Michel; Biskaborn, Boris Kolumban; Burba, George; Christiansen, Hanne H; Duguay, Claude R; Grosse, Guido; Günther, Frank; Heim, Birgit; Högström, Elin; Kääb, Andreas; Keuper, Frida; Lanckman, Jean-Pierre; Lantuit, Hugues; Lauknes, Tom Rune; Leibman, Marina O; Liu, Lin; Morgenstern, Anne; Necsoiu, Marius; Overduin, Pier Paul; Pope, Allen; Sachs, Torsten; Séjourné, Antoine; Streletskiy, Dmitry A; Strozzi, Tazio; Ullmann, Tobias; Ullrich, Matthias S; Vieira, Goncalo; Widhalm, Barbara (2014): Requirements for monitoring of permafrost in polar regions - A community white paper in response to the WMO Polar Space Task Group (PSTG), Version 4, 2014-10-09. Austrian Polar Research Institute, Vienna, Austria, 20 pp, hdl:10013/epic.45648.d001

Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: Method development and intercomparison

NASA Astrophysics Data System (ADS)

Harris, E. J.; Eyer, S.; Mohn, J.; Röckmann, T.; Popa, E.; Lowry, D.; Nisbet, E. G.; Fisher, R. E.; Brennwald, M. S.; Fischer, H.; Emmenegger, L.; Tuzson, B.; Zellweger, C.

2015-12-01

Methane (CH4) is the second most important anthropogenically emitted greenhouse gas after carbon dioxide (CO2). Its mole fraction has increased from around 722 ppb in pre-industrial times to 1824 ppb in 2013 and the anthropogenic fraction is estimated to be 60 % of the total emissions. A promising approach to improve the understanding of the CH4 budget is the use of isotopologues to distinguish between various CH4 source processes. In the presented study in situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, mmole/mole) methane is 0.1‰ and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. [1] Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 ‰ and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to IRMS based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers (Figure). Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX-QCLAS data and bag/flask sampling-IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and δD-CH4, respectively. Thus, the intercomparison also reveals the need for reference air samples with accurately determined isotopic composition of CH4 to further improve the interlaboratory compatibility. [1] References: [1] S. Eyer et al. (2015) submitted to AMTD

Toward an integrated storm surge application: ESA Storm Surge project

NASA Astrophysics Data System (ADS)

Lee, Boram; Donlon, Craig; Arino, Olivier

2010-05-01

Storm surges and their associated coastal inundation are major coastal marine hazards, both in tropical and extra-tropical areas. As sea level rises due to climate change, the impact of storm surges and associated extreme flooding may increase in low-lying countries and harbour cities. Of the 33 world cities predicted to have at least 8 million people by 2015, at least 21 of them are coastal including 8 of the 10 largest. They are highly vulnerable to coastal hazards including storm surges. Coastal inundation forecasting and warning systems depend on the crosscutting cooperation of different scientific disciplines and user communities. An integrated approach to storm surge, wave, sea-level and flood forecasting offers an optimal strategy for building improved operational forecasts and warnings capability for coastal inundation. The Earth Observation (EO) information from satellites has demonstrated high potential to enhanced coastal hazard monitoring, analysis, and forecasting; the GOCE geoid data can help calculating accurate positions of tide gauge stations within the GLOSS network. ASAR images has demonstrated usefulness in analysing hydrological situation in coastal zones with timely manner, when hazardous events occur. Wind speed and direction, which is the key parameters for storm surge forecasting and hindcasting, can be derived by using scatterometer data. The current issue is, although great deal of useful EO information and application tools exist, that sufficient user information on EO data availability is missing and that easy access supported by user applications and documentation is highly required. Clear documentation on the user requirements in support of improved storm surge forecasting and risk assessment is also needed at the present. The paper primarily addresses the requirements for data, models/technologies, and operational skills, based on the results from the recent Scientific and Technical Symposium on Storm Surges (www.surgesymposium.org, organized by the WMO-IOC Joint technical Commission for Oceanography and Marine Meteorology, JCOMM) and following activities, that have been supported by the Intergovernmental Oceanographic Commission (IOC) of UNESCO through JCOMM. The paper also reviews the capabilities of storm surge models, and current status in using Earth Observation (EO) information for advancing storm surge application tools, and further, for improving operational forecasts and warning capability for coastal inundation. In this context, the plans and expected results of the ESA Storm Surge Project (2010-2011) will be introduced.

The total column of CO2 and CH4 measured with a compact Fourier transform spectrometer at NASA Armstrong Flight Research Center and Railroad Valley, Nevada, USA

NASA Astrophysics Data System (ADS)

Kawakami, S.; Shiomi, K.; Suto, H.; Kuze, A.; Hillyard, P. W.; Tanaka, T.; Podolske, J. R.; Iraci, L. T.; Albertson, R. T.

2014-12-01

The total columns of carbon dioxide (XCO2) and methane (XCH4) were measured with a compact Fourier transform spectrometer (FTS) at NASA Armstrong Flight Research Center (AFRC) and Railroad Valley, Nevada, USA (RRV) during a vicarious calibration campaign in June 2014. The campaign was performed to estimate changes in the radiometric response of the Thermal and Near Infrared Sensor for carbon Observations Fourier Transform Spectrometer (TANSO-FTS) and the Cloud and Aerosol Imager (TANSO-CAI) aboard Greenhouse gases Observing SATellite (GOSAT). TANSO-FTS measures spectra of radiance scattered by the Earth surface with high- and medium-gain depending on the surface reflectance. At high reflectance areas, such as deserts over north Africa and Australia, TANSO-FTS collects spectra with medium-gain. There was differences on atmospheric pressure and XCO2 retrieved from spectra obtained between high-gain and medium-gain. Because the retrieved products are useful for evaluating the difference of spectral qualities between high- and medium-gain, this work is an attempt to collect validation data for spectra with medium-gain of TANSO-FTS at remote and desert area with a compact and medium-spectral resolution instrument. As a compact FTS, EM27/SUN was used. It was manufactured and newly released on April 1, 2014 by Bruker. It is robust and operable in a high temperature environment. It was housed in a steel box to protect from dust and rain and powered by Solar panels. It can be operated by such a remote and desert area, like a RRV. Over AFRC and RRV, vertical profiles of CO2 and CH4 were measured using the Alpha Jet research aircraft as part of the Alpha Jet Atmospheric eXperiment (AJAX) of ARC, NASA. The values were calibrated to standard gases. To make the results comparable to WMO (World Meteorological Organization) standards, the retrieved XCO2 and XCH4 values are divided by a calibration factor. This values were determined by comparisons with in situ profiles measured by the aircraft. At AFRC it was operated by the side of a ground-based Total Carbon Column Observing Network (TCCON) FTS (Bruker IFS 125HR) and the diurnal variation agreed well . In this presentation, we will show results on XCO2 and XCH4 observations made by a compact FTS at AFRC and RRV and comparison of GOSAT and TCCON FTS.

CLIMANDES climate science e-learning course

NASA Astrophysics Data System (ADS)

Hunziker, Stefan; Giesche, Alena; Jacques-Coper, Martín; Brönnimann, Stefan

2016-04-01

Over the past three years, members of the Oeschger Centre for Climate Change Research (OCCR) and the Climatology group at the Institute of Geography at the University of Bern, have developed a new climate science e-learning course as part of the CLIMANDES project. This project is a collaboration between Peruvian and Swiss government, research, and education institutions. The aim of this e-learning material is to strengthen education in climate sciences at the higher education and professional level. The course was recently published in 2015 by Geographica Bernensia, and is hosted online by the Peruvian Servicio Nacional de Meteorología e Hidrología (SENAMHI): http://surmx.com/chamilo/climandes/e-learning/. The course is furthermore available for offline use through USB sticks, and a number of these are currently being distributed to regional training centers around the world by the WMO (World Meteorological Organization). There are eight individual modules of the course that each offer approximately 2 hours of individual learning material, featuring several additional learning activities, such as the online game "The Great Climate Poker" (http://www.climatepoker.unibe.ch/). Overall, over 50 hours of learning material are provided by this course. The modules can be integrated into university lectures, used as single units in workshops, or be combined to serve as a full course. This e-learning course presents a broad spectrum of topics in climate science, including an introduction to climatology, atmospheric and ocean circulation, climate forcings, climate observations and data, working with data products, and climate models. This e-learning course offers a novel approach to teaching climate science to students around the world, particularly through three important features. Firstly, the course is unique in its diverse range of learning strategies, which include individual reading material, video lectures, interactive graphics, responsive quizzes, as well as group activities and discussions that are led by a tutor. This combination of self-learning and group-based learning presents a new and more interactive style of online education. Secondly, the course provides links to many existing e-learning and other online learning resources for specific climate science topics. This makes the course a starting point for students looking to deepen their knowledge in specific areas. Lastly, the existing course template is available upon request, for teachers to add modules that they would like to offer in addition to the CLIMANDES course. This gives instructors an easy way to adapt the course to their needs and learn about the software needed to make more e-learning material.

Progress toward an Integrated Global GHG Information System (IG3IS)

NASA Astrophysics Data System (ADS)

DeCola, Philip

2016-04-01

Accurate and precise atmospheric measurements of greenhouse gas (GHG) concentrations have shown the inexorable rise of global GHG concentrations due to human socioeconomic activity. Scientific observations also show a resulting rise in global temperatures and evidence of negative impacts on society. In response to this amassing evidence, nations, states, cities and private enterprises are accelerating efforts to reduce emissions of GHGs, and the UNFCCC process recently forged the Paris Agreement. Emission reduction strategies will vary by nation, region, and economic sector (e.g., INDCs), but regardless of the strategies and mechanisms applied, the ability to implement policies and manage them effectively over time will require consistent, reliable and timely information. A number of studies [e.g., Verifying Greenhouse Gas Emissions: Methods to Support International Climate Agreements (2010); GEO Carbon Strategy (2010); IPCC Task Force on National GHG Inventories: Expert Meeting Report on Uncertainty and Validation of Emission Inventories (2010)] have reported on the state of carbon cycle research, observations and models and the ability of these atmospheric observations and models to independently validate and improve the accuracy of self-reported emission inventories based on fossil fuel usage and land use activities. These studies concluded that by enhancing our in situ and remote-sensing observations and atmospheric data assimilation modeling capabilities, a GHG information system could be achieved in the coming decade to serve the needs of policies and actions to reduce GHG emissions. Atmospheric measurements and models are already being used to provide emissions information on a global and continental scale through existing networks, but these efforts currently provide insufficient information at the human-dimensions where nations, states, cities, and private enterprises can take valuable, and additional action that can reduce emissions for a specific GHG from a specific human activity. Based upon the recent advances in GHG observation technologies, new data-mining tools for acquiring socioeconomic activity data, and enhancements to the computational models used to merge this data, WMO and its partners are developing a plan for an Integrated Global GHG Information System (IG3IS) able to evaluate the efficacy of policy, reduce emission inventory uncertainty, and inform additional mitigation actions. The presentation will cover the principles and objectives of IG3IS, as well as progress toward answering the questions: What research capabilities are ready and able to deliver useful information for whom? What decisions will be informed? What valuable and additional outcomes will result?

Distribution of oxygen-18 and deuteriun in river waters across the United States

USGS Publications Warehouse

Kendall, Carol; Coplen, Tyler B.

2001-01-01

Reconstruction of continental palaeoclimate and palaeohydrology is currently hampered by limited information about isotopic patterns in the modern hydrologic cycle. To remedy this situation and to provide baseline data for other isotope hydrology studies, more than 4800, depth- and width-integrated, stream samples from 391 selected sites within the USGS National Stream Quality Accounting Network (NASQAN) and Hydrologic Benchmark Network (HBN) were analysed for δ18O and δ2H (http://water.usgs.gov/pubs/ofr/ofr00-160/pdf/ofr00-160.pdf). Each site was sampled bimonthly or quarterly for 2·5 to 3 years between 1984 and 1987. The ability of this dataset to serve as a proxy for the isotopic composition of modern precipitation in the USA is supported by the excellent agreement between the river dataset and the isotopic compositions of adjacent precipitation monitoring sites, the strong spatial coherence of the distributions of δ18O and δ2H, the good correlations of the isotopic compositions with climatic parameters, and the good agreement between the ‘national’ meteoric water line (MWL) generated from unweighted analyses of samples from the 48 contiguous states of δ2H=8·11δ18O+8·99 (r2=0·98) and the unweighted global MWL of sites from the Global Network for Isotopes in Precipitation (GNIP) of the International Atomic Energy Agency and the World Meteorological Organization (WMO) of δ2H=8·17δ18O+10·35. The national MWL is composed of water samples that arise in diverse local conditions where the local meteoric water lines (LMWLs) usually have much lower slopes. Adjacent sites often have similar LMWLs, allowing the datasets to be combined into regional MWLs. The slopes of regional MWLs probably reflect the humidity of the local air mass, which imparts a distinctive evaporative isotopic signature to rainfall and hence to stream samples. Deuterium excess values range from 6 to 15‰ in the eastern half of the USA, along the northwest coast and on the Colorado Plateau. In the rest of the USA, these values range from −2 to 6‰, with strong spatial correlations with regional aridity. The river samples have successfully integrated the spatial variability in the meteorological cycle and provide the best available dataset on the spatial distributions of δ18O and δ2H values of meteoric waters in the USA.

Climatological features of stratospheric streamers in the FUB-CMAM with increased horizontal resolution

NASA Astrophysics Data System (ADS)

Krüger, K.; Langematz, U.; Grenfell, J. L.; Labitzke, K.

2005-01-01

The purpose of this study is to investigate horizontal transport processes in the winter stratosphere using data with a resolution relevant for chemistry and climate modeling. For this reason the Freie Universität Berlin Climate Middle Atmosphere Model (FUB-CMAM) with its model top at 83 km altitude, increased horizontal resolution T42 and the semi-Lagrangian transport scheme for advecting passive tracers is used.

A new approach of this paper is the classification of specific transport phenomena within the stratosphere into tropical-subtropical streamers (e.g. Offermann et al., 1999) and polar vortex extrusions hereafter called polar vortex streamers. To investigate the role played by these large-scale structures on the inter-annual and seasonal variability of transport processes in northern mid-latitudes, the global occurrence of such streamers was calculated based on a 10-year model climatology, concentrating on the existence of the Arctic polar vortex. For the identification and counting of streamers, the new method of zonal anomaly was chosen. The analysis of the months October-May yielded a maximum occurrence of tropical-subtropical streamers during Arctic winter and spring in the middle and upper stratosphere. Synoptic maps revealed highest intensities in the subtropics over East Asia with a secondary maximum over the Atlantic in the northern hemisphere. Furthermore, tropical-subtropical streamers exhibited a higher occurrence than polar vortex streamers, indicating that the subtropical barrier is more permeable than the polar vortex barrier (edge) in the model, which is in good correspondence with observations (e.g. Plumb, 2002; Neu et al., 2003). Interesting for the total ozone decrease in mid-latitudes is the consideration of the lower stratosphere for tropical-subtropical streamers and the stratosphere above ~20 km altitude for polar vortex streamers, where strongest ozone depletion is observed at polar latitudes (WMO, 2003). In the lower stratosphere the FUB-CMAM simulated a climatological maximum of 10% occurrence of tropical-subtropical streamers over East-Asia/West Pacific and the Atlantic during early- and mid-winter.

The results of this paper demonstrate that stratospheric streamers e.g. large-scale, tongue-like structures transporting tropical-subtropical and polar vortex air masses into mid-latitudes occur frequently during Arctic winter. They can therefore play a significant role on the strength and variability of the observed total ozone decrease at mid-latitudes and should not be neglected in future climate change studies.

Monitoring, modeling and mitigating impacts of wind farms on local meteorology

NASA Astrophysics Data System (ADS)

Baidya Roy, Somnath; Traiteur, Justin; Kelley, Neil

2010-05-01

Wind power is one of the fastest growing sources of energy. Most of the growth is in the industrial sector comprising of large utility-scale wind farms. Recent modeling studies have suggested that such wind farms can significantly affect local and regional weather and climate. In this work, we present observational evidence of the impact of wind farms on near-surface air temperatures. Data from perhaps the only meteorological field campaign in an operational wind farm shows that downwind temperatures are lower during the daytime and higher at night compared to the upwind environment. Corresponding radiosonde profiles at the nearby Edwards Air Force Base WMO meteorological station show that the diurnal environment is unstable while the nocturnal environment is stable during the field campaign. This behavior is consistent with the hypothesis proposed by Baidya Roy et al. (JGR 2004) that states that turbulence generated in the wake of rotors enhance vertical mixing leading to a warming/cooling under positive/negative potential temperature lapse rates. We conducted a set of 306 simulations with the Regional Atmospheric Modeling System (RAMS) to test if regional climate models can capture the thermal effects of wind farms. We represented wind turbines with a subgrid parameterization that assumes rotors to be sinks of momentum and sources of turbulence. The simulated wind farms consistently generated a localized warming/cooling under positive/negative lapse rates as hypothesized. We found that these impacts are inversely correlated with background atmospheric boundary layer turbulence. Thus, if the background turbulence is high due to natural processes, the effects of additional turbulence generated by wind turbine rotors are likely to be small. We propose the following strategies to minimize impacts of wind farms: • Engineering solution: design rotors that generate less turbulence in their wakes. Sensitivity simulations show that these turbines also increase the productivity of wind farms and reduce damages to downwind rotors. • Siting solution: develop wind farms in regions where ABL turbulence is naturally high. Since, turbulence data is not widely recorded, we use surface KE dissipation rate as a proxy for ABL turbulence. Indeed, in our simulations, these 2 parameters are strongly positively correlated (P<0.99). Using the JRA25 dataset, comprising of 25-year long 6-hourly global meteorological data, we identify such regions in the world. These regions that include the Midwest and Great Plains as well as large parts of northern Europe and western China are appropriate sites for low-impact wind farms.

Revised Masses and Densities of the Planets around Kepler-10

NASA Astrophysics Data System (ADS)

Weiss, Lauren M.; Rogers, Leslie A.; Isaacson, Howard T.; Agol, Eric; Marcy, Geoffrey W.; Rowe, Jason F.; Kipping, David; Fulton, Benjamin J.; Lissauer, Jack J.; Howard, Andrew W.; Fabrycky, Daniel

2016-03-01

Determining which small exoplanets have stony-iron compositions is necessary for quantifying the occurrence of such planets and for understanding the physics of planet formation. Kepler-10 hosts the stony-iron world Kepler-10b, and also contains what has been reported to be the largest solid silicate-ice planet, Kepler-10c. Using 220 radial velocities (RVs), including 72 precise RVs from Keck-HIRES of which 20 are new from 2014 to 2015, and 17 quarters of Kepler photometry, we obtain the most complete picture of the Kepler-10 system to date. We find that Kepler-10b ({R}{{p}}=1.47 {R}\\oplus ) has mass 3.72\\quad +/- \\quad 0.42\\quad {M}\\oplus and density 6.46\\quad +/- \\quad 0.73\\quad {{g}} {{cm}}-3. Modeling the interior of Kepler-10b as an iron core overlaid with a silicate mantle, we find that the iron core constitutes 0.17 ± 0.11 of the planet mass. For Kepler-10c ({R}{{p}}=2.35 {R}\\oplus ) we measure mass 13.98\\quad +/- \\quad 1.79\\quad {M}\\oplus and density 5.94\\quad +/- \\quad 0.76\\quad {{g}} {{cm}}-3, significantly lower than the mass computed in Dumusque et al. (17.2+/- 1.9 {M}\\oplus ). Our mass measurement of Kepler-10c rules out a pure stony-iron composition. Internal compositional modeling reveals that at least 10% of the radius of Kepler-10c is a volatile envelope composed of hydrogen-helium (0.2% of the mass, 16% of the radius) or super-ionic water (28% of the mass, 29% of the radius). However, we note that analysis of only HIRES data yields a higher mass for planet b and a lower mass for planet c than does analysis of the HARPS-N data alone, with the mass estimates for Kepler-10 c being formally inconsistent at the 3σ level. Moreover, dividing the data for each instrument into two parts also leads to somewhat inconsistent measurements for the mass of planet c derived from each observatory. Together, this suggests that time-correlated noise is present and that the uncertainties in the masses of the planets (especially planet c) likely exceed our formal estimates. Transit timing variations (TTVs) of Kepler-10c indicate the likely presence of a third planet in the system, KOI-72.X. The TTVs and RVs are consistent with KOI-72.X having an orbital period of 24, 71, or 101 days, and a mass from 1 to 7 {M}\\oplus . W.M.O. Keck Observatory.

How to most effectively expand the global surface ozone observing network

NASA Astrophysics Data System (ADS)

Sofen, E. D.; Bowdalo, D.; Evans, M. J.

2016-02-01

Surface ozone observations with modern instrumentation have been made around the world for more than 40 years. Some of these observations have been made as one-off activities with short-term, specific science objectives and some have been made as part of wider networks which have provided a foundational infrastructure of data collection, calibration, quality control, and dissemination. These observations provide a fundamental underpinning to our understanding of tropospheric chemistry, air quality policy, atmosphere-biosphere interactions, etc. brought together eight of these networks to provide a single data set of surface ozone observations. We investigate how representative this combined data set is of global surface ozone using the output from a global atmospheric chemistry model. We estimate that on an area basis, 25 % of the globe is observed (34 % land, 21 % ocean). Whereas Europe and North America have almost complete coverage, other continents, Africa, South America, Australia, and Asia (12-17 %) show significant gaps. Antarctica is surprisingly well observed (78 %). Little monitoring occurs over the oceans, with the tropical and southern oceans particularly poorly represented. The surface ozone over key biomes such as tropical forests and savanna is almost completely unmonitored. A chemical cluster analysis suggests that a significant number of observations are made of polluted air masses, but cleaner air masses whether over the land or ocean (especially again in the tropics) are significantly under-observed. The current network is unlikely to see the impact of the El Niño-Southern Oscillation (ENSO) but may be capable of detecting other planetary-scale signals. Model assessment and validation activities are hampered by a lack of observations in regions where the models differ substantially, as is the ability to monitor likely changes in surface ozone over the next century. Using our methodology we are able to suggest new sites which would help to close the gap in our ability to measure global surface ozone. An additional 20 surface ozone monitoring sites (a 20 % increase in the World Meteorological Organization Global Atmosphere Watch (WMO GAW) ozone sites or a 1 % increase in the total background network) located on 10 islands and in 10 continental regions would almost double the area observed. The cost of this addition to the network is small compared to other expenditure on atmospheric composition research infrastructure and would provide a significant long-term benefit to our understanding of the composition of the atmosphere, information which will also be available for consideration by air quality control managers and policy makers.

Use of a Weather Generator for analysis of projections of future daily temperature and its validation with climate change indices

NASA Astrophysics Data System (ADS)

Di Piazza, A.; Cordano, E.; Eccel, E.

2012-04-01

The issue of climate change detection is considered a major challenge. In particular, high temporal resolution climate change scenarios are required in the evaluation of the effects of climate change on agricultural management (crop suitability, yields, risk assessment, etc.) energy production and water management. In this work, a "Weather Generator" technique was used for downscaling climate change scenarios for temperature. An R package (RMAWGEN, Cordano and Eccel, 2011 - available on http://cran.r-project.org) was developed aiming to generate synthetic daily weather conditions by using the theory of vectorial auto-regressive models (VAR). The VAR model was chosen for its ability in maintaining the temporal and spatial correlations among variables. In particular, observed time series of daily maximum and minimum temperature are transformed into "new" normally-distributed variable time series which are used to calibrate the parameters of a VAR model by using ordinary least square methods. Therefore the implemented algorithm, applied to monthly mean climatic values downscaled by Global Climate Model predictions, can generate several stochastic daily scenarios where the statistical consistency among series is saved. Further details are present in RMAWGEN documentation. An application is presented here by using a dataset with daily temperature time series recorded in 41 different sites of Trentino region for the period 1958-2010. Temperature time series were pre-processed to fill missing values (by a site-specific calibrated Inverse Distance Weighting algorithm, corrected with elevation) and to remove inhomogeneities. Several climatic indices were taken into account, useful for several impact assessment applications, and their time trends within the time series were analyzed. The indices go from the more classical ones, as annual mean temperatures, seasonal mean temperatures and their anomalies (from the reference period 1961-1990) to the climate change indices selected from the list recommended by the World Meteorological Organization Commission for Climatology (WMO-CCL) and the Research Programme on Climate Variability and Predictability (CLIVAR) project's Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI). Each index was applied to both observed (and processed) data and to synthetic time series produced by the Weather Generator, over the thirty year reference period 1981-2010, in order to validate the procedure. Climate projections were statistically downscaled for a selection of sites for the two 30-year periods 2021-2050 and 2071-2099 of the European project "Ensembles" multi-model output (scenario A1B). The use of several climatic indices strengthens the trend analysis of both the generated synthetic series and future climate projections.

Some seasonal characteristics in atmospheric methane concentration in the beginning of the XXI century

NASA Astrophysics Data System (ADS)

Vinogradova, Anna; Ginzburg, Alexander; Fedorova, Evgeniya

2010-05-01

Global average value of atmospheric methane concentrations have been increasing during the XX century, but this growth nearly stopped with the beginning of the 2000th. Such "stable" situation is the proper time for studying the seasonal cycle and extreme changes of air methane concentration. One of the most interesting periods for such investigations is autumn and winter 2006/07 [1] when a number of weather abnormalities (warm air temperature up to above 0°C, almost permanent cloudiness and absence of snow cover, and so on) in Moscow region created very specific conditions for air methane existence. Temporal variations in air methane concentration within the Moscow city have been studied using the data of observations at 12 stations of Moscow municipal environmental monitoring agency "Mosecomonitoring" in 2004-2008 [2]. It was found that near-surface air concentration of methane was much higher this time than few years before and after. The values of cold season methane concentrations in Moscow region have been compared with similar data measured in the North of Kola Peninsula (at WMO GAW station "Teriberka"), in the Sankt Petersburg region (the two stations of Roshydromet), in Finland and Hungary (the stations of NOAA GMD Carbon Cycle Sampling Network). Winter maxima (more or less) of methane concentrations were revealed almost each year at all these stations, but not everywhere they were simultaneous and as high as those had been found in Moscow. The reasons of winter 2006/07 high methane concentrations in Moscow and other regions of Northern Eurasia may be special weather conditions which could cause both decrease of air methane sinks and increase of methane emissions from natural and anthropogenic sources. Perhaps, the late growth of global atmospheric methane concentration after 2007 [3] was partly produced by those seasonal anomalies in the Northern Hemisphere. References: 1. E. Fedorova, A. Ginzburg, A. Vinogradova. Seasonal variations of atmospheric methane and hot winter 2006-2007 // Geophys. Res. Abstracts, 2007, Vol. 9, SRef-ID: 1607-7962/gra/EDU2007-A-06049. 2. A.A. Vinogradova, E.I. Fedorova, I.B. Belikov, et al. Temporal variations in carbon dioxide and methane concentrations under urban conditions // Izv., Atmospheric and Oceanic Physics, 2007, Vol. 43, No. 5, pp. 599-611. 3. Rigby M., Prinn R.G., Fraser P.J., et al. Renewed growth of atmospheric methane // Geophys. Res. Lett., 2008, Vol. 35. doi: 10,1029/2008GL036037

Examination of the Behavior of Bismuth in Shallow-Level Hydrothermal Ore Systems: Constraints Based on Hydrothermal Experiments at 800°C and 100 MPa

NASA Astrophysics Data System (ADS)

Wilmot, M. S.; Candela, P. A.; Piccoli, P. M.; Simon, A. C.; McDonough, W. F.

2006-05-01

The partitioning of ore metals between melt and crystals affects the concentrations of these metals in an evolving ore fluid, and therefore the efficiency of their removal from the magma by hydrothermal processes. Some porphyry-type W-Mo deposits contain recoverable amounts of Bi, whereas others contain only trace amounts. In order to determine the magmatic controls on the ratio of Bi to other commodities in these and other deposits, we examined the partitioning behavior of bismuth between melt, minerals and aqueous phases. Hydrothermal experiments were performed by using externally heated cold seal vessels and employing a double capsule technique. Experiments contained 40 mg of Bishop Tuff glass (SiO2 = 74% ) and 40 mg of either magnetite or pyrrhotite. Bi was added as elemental Bi (< 1 mg). Two different aqueous solutions were used. Initially, the added aqueous phase comprised the solutes HCl, KCl and NaCl in a molar1:1:1 ratio, with a bulk salinity of 10 wt % NaCl eq. The aqueous phase for later experiments contained only the solutes KCl and NaCl in a 1:1 molar ratio. Pre-fractured quartz was added to the experiments to trap fluid inclusions at run PTX conditions. Experiments were performed in Au or Pt capsules held inside Rene 41 cold-seal vessels at 800°C and 100 MPa for durations of up to 36 hours. Analytical data have been collected from the run product solids by using an electron probe microanalyzer (major and trace elements) and laser ablation inductively coupled plasma mass spectrometry (trace elements). Bi in Mt is found in concentrations up to 100 ppm, with higher concentrations in runs where Po decomposed to form magnetite. The Bi concentration in the glass ranges up to 100 ppm. In the Po-bearing runs, data were only collected from Po grains in the experiments containing the HCl-free aqueous solution (the Po grains in the other experiments were too small to analyze). Pyrrhotite contained 10-20 ppm Bi, whereas the glass contained 5-10 ppm. Preliminary Nernst- type partition coefficients for Bi between Mt and melt and Po and melt are approximately 5 and 2, respectively. These data reveal that Bi is only slightly compatible in Mt and Po, and that the Po/melt partition coefficient for Bi is much lower than for Cu, Ag and Au, and is comparable to Mn and Zn. Additional experiments are in progress to more compare the partitioning of Bi with that of W and Mo.

Agricultural drought risk monitoring and yield loss forecast with remote sensing data

NASA Astrophysics Data System (ADS)

Nagy, Attila; Tamás, János; Fehér, János

2015-04-01

The World Meteorological Organization (WMO) and Global Water Partnership (GWP) have launched a joint Integrated Drought Management Programme (IDMP) to improve monitoring and prevention of droughts. In the frame of this project this study focuses on identification of agricultural drought characteristics and elaborates a monitoring method (with application of remote sensing data), which could result in appropriate early warning of droughts before irreversible yield loss and/or quality degradation occur. The spatial decision supporting system to be developed will help the farmers in reducing drought risk of the different regions by plant specific calibrated drought indexes. The study area was the Tisza River Basin, which is located in Central Europe within the Carpathian Basin. For the investigations normalized difference vegetation index (NDVI) was used calculated from 16 day moving average chlorophyll intensity and biomass quantity data. The results offer concrete identification of remote sensing and GIS data tools for agricultural drought monitoring and forecast, which eventually provides information on physical implementation of drought risk levels. In the first step, we statistically normalized the crop yield maps and the MODIS satellite data. Then the drought-induced crop yield loss values were classified. The crop yield loss data were validated against the regional meteorological drought index values (SPI), the water management and soil physical data. The objective of this method was to determine the congruency of data derived from spectral data and from field measurements. As a result, five drought risk levels were developed to identify the effect of drought on yields: Watch, Early Warning, Warning, Alert and Catastrophe. In the frame of this innovation such a data link and integration, missing from decision process of IDMP, are established, which can facilitate the rapid spatial and temporal monitoring of meteorological, agricultural drought phenomena and its economic relations, increasing the time factors effectiveness of decision support system. This methodology will be extendable for other Central European countries when country specific data are available and entered into the system. This new drought risk monitoring and forecasting method is an improvement for hydrologists, meteorologists and farmers, allowing to set up a complex drought monitoring system, where for a given period and respective catchment area the expected yield loss can be predicted, and the role of vegetation in the hydrological cycle could be more precisely quantified. Based on the results more water-saving agricultural land use alternatives could be planned on drought areas.

PREFACE: XXIVth Conference of the Danubian Countries on the Hydrological Forecasting and Hydrological Bases of Water Management

NASA Astrophysics Data System (ADS)

Brilly, Mitja; Bonacci, Ognjen; Nachtnebel, Peter Hans; Szolgay, Ján; Balint, Gabor

2008-10-01

This volume of IOP Conference Series: Earth and Environmental Science presents a selection of papers that were given at the 24th Conference of the Danube Countries. Within the framework of the International Hydrological Program IHP of UNESCO. Since 1961 the Danube countries have successfully co-operated in organizing conferences on Hydrological Forecasting and Hydrological Water Management Issues. The 24th Conference of the Danube Countries took place between 2-4 June 2008 in Bled, Slovenia and was organized by the National Committee of Slovenia for the International Hydrological Program of UNESCO, under the auspices of the President of Republic of Slovenia. It was organized jointly by the Slovenian National Commission for UNESCO and the Environmental Agency of the Republic of Slovenia, under the support of UNESCO, WMO, and IAHS. Support for the attendance of some participants was provided by UNESCO. Additional support for the symposium was provided by the Slovene Commission for UNESCO, Environmental Agency of Slovenia, Karst Research Institute, Hydropower plants on the lower Sava River and Chair of Hydraulics Engineering FGG University of Ljubljana. All participants expressed great interest and enthusiasm in presenting the latest research results and sharing practical experiences in the Hydrology of the Danube River basin. The Editorial Board, who were nominated at the Conference, initially selected 80 full papers for publication from 210 submitted extended abstracts and papers provided by authors from twenty countries. Altogether 51 revised papers were accepted for publishing in this volume. Papers are divided by conference topics: Hydrological forecasting Hydro-meteorological extremes, floods and droughts Global climate change and antropogenic impacts on hydrological processes Water management Floods, morphological processes, erosion, sediment transport and sedimentation Developments in hydrology Mitja Brilly, Ognjen Bonacci, Peter Hans Nachtnebel, Ján Szolgay and Gabor Balint Editorial Board International Scientific Committee: P Hubert: Centre d'Informatique Géologique, France H P Nachtnebel: Universität für Bodenkultur Wien, Austria H Weber: Bavarian Water Management Administration, Germany H Moser: Federal Institute of Hydrology, Germany M Domokos: VITUKI, Hungary P Stanciu: National Institute of Meteorology and Hydrology, Romania O Bonacci: University of Split, Croatia S Prohaska: Institute Jaroslav Černi, Belgrade, Serbia J Szolgay: Faculty of Civil Engineering, Bratislava, Slovak Republic K Tzankov: Institute of Meteorology and Hydrology, Sofia, Bulgaria E Soukalová: Czech Hydrometeorological Institute, Czech Republic B Matičič: National Committee on Irrigation and Drainage, Slovenia M Mikoš: University of Ljubljana, Ljubljana, Slovenia J Rakovec: University of Ljubljana, Ljubljana, Slovenia M Brilly: University of Ljubljana, Ljubljana, Slovenia M Veselič: ARAO, Slovenia

Evaluation of atmospheric dust prediction models using ground-based observations

NASA Astrophysics Data System (ADS)

Terradellas, Enric; María Baldasano, José; Cuevas, Emilio; Basart, Sara; Huneeus, Nicolás; Camino, Carlos; Dundar, Cinhan; Benincasa, Francesco

2013-04-01

An important step in numerical prediction of mineral dust is the model evaluation aimed to assess its performance to forecast the atmospheric dust content and to lead to new directions in model development and improvement. The first problem to address the evaluation is the scarcity of ground-based routine observations intended for dust monitoring. An alternative option would be the use of satellite products. They have the advantage of a large spatial coverage and a regular availability. However, they do have numerous drawbacks that make the quantitative retrievals of aerosol-related variables difficult and imprecise. This work presents the use of different ground-based observing systems for the evaluation of dust models in the Regional Center for Northern Africa, Middle East and Europe of the World Meteorological Organization (WMO) Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). The dust optical depth at 550 nm forecast by different models is regularly compared with the AERONET measurements of Aerosol Optical Depth (AOD) for 40 selected stations. Photometric measurements are a powerful tool for remote sensing of the atmosphere allowing retrieval of aerosol properties, such as AOD. This variable integrates the contribution of different aerosol types, but may be complemented with spectral information that enables hypotheses about the nature of the particles. Comparison is restricted to cases with low Ångström exponent values in order to ensure that coarse mineral dust is the dominant aerosol type. Additionally to column dust load, it is important to evaluate dust surface concentration and dust vertical profiles. Air quality monitoring stations are the main source of data for the evaluation of surface concentration. However they are concentrated in populated and industrialized areas around the Mediterranean. In the present contribution, results of different models are compared with observations of PM10 from the Turkish air quality network for April 2011, when several dust episodes where recorded. In regions devoid of air quality stations (as Saharan and Arabian deserts), model forecasts are regularly evaluated for 38 dust-prone sites through the use of an empirical relationship between visibility data (obtained from meteorological reports) and dust surface concentration. Finally, active remote sensing with lidar or ceilometers is the only way to inquire about the dust vertical distribution. Analysis of selected cases comparing model forecasts and lidar observations at Santa Cruz de Tenerife (Canary Islands) yields promising results regarding the identification of the dust plume thickness. From the results of this pilot trial, the convenience of a regular evaluation will be assessed.

Seasonal variability of carbonaceous aerosols in an urban background area in Southern Italy

NASA Astrophysics Data System (ADS)

Cesari, D.; Merico, E.; Dinoi, A.; Marinoni, A.; Bonasoni, P.; Contini, D.

2018-02-01

Organic (OC) and Elemental Carbon (EC) are important components of atmospheric aerosol particles, playing a key role in climate system and potentially affecting human health. There is a lack of data reported for Southern Italy and this work aims to fill this gap, focusing the attention on the long-term trends of OC and EC concentrations in PM2.5 and PM10, and on atmospheric processes and sources influencing seasonal variability. Measurements were taken at the Environmental-Climate Observatory of Lecce (SE Italy, 40°20‧8″N-18°07‧28″E, 37 m a.s.l.), regional station of the Global Atmosphere Watch program (GAW-WMO). Daily PM10 and PM2.5 samples were collected between July 2013 and July 2016. In addition, starting in December 2014, simultaneous equivalent Black Carbon (eBC) concentrations in PM10 were measured using a Multi Angle Absorption Photometer. A subset of 722 PM samples (361 for each size fraction) was analysed by using a thermo-optical method with a Sunset Laboratory OC/EC analyser, to determine elemental and organic carbon concentrations. The average PM10 and PM2.5 concentrations were 28.8 μg/m3 and 17.5 μg/m3. The average OC and EC concentrations in PM10 were 5.4 μg/m3 and 0.8 μg/m3, in PM2.5 these were 4.7 μg/m3 and 0.6 μg/m3. Carbonaceous content was larger during cold season with respect to warm season as well as secondary organic carbon (SOC) that was evaluated using the OC/EC minimum ratio method. SOC was mainly segregated in PM2.5 and represented 53% - 75% of the total OC. A subset of EC data was compared with eBC measurements, showing a good correlation (R2 = 0.80), however, eBC concentrations were higher than EC concentrations of an average factor of 1.95 (+/- 0.55 standard deviation). This could be explained by the presence of a contribution of Brown Carbon (BrC), for example from biomass burning, in eBC measurements. Weekly patterns showed a slight decrease of carbon content during weekends with respect to weekdays especially visible on eBC concentration due to the decrease of road traffic emissions. The daily patterns of hourly eBC concentrations showed a decrease in central diurnal hours, due to the cycle of planetary boundary-layer height, and concentrations peaks during rush hours due to road traffic emissions.

High altitude environmental monitoring: the SHARE project and CEOP-HE

NASA Astrophysics Data System (ADS)

Tartari, G.

2009-04-01

Mountain areas above 2,500 m a.s.l. constitute about 25% of the Earth's surface and play a fundamental role in the global water balance, while influencing global climate and atmospheric circulation systems. Several millions, including lowlanders, are directly affected by the impacts of climate change on glaciers and water resource distribution. Mountains and high altitude plateaus are subject to the highest rate of temperature increase (e.g., Tibetan Plateau) and are recognized as particularly vulnerable to the effects of climate change. In spite of this, the number of permanent monitoring sites in the major environmental networks decreases with altitude. On a sample of two hundred high altitude automatic weather stations located above 2,500 m a.s.l., less than 20% are over 4,000 m, while there are only 24 stations in the world that could be considered "complete" high altitude observatories. Furthermore, entire mountain areas are left uncovered, creating significant data gaps which make reliable modelling and forecasting nearly impossible. In response to these problems, Ev-K2-CNR has developed the project SHARE (Stations at High Altitude for Research on the Environment) with the support of the Italian government and in collaboration with UNEP. This integrated environmental monitoring and research project aims to improve knowledge on the local, regional and global consequences of climate change in mountain regions and on the influence of high elevations on climate, atmospheric circulation and hydrology. SHARE today boasts a network of 13 permanent monitoring stations between 2,165 m and 8,000 m. Affiliated researchers have produced over 150 scientific publications in atmospheric sciences, meteorology and climate, glaciology, limnology and paleolimnology and geophysics. SHARE network data is also contributed to international programs (UNEP-ABC, WMO-GAW, WCRP-GEWEX-CEOP, NASA-AERONET, ILTER, EU-EUSAAR, EU-ACCENT). Within this context, the CEOP-High Elevations (CEOP-HE) element of regional focus was developed under the GEWEX CEOP programme to study multi-scale variability in water and energy cycles in high elevation areas, and to help improve observations, modelling and data management. Future plans include expansion of the SHARE network, addition of other key research areas including hydrology, and creation of mechanisms to favour exchange of data amongst high altitude networks. In coordination with other global research and monitoring projects (CliC, etc.), SHARE and CEOP-HE could provide a more organic and well-distributed interdisciplinary network, thus allowing governments and international agencies to better face impacts of climate change effects on energy and water budgets and elaborate appropriate adaptation strategies.

Absorption Cross-Sections of Ozone in the Ultraviolet and Visible Spectral Regions: Status report 2015

NASA Technical Reports Server (NTRS)

Orphal, Johannes; Staehelin, Johannes; Tamminen, Johanna; Braathen, Geir; De Backer, Marie-Renee; Bais, Alkiviadis; Balis, Dimitris; Barbe, Alain; Bhartia, Pawan K.; Birk, Manfred;

Characterisation of the input signal to aquifers in the French Basque Country: Emphasis on parameters influencing the chemical and isotopic composition of recharge waters

NASA Astrophysics Data System (ADS)

Jaunat, J.; Celle-Jeanton, H.; Huneau, F.; Dupuy, A.; Le Coustumer, P.

2013-07-01

A hydrochemical and isotopic survey of rainwater and groundwater has been carried out during almost two years on the Ursuya Mount in the northern Basque Country (southwestern France) with the aim of enhancing the understanding of the behaviour of this aquifer and more peculiarly the recharge mode of groundwater. The input signal of this aquifer is defined thanks to 112 rainwater samples. The computed meteoric water line (δD = 7.3 δ18O + 5.1; r = 0.96) is consistent with that defined in the European IAEA/WMO network stations. The weighted mean deuterium excess about 9.7‰ is really close to the value obtained for Atlantic precipitations and clearly demonstrates an oceanic major origin. The computations conducted on the chemical dataset show that the rainwater composition is controlled by four major factors: (1) a mixed source of anthropogenic pollution and crustal material; (2) a marine source; (3) an urban source; (4) an acid source. Further, the quantification of neutralizing potentials clearly revealed below cloud processes in which crustal and anthropogenic components are responsible for the neutralization of anions. Besides the major Atlantic origin of the recharge water, the chemical and isotopic content of the samples coupled with the corresponding air mass back trajectories revealed four major geographical origins of the components: (1) northwestern part of Atlantic Ocean and (2) Southwestern part of Atlantic Ocean. The oceanic influence in airmasses from these origins is highlighted by the stable isotopic content (weighted mean close to the Atlantic Ocean signature) and by the chemical concentrations dominated by sea salt elements. (3) Northern Europe with a continental influence shown by a light depletion on isotopic signal besides purely oceanic origin and a higher concentration of crustal and anthropogenic components. 4) Southeastern area (Southeastern Europe, Northern Africa and Mediterranean Sea) with an isotopic signature consistent with the Mediterranean one and a chemical composition clearly influenced by the industrial activities of this region. The dataset is confronted with the chemical and isotopic characteristics of groundwater in order to assess the recharge water signature of the aquifer of the Ursuya Mount. The groundwater isotopic signal is close to the defined LMWL, showing actual and local recharge. Nevertheless, a slightly difference is observed between the mean value of stable isotopic content in groundwater and in rainwater. The slightly depleted values of groundwater besides rainwater can be attributed to a preferential winter/autumn recharge. An altitudinal gradient about -0.11‰ δ18O/100 m is defined and both water-rock interactions and physicochemical processes fingerprint on the groundwater composition are characterised.

Midlatitude cirrus classification at Rome Tor Vergata through a multichannel Raman-Mie-Rayleigh lidar

NASA Astrophysics Data System (ADS)

Dionisi, D.; Keckhut, P.; Liberti, G. L.; Cardillo, F.; Congeduti, F.

2013-12-01

A methodology to identify and characterize cirrus clouds has been developed and applied to the multichannel-multiwavelength Rayleigh-Mie-Raman (RMR) lidar in Rome Tor Vergata (RTV). A set of 167 cirrus cases, defined on the basis of quasi-stationary temporal period conditions, has been selected in a data set consisting of about 500 h of nighttime lidar sessions acquired between February 2007 and April 2010. The derived lidar parameters (effective height, geometrical and optical thickness and mean back-scattering ratio) and the cirrus mid-height temperature (estimated from the radiosonde data of Pratica di Mare, WMO, World Meteorological Organization, site no. 16245) of this sample have been analyzed by the means of a clustering multivariate analysis. This approach identified four cirrus classes above the RTV site: two thin cirrus clusters in mid- and upper troposphere and two thick cirrus clusters in mid-upper troposphere. These results, which are very similar to those derived through the same approach at the lidar site of the Observatoire de Haute-Provence (OHP), allows characterization of cirrus clouds over the RTV site and attests to the robustness of such classification. To acquire some indications about the cirrus generation methods for the different classes, analyses of the extinction-to-backscatter ratio (lidar ratio, LReff, in terms of frequency distribution functions and dependencies on the mid-height cirrus temperature, have been performed. A preliminary study relating some meteorological parameters (e.g., relative humidity, wind components) to cirrus clusters has also been conducted. The RTV cirrus results, recomputed through the cirrus classification by Sassen and Cho (1992), show good agreement with other midlatitude lidar cirrus observations for the relative occurrence of subvisible (SVC), thin and opaque cirrus classes (10%, 49% and 41%, respectively). The overall mean value of cirrus optical depth is 0.37 ± 0.18, while most retrieved LReff values range between 10-60 sr, and the estimated mean value is 31 ± 15 sr, similar to LR values of lower latitude cirrus measurements. The obtained results are consistent with previous studies conducted with different systems and confirm that cirrus classification based on a statistical approach seems to be a good tool both to validate the height-resolved cirrus fields calculated by models and to investigate the key processes governing cirrus formation and evolution. However, the lidar ratio and optical depth analyses are affected by some uncertainties (e.g., lidar error noise, multiple scattering effects, supercooled water clouds) that reduce the confidence of the results. Future studies are needed to improve the characterization of the cirrus optical properties and, thus, the determination of their radiative impact.

Ice Velocity Mapping in Antarctica - Towards a Virtual Satellite Constellation

NASA Astrophysics Data System (ADS)

Scheuchl, B.; Mouginot, J.; Rignot, E. J.; Crevier, Y.

2013-12-01

Ice sheets are acknowledged by the World Meteorological Organization (WMO) and the United Nations Framework Convention on Climate Change (UNFCCC) as an Essential Climate Variable (ECV) needed to make significant progress in the generation of global climate products and derived information. Ice velocity is a crucial geophysical parameter that can be measured using spaceborne Synthetic Aperture Radar (SAR) data. Here, we report on an update to available Earth System Data Records (ESDR) of ice velocity in Antarctica based on data from a suite of spaceborne (SAR) sensors and provide an overview on international coordination in an effort to best utilize the available SAR satellites. Building on the first complete mapping of the flow of ice surface over the Antarctic continent using data predominantly acquired during IPY, we are working on a series of regional studies analyzing data from several different epochs. The analysis of velocity changes between discrete measurements requires even more careful data processing in order to be able to accurately measure subtle changes. Examples for Larsen-C and the Amundsen Sea Embayment will be presented. Data continuity is a crucial aspect to this work, particularly in light of the fact that 4 SAR missions have ceased operations since IPY and all available missions have a primary mandate that is not scientific data collection. Following the successful internationally coordinated SAR data acquisitions over ice sheets during the International Polar Year 2007/2008, efforts are undertaken to continue data acquisitions in the spirit of collaboration. The Polar Space Task Group (PSTG) is succeeding the IPY coordinating body of international space agencies, Space Task Group (STG). The PSTG SAR Coordination Working Group was created to address the issue of SAR data acquisitions in the cryosphere. A review of ice sheet requirements was undertaken by the science community, presented to PSTG, and followed up with a set of sensor specific recommendations. PSTG includes this information in coordinated acquisition planning going forward. In 2013 the Canadian Space Agency committed RADARSAT-2 to a large scale Antarctic data acquisition campaign. This effort will be supported in the near future by the European Space Agency and the Japan Space Exploration Agency once Sentinel-1 and ALOS-2 are launched. In addition, the German Space Agency and the Italian Space Agency acquire high resolution SAR data in high priority sites. We provide an overview of high-level plans and show first results from the RADARSAT-2 campaign. Data analysis and ESDR production is conducted at the Department of Earth System Science, University of California Irvine under a contract with the National Aeronautics and Space Administration's MEaSUREs program. Spaceborne SAR data are made available courtesy of the Polar Space Task Group.

2.8-Ma ash-flow caldera at Chegem River in the northern Caucasus Mountains (Russia), contemporaneous granites, and associated ore deposits

USGS Publications Warehouse

Lipman, P.W.; Bogatikov, O.A.; Tsvetkov, A.A.; Gazis, C.; Gurbanov, A.G.; Hon, K.; Koronovsky, N.V.; Kovalenko, V.I.; Marchev, P.

1993-01-01

Diverse latest Pliocene volcanic and plutonic rocks in the north-central Caucasus Mountains of southern Russia are newly interpreted as components of a large caldera system that erupted a compositionally zoned rhyolite-dacite ash-flow sheet at 2.83 ?? 0.02 Ma (sanidine and biotite 40Ar/39Ar). Despite its location within a cratonic collision zone, the Chegem system is structurally and petrologically similar to typical calderas of continental-margin volcanic arcs. Erosional remnants of the outflow Chegem Tuff sheet extend at least 50 km north from the source caldera in the upper Chegem River. These outflow remnants were previously interpreted by others as erupted from several local vents, but petrologic similarities indicate a common origin and correlation with thick intracaldera Chegem Tuff. The 11 ?? 15 km caldera and associated intrusions are superbly exposed over a vertical range of 2,300 m in deep canyons above treeline (elev. to 3,800 m). Densely welded intracaldera Chegem Tuff, previously described by others as a rhyolite lava plateau, forms a single cooling unit, is > 2 km thick, and contains large slide blocks from the caldera walls. Caldera subsidence was accommodated along several concentric ring fractures. No prevolcanic floor is exposed within the central core of the caldera. The caldera-filling tuff is overlain by andesitic lavas and cut by a 2.84 ?? 0.03-Ma porphyritic granodiorite intrusion that has a cooling age analytically indistinguishable from that of the tuffs. The Eldjurta Granite, a pluton exposed low in the next large canyon (Baksan River) 10 km to the northwest of the caldera, yields variable K-feldspar and biotite ages (2.8 to 1.0 Ma) through a 5-km vertical range in surface and drill-hole samples. These variable dates appear to record a prolonged complex cooling history within upper parts of another caldera-related pluton. Major W-Mo ore deposits at the Tirniauz mine are hosted in skarns and hornfels along the roof of the Eldjurta Granite, and associated aplitic phases have textural features of Climax-type molybdenite porphyries in the western USA. Similar 40Ar/39Ar ages, mineral chemistry, and bulk-rock compositions indicate that the Chegem Tuff, intracaldera intrusion, and Eldjurta Granite are all parts of a large magmatic system that broadly resembles the middle Tertiary Questa caldera system and associated Mo deposits in northern New Mexico, USA. Because of their young age and superb three-dimensional exposures, rocks of the Chegem-Tirniauz region offer exceptional opportunities for detailed study of caldera structures, compositional gradients in volcanic rocks relative to cogenetic granites, and the thermal and fluid-flow history of a large young upper-crustal magmatic system. ?? 1993.

Water Sciences - Connecting the dots to achieve the 2030 Agenda for Sustainable Development

NASA Astrophysics Data System (ADS)

Uhlenbrook, Stefan; Ortigara, Angela; Minelli, Lucilla

2017-04-01

Land use change, urbanisation, climate change, demographic development and migration, conflicts and peace, change of diets, industry 4.0, globalisation etc. are among the challenges that water sciences need to address to serve societal needs. Water availability per capita is decreasing, water quality is deteriorating at many places, but water demand is continuously escalating. Business as usual in water science is not up to the related challenges. In fact, business as usual cannot be the answer in all aspects, i.e. also current policy making processes will need to improve and take stock of evidences provided by science in order to better address societal challenges. However, exciting developments have been taking place. The global community agreed on a new and ambitious agenda for development, which aims to be comprehensive and include the participation of all stakeholders in one integrated framework. The 2030 Agenda for Sustainable Development provides a stimulating new era, with unique opportunities to reconcile science, society and policy making. Hydrology and water management - in all its facets including wastewater - play a central role in the Agenda 2030, as it is not only central in Sustainable Development Goal (SDG) 6, but it is fundamental for the realization of other SDGs related to, for instance, poverty reduction, sustainable growth, health, food security, climate change, ecosystems (land and sea), gender equality, etc. Despite the recognition of the critical importance of water in this agenda, the implementation of related policies and use of scientific developments represent a difficult task. Two main challenges remain: (i) the utilization of the knowledge and developments already available, and (ii) the need to overcome current and future knowledge gaps ensuring that scientific results support sustainable development effectively. The UN system will produce a Synthesis Report for SDG 6, which is currently being prepared by a UN-Water Task Force that includes several international organizations (i.e., CEO Water Mandate, FAO, ILO, UNDP, UNECE, UNEP, UNESCO, UNICEF, UN-Water TAU, WHO and WMO) and is coordinated by the UN World Water Assessment Programme of UNESCO. The Synthesis Report will provide an integrated analysis and synthesis of data, information and policy linkages between different SDG targets and indicators, providing Member Stater with 'the big picture' on progress made in achieving SDG 6, and recommendations for policy and decision makers and stakeholders in the water and development sectors. The role of (water) science is more critical than ever. In this era of rapid developments we are in dire need for action: further insights are needed to fully understand and quantify the systematic links between the different SDGs in order to explore future possible development pathways. Sound scientific basis has to support the development of effective policy implementation strategies.

Promoting Scientific Collaboration in South America through IDD-Brazil

NASA Astrophysics Data System (ADS)

Chagas, G. O.

2006-05-01

The IDD-Brazil constitutes of an expansion of the Unidata Internet Data Distribution (IDD), a joint effort among the Laboratório de Prognósticos em Mesoescala - Universidade Federal do Rio de Janeiro (LPM/UFRJ), Centro de PreviSão de Tempo e Estudos Climáticos (CPTEC, a division of INPE) and the Unidata Program Center, linking several Brazilian and South American Institutions in a network for near-real time data sharing. This international cooperation is modifying drastically the way that researchers use data, providing access to broaden and more detailed information, available freely for the participants of this network. Data-sharing is one of the biggest issues in Brazil, and the solutions developed at Unidata Program Center enhances not only data access and management, but also the display and analysis of a variety of datasets. Using the Local Data Manager (LDM), a site can both receive and send data trough the IDD network, on a client-server architecture. Moreover, this system also provides a seamless integration with many decoders, following WMO standards for a large array of data, ranging from METAR messages to GRIB. Using this network as a new path to deliver and acquire observational data, IDD-Brazil participants are now capable of receiving observational data not only from GTS (Global Telecommunication System), but also from CPTECs PCD (automatic stations) network and the entire array of METAR and SYNOP observations, in a near-real time basis. This network is capable of addressing a gap in data sharing, since it has no cost for educational and research purposes. The UFRJ has been working closely with CPTEC and Unidata, porting new datasets to this system, such as the output from CPTEC's ETA 40km regional model, local acquired Satellite Imagery from GOES, and LPM's MM5 and WRF 20km mesoscale models. The IDD-Brazil is creating a new cooperation among several institutions that traditionally face the same issues, but never had a link to a community. The new challenge faced is the dissemination of this knowledge, a key factor to increase the number of participants. In order to facilitate the dialogue among these institutions, training sessions are planned to occur, and also the involvement in key events - such as the Brazilian Meteorology Meeting an the 8th International Conference on Southern Hemisphere Meteorology and Oceanography. Any University or Research Center can, and its encouraged to, share its data with other IDD participants. Constant outreach efforts driven by Unidata, UFRJ and CPTEC are increasing the number of participants in IDD-Brazil, setting new paths for research, empowering Meteorology nationwide, and creating new collaborations throughout the Americas.

Validation of Copernicus Height-resolved Ozone data Products from Sentinel-5P TROPOMI using global sonde and lidar networks (CHEOPS-5P)

NASA Astrophysics Data System (ADS)

Keppens, Arno; Lambert, Jean-Christopher; Hubert, Daan; Verhoelst, Tijl; Granville, José; Ancellet, Gérard; Balis, Dimitris; Delcloo, Andy; Duflot, Valentin; Godin-Beekmann, Sophie; Koukouli, Marilisa; Leblanc, Thierry; Stavrakou, Trissevgeni; Steinbrecht, Wolfgang; Stübi, Réné; Thompson, Anne

2017-04-01

Monitoring of and research on air quality, stratospheric ozone and climate change require global and long-term observation of the vertical distribution of atmospheric ozone, at ever-improving resolution and accuracy. Global tropospheric and stratospheric ozone profile measurement capabilities from space have therefore improved substantially over the last decades. Being a part of the space segment of the Copernicus Atmosphere and Climate Services that is currently under implementation, the upcoming Sentinel-5 Precursor (S5P) mission with its imaging spectrometer TROPOMI (Tropospheric Monitoring Instrument) is dedicated to the measurement of nadir atmospheric radiance and solar irradiance in the UV-VIS-NIR-SWIR spectral range. Ozone profile and tropospheric ozone column data will be retrieved from these measurements by use of several complementary retrieval methods. The geophysical validation of the enhanced height-resolved ozone data products, as well as support to the continuous evolution of the associated retrieval algorithms, is a key objective of the CHEOPS-5P project, a contributor to the ESA-led S5P Validation Team (S5PVT). This work describes the principles and implementation of the CHEOPS-5P quality assessment (QA) and validation system. The QA/validation methodology relies on the analysis of S5P retrieval diagnostics and on comparisons of S5P data with reference ozone profile measurements. The latter are collected from ozonesonde, stratospheric lidar and tropospheric lidar stations performing network operation in the context of WMO's Global Atmosphere Watch, including the NDACC global and SHADOZ tropical networks. After adaptation of the Multi-TASTE versatile satellite validation environment currently operational in the context of ESA's CCI, EUMETSAT O3M-SAF, and CEOS and SPARC initiatives, a list of S5P data Quality Indicators (QI) will be derived from complementary investigations: (1) data content and information content studies of the S5P data retrievals; (2) traceable preparation of the S5P data and correlative measurements in view of data comparisons (co-location studies, unit and representation conversions, handling of smoothing and sampling issues, independent estimate of tropopause altitude, (sub-)column integration...), with associated error propagation; (3) data comparisons leading to statistical estimates of the systematic bias and random difference between S5P and reference network data as a function of latitude, their cycles, their long-term evolution, and their dependences on influence quantities (e.g., clouds, solar zenith angle, and slant column density); (4) and finally the assessment of compliance with user requirements as formulated, e.g., by Copernicus Atmosphere and Climate services and by GCOS.

The IAGOS GHG package: a measurement system for continuous airborne observations of CO2, CH4, H2O and CO

NASA Astrophysics Data System (ADS)

Gerbig, C.; Filges, A.; Franke, H.; Klaus, C.; Chen, H.

2012-12-01

A cavity ring-down spectroscopy (CRDS) based measurement system for greenhouse gases was designed, tested, and qualified for deployment on commercial airliners within the IAGOS-ERI (In-service Aircraft for a Global Observing System - European Research Infrastructure) project. The design meets requirements regarding physical dimensions (size, weight), performance (long term stability, low maintenance, robustness, full automation) and safety issues (fire prevention regulations). The system uses components of a commercially available CRDS instrument (G2401-m, Picarro Inc.) integrated in a frame suitable for integration in the avionics bay of the Airbus A-340. The first of the IAGOS GHG packages is scheduled for integration in early 2013. The aim is to have seven systems operational within four years, providing for long-term GHG observations with near-global coverage. To enable robust and automated operation of the IAGOS GHG package over six-month deployment periods, numerous technical issues had to be addressed. An inlet system, designed as virtual impactor to eliminate sampling of larger aerosols, ice particles, and water droplets, and provides additional positive ram-pressure. In combination with a lowered sample flow of 0.1 slpm, this ensures a fully controlled sample pressure in the cavity of 140 torr throughout the aircraft altitude operating range up to 12.5 km without the need of an upstream sampling pump. Furthermore, no sample drying is required, as the simultaneously measured water vapor mole fraction is used to correct for dilution and spectroscopic effects. This also enables the collection of science-quality water vapor measurements throughout the atmosphere. To allow for trace gas measurements to be fully traceable to WMO scales, a two-standard calibration system has been designed and tested that periodically provides calibration gas to the instrument during flight and on ground. A targeted six-month deployment cycle followed by maintenance of the package ensures a safe operation. During maintenance, calibration gases are analysed and replenished, and a functional inspection, followed by replacement of depleted or damaged parts, will be undertaken. Spare instrumentation will be used to provide for year-round GHG measurements on board each aircraft. We present results from recent test flights and laboratory tests that document the performance for GHG and water vapor measurements. Furthermore, future applications of the IAGOS-GHG data stream, provided in near-real-time via SatCom to the weather prediction centres, will be discussed, including the improved estimation of GHG budgets at regional to continental scales, the assessment of vertical transport in atmospheric models through comparison with observed vertical tracer distributions, and the validation of remote sensing measurements of GHGs.

Climate change effects on Glacier recession in Himalayas using Multitemporal SAR data and Automatic Weather Station observations

NASA Astrophysics Data System (ADS)

Kumar, V.; Singh, S. K.; Venkataraman, G.

2009-04-01

The Himalaya is the highest but the youngest mountain belt (20 to 60 million years B.P.) of the earth running in arc shape for about 2500 km. It has more than 90 peaks above 6000 m and contains about 50% of all glaciers outside of the polar environments (Bahadur, 1993). All glaciers in this region are in general recession since last 150 years (Paul et al.,1979). Gangotri, Siachen, Bara Shigri and Patsio are major glaciers in this region which are showing retreat with different rates and their respective tributary glaciers are completely disconnected from main body of glaciers. Spaceborne synthetic aperture radar data provide an important tool for monitoring the fluctuation of the glaciers. In this paper attempt has been made for quantifying the glacier retreat using multitemporal synthetic aperture radar (SAR) data. SAR intensity and phase information will be exploited separately under SAR intensity tracking and interferometric SAR (InSAR) coherence tracking (Strozzi et al., 2002) respectively. Glacier retreat study have been done using time series coregistered multi temporal SAR images. Simultaneously InSAR coherence thresholding is applied for tracking the snout of Gangotri glacier. It is observed that glacier is retreating at the rate of 21 m/a. Availability of high resolution spotlight mode TerraSAR-X SAR data will supplement the ENVISAT ASAR and ERS-1/2 based observations. The observatory in the proximity of Gangotri glacier has been made functional at Bhojbasa and all weather parameters viz. Snow fall, temperature, pressure, air vector, column water vapor and humidity are recorded twice a day as per WMO standards manually and automatically. Three Automatic Weather Stations (AWS) have been established in the glacier area at Bhojbasa , Kalindipass and Nandaban. Since Himalayan environment is presently under great stress of decay and degeneration, AWS data will be analyzed in the context of climate change effects on fluctuation of glaciers. References 1.Jagdish Hahadur, The Himalayas: A Third Polar Region, Snow and Glacier Hydrology (Proceedings of the Kathmandu Symposium, November 1992). IAHSPubl.no. 218,1993. 2.A. Paul, Mayewski and Peter, Jeschke A., Himalayan and Trans-Himalayan Glacier Fluctuations Since AD 1812, Arctic and Alpine Research, Vol. 11, No. 3, pp. 267-287 1979) 3.Tazio Strozzi, Adrian Luckman, Tavi Murray, Urs Wegmüller, and Charles L. Werner, IEEE Transaction on Geoscience and Remote Sensing, Vol. 40, NO. 11, November 2002 4.Vijay Kumar, Y.S.Rao, Gulab Singh G.Venkataraman, Snehmani , "Spaceborne InSAR technique for study of Himalayan glaciers using ENVISAT ASAR and ERS data", Proc. IGARSS 2008, July 6-11, 2008 Bostan, USA,2008.

Simulated trends of extreme climate indices for the Carpathian basin using outputs of different regional climate models

NASA Astrophysics Data System (ADS)

Pongracz, R.; Bartholy, J.; Szabo, P.; Pieczka, I.; Torma, C. S.

2009-04-01

Regional climatological effects of global warming may be recognized not only in shifts of mean temperature and precipitation, but in the frequency or intensity changes of different climate extremes. Several climate extreme indices are analyzed and compared for the Carpathian basin (located in Central/Eastern Europe) following the guidelines suggested by the joint WMO-CCl/CLIVAR Working Group on climate change detection. Our statistical trend analysis includes the evaluation of several extreme temperature and precipitation indices, e.g., the numbers of severe cold days, winter days, frost days, cold days, warm days, summer days, hot days, extremely hot days, cold nights, warm nights, the intra-annual extreme temperature range, the heat wave duration, the growing season length, the number of wet days (using several threshold values defining extremes), the maximum number of consecutive dry days, the highest 1-day precipitation amount, the greatest 5-day rainfall total, the annual fraction due to extreme precipitation events, etc. In order to evaluate the future trends (2071-2100) in the Carpathian basin, daily values of meteorological variables are obtained from the outputs of various regional climate model (RCM) experiments accomplished in the frame of the completed EU-project PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects). Horizontal resolution of the applied RCMs is 50 km. Both scenarios A2 and B2 are used to compare past and future trends of the extreme climate indices for the Carpathian basin. Furthermore, fine-resolution climate experiments of two additional RCMs adapted and run at the Department of Meteorology, Eotvos Lorand University are used to extend the trend analysis of climate extremes for the Carpathian basin. (1) Model PRECIS (run at 25 km horizontal resolution) was developed at the UK Met Office, Hadley Centre, and it uses the boundary conditions from the HadCM3 GCM. (2) Model RegCM3 (run at 10 km horizontal resolution) was developed by Giorgi et al. and it is available from the ICTP (International Centre for Theoretical Physics). Analysis of the simulated daily temperature datasets suggests that the detected regional warming is expected to continue in the 21st century. Cold temperature extremes are projected to decrease while warm extremes tend to increase significantly. Expected changes of annual precipitation indices are small, but generally consistent with the detected trends of the 20th century. Based on the simulations, extreme precipitation events are expected to become more intense and more frequent in winter, while a general decrease of extreme precipitation indices is expected in summer.

Spatial variations in atmospheric CO2 concentrations during the ARCTAS-CARB 2008 Summer Campaign

NASA Astrophysics Data System (ADS)

Vadrevu, K. P.; Choi, Y.; Vay, S. A.

2009-12-01

The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) was a major NASA field campaign designed to understand the transport and transformation of trace gases and aerosols on transcontinental and intercontinental scales and their impact on the composition of the arctic atmosphere and climate. Preceding the summer ARCTAS deployment, measurements were conducted over the state of California in collaboration with the California Air Resources Board (CARB) utilizing the airborne chemistry payload already integrated on the NASA DC-8. In situ CO2 measurements were made using a modified infrared CO2 gas analyzer having a precision of 0.1 ppmv and accuracy of ±0.25 ppmv traceable to the WMO scale. This analysis focuses on the atmospheric CO2 variability and biospheric/atmospheric exchange over California. We used multi-satellite remote sensing datasets to relate airborne observations of CO2 to infer sources and sinks. Georeferencing the airborne CO2 transect data with the LANDSAT derived land cover datasets over California suggested significant spatial variations. The airborne CO2 concentrations were found to be 375-380ppm over the Pacific ocean, 385-391ppm in the highly vegetated agricultural areas, 400-420 in the near coastal areas and greater than 425ppmv in the urban areas. Analysis from MODIS fire products suggested significant fires in northern California. CO2 emissions exceeded 425ppmv in the fire affected regions, where mostly Douglas and White Fir conifers and mixed Chaparral vegetation was burnt. Analysis from GOES-East and GOES-West visible satellite imagery suggested significant smoke plumes moving from northern California towards Nevada and Idaho. To infer the biospheric uptake of CO2, we tested the potential correlations between airborne CO2 data and MODIS normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). Results suggested significant anti-correlations between the airborne CO2 data and vegetation indices. The correlations were stronger in agriculture than forested regions. We also tested the correlations between the MODIS leaf area index (LAI) and airborne CO2 data. Although, the correlation strength was low, higher LAI values were associated with low CO2 concentrations suggesting biospheric uptake. Particulate matter (PM2.5) concentration records obtained from the US EPA corresponding to the airborne sampling domain in the peak forest fire areas suggested concentrations exceeded 42.0ug/m3. Furthermore, analysis of MODIS aerosol optical depth values at 500nm exceeded 0.70 at several places, suggesting intense fire activity. Using the airborne measurements as well as multi-satellite remote sensing datasets, the implications of fire and other land use activities on atmospheric CO2 concentrations in California during the summer of 2008 will be presented.

Sharing Data in the Global Ocean Observing System (Invited)

NASA Astrophysics Data System (ADS)

Lindstrom, E. J.; McCurdy, A.; Young, J.; Fischer, A. S.

2010-12-01

We examine the evolution of data sharing in the field of physical oceanography to highlight the challenges now before us. Synoptic global observation of the ocean from space and in situ platforms has significantly matured over the last two decades. In the early 1990’s the community data sharing challenges facing the World Ocean Circulation Experiment (WOCE) largely focused on the behavior of individual scientists. Satellite data sharing depended on the policy of individual agencies. Global data sets were delivered with considerable delay and with enormous personal sacrifice. In the 2000’s the requirements for global data sets and sustained observations from the likes of the U.N. Framework Convention on Climate Change have led to data sharing and cooperation at a grander level. It is more effective and certainly more efficient. The Joint WMO/IOC Technical Commission on Oceanography and Marine Meteorology (JCOMM) provided the means to organize many aspects of data collection and data dissemination globally, for the common good. In response the Committee on Earth Observing Satellites organized Virtual Constellations to enable the assembly and sharing of like kinds of satellite data (e.g., sea surface topography, ocean vector winds, and ocean color). Individuals in physical oceanography have largely adapted to the new rigors of sharing data for the common good, and as a result of this revolution new science has been enabled. Primary obstacles to sharing have shifted from the individual level to the national level. As we enter into the 2010’s the demands for ocean data continue to evolve with an expanded requirement for more real-time reporting and broader disciplinary coverage, to answer key scientific and societal questions. We are also seeing the development of more numerous national contributions to the global observing system. The drivers for the establishment of global ocean observing systems are expanding beyond climate to include biological and biogeochemical issues (e.g. biodiversity and ecosystem services, fisheries collapse, and ocean acidification). This expanded suite of demands and drivers challenge us further to share data for the common good across specialties. This requires that more ocean scientific communities and national ocean observing programs move towards maturity in terms of global data collection capability, sharing capacity, and data management standards. In oceanography the time has arrived for a cultural shift toward more shared collective observing capabilities. Necessarily we must also rapidly move toward harmony in national data sharing policies for the ocean environment. Building capacity to share ocean observations has been an objective for decades and has resulted in an expanded understanding of technologies and management policies that foster data sharing and provenance tracking.

Pan-Arctic observations in GRENE Arctic Climate Change Research Project and its successor

NASA Astrophysics Data System (ADS)

Yamanouchi, Takashi

2016-04-01

We started a Japanese initiative - "Arctic Climate Change Research Project" - within the framework of the Green Network of Excellence (GRENE) Program, funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT), in 2011. This Project targeted understanding and forecasting "Rapid Change of the Arctic Climate System and its Global Influences." Four strategic research targets are set by the Ministry: 1. Understanding the mechanism of warming amplification in the Arctic; 2. Understanding the Arctic climate system for global climate and future change; 3. Evaluation of the impacts of Arctic change on the weather and climate in Japan, marine ecosystems and fisheries; 4. Projection of sea ice distribution and Arctic sea routes. Through a network of universities and institutions in Japan, this 5-year Project involves more than 300 scientists from 39 institutions and universities. The National Institute of Polar Research (NIPR) works as the core institute and The Japan Agency for Marine- Earth Science and Technology (JAMSTEC) joins as the supporting institute. There are 7 bottom up research themes approved: the atmosphere, terrestrial ecosystems, cryosphere, greenhouse gases, marine ecology and fisheries, sea ice and Arctic sea routes and climate modeling, among 22 applications. The Project will realize multi-disciplinal study of the Arctic region and connect to the projection of future Arctic and global climatic change by modeling. The project has been running since the beginning of 2011 and in those 5 years pan-Arctic observations have been carried out in many locations, such as Svalbard, Russian Siberia, Alaska, Canada, Greenland and the Arctic Ocean. In particular, 95 GHz cloud profiling radar in high precision was established at Ny-Ålesund, Svalbard, and intensive atmospheric observations were carried out in 2014 and 2015. In addition, the Arctic Ocean cruises by R/V "Mirai" (belonging to JAMSTEC) and other icebreakers belonging to other countries were conducted and mooring buoy observations were also carried out. The data retrieved during these observations was accumulated in the "Arctic Data archive System (ADS)" (https://ads.nipr.ac.jp/) and served with interfaces for analysis. In addition, modeling studies have been promoted from fundamental process model to general circulation model. The successor of the project, ArCS (Arctic Challenge for Sustainability), which lays delivering emphasis 
on robust scientific information to stakeholders for decision making and solving problems, was started in FY2015. Within this project, a cooperative observation of black carbon are planned to be started at Cape Baranova Station (AARI, Rusia), Severnaya Zemlya, and new activities including emphasizing aerological observations are also planned to be started for contributing to "Year of Polar Prediction (YOPP)" of Polar Prediction Project (PPP/ WMO). It will be desirable to have a future collaboration with IASOA.

Data Democratization - Promoting Real-Time Data Sharing and Use Worldwide

NASA Astrophysics Data System (ADS)

Yoksas, T. C.; Almeida, W. G.; Leon, V. C.

2007-05-01

The Unidata Program Center (Unidata) of the University Corporation of Atmospheric Research (UCAR) is actively involved in international collaborations whose goals are the free-and-open sharing of hydro-meteorological data; the distribution of analysis and visualization tools for those data; the establishment of server technologies that provide easy-to-use, programmatic remote-access to a wide variety of datasets, and in the building of a community where data, tools, and best practices in education and research are shared. The tools and services provided by Unidata are available to the research and education community free-of-charge. Data sharing capabilities are being provided by Unidata's Internet Data Distribution (IDD) system, a community-based effort that has been the primary source of real-time meteorological data in the US university community for over a decade. A collaboration among Unidata, Brazil's Centro de Previso de Tempo e Estudos Climaticos (CPTEC), the Universidad Federal do Rio de Janeiro (UFRJ), and the Universidade de Sao Paulo (USP) has resulted in the creation of a Brazilian peer of the North American IDD, the IDD-Brasil. Collaboration between Unidata and the Universidad de Costa Rica (UCR) seeks to extend IDD data sharing throughout Central America and the Caribbean in an IDD-Caribe. Efforts aimed at creating a data sharing network for researchers on the Antarctic continent have resulted in the establishment of the Antarctic-IDD. Most recently, explorations of data sharing between UCAR and select countries in Africa have begun. Data analysis and visualization capabilities are available through Unidata in a suite of freely-available applications: the National Centers for Environmental Prediction (NCEP) GEneral Meteorology PAcKage (GEMPAK); the Unidata Integrated Data Viewer (IDV); and University of Wisconsin, Space Science and Engineering Center (SSEC) Man-computer Interactive Data Access System (McIDAS). Remote data access capabilities are provided by Unidata's Thematic Realtime Environmental Data Services (THREDDS) servers (which incorporate Open-source Project for a Network Data Access (OPeNDAP) data services), and the Abstract Data Distribution Environment (ADDE) of McIDAS. It is envisioned that the data sharing capabilities available in the IDD, IDD-Brasil, IDD-Caribe, and Antarctic-IDD, remote data access capabilities available in THREDDS and ADDE, and analysis capabilities available in GEMPAK, the IDV, and McIDAS will help foster new collaborations among prominent universities, national meteorological agencies, and WMO Regional Meteorological Training Centers throughout North, Central, and South America, in the Antarctic research community, and eventually in Africa. This paper is intended to inform AGU 2007 Joint Assembly attendees, especially those in Mexico and Central America, of the availability of real-time data and tools to analyze/visualize those data, and to promote the free-and-open sharing of data, especially of locally-held datasets of general interest.

The Integrated Ocean Observing System Data Assembly Center

NASA Astrophysics Data System (ADS)

Bouchard, R. H.; Henderson, D.; Burnett, W.; Hervey, R. V.; Crout, R.

2008-05-01

The Integrated Ocean Observing System (IOOS) is the U.S. contribution to the Global Ocean Observing System and the Global Earth Observing System of Systems (GEOSS). As the Integrated Ocean Observing System Data Assembly Center (IOOS DAC), the National Oceanic and Atmospheric Administration`s (NOAA) National Data Buoy Center (NDBC) collects data from ocean observing systems and performs quality control on the data. Once the IOOS DAC performs the quality control, it distributes them in real-time: (1) in World Meteorological Organization alphanumeric data formats via the Global Telecommunications System (GTS) that provides instant availability to national and international users (2) in text files via its website (http://www.ndbc.noaa.gov) that provide easy access and use, and (3) in netCDF format via its OPeNDAP/DODS Server (http://dods.ndbc.noaa.gov) that provides higher resolution data than available in WMO alphanumeric or text file formats. The IOOS DAC routinely checks and distributes data from about 200 NDBC stations that include meteorological and oceanographic observations from buoys and coastal stations, water-level estimations from tsunameters (DART), and climate monitoring from buoys (Tropical Atmosphere Ocean array (TAO)). The IOOS DAC operates continuously - 24 hours per day, 7 days per week. In addition to data from NDBC`s platforms, the IOOS DAC applies its scientific expertise and data management and communications capabilities to facilitate partnerships for the exchange and application of data and to coordinate and leverage regional assets and resources from about 350 IOOS Partner stations. The IOOS DAC through its quality control process provides feedback to its partners on the quality of their observation that can lead to improved quality of the observations. The NDBC-IOOS Data Partnerships span the Western Hemisphere with data collection from the Beaufort Sea to the Peru Current, from the International Date Line to the central Atlantic Ocean, and include some 70 government organizations, non-government organizations, industry and academia. Data exchange is facilitated by the IOOS DAC`s capability to ingest some sensor native formats and its own eXtensible Mark-up Language (XML). The IOOS DAC handles a variety of observations among them atmospheric winds, pressure, and temperature, rainfall, directional waves, solar radiation, tides and water-levels, water-quality parameters, such as dissolved oxygen, turbidity, pH, chlorophyll, surface and subsurface currents, temperature, and salinity (conductivity) and from a diverse collection of observing platforms - moored and drifting buoys, coastal stations, oil and gas platforms, and HF Radar stations. The IOOS DAC efforts have resulted in making more than seven million in situ observations available in real- time to the global community during 2007.

Assessing Challenges and Opportunities for Education and Communication Activities for International Polar Year 2007-2008

NASA Astrophysics Data System (ADS)

McCaffrey, M. S.

2005-05-01

Considerable planning has gone into identifying ways to maximize International Polar Year 2007-2008 (IPY) as a global event that will facilitate the integration of research and education inherent in IPY, and draw the interest and involvement of people around the world. Documents developed through the IPY planning process, including NRC Reports (2004), and drafts reports on education and outreach from the ICSU IPY Planning Group in the Fall of 2004, and the Bridging the Poles workshop of June, 2004, articulate the tremendous potential for IPY beyond the formal research agenda and goals. With less that two years before the start of IPY and fewer than fours years before the activities are completed, these and emerging opportunities face a number of challenges. In addition to the limited time frame remaining to prepare for these activities, participants involved with IPY education and outreach will also need to consider factors such as: uncertain funding for such activities; the lack of established international networks for geoscience education; the need for high level coordination of IPY education and communication; and the creative and intellectual challenge of making the polar regions relevant to people around the world. The planning process has identified six constituencies as key audiences of IPY communication efforts: i) the scientific/research community, ii) young and potentially new polar researchers, iii) the pre-university education community, iv) arctic communities, iv) the general public, and v) decision-makers. Understanding and meeting these audiences' expectations through on-going evaluation and engagement will be key to successful IPY education and outreach efforts. A number of distinct education and outreach projects have been proposed to the ICSU-WMO IPY planning process, such as courses and workshops on specific aspects of IPY, including efforts to address the social and cultural dimension of Arctic peoples. To help meet the challenges, achieve the goals, contribute to building a lasting legacy for IPY, and support prior IPY Education and Outreach planning efforts, a Center for Polar Education and Coordination, and an online journal entitled the POLAR Post, modeled after the NASA Earth Observatory, have been proposed by the Outreach Department at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado, in conjunction with the National Snow and Ice Data Center (NSIDC), the Institute for Arctic and Alpine Research (INSTAAR), and UCAR Education and Outreach. National Research Council (2004). A Vision for the International Polar Year. "Increasing Public Understanding and Participation in Polar Science Through the International Polar Year" and "Actions Needed to Make the International Polar Year Succeed." 65-79. National Research Council (2004). Planning for the International Polar Year 2007-2008: Report from the Implementation Workshop. "Data Education and Outreach Initiatives." 32-34.

Socio-economic vulnerability, adaptation to agro-climatic risk and the potential of user-tailored climate services for the Andean Highlands: The case of quinoa production in the region of Puno

NASA Astrophysics Data System (ADS)

Flubacher, Moritz; Sedlmeier, Katrin; Lechthaler, Filippo; Rohrer, Mario; Cristobal, Lizet; Vinogradova, Alexandra

2017-04-01

In the semi-arid Altiplano in Peru, smallholder farmers are extremely exposed to climatic hazards like drought, frost and hail. These unfavorable weather and climate events can lead to significant crop losses and thereby provoke periods of food insecurity for subsistence farmers. The use of specific climate information can serve as an adaptation strategy to reduce the impact of these natural hazards. In this context, the Climandes project (a project of the Global Framework for Climate Services led by WMO) aims at developing user-tailored seasonal forecast products for the agricultural sector in the Peruvian Andes such as indices on increased frost risk, the occurrence of long dry periods, or the start of the rainy season. In order to develop such user-tailored climate information and link it efficiently to the existing implementation context, it is important to understand the complex interrelation between climate variability and change, socio-economic vulnerability and adaptation limits. Moreover, as it has been widely shown, the process of making climate information useful for end-users, in particular for smallholder farmers in developing countries, remains a considerable challenge due to existing cognitive, cultural and institutional constraints. In this sense, it is necessary to identify these constraints and formulate strategies to overcome them. While there exist different studies about climate change and anomalies in Puno, there is no consolidated evidence on the corresponding socio-economic vulnerabilities in the specific agricultural context of Puno. In order to fill this gap, we conducted a field survey collecting primary data in the Andean highlands based on a representative sample of 726 smallholder farmers in the region of Puno (Peru). The assessment primarily focused on exploring smallholders' agro-climatic risk exposure, socio-economic profiles, existing coping strategies as well as prevailing barriers to utilization of science-based climate information. The study was complemented with an artefactual experimental game performed with 176 smallholders to identify and describe their risk preferences. The existing economic literature shows that farmers' risk preferences generally play a decisive role for agricultural decision-making indicating the importance of understanding farmer's risk profile when evaluating the potential use of climate information at the individual level. First results indicate that smallholders in the region are regularly exposed to extreme weather events such as frost, hailstorms and droughts. Under these conditions, farmers often do not have the capacity and sufficient resources to prevent periods of food insecurity at the end of the growing period. Hereby climate information can support the agricultural production decisions and improve food security but only if developed in close collaboration with the end-users.

A laboratory evaluation of the influence of weighing gauges performance on extreme events statistics

NASA Astrophysics Data System (ADS)

Colli, Matteo; Lanza, Luca

2014-05-01

The effects of inaccurate ground based rainfall measurements on the information derived from rain records is yet not much documented in the literature. La Barbera et al. (2002) investigated the propagation of the systematic mechanic errors of tipping bucket type rain gauges (TBR) into the most common statistics of rainfall extremes, e.g. in the assessment of the return period T (or the related non-exceedance probability) of short-duration/high intensity events. Colli et al. (2012) and Lanza et al. (2012) extended the analysis to a 22-years long precipitation data set obtained from a virtual weighing type gauge (WG). The artificial WG time series was obtained basing on real precipitation data measured at the meteo-station of the University of Genova and modelling the weighing gauge output as a linear dynamic system. This approximation was previously validated with dedicated laboratory experiments and is based on the evidence that the accuracy of WG measurements under real world/time varying rainfall conditions is mainly affected by the dynamic response of the gauge (as revealed during the last WMO Field Intercomparison of Rainfall Intensity Gauges). The investigation is now completed by analyzing actual measurements performed by two common weighing gauges, the OTT Pluvio2 load-cell gauge and the GEONOR T-200 vibrating-wire gauge, since both these instruments demonstrated very good performance under previous constant flow rate calibration efforts. A laboratory dynamic rainfall generation system has been arranged and validated in order to simulate a number of precipitation events with variable reference intensities. Such artificial events were generated basing on real world rainfall intensity (RI) records obtained from the meteo-station of the University of Genova so that the statistical structure of the time series is preserved. The influence of the WG RI measurements accuracy on the associated extreme events statistics is analyzed by comparing the original intensity-duration-frequency (IDF) curves with those obtained from the measuring of the simulated rain events. References: Colli, M., L.G. Lanza, and P. La Barbera, (2012). Weighing gauges measurement errors and the design rainfall for urban scale applications, 9th International Workshop On Precipitation In Urban Areas, 6-9 December, 2012, St. Moritz, Switzerland Lanza, L.G., M. Colli, and P. La Barbera (2012). On the influence of rain gauge performance on extreme events statistics: the case of weighing gauges, EGU General Assembly 2012, April 22th, Wien, Austria La Barbera, P., L.G. Lanza, and L. Stagi, (2002). Influence of systematic mechanical errors of tipping-bucket rain gauges on the statistics of rainfall extremes. Water Sci. Techn., 45(2), 1-9.

GNSS Remote Sensing at GFZ: Overview and Recent Results

NASA Astrophysics Data System (ADS)

Wickert, Jens; Alshawaf, Fadwa; Arras, Christina; Asgarimehr, Milad; Dick, Galina; Heise, Stefan; Larson, Kristine; Li, Xingxing; Lu, Cuixian; Peraza, Luis; Ramatschi, Markus; Schmidt, Torsten; Schuh, Harald; Semmling, Maximilian; Simeonov, Tzvetan; Vey, Sibylle; Zus, Florian

2017-04-01

GNSS atmospheric remote sensing was successfully established during the last two decades and evolved into a major application for high precision GNSS. The most prominent example for this development is the use of GNSS atmospheric data to improve day-by-day regional and global weather forecasts since 2006. Globally distributed vertical profiles of refractivity, temperature and water vapour are derived from satellite based GNSS data (Radio Occultation, RO). Ground based measurements, provided by global and regional GNSS networks, allow for the derivation of vertically (IWV) or along the line-of-sight integrated water vapour (SWV). Another important GNSS remote sensing technique, the exploitation of Earth reflected signals (GNSS Reflectometry, GNSS-R), is not yet operationally applied. But the huge potential for the determination of various physical parameters, as, e.g., sea surface height, wind speed over water and soil moisture on regional and global scales is recognized by the Earth Observation community. Therefore GNSS-R is recently a major challenge of international geophysical research. We review related activities at the German Research Centre for Geosciences GFZ and introduce recent results. The status of the GNSS-RO experiments aboard the satellites GRACE-A, TerraSAR-X and TanDEM-X, which are coordinated by GFZ, is reviewed. Examples of GNSS RO applications are given, as, e.g., climatological investigations of the global vertical temperature structure or the detection of ionospheric irregularities in the E-region. We also focus on ground based activities for GNSS water vapour monitoring. Observations of a global and regionally densified German network, with about 600 stations in total, are processed in near-real time to operationally provide IWV data. These data are assimilated into atmospheric models by several European weather centers. Current research activities are focused on the generation and meteorological application of GNSS based slant data, on real-time and multi-GNSS meteorology. In addition, climatological investigations are described to analyse long-term trends of the atmospheric water vapour over Germany but also as part of the Global Climate Observing System (GCOS) of the WMO (World Meteorological Organization). Multipath data from standard GNSS receivers are used to derive information on soil moisture, vegetation and snow properties. This technique exhibits a large potential to get geophysical parameters for Earth surface monitoring from the existing global and regional GNSS networks. GFZ also applies dedicated GNSS receivers aboard flight and ship platforms to derive sea surface heights using the GNSS-R phase altimetry technique. Other research activities contribute to the preparation of satellite missions for geophysical GNSS-R applications on a global scale. The most prominent current example is the ESA mission GEROS-ISS for global sea surface monitoring.

Monitoring and assessment of the outdoor thermal comfort in Bucharest (Romania)

NASA Astrophysics Data System (ADS)

Cheval, Sorin; Ciobotaru, Ana-Maria; Andronache, Ion; Dumitrescu, Alexandru

2017-04-01

Bucharest is one of the European cities most at risk of being affected by meteorological hazards. Heat or cold waves, extreme temperature events, heavy rains or prolonged precipitation deficits are all-season phenomena, triggering damages, discomfort or even casualties. Temperature hazards may occur annually and challenge equally the public, local business and administration to find adequate solutions for securing the thermal comfort in the outdoor environment of the city. The accurate and fine resolution monitoring of the air temperature pledges for the comprehensive assessment of the thermal comfort in order to capture as much as possible the urban influence. This study uses sub-hourly temperature data (10-min temporal resolution) retrieved over the period November 2014 - November 2016 collected from nine sensors placed either in plain urban conditions or within the three meteorological stations of the national network which are currently monitoring the climate of Bucharest (Băneasa, Filaret, Afumați). The relative humidity was estimated based on the data available at the three stations placed in WMO standard conditions, and the 10-min values of 8 Thermal Comfort Indices were computed, namely: Heat Index, Humidex, Relative Strain Index, Scharlau, Summer Simmer Index, Physiological Equivalent Index, Temperature-Humidity Index, Thom Discomfort Index. The indices were analysed statistically, both individually and combined. Despite the short range of the available data, this study emphasizes clear spatial differentiations of the thermal comfort, in a very good agreement with the land cover and built zones of the city, while important variations were found in the temporal regime, due to large variations of the temperature values (e.g. >4 centigrade between consecutive hours or >15 centigrade between consecutive days). Ultimately, this study has revealed that the continuous monitoring of the urban climate, at fine temporal and spatial resolution, may deliver fundamental information for supporting the immediate measures and the long-term urban planning and the sustainable thermal comfort of the urban inhabitants. Acknowledgements: The urban meteorological network of Bucharest was developed within the project UCLIMESA (Urban Heat Island Monitoring under Present and Future Climate), in the framework of the Programme for Research-Development-Innovation for Space Technology and Advanced Research (STAR), administrated by the Romanian Space Agency. (STAR CDI Programme, contract no 92/2013, Contractor Romanian Spatial Agency). This work was supported by a grant of the University of Bucharest- "Spatial projection of the human pressure on forest ecosystems in Romania" (UB/1365)-and was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS - UEFISCDI, project number PN-II-RU-TE-2014-4-0835-Development of the theory of the dynamic context by analyzing the role of the aridization in generating and amplifying the regressive phenomena from the territorial systems.

Application of trajectory clustering and source attribution methods for investigating regional CO2 and CH4 concentrations at Germany's highest mountain site

NASA Astrophysics Data System (ADS)

Giemsa, Esther; Jacobeit, Jucundus; Ries, Ludwig; Frank, Gabriele; Hachinger, Stephan; Meyer-Arnek, Julian

2017-04-01

Carbon dioxide (CO2) and methane (CH4) represent the most important contributors to increased radiative forcing enhancing it together by contemporary 2.65 W/m2 on the global average (IPCC 2013). The unbroken increase of atmospheric greenhouse gases (GHG) has been unequivocally attributed to human emissions mainly coming from fossil fuel burning and land-use changes, while the oceans and terrestrial ecosystems slightly attenuate this rise with seasonally varying strength. Short-term fluctuations in the GHG concentrations that superimpose the seasonal cycle and the climate change driven trend reflect the presence of regional sources and sinks. A perfect place for investigating the comprehensive influence of these regional emissions is provided by the Environmental Research Station Schneefernerhaus (47.42°N, 10.98°E, 2.650m a.s.l.) situated in the eastern Alps at the southern side of Zugspitze mountain. Located just 300m below the highest peak of the German Alps, the exposed site is one of the currently 30 global core sites of the World Meteorological Organisation (WMO) Global Atmosphere Watch (GAW) programme and thus provides ideal conditions to study source-receptor relationships for greenhouse gases. We propose a stepwise statistical methodology for examining the relationship between synoptic-scale atmospheric transport patterns and climate gas mole fractions to finally receive a characterization of the sampling site with regard to the key processes driving CO2 and CH4 concentration levels. The first step entails a reliable radon-based filtering approach to subdivide the detected air masses according to their regional or 'background' origin. Simultaneously, a large number of ten-day back-trajectories from Schneefernerhaus every two hours over the entire study period 2011 - 2015 is calculated with the Lagrangian transport and dispersion model FLEXPART (Stohl et al. 2005) and subjected to cluster analysis. The weather- and emission strength-related (short-term) components of the regional CO2 and CH4 concentration time-series are assigned to the back-trajectory clusters. The significant differences in the greenhouse gases' distributions associated with each cluster are confirmed by the non-parametric Kruskal-Wallis test thereby delivering the prerequisites for further investigations, in particular by Potential Source Contribution Functions for the detection of probable locations of within-cluster emission sources. The advantages of this comprehensive approach are site-specificity (by considering trajectories arriving at Schneefernerhaus as well as a site-appropriate filter method) and concentration-specificity (each greenhouse gas has its own source regions) combined with granting the space and time scales related to the synoptic flow patterns in source attribution studies. This research received funding from the Bavarian State Ministry of the Environment and Consumer Protection.

Quality control of climatological time series in the province of macerata (adriatic side of central italy)

NASA Astrophysics Data System (ADS)

Gentilucci, Matteo; Bisci, Carlo; Fazzini, Massimiliano; Tognetti, Danilo

2016-04-01

The analysis is focused on more than 100 meteorological recording stations located in the Province of Macerata (Marche region, Adriatic side of Central Italy) and in its neighbours; it aims to check the time series of their climatological data (temperatures and precipitations), covering about one century of observations, in order to remove or rectify any errors. This small area (about 2.800Km2) features many different climate types, because of its varied topography ranging, moving westward, from the Adriatic coast to the Appennines (over 2.100m of altitude). In this irregular context, it is difficult to establish a common procedure for each sector; therefore, it has been followed the general guidelines of the WMO, with some important difference (mostly in the method). Data are classified on the basis of validation codes (VC): missing datum (VC=-1), correct or verified datum (VC=0), datum under investigation (VC=1), datum removed after the analysis (VC=2), datum reconstructed through interpolation or by estimating the errors of digitization (VC=3). The first step was the "Logical Control", consisting in the investigation of gross errors of digitization: the data found in this phase of the analysis has been removed without any other control (VC=2). The second step, represented by the "Internal Consistency Check", leads to the elimination (VC=2) of all the data out of range, estimated on the basis of the climate zone for each investigated variable. The third one is the "Tolerance Test", carried out comparing each datum with the historical record it belongs to, in order to apply this test, the normal distribution of data has been evaluated. The "Tolerance Test" usually defines only suspect data (VC=1) to be verified with further tests, such as the "Temporal Consistency" and the "Spatial Consistency". The "Temporal Consistency" allows an evaluation of the time sequence of data, setting a specified range for each station basing upon its historical records. Data out of range have been considered under investigation (VC=1). Data are finally compared with the ones contemporaneously recorded in a set of neighboring meteorological stations through the "Spatial Consistency" test, thus eliminating every suspicious datum (recoded VC=2 or VC=0, depending upon the results of this analysis). This procedure uses a series of different statistic steps to avoid uncertainties: at its end, all the investigated data are either accepted (VC=0) or refused (VC=2). Refused and missing data (VC=-1 and VC=2) have been reconstructed through interpolation using co-kriging techniques (assigning VC=3), when necessary, in the final stage of the process. All the above procedure has been developed using a database managing software in a GIS (ESRI ArcGIS ®) environment. The refused data are 1.286 in 77.021 (1,67%) for the precipitations and 375 in 1.821.054 for the temperatures (0,02%).

An assessment of the isotopic (2H/18O) integrity of water samples collected and stored by unattended precipitation totalizers

NASA Astrophysics Data System (ADS)

Terzer, Stefan; Wassenaar, Leonard I.; Douence, Cedric; Araguas-Araguas, Luis

2016-04-01

The IAEA-WMO Global Network of Isotopes in Precipitation (GNIP) provides worldwide δ18O and δ2H data for numerous hydrological and climatological studies. The traditional GNIP sample collection method relies on weather station operators to accumulate precipitation obtained from manual rain gauges. Over the past decades, widespread weather station automatization resulted in the increased use of unattended precipitation totalizers that accumulate and store the rainwater in the field for up to one month. Several low-tech measures were adopted to prevent in situ secondary evaporative isotopic enrichment (SEE) of totalized water samples (i.e. disequilibrium isotopic fractionation after precipitation is stored in the collection device). These include: (a) adding a 0.5-1 cm floating layer of paraffin oil to the totalizer bottle, (b) using an intake tube leading from the collection funnel and submerged to the bottom of the totalizer bottle, or (c) placing a table tennis ball in the funnel aiming to reduce evaporation of the collected water from the receiving bottle to the atmosphere. We assessed the isotopic integrity of stored rainwater samples for three totalizers under controlled settings: each aforementioned totalizer was filled with a 100 or 500 mL of isotopically known water and installed in the field with the intake funnels sheltered to prevent rainwater collection. Potential evapotranspiration (PET) was obtained from on-site meteorological recordings. Stored evaporative loss from each totalizer was evaluated on a monthly basis; gravimetrically and by analysing δ18O and δ2H of the stored water, for a period of 6 months and a cumulative PET of ˜500 mm. The gravimetric and isotope results revealed that for smaller water volumes (100 ml, corresponding to ca. 5 mm of monthly precipitation), negligible isotope enrichment (δ18O) was observed in the paraffin-oil based totalizer, whereas unacceptable evaporative isotope effects were observed for the ball-in-funnel collector. For the submerged-tube sampler, the evaporative effect depended on the amount of stored water: 100 ml showed unacceptable isotopic enrichment, whereas the SEE of 500 ml stored water was acceptable. These data allowed us to estimate the impact of secondary evaporative enrichment on a device-specific basis as a function of PET. Based on global PET grids (e.g. CGIAR data), and benchmarking the expected SEE against the reasonable uncertainty of isotope spectrometry (< ±0.1‰ for δ18O), these findings reveal the most suitable totalizer device for any given climatic condition. Under extreme conditions (e.g. high aridity, little precipitation vs. high PET), a paraffin-oil based rain totalizer is most appropriate for monthly collections. Submerged-tube samplers may be considered if either a higher frequency of collection were possible, or monthly under pluvial/temperate climate conditions. The use of ball-in-funnel type totalizers are not recommended at all, unless samples could be collected on a daily basis.

Validation of HOAPS- and ERA-Interim precipitation estimates over the ocean

NASA Astrophysics Data System (ADS)

Bumke, Karl; Schröder, Marc; Fennig, Karsten

2014-05-01

Although precipitation is one of the key parameters of the global hydrological cycle there are still large gaps in the global observation networks, especially over the oceans. But the progress in satellite technology has provided the possibility to retrieve global data sets from space, including precipitation. Levizzani et al. (2007) showed that precipitation over the oceans can be derived with sufficient accuracy from passive microwave radiometry. Advances in analysis techniques have also improved our knowledge of the global precipitation. On the other hand, e.g. Andersson et al. (2011) or Pfeifroth et al. (2012) pointed out that even state-of-the-art satellite retrievals and reanalysis data sets still disagree on global or regional precipitation with respect to amounts, patterns, variability or temporal behavior compared to observations. That creates the need for a validation study over data sparse areas. Within this study, a validation of HOAPS-3.0 (Hamburg Ocean Atmosphere Parameters and fluxes from Satellite Data) based precipitation at pixel-level resolution and of ERA-Interim reanalysis data for 1995-1997 is performed mainly over the Atlantic Ocean using information from ship rain gauges and optical disdrometers mounted onboard of research vessels. The satellite and ERA-Interim data are compared to the in situ measurement by the nearest neighbor approach. Therefore, it must be ensured that both observations are related to each other, which can be determined by the decorrelation lengths in space and time. At least a number of 658 precipitation events are at our disposal including 127 snow events. The statistical analysis follows the recommendations given by the World Meteorological Organization (WMO) for dichotomous or binary forecasts (WWRP/WGNE: http://www.cawcr.gov.au/projects/verification/#Methods_for_dichotomous_forecasts). Based on contingency tables a number of statistical parameters like the accuracy, the bias, the false alarm rate, success ratio or hit rate have been computed. Summarized, the results show that HOAPS data agrees well with observations with respect to the frequency of precipitation events while ERA-Interim overestimates considerably the number of precipitation events. Results are similar for rain and snow events. Although it is difficult to compare rain rates directly due to the limited number of collocated events and different spatial resolution, the results suggest a slight underestimation of precipitation rates by HOAPS and an overestimation by ERA-Interim. References Andersson, A., Klepp, C., Fennig, K., Bakan, S., Graßl, H. and495 co-authors. 2011. Evaluation of HOAPS-3 ocean surface freshwater flux components. J. Appl. Meteorol. Climatol. 50, 379-398, doi:10.1175/2010JAMC2341.1. Levizzani, V., Bauer, P. and Turk, F. J.) 2007. Measuring Precipitation from Space, EURAINSAT and the Future. Advances in Global Change Research, Vol. 28, Springer, 724 p. Pfeifroth,U.,R.Mueller, and B.Ahrens, 2012: Evaluation of Satellite-Based and Reanalysis Precipitation Data in the Tropical Pacific, J. of Appl. Meteorology and Climatology 52, 634-644

Ice nuclei measurements at a high altitude remote station in the Northern Apennines

NASA Astrophysics Data System (ADS)

Schrod, Jann; Bingemer, Heinz; Haunold, Werner; Curtius, Joachim; Decesari, Stefano; Marinoni, Angela; Rinaldi, Matteo; Bonasoni, Paolo; Cristofanelli, Paolo

2013-04-01

During a field campaign of the PEGASOS (Pan-European Gas-AeroSOls-climate interactions Study, http://pegasos.iceht.forth.gr/) project in June 2012 we have made daily ice nucleus measurements on top of the Monte Cimone (44.18° N, 10.70° E, 2165 m asl) in the Northern Apennines at the "O. Vittori" Climate Observatory. Samples were taken at this GAW-WMO Global Station in a six hour rhythm (4 a.m., 10 a.m., 4 p.m. and 10 p.m.) and at increased frequency during specific events (e.g. dust transport episodes). Ice nuclei were measured by an offline technique. Aerosol particles of 40 liters of air were collected by electrostatic precipitation on a silicon substrate. Subsequently the ice nuclei were analyzed in the vacuum diffusion chamber FRIDGE [Klein et al. 2010] (FRankfurt Ice Nuclei Deposition FreezinG Experiment) by exposing the particles to supersaturation with respect to ice (106 % to 119 %) at -8 ° C, -13 ° C and -18 ° C. In our setup ice nuclei are activated in deposition and condensation freezing modes. A camera detects and counts ice crystals grown on ice nuclei. Every ice crystal counted is assumed to represent at least one ice nucleus. The mean IN concentration at Mt. Cimone was 60 IN per liter (at -18 ° C and 119% relative humility over ice), significantly higher than a longstanding mean at Mt. Kleiner Feldberg (30 IN/l), Germany for June. A mean active site density (IN per surface area of large aerosol particles) of 2.3 * 109 m-2 was calculated. The origin of the air masses sampled was established based on backward trajectories. With more than 100 IN/l on average (at -18° C and 119% relative humility over ice) the samples originating from North Africa were highest, and activated fractions were 4 to 20 times higher than for other transport sectors. An intensive event of dust transport was recorded by several instruments in the middle of June. At its peak in the morning of the 21st of June large aerosol surface and mass concentrations were observed by an optical particle sizer. A clear increase of submicron particles was noted during the passage of the dust plume. The heavily dust loaded air had high IN concentrations up to 270 IN/l . The maximum fraction of large aerosol particles activated as ice nuclei during this dust event was one ice nucleus in 1250 aerosol particles. Acknowledgements: This work was funded by Deutsche Forschungsgemeinschaft (DFG) under the Research Unit INUIT. References [Klein et al. 2010] Klein, H. ; Haunold, W. ; Bundke, U. ; Nillius, B. ; Wetter, T. ; Schallenberg, S. ; Bingemer, H.: A new method for sampling of atmospheric ice nuclei with subsequent analysis in a static diffusion chamber. In: Atmospheric Research 96 (2010), p. 218 - 224.

The use of Meteonorm weather generator for climate change studies

NASA Astrophysics Data System (ADS)

Remund, J.; Müller, S. C.; Schilter, C.; Rihm, B.

2010-09-01

The global climatological database Meteonorm (www.meteonorm.com) is widely used as meteorological input for simulation of solar applications and buildings. It's a combination of a climate database, a spatial interpolation tool and a stochastic weather generator. Like this typical years with hourly or minute time resolution can be calculated for any site. The input of Meteonorm for global radiation is the Global Energy Balance Archive (GEBA, http://proto-geba.ethz.ch). All other meteorological parameters are taken from databases of WMO and NCDC (periods 1961-90 and 1996-2005). The stochastic generation of global radiation is based on a Markov chain model for daily values and an autoregressive model for hourly and minute values (Aguiar and Collares-Pereira, 1988 and 1992). The generation of temperature is based on global radiation and measured distribution of daily temperature values of approx. 5000 sites. Meteonorm generates also additional parameters like precipitation, wind speed or radiation parameters like diffuse and direct normal irradiance. Meteonorm can also be used for climate change studies. Instead of climate values, the results of IPCC AR4 results are used as input. From all 18 public models an average has been made at a resolution of 1°. The anomalies of the parameters temperature, precipitation and global radiation and the three scenarios B1, A1B and A2 have been included. With the combination of Meteonorm's current database 1961-90, the interpolation algorithms and the stochastic generation typical years can be calculated for any site, for different scenarios and for any period between 2010 and 2200. From the analysis of variations of year to year and month to month variations of temperature, precipitation and global radiation of the past ten years as well of climate model forecasts (from project prudence, http://prudence.dmi.dk) a simple autoregressive model has been formed which is used to generate realistic monthly time series of future periods. Meteonorm can therefore be used as a relatively simple method to enhance the spatial and temporal resolution instead of using complicated and time consuming downscaling methods based on regional climate models. The combination of Meteonorm, gridded historical (based on work of Luterbach et al.) and IPCC results has been used for studies of vegetation simulation between 1660 and 2600 (publication of first version based on IS92a scenario and limited time period 1950 - 2100: http://www.pbl.nl/images/H5_Part2_van%20CCE_opmaak%28def%29_tcm61-46625.pdf). It's also applicable for other adaptation studies for e.g. road surfaces or building simulation. In Meteonorm 6.1 one scenario (IS92a) and one climate model has been included (Hadley CM3). In the new Meteonorm 7 (coming spring 2011) the model averages of the three above mentioned scenarios of the IPCC AR4 will be included.

Late Paleozoic tectonic evolution and concentrated mineralization in Balkhash and West Junggar, western part of the Central Asian Orogenic Belt

NASA Astrophysics Data System (ADS)

Dong, Shuwen; Chen, Xuanhua; Chen, Zhengle

2016-04-01

The Central Asia Orogenic Belt (CAOB) is an important area with significant growth of the crust and metallogeny in the Late Paleozoic. The Balkhash-Junggar tectono-metallogenic belt consists of the Balkhash, the West Junggar, and the East Junggar tectono-metallogenic belts in western part of the Central Asian Orogenic Belt (CAOB). According to the structural geological relationship, the East Junggar, the West Junggar, and the Balkhash belts are considered to be once a continuous E-W-trending tectono-metallogenic belt in Late Carboniferous. The West Junggar belt is featured with NE-trending left-lateral strike-slip faulting tectonic system (WJTS), while the left-lateral strike-slip faults are E-W-trending in the Balkhash belt. The WJTS consists of the Darabut, the Mayile, and the Baerluke faults, and the blocks among them. All these left-lateral strike-slip faults are forming due to the transition of tectonic settings from syn-collisional orogeny to post-collisional extension during the closure of the ocean (the Junggar Sea) in Late Carboniferous, with significant intrusion of batholiths and crust growth occurred in this period. These faults are truncated by the right-lateral strike-slip faults, such as the Chingiz-Junggar fault, and the Central Balkhash fault in Mesozoic. The Balkhash-Junggar tectono-metallogenic belt is important for the occurrence of many well-known super-large and large porphyry Cu-Mo deposits (such as the Kounrad, the Aktogai, the Borly, and the Baogutu deposits), large skarn Cu deposits (in the Sayak ore-filed), large rare metal deposits (such as the East Kounrad, the Zhanet, and the Akshatau deposits), and large gold deposits (such as the Hatu deposit). Zircon U-Pb ages, Re-Os isotopic dating of molybdenites, 40Ar/39Ar thermochronology of hornblendes, muscovites, biotites, and K-feldspars, and zircon and apatite fission track (FT) and (U-Th)/He dating and thermal history modeling, provide a multidisciplinary approach to constrain the whole course thermo-history of the minearl deposits from their formation in the deep to the exhumation in the surface. It reveals the arc-related granitic magmatism and the metallogeneses of skarn Cu, porphyry Cu-Mo, quartz-vein/greisen W-Mo, and orogenic Au in Late Paleozoic, the medium-temperature regional cooling in Late Paleozoic and Early Mesozoic, and the low-temperature exhumation of the deposits in Mesozoic. The timing, combined with geochemistry of granitoids, suggests a transition of tectonic environment from syn-collision and volcanic arc in Late Carboniferous to post-collision extension in Early Permian, and the concentrated mineralization of Cu, Mo, rare metals, and Au during this tectonic transition. The complete metallogenic series for the concentrated mineralization are from skarn and porphyry Cu-Mo deposits to rare metal and gold deposits. Key words: Late Paleozoic; Tectonic evolution; Concentrated mineralization; Balkhash-Junggar tectono-metallogenic belt; Central Asian Orogenic Belt

Semantic Web Infrastructure Supporting NextFrAMES Modeling Platform

NASA Astrophysics Data System (ADS)

Lakhankar, T.; Fekete, B. M.; Vörösmarty, C. J.

2008-12-01

Emerging modeling frameworks offer new ways to modelers to develop model applications by offering a wide range of software components to handle common modeling tasks such as managing space and time, distributing computational tasks in parallel processing environment, performing input/output and providing diagnostic facilities. NextFrAMES, the next generation updates to the Framework for Aquatic Modeling of the Earth System originally developed at University of New Hampshire and currently hosted at The City College of New York takes a step further by hiding most of these services from modeler behind a platform agnostic modeling platform that allows scientists to focus on the implementation of scientific concepts in the form of a new modeling markup language and through a minimalist application programming interface that provide means to implement model processes. At the core of the NextFrAMES modeling platform there is a run-time engine that interprets the modeling markup language loads the module plugins establishes the model I/O and executes the model defined by the modeling XML and the accompanying plugins. The current implementation of the run-time engine is designed for single processor or symmetric multi processing (SMP) systems but future implementation of the run-time engine optimized for different hardware architectures are anticipated. The modeling XML and the accompanying plugins define the model structure and the computational processes in a highly abstract manner, which is not only suitable for the run-time engine, but has the potential to integrate into semantic web infrastructure, where intelligent parsers can extract information about the model configurations such as input/output requirements applicable space and time scales and underlying modeling processes. The NextFrAMES run-time engine itself is also designed to tap into web enabled data services directly, therefore it can be incorporated into complex workflow to implement End-to-End application from observation to the delivery of highly aggregated information. Our presentation will discuss the web services ranging from OpenDAP and WaterOneFlow data services to metadata provided through catalog services that could serve NextFrAMES modeling applications. We will also discuss the support infrastructure needed to streamline the integration of NextFrAMES into an End-to-End application to deliver highly processed information to end users. The End-to-End application will be demonstrated through examples from the State-of-the Global Water System effort that builds on data services provided through WMO's Global Terrestrial Network for Hydrology to deliver water resources related information to policy makers for better water management. Key components of this E2E system are promoted as Community of Practice examples for the Global Observing System of Systems therefore the State-of-the Global Water System can be viewed as test case for the interoperability of the incorporated web service components.

Practical Experience of Discharge Measurement in Flood Conditions with ADP

NASA Astrophysics Data System (ADS)

Vidmar, A.; Brilly, M.; Rusjan, S.

2009-04-01

Accurate discharge estimation is important for an efficient river basin management and especially for flood forecasting. The traditional way of estimating the discharge in hydrological practice is to measure the water stage and to convert the recorded water stage values into discharge by using the single-valued rating curve .Relationship between the stage and discharge values of the rating curve for the extreme events are usually extrapolated by using different mathematical methods and are not directly measured. Our practice shows that by using the Accoustic Doppler Profiler (ADP) instrument we can record the actual relation between the water stage and the flow velocity at the occurrence of flood waves very successfully. Measurement in flood conditions it is not easy task, because of high water surface velocity and large amounts of sediments in the water and floating objects on the surface like branches, bushes, trees, piles and others which can also easily damage ADP instrument. We made several measurements in such extreme events on the Sava River down to the nuclear power plant Kr\\vsko where we have install fixed cable way. During the several measurement with traditional "moving-boat" measurement technique a mowing bed phenomenon was clearly seen. Measuring flow accurately using ADP that uses the "moving-boat" technique, the system needs a reference against which to relate water velocities to. This reference is river bed and must not move. During flood events we detected difficulty finding a static bed surface to which to relate water velocities. This is caused by motion of the surface layer of bed material or also sediments suspended in the water near bed very densely. So these traditional »moving-boat« measurement techniques that we normally use completely fail. Using stationary measurement method to making individual velocity profile measurements, using an Acoustic Doppler Profiler (ADP), at certain time at fixed locations across the width of a stream gave us much better results. We use Stationary Measurement Software from SONTEK ADP manufacture to provide the tools to make USGS/ISO/WMO "Mid-Section Method" measurements using an ADP. We have ADP with 3.0 MHz which gave us 0,15m cell size in which is capable to gauge from 0,3m to a maximum depth of 6m. The beauty of using the Stationary Measurement Software is not only to overcome common moving-bed problems, but that gave us possibility to measure at depth beyond the range of the instrument. The water depth at certain profile can be inputted with known values of cross section and velocities are then extrapolated to the bed with use of velocity profile power-law equation. In practice the other good advantage to use this method is that we can repeat each profile of measurement if we detected some anomalies in the profile of measured velocities or in the case that we must quickly remove instrument from location because of floating destroying material.

Capacity building in Developing Countries: a challenge ahead for the European Space Agency to continue its successful experience to date

NASA Astrophysics Data System (ADS)

Fea, M.

The European Space Agency (ESA) has built a long tradition and a large experience in the domain of education, training and capacity building throughout its space programmes. As an example, the ESA Science Programme dedicates 1% of its budget to these activities. One of the key reasons for it is the need of closing the loop along the chain from the provider to the user, that is to say between the space and the users elements. In fact, besides the obvious need for technology development, there is actually not very much justification in the long term for a space programme if the user communities are not able to make good use of programme outputs and provide feedback and proper requirements to space agencies. The case of ESA Earth Observation programmes is described to illustrate these considerations, as a way to also implement the European Space Policy and UNISPACE III recommendations. Since its foundation in 1975 and the implementation of its EO programme with the launch of Meteosat-1 in 1977 and the birth of the Earthnet Programme Office in 1978, the European Space Agency is very active in the field of capacity building in developing countries. That is performed through both ESA's specific projects and international co-operation activities. In the latter domain, ESA enjoys a long-standing collaboration with many entities, such as the Committee of Earth Observation Satellites (CEOS), and organisations, such as WMO, UN and its specialised agencies (FAO, UNESCO, UNEP, and so on). In that respect, the Agency is an active member of the CEOS Working Group on Education (WGEdu) and of the World Summit for Sustainable Development Follow-Up (WSSD) Module 1 group dedicated to education, training and capacity building. The overall ESA strategy targets various citizen communities and takes into account the fact that today's young generations will become tomorrow's professionals and decision makers. ESA's activities in this domain are in particular based on an end-to-end concept that includes a) the "train the trainer" approach, b) the prerequisite of a project proposal prepared by the trainee of a target institution on an issue of, possibly, national interest and focused towards establishing an operational autonomy and a routine practice in the integration and use of EO satellite data, c) the firm commitment of the institution to support the project and the trainee, d) the involvement of final users since the very beginning, and e) the exposure of trainees to public for presenting their results. In order to demonstrate how the Agency implements all the above, besides the typical training of external satellite ground station operators, and the way ahead strategy considered within the CEOS WGEdu and WSSD Mod.1 framework, three ESA endeavours are presented, namely the multi-language EDUSPACE web portal (www.eduspace.esa.int), the hosting of UN trainees, and the UN/ESA Course Follow-up Programme.

Comparison of meteorological forcing (WFDEI, AGRI4CAST) to in-situ observations in a semi arid catchment. The case of Merguellil in Tunisia.

NASA Astrophysics Data System (ADS)

Le Page, Michel; Gosset, Cindy; Oueslati, Ines; Calvez, Roger; Zribi, Mehrez; Lilli Chabaane, Zohra

2015-04-01

Meteorological forcing is essential to hydrological and hydro-geological modeling. In the case of the semi-arid catchment of Merguellil in Tunisia, long term time series are only available in the plain for a SYNOP station. Other meteorological stations have been installed since 2010. Therefore, this study aims at qualifying the reliability of the meteorological forcing necessary for an integrated model conception. We compare the meteorological data from 7 stations (sources: WMO and our own station), inside and around the Merguellil catchment, with daily gridded data at 25*25 km from AGRI4CAST and 50*50km from WFDEI. AGRI4CAST (Biaveti et al, 2008) is an interpolated dataset based on actual weather stations produced by the Joint Research Centre (JRC) for the Monitoring Agricultural Resources Unit (MARS). The WFDEI second version dataset (Weedon et al, 2014) has been generated using the same methodology as the widely used WATCH Forcing Data (WFD) by making use of the ERA-Interim reanalysis data. The studied meteorological variables are Rs, Tmoy, U2, P, RH and ET0, with the scores RMSE, bias and R pearson. Regarding the AGRI4CAST dataset, the scores are established over different periods according to variables based on stepping between the observed and interpolated data. The scores show good correlations between the observed temperatures, but with a spatial variability bound to the stations elevations. The moderate and interpolated radiations also show a good concordance indicating a good reliability. The R pearson score obtained for the values of relative humidity show a good correlation between the observations and the interpolations, however, the short periods of comparisons do not allow obtaining significant information and the RMSE and bias are important. Wind speed has an important negative bias for a majority of stations (positively for only one). Only one station shows concordances between the data. The study of the data indicates that we shall have to adjust the wind speeds and the relative humidity of the air for the implementation of a model. Finally the reference evapotranspiration seems relatively coherent, in spite of the dispersal observed during the meteorological measures, but with biases rather high and RMSE also rather high (> 1.3 mm). After revised the parameter U2 and RH, AGRI4CAST can possibly be corrected by ancillary ground stations. The analysis of the WFDEI dataset is currently under evaluation. (1) Biavetti, I., Karetsos, S., Ceglar, A., Toreti, A., Panagos P. (2014), European meteorological data: contribution to research, development and policy support, Proc. of SPIE Vol. 9229 922907-1 (2) Weedon, G. P., G. Balsamo, N. Bellouin, S. Gomes, M. J. Best, and P. Viterbo (2014), The WFDEI meteorological forcing data set: WATCH Forcing Data methodology applied to ERA-Interim reanalysis data, Water Resour. Res., 50, 7505-7514, doi:10.1002/ 2014WR015638.

TIDE TOOL: Open-Source Sea-Level Monitoring Software for Tsunami Warning Systems

NASA Astrophysics Data System (ADS)

Weinstein, S. A.; Kong, L. S.; Becker, N. C.; Wang, D.

2012-12-01

A tsunami warning center (TWC) typically decides to issue a tsunami warning bulletin when initial estimates of earthquake source parameters suggest it may be capable of generating a tsunami. A TWC, however, relies on sea-level data to provide prima facie evidence for the existence or non-existence of destructive tsunami waves and to constrain tsunami wave height forecast models. In the aftermath of the 2004 Sumatra disaster, the International Tsunami Information Center asked the Pacific Tsunami Warning Center (PTWC) to develop a platform-independent, easy-to-use software package to give nascent TWCs the ability to process WMO Global Telecommunications System (GTS) sea-level messages and to analyze the resulting sea-level curves (marigrams). In response PTWC developed TIDE TOOL that has since steadily grown in sophistication to become PTWC's operational sea-level processing system. TIDE TOOL has two main parts: a decoder that reads GTS sea-level message logs, and a graphical user interface (GUI) written in the open-source platform-independent graphical toolkit scripting language Tcl/Tk. This GUI consists of dynamic map-based clients that allow the user to select and analyze a single station or groups of stations by displaying their marigams in strip-chart or screen-tiled forms. TIDE TOOL also includes detail maps of each station to show each station's geographical context and reverse tsunami travel time contours to each station. TIDE TOOL can also be coupled to the GEOWARE™ TTT program to plot tsunami travel times and to indicate the expected tsunami arrival time on the marigrams. Because sea-level messages are structured in a rich variety of formats TIDE TOOL includes a metadata file, COMP_META, that contains all of the information needed by TIDE TOOL to decode sea-level data as well as basic information such as the geographical coordinates of each station. TIDE TOOL can therefore continuously decode theses sea-level messages in real-time and display the time-series data in the GUI as well. This GUI also includes mouse-clickable functions such as zooming or expanding the time-series display, measuring tsunami signal characteristics (arrival time, wave period and amplitude, etc.), and removing the tide signal from the time-series data. De-tiding of the time series is necessary to obtain accurate measurements of tsunami wave parameters and to maintain accurate historical tsunami databases. With TIDE TOOL, de-tiding is accomplished with a set of tide harmonic coefficients routinely computed and updated at PTWC for many of the stations in PTWC's inventory (~570). PTWC also uses the decoded time series files (previous 3-5 days' worth) to compute on-the-fly tide coefficients. The latter is useful in cases where the station is new and a long-term stable set of tide coefficients are not available or cannot be easily obtained due to various non-astronomical effects. The international tsunami warning system is coordinated globally by the UNESCO IOC, and a number of countries in the Pacific and Indian Ocean, and Caribbean depend on Tide Tool to monitor tsunamis in real time.

Practical Applications of the Standardised Precipitation Index (SPI) as a Tool for Very Early Warning of Droughts and Floods in the Balkans Region

NASA Astrophysics Data System (ADS)

Faulkner, Brian

2016-04-01

Southern Europe is repeatedly identified in IPCC Reports as being particularly vulnerable to water resource impacts with risks being assessed as medium to high with current (low) levels of adaptation. Drought frequency will likely increase by the end of the 21st century under IPCC RCP8.5 (medium confidence) . The Balkans region has encountered some of its most significant ever floods and droughts since 2000, highly symptomatic of intense climate change. Foremost of these are the regional catastrophic floods in Albania (2009-10) (2010-11), Bosnia, Herzegovina and Serbia (2014), and the widespread droughts of 2007-08 and 2013-14. There is an urgent need to improve the awareness and implementation of drought and flood risk management tools in the national Ministries and National Hydrometeorological Services (NHMSs) of s.e. Europe generally. This paper describes the development and application of a practical user-friendly tool to calculate SPI across a range of timescales as recommended by the WMO , using a conventional 'Year Book' format to enter monthly precipitation values, coupled with some automated and relatively simple VBA code. Since the tool is spreadsheet based, it is user-friendly and graphically intuitive. The conditional formatting capability introduces a visualisation element to the SPI which is extremely helpful to NHMSs and other non-expert decision makers in understanding SPI significance. Recent practical application of the tool in relation to significant recent floods and droughts in Albania, Kosovo and Macedonia has demonstrated its value as a Very Early Warning tool. However, there are some implicit dangers in simply tracking the SPI 1, 2, n value per se without taking account of the actual accumulated deficits that may generate agricultural and ultimately hydrological droughts. It is conventionally assumed that the sum of the SPI for all months within a drought event can be termed the drought's "magnitude". In fact this is not the case. In regions where rainfall is normally low during a month, large negative or positive SPIs may result even though the departure from the mean is relatively small, and the associated precipitation deficit will also be small. Conversely, a moderate SPI value in a high(er) precipitation month is likely to be much more significant with regard to precipitation 'hazard'. The paper therefore illustrates within the SPI procedures the parallel use of a 'Precipitation Hazard Index' (PHI) which employs two key principles: • The relative value of the SPI 1, 2, n is transformed to the PHI by simply by multiplying the SPI x the precipitation mean value for the same time period. The resultant score is more meaningful in precipitation deficit terms. • The monthly PHI score is then accumulated continuously. The possibility for the SPI to fluctuate from negative to positive or vice-versa within a time period can disguise the continuing presence of a significant hydrological drought or flood hazard. Continuous accounting of the PHI arguably provides greater insight into the potential onset, severity and duration of a significant hydrological event.

Cold Season Ground Validation Activities in support of GPM

NASA Astrophysics Data System (ADS)

Hudak, D. R.; Petersen, W. A.

2012-12-01

A fundamental component of the next-generation global precipitation data products that will be addressed by the GPM mission is the hydrologic cycle at higher latitudes. In this respect, falling snow represents a primary contribution to regional atmospheric and terrestrial water budgets. The current study provides provide information on the precipitation microphysics and processes associated with cold season precipitation and precipitating cloud systems across multiple scales. It also addresses the ability of in-situ ground-based sensors as well as multi-frequency active and passive microwave sensors to detect and estimate falling snow, and more generally to contribute to our knowledge and understanding of the complete global water cycle. The work supports the incorporation of appropriate physics into GPM snowfall retrieval algorithms and the development of improved ground validation techniques for GPM product evaluation. Important information for developing GPM falling snow retrieval algorithms will be provided by a field campaign that took place in the winter of 2011/12 in the Great Lakes area of North America, termed the GPM Cold Season Precipitation Experiment (GCPEx). GCPEx represented a collaboration among the NASA, Environment Canada (EC), the Canadian Space Agency and several US, Canadian and European universities. The data collection strategy for GCPEx was coordinated, stacked high-altitude and in-situ cloud aircraft missions sampling within a broader network of ground-based volumetric observations and measurements. The NASA DSC-8 research aircraft provided a platform for the downward-viewing dual-frequency radar and multi-frequency radiometer observations. The University of North Dakota Citation and the Canadian NRC Convair-580 aircraft provided in-situ profiles of cloud and precipitation microphysics using a suite of optical array probes and bulk measurement instrumentation. Ground sampling was focused about a densely-instrumented central location that is well situated within both mid-latitude synoptic and lake-effect snowfall regimes. The instrumentation suite at CARE included active remote sensing observations as follows: W, Ku, and X-band vertically pointing radars, a Ku and Ka-band dual polarization full scanning radar, and nearby C-band dual polarization, scanning radar. The passive remote sensing suite includes a triple channel profiling microwave radiometer (10, 21, 36 GHz), and a dual channel polarization radiometer (89 and 150 GHz). In-situ measurements at CARE include a 2D video disdrometer, the Precipitation Video Imager, digital photography and a number of other technologies that estimate instantaneous precipitation rate. GCPEX collected ground-based data on 22 distinct precipitation events, 2 rain, 3 mixed and 17 snow. For 16 of these events, there were also aircraft observations. In addition, there were two clear air flights. The presentation will provide an overview of the data collection. It will also summarize the ground-based event precipitation estimates from various sensors as compared to a manual double fence reference to assess measurement uncertainties. Examples will be presented from radar and aircraft in-situ data highlighting the variability of snowfall characteristics relative to the synoptic context. Plans for ongoing validation studies with the WMO Solid Precipitation Intercomparison Experiment beginning in 2013 will be described.

WaterML, an Information Standard for the Exchange of in-situ hydrological observations

NASA Astrophysics Data System (ADS)

Valentine, D.; Taylor, P.; Zaslavsky, I.

2012-04-01

The WaterML 2.0 Standards Working Group (SWG), working within the Open Geospatial Consortium (OGC) and in cooperation with the joint OGC-World Meteorological Organization (WMO) Hydrology Domain Working Group (HDWG), has developed an open standard for the exchange of water observation data; WaterML 2.0. The focus of the standard is time-series data, commonly generated from in-situ style monitoring. This is high value data for hydrological applications such as flood forecasting, environmental reporting and supporting hydrological infrastructure (e.g. dams, supply systems), which is commonly exchanged, but a lack of standards inhibits efficient reuse and automation. The process of developing WaterML required doing a harmonization analysis of existing standards to identify overlapping concepts and come to agreement on a harmonized definition. Generally the formats captured similar requirements, all with subtle differences, such as how time-series point metadata was handled. The in-progress standard WaterML 2.0 incorporates the semantics of the hydrologic information: location, procedure, and observations, and is implemented as an application schema of the Geography Markup Language version 3.2.1, making use of the OGC Observations & Measurements standards. WaterML2.0 is designed as an extensible schema to allow encoding of data to be used in a variety of exchange scenarios. Example areas of usage are: exchange of data for operational hydrological monitoring programs; supporting operation of infrastructure (e.g. dams, supply systems); cross-border exchange of observational data; release of data for public dissemination; enhancing disaster management through data exchange; and exchange in support of national reporting The first phase of WaterML2.0 focused on structural definitions allowing for the transfer of time-series, with less work on harmonization of vocabulary items such as quality codes. Vocabularies from various organizations tend to be specific and take time to come to agreement on. This will be continued in future work for the HDWG, along with extending the information model to cover additional types of hydrologic information: rating and gauging information, and water quality. Rating curves, gaugings and river cross sections are commonly exchanged in addition to standard time-series data to allow information relating to conversions such as river level to discharge. Members of the HDWG plan to initiate this work in early 2012. Water quality data is varied in the way it is processed and in the number of phenomena it measures. It will require specific components of extension to the WaterML2.0 model, most likely making use of the specimen types within O&M and extensive use of controlled vocabularies. Other future work involves different target encodings for the WaterML2.0 conceptual model, such as JSON, netCDF, CSV etc. are optimized for particular needs, such as efficiency in size of the encoding and parsing of structure, but may not be capable of representing the full extent of the WaterML2.0 information model. Certain encodings are best matched for particular needs; the community has begun investigation into when and how best to implement these.

Slovenian Network of Isotopes in Precipitation (SLONIP) - a review of activities in the period 1981-2015

NASA Astrophysics Data System (ADS)

Vreča, Polona; Kanduč, Tjaša; Kocman, David; Lojen, Sonja; Štrok, Marko; Robinson, Johanna Amalia

2017-04-01

The importance of collecting data on the water isotope composition of precipitation in the frame of the Global Network of Isotopes in Precipitation (GNIP) has been steadily increasing since it was initiated by the IAEA and the WMO in 1958, particularly in the last decade (Terzer et al., 2013). GNIP provides an important database for water resources management, verifying and improving atmospheric circulation models, studying climates and the interactions between water in the atmosphere and the biosphere, providing baseline information for the authentication of commodities, etc. Geographical diversity of Slovenia influences the climate and also the water cycle considerably, therefore monitoring of isotopes in precipitation is of particular interest. A review on monitoring of isotopes in precipitation was performed and information about sampling, analytical methods, available data and their evaluation was collected for the period 1981-2015. The first regular and systematic monitoring began in 1981 in Ljubljana (Pezdič, 1999). Later, a programme of collecting new data at a higher spatial density and temporal frequency in different parts of the country by different research groups has been initiated and was extended several times. Consequently, the number of sampling locations has grown within Slovenian Network of Isotopes in Precipitation (SLONIP) and altogether isotopes were monitored at more than 30 different locations countrywide (Vreča and Malenšek, 2016). However, the network is still not a part of a national monitoring programme, such as that operating in some European countries, for example, in Switzerland (Schürch et al., 2003). Only part of Slovenian data is available in GNIP database. Based on the collected data, we identified gaps in the research and made recommendations for future monitoring in the frame of the SLONIP. The list of main gaps includes limited information about sampling (e.g. missing coordinates, type of collector, period, frequency, treatment, storage), methods (e.g. instrumentation, quality control, measurement uncertainty) and data evaluation. Different researchers have used different approaches and only rarely have the IAEA guidelines been strictly followed. Due to the importance of water isotope data it is clear that inappropriate sampling, storage, analyses and finally data evaluation can lead to wrong interpretations, for instance of spatial and temporal predictions of water isotope values at different scales. To this end, this contribution focuses on current activities in the frame of SLONIP and collected data represent the basis for study of spatial distribution of water isotopes in precipitation over Slovenia as well as other regions like the transect from the Adriatic Coast to the Pannonian Plain studied in the frame of ongoing Hungarian-Slovenian research cooperation. Pezdič, J. 1999: Isotopes and geochemical processes, Faculty of Natural Sciences and Engineering, Department of geology, 269. Schürch, M., Kozel, R., Schotterer, U. & Tripet, J. P. 2003, Environ. Geol. 45: 1-11, doi: 10.1007/s00254-003-0843-9. Terzer, S., Wassenaar, L. I., Araguas-Araguas, L. & Aggarwal, P. 2013, Earth Syst. Sci. 17: 4713-4728, doi:10.5194/hess-17-4713-2013. Vreča, P., Malenšek, N. 2016, Geologija 59, 67-83, doi: 10.5474/geologija.2016.004.

Towards a well-connected, global, interdisciplinary research community for rational decision making in the Anthropocene

NASA Astrophysics Data System (ADS)

Rauser, Florian

2016-04-01

The Young Earth System Scientists community YESS (yess-community.org) is a global network of Earth System Science early career researchers focussing on interdisciplinarity. One of the central goals of our early career network is to communicate to the world that Earth System Science has accepted the central challenge of creating tangible products for the benefit of society. A coordinated and truly global approach to Earth System Science is our best attempt to focus our understanding of the complex interplay of Earth's processes into tools for future societies, i.e., for humanity to move away from being a sorcerer's apprentice and to become a rational actor. We believe that starting with the next generation of Earth system scientists to work on that unified approach and creating an environment that allows ambitious, forward-thinking, interdisciplinary science to blossom will be our best way forward into a mature Anthropocene. In 2015 YESS started a process to come up with a definition of the Frontiers of Earth System Science research from an early career perspective, together with the research arms of the World Meteorological Organisation (WMO). During this process it became apparent that there are a few major aspects that cannot be put into the forefront often enough: one, the reality of capacity building; societies can only have robust decision-making if their decision makers can be advised not only by global assessment processes like the Intergovernmental Panel on Climate Change (IPCC) but also by local experts. The reality of a globalised science community is often only true for a few scientists at the very top from a selected number of countries. Two, the integration and balance of both user-driven and fundamental research is key to make science one pillar of a global, mature Anthropocene. This includes a better way to communicate science to end users and a more comprehensive homogenisation of weather and climate research agendas. Three, a complete overview of the scales of predictability and control of the Earth system has to be developed and maintained as a basis of societal decision making. Four, the interdisciplinary research that is required for better understanding the Anthropocene requires global research coordination across fields that is currently not necessarily reflected in standing research organisation structures. Five, the necessity of better integration of science into societal decision processes. The 2015 Conference of the Parties 21 in Paris has shown what is possible on a global, aggregated policy level - but the next years will have to show which societal actors can be thought of as rational and deliberate. This point addresses the issue that science alone is not the rational actor we need in the future, but can only advise those actors. In this session we want to outline those arguments with examples and discuss the influence of a global research funding structure that often reflects what we did in the past more, than what we want to do in the future. This discussion includes an example of the concept of science based target setting, a methodology developed to transfer scientific information into guidelines for companies.

Assessment of atmospheric acidified pollutants trends observed by EANET in North-East Asia in the first decade of XXI century

NASA Astrophysics Data System (ADS)

Gromov, Sergey A.; Trifonova-Yakovleva, Alisa; Gromov, Sergey S.

2015-04-01

Owing to rapid development and subsequent enormous increase in energy consumption/fossil fuel use, anthropogenic emissions of sulphur and nitrogen oxides in China and other Asian countries surpass those in North America and Europe since mid-1990s. Consequently, regional air pollution has become an issue for the most of developing countries in North-East Asia. Since 1998, the Acid Deposition Monitoring Network in East Asia (EANET, http://www.eanet.asia/) provides constant monitoring of the air quality and precipitation (including gaseous and particulate phase chemistry) in 13 countries of the region. The measurements are conducted at 45 rural and remote stations using both filter pack sampling techniques and automatic monitoring equipment. In this study we present a comprehensive trend analysis of the long-term (last 15 years) air pollution monitoring data from selected EANET monitoring sites. Using several statistical approaches, we estimate the quality of the data and perform distribution tests, single out special events (detect outliers) and calculate an ensemble of trends (monthly, seasonal, long-term and quartile) and their statistical significance for a suite of observed compounds. Based on this analysis, we further estimate the statistics and overall significance of the observed temporal dynamics for each pollutant. Ultimately we derive more than 20 trend estimates for a total of up to 12 gas-phase and particulate compounds for each station. Our calculations ascertain that about half of the trends (either negative or positive) observed at the EANET stations in Russia, Korea and Japan are significant. Whilst an increase in SO2, HCl, Cl-, NO3 (except for the stations in Russia) concentrations is distinct, small or insignificant trends are reckoned for HNO3-. A marked decrease in K+ content is seen at all regarded stations. We commonly find station-wise correlation for the trends of the remaining compounds, and for several species we conclude a general spatial pattern, viz. an eastward increase in trend magnitudes in the north-south direction. We further identify special cases of statistically significant seasonal trends for the series that otherwise do not exhibit apparent long-term dynamics, i.e. show an insignificant overall trend. A case in point is the NH3 observational record at Mondy station (Russia), for which the spring-summer negative trends are comparable to the winter positive trends, and both significant. Finally, we discuss and compare these first results with an evaluation of changes in acid deposition over region from 2000 provided by WMO PC-SAG in its global wet deposition assessment (Vet et al., 2014). References: Vet, R., Artz, R. S., Carou, S., Shaw, M., Ro, C. U., Aas, W., Baker, A., Bowersox, V. C., Dentener, F., Galy Lacaux, C., Hou, A., Pienaar, J. J., Gillett, R., Forti, M. C., Gromov, S., Hara, H., Khodzher, T., Mahowald, N. M., Nickovic, S., Rao, P. S. P., and Reid, N. W.: A global assessment of precipitation chemistry and deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity and pH, and phosphorus. Atmos. Environ., 93, 3-100, 2014.

Using Relative Humidity Forecasts to Manage Meningitis in the Sahel

NASA Astrophysics Data System (ADS)

Pandya, R. E.; Adams-Forgor, A.; Akweogno, P.; Awine, T.; Dalaba, M.; Dukic, V.; Dumont, A.; Hayden, M.; Hodgson, A.; Hopson, T. M.; Hugonnet, S.; Yoksas, T. C.

2012-12-01

Meningitis epidemics in the Sahel occur quasi-regularly and with devastating impact. In 2008, for example, eighty-eight thousand people contracted meningitis and over five thousand died. Until very recently, the protection provided by the only available vaccine was so limited and short-lived that the only practical strategy for vaccination was reactive: waiting until an epidemic occurred in the region and then vaccinating in that region to prevent the epidemic's further growth. Even with that strategy, there were still times when demand outpaced available vaccine. While a new vaccine has recently been developed that is effective and inexpensive enough to be used more broadly and proactively, it is only effective against the strain of bacteria that causes the most common kind of bacterial meningitis. As a result, there will likely be continued need for reactive vaccination strategies. It is widely known that meningitis epidemics in the Sahel occur only in the dry season. Our project investigated this relationship, and several independent lines of evidence demonstrate a robust relationship between the onset of the rainy season, as marked by weekly average relative humidity above 40%, and the end of meningitis epidemics. These lines of evidence include statistical analysis of two years of weekly meningitis and weather data across the Sahel, cross-correlation of ten years of meningitis and weather data in the Upper East region of northern Ghana, and high-resolution weather simulations of past meningitis seasons to interpolate available weather data. We also adapted two techniques that have been successfully used in public health studies: generalized additive models, which have been used to relate air quality and health, and a linearized version of the compartmental epidemics model that has been used to understand MRSA. Based on these multiple lines of evidence, average weekly relative humidity forecast two weeks in advance appears consistently and strongly related to the number cases of meningitis in the Sahel. Using currently available forecast models contributed through the WMO Thorpex-Tigge project, and applying quantile regression to enhance their accuracy, we can forecast the average weekly relative humidity to two weeks in advance which allows us to anticipate the end of an epidemic in a region of the Sahel up to four weeks in advance. This would allow public health officials to deploy vaccines to areas in which the epidemics are likely to persist due to continued dryness and avoid vaccinating in areas where the epidemics will end with higher humidity. Our presentation will conclude by introducing the relative humidity decision-information tool developed for use by public-health officials. We will also summarize the results of a weekly meningitis forecast exercise held during the 2011-2012 dry season with public health decision makers from several African countries and the World Health Organization. Finally, we highlight some results of concurrent socio-economic research that suggests other interventions for managing meningitis and helps quantify the economic impact of the disease in Ghana. Overall, while our research has demonstrated an actionable relationship between weather and disease, this relationship is only one factor in a complex and coupled human-natural system which merits continued investigation.

Global Ocean Carbon and Biogeochemistry Coordination

NASA Astrophysics Data System (ADS)

Telszewski, Maciej; Tanhua, Toste; Palacz, Artur

2016-04-01

The complexity of the marine carbon cycle and its numerous connections to carbon's atmospheric and terrestrial pathways means that a wide range of approaches have to be used in order to establish it's qualitative and quantitative role in the global climate system. Ocean carbon and biogeochemistry research, observations, and modelling are conducted at national, regional, and global levels to quantify the global ocean uptake of atmospheric CO2 and to understand controls of this process, the variability of uptake and vulnerability of carbon fluxes into the ocean. These science activities require support by a sustained, international effort that provides a central communication forum and coordination services to facilitate the compatibility and comparability of results from individual efforts and development of the ocean carbon data products that can be integrated with the terrestrial, atmospheric and human dimensions components of the global carbon cycle. The International Ocean Carbon Coordination Project (IOCCP) was created in 2005 by the IOC of UNESCO and the Scientific Committee on Oceanic Research. IOCCP provides an international, program-independent forum for global coordination of ocean carbon and biogeochemistry observations and integration with global carbon cycle science programs. The IOCCP coordinates an ever-increasing set of observations-related activities in the following domains: underway observations of biogeochemical water properties, ocean interior observations, ship-based time-series observations, large-scale ocean acidification monitoring, inorganic nutrients observations, biogeochemical instruments and autonomous sensors and data and information creation. Our contribution is through the facilitation of the development of globally acceptable strategies, methodologies, practices and standards homogenizing efforts of the research community and scientific advisory groups as well as integrating the ocean biogeochemistry observations with the multidisciplinary global ocean observing system. Over the past 4-5 years IOCCP's long standing experience in coordinating biogeochemical observations and data flows globally, resulted in assuming a leadership role during the design and implementation of the biogeochemistry portion of the Framework for Ocean Observing (FOO, 2012). To optimize and enhance the global ocean observing system IOCCP started to implement major elements of the system's approach outlined in the FOO. Starting by setting of ocean observing requirements representing the needs of societal and scientific stakeholders, followed by development of a set of essential ocean variables (EOVs) with spatial and temporal resolution specifications to best meet current demands for data and information services given current and potential national capabilities. The IOCCP works directly with projects and programs programmatically connected to GOOS as well as the WMO-IOC JCOMM to integrate ocean carbon and biogeochemistry observation information into the plans of the Global Climate Observing System in support of the United Nations Framework Convention on Climate Change, the World Summit on Sustainable Development, the Group on Earth Observations, and other international and intergovernmental strategies. We would like to update our partners across disciplines and domains on our short- and long-term strategies as well as learn from their combined experience and knowledge so that our individual activities align more with those undertaken by our counterparts in biological and physical oceanography as well as in terrestrial and atmospheric domains.

Evaluating the catching performance of aerodynamic rain gauges through field comparisons and CFD modelling

NASA Astrophysics Data System (ADS)

Pollock, Michael; Colli, Matteo; Stagnaro, Mattia; Lanza, Luca; Quinn, Paul; Dutton, Mark; O'Donnell, Greg; Wilkinson, Mark; Black, Andrew; O'Connell, Enda

2016-04-01

Accurate rainfall measurement is a fundamental requirement in a broad range of applications including flood risk and water resource management. The most widely used method of measuring rainfall is the rain gauge, which is often also considered to be the most accurate. In the context of hydrological modelling, measurements from rain gauges are interpolated to produce an areal representation, which forms an important input to drive hydrological models and calibrate rainfall radars. In each stage of this process another layer of uncertainty is introduced. The initial measurement errors are propagated through the chain, compounding the overall uncertainty. This study looks at the fundamental source of error, in the rainfall measurement itself; and specifically addresses the largest of these, the systematic 'wind-induced' error. Snowfall is outside the scope. The shape of a precipitation gauge significantly affects its collection efficiency (CE), with respect to a reference measurement. This is due to the airflow around the gauge, which causes a deflection in the trajectories of the raindrops near the gauge orifice. Computational Fluid-Dynamic (CFD) simulations are used to evaluate the time-averaged airflows realized around the EML ARG100, EML SBS500 and EML Kalyx-RG rain gauges, when impacted by wind. These gauges have a similar aerodynamic profile - a shape comparable to that of a champagne flute - and they are used globally. The funnel diameter of each gauge, respectively, is 252mm, 254mm and 127mm. The SBS500 is used by the UK Met Office and the Scottish Environmental Protection Agency. Terms of comparison are provided by the results obtained for standard rain gauge shapes manufactured by Casella and OTT which, respectively, have a uniform and a tapered cylindrical shape. The simulations were executed for five different wind speeds; 2, 5, 7, 10 and 18 ms-1. Results indicate that aerodynamic gauges have a different impact on the time-averaged airflow patterns observed in the vicinity of the collector, compared to the standard gauge shapes. Both the air velocity and the turbulent kinetic energy fields present structures that may improve the interception of particles by the aerodynamic gauge collector. To provide empirical validation, a field-based experimental campaign was undertaken at four UK research stations to compare the results of aerodynamic and conventional gauges, mounted in juxtaposition. The reference measurement is recorded using a rain gauge pit, as specified by the WMO. The results appear to demonstrate how the effect of the wind on rainfall measurements is influenced by the gauge shape and the mounting height. Significant undercatch is observed compared to the reference measurement. Aerodynamic gauges mounted on the ground catch more rainfall than juxtaposed straight-sided gauges, in most instances. This appears to provide some preliminary validation of the CFD model. The indication that an aerodynamic profile improves the gauge catching capability could be confirmed by tracking the hydrometeor trajectories with a Lagrangian method, based on the available set of airflows; and investigating time-dependent aerodynamic features by means of dedicated CFD simulations. Furthermore, wind-tunnel tests could be carried out to provide more robust physical validation of the CFD model.

In Pursuit of a Multi-lateral Dialogue - the Swiss National Centre for Climate Services (NCCS)

NASA Astrophysics Data System (ADS)

Michiko Hama, Angela; Croci-Maspoli, Mischa; Liniger, Mark; Schwierz, Cornelia; Stöckli, Reto; Fischer, Andreas; Gubler, Stefanie; Kotlarski, Sven; Rossa, Andrea; Zubler, Elias; Appenzeller, Christof

2017-04-01

Kick-starting, fostering and maintaining a dialogue between primarily public and academic actors involved in the co-design, co-delivery and use of climate services is at the core of Switzerland's National Centre for Climate Services (NCCS), which was founded in late 2015 in recognition of the Global Framework for Climate Services (GFCS). This coordination and innovation mechanism is a concerted national effort comprised of seven Federal Agencies and Institutes and further partners from academia committed to implementing the Framework at national to subnational level and creating synergies the world over. The NCCS is to be regarded as vital alongside the Swiss National Adaptation Strategy, and it also contributes to putting words into action with respect to the UN's Sustainable Development Goals, the UNFCCC and the Sendai Framework for Disaster Risk Reduction. The services of the Centre provide information to support policy-makers from national to local level as well as the private sector and society at large in minimising their risks, maximising opportunities and optimising costs in the context of climate change and variability. They are indispensable for setting effective mitigation and adaptation measures and for instigating societal transformation. Hence, the goals of the NCCS are to bundle the existing climate services of the Swiss Federation, co-create new tailored solutions with users, act as a network agent and knowledge broker - to boost climate literacy and enable climate-sensitive decision-making leading to increased resilience. The services reflect the specificities and requirements of the Alpine region and its particular challenges and vulnerabilities. Pursuing a participatory approach, the NCCS has brought together essential key players, acted as a sounding board for governmental stakeholders and their needs, and accordingly defined and populated six priority themes in line with the priority areas of the GFCS. These themes are: natural hazards, health, agriculture, energy, forestry and water resources. Specific studies are underway within each theme, encompassing, inter alia, questions on extreme events, solar energy potentials in the housing sector as well as spread of pests and invasive species. In response to the GFCS advocating stronger international development cooperation, Peru and Switzerland are frontrunners in climate services twinning, jointly developing climate services-related capacities and sharing knowledge via the WMO-GFCS project CLIMANDES2. In order to gain further traction in 2017, a communications and network strategy will be designed and rolled out, the set-up of an interactive web portal initiated and the engagement in international cooperation activities strengthened. As one of the core products of the NCCS, the new Swiss climate scenarios for 2018 will be developed in a user-oriented fashion. Enhancing the relevance and uptake of the CH2018 scenarios, stakeholder dialogues will be conceptualized and conducted in all phases and communication formats collaboratively devised and tested. This presentation will give an overview of the founding phase of the NCCS and its first accomplishments since its inception as well as discuss its strategies, activities and current challenges. Following the interactive nature of the session, feedback and input will be sought from the participants with regard to user requirements and communciation tools.

Streamflow Forecasting Using Nuero-Fuzzy Inference System

NASA Astrophysics Data System (ADS)

Nanduri, U. V.; Swain, P. C.

2005-12-01

The prediction of flow into a reservoir is fundamental in water resources planning and management. The need for timely and accurate streamflow forecasting is widely recognized and emphasized by many in water resources fraternity. Real-time forecasts of natural inflows to reservoirs are of particular interest for operation and scheduling. The physical system of the river basin that takes the rainfall as an input and produces the runoff is highly nonlinear, complicated and very difficult to fully comprehend. The system is influenced by large number of factors and variables. The large spatial extent of the systems forces the uncertainty into the hydrologic information. A variety of methods have been proposed for forecasting reservoir inflows including conceptual (physical) and empirical (statistical) models (WMO 1994), but none of them can be considered as unique superior model (Shamseldin 1997). Owing to difficulties of formulating reasonable non-linear watershed models, recent attempts have resorted to Neural Network (NN) approach for complex hydrologic modeling. In recent years the use of soft computing in the field of hydrological forecasting is gaining ground. The relatively new soft computing technique of Adaptive Neuro-Fuzzy Inference System (ANFIS), developed by Jang (1993) is able to take care of the non-linearity, uncertainty, and vagueness embedded in the system. It is a judicious combination of the Neural Networks and fuzzy systems. It can learn and generalize highly nonlinear and uncertain phenomena due to the embedded neural network (NN). NN is efficient in learning and generalization, and the fuzzy system mimics the cognitive capability of human brain. Hence, ANFIS can learn the complicated processes involved in the basin and correlate the precipitation to the corresponding discharge. In the present study, one step ahead forecasts are made for ten-daily flows, which are mostly required for short term operational planning of multipurpose reservoirs. A Neuro-Fuzzy model is developed to forecast ten-daily flows into the Hirakud reservoir on River Mahanadi in the state of Orissa in India. Correlation analysis is carried out to find out the most influential variables on the ten daily flow at Hirakud. Based on this analysis, four variables, namely, flow during the previous time period, ql1, rainfall during the previous two time periods, rl1 and rl2, and flow during the same period in previous year, qpy, are identified as the most influential variables to forecast the ten daily flow. Performance measures such as Root Mean Square Error (RMSE), Correlation Coefficient (CORR) and coefficient of efficiency R2 are computed for training and testing phases of the model to evaluate its performance. The results indicate that the ten-daily forecasting model is efficient in predicting the high and medium flows with reasonable accuracy. The forecast of low flows is associated with less efficiency. REFERENCES Jang, J.S.R. (1993). "ANFIS: Adaptive - network- based fuzzy inference system." IEEE Trans. on Systems, Man and Cybernetics, 23 (3), 665-685. Shamseldin, A.Y. (1997). "Application of a neural network technique to rainfall-runoff modeling." Journal of Hydrology, 199, 272-294. World Meteorological Organization (1975). Intercomparison of conceptual models used in operational hydrological forecasting. World Meteorological Organization, Technical Report No.429, Geneva, Switzerland.

A measurement system for continuous observations of CO2, CH4, H2O and CO onboard passenger aircraft

NASA Astrophysics Data System (ADS)

Gerbig, Christoph; Filges, Annette; Franke, Harald; Klaus, Christoph; Chen, Huilin

2013-04-01

Improved quantification and understanding of surface-atmosphere exchange fluxes of greenhouse gases (GHGs) caused by natural as well as anthropogenic processes is of paramount importance in a world of a changing climate and ever increasing emissions. Top-down estimation of GHG fluxes is traditionally done by inverse transport modeling, using GHG observations from a global network of stations. Uncertainties in modeled vertical transport rates (moist convection, turbulent mixing, stratosphere-troposphere exchange) however greatly affect the quality of flux estimates. More recently, remote sensing of vertical column mole fractions of GHGs have become available for inverse modeling, reducing the impact of vertical transport uncertainties to first order. However, those need validation against in-situ observations. A strategy for regular, global in-situ atmospheric profiling of GHGs, covering at least the troposphere, is thus needed to provide validation of remote sensing and of forward transport modeling of GHGs, to serve as input for inverse modeling, and to reduce the impact of transport uncertainties. IAGOS-ERI (In-service Aircraft for a Global Observing System - European Research Infrastructure) exploits the synergy between globally operating civil aviation and the need for long-term monitoring of atmospheric composition. Within the framework of IAGOS-ERI a cavity ring-down spectroscopy (CRDS) based measurement system for greenhouse gases was designed, tested, and qualified for deployment on commercial airliners. The design meets requirements regarding physical dimensions (size, weight), performance (long-term stability, low maintenance, robustness, full automation) and safety issues (fire prevention regulations, airworthiness). The system uses components of a commercially available CRDS instrument (G2401-m, Picarro Inc.) mounted into a frame suitable for integration in the avionics bay of the Airbus A-340. The first of the IAGOS GHG packages is scheduled for integration in mid 2013. The aim is to have seven systems operational within four years, providing for long-term GHG observations with near-global coverage. To enable robust and automated operation of the IAGOS GHG package over six-month deployment periods, numerous technical issues had to be addressed. An inlet system, designed as virtual impactor to eliminate sampling of larger aerosols, ice particles, and water droplets, provides additional positive ram-pressure to ensure operation without an upstream sampling pump. Furthermore, no sample drying is required, as the simultaneously measured water vapor mole fraction is used to correct for dilution and spectroscopic effects. This also enables the collection of science-quality water vapor measurements throughout the atmosphere. To allow for trace gas measurements to be fully traceable to WMO scales, a two-standard calibration system has been designed and tested that periodically provides calibration gas to the instrument during flight and on ground for each six-month deployment period. We present results from recent test flights and laboratory tests that document the performance for GHG and water vapor measurements. Furthermore, future applications of the IAGOS-GHG data stream, provided in near-real-time via SatCom to the weather prediction centres, will be discussed.

The extent of wind-induced undercatch in the UK winter storms of 2015

NASA Astrophysics Data System (ADS)

Pollock, Michael; Colli, Matteo; Stagnaro, Mattia; Quinn, Paul; Dutton, Mark; O'Donnell, Greg; Wilkinson, Mark; Black, Andrew; O'Connell, Enda; Lanza, Luca

2016-04-01

The most widely used device for measuring rainfall is the rain gauge, of which the tipping bucket (TBR) is the most prevalent type. Rain gauges are considered by many to be the most accurate method currently available. The data they produce are used in flood-forecasting and flood risk management, water resource management, hydrological modelling and evaluating impacts on climate change; to name but a few. Rain gauges may provide the most accurate measurement of rainfall at a point in space and time, but they are subject to errors - and some gauges are more prone than others. The most significant error is the 'wind-induced undercatch'. This is caused by the gauge itself contributing to an acceleration of the wind speed near the orifice, which disturbs and distorts the airflow. The trajectories of precipitation particles are affected, resulting in an undercatch. Results from Computational Fluid Dynamics (CFD) simulations, presented herein, describe in detail the physical processes contributing to this. High resolution field measurements of rainfall and wind are collected at four field research stations in the UK. Each site is equipped with juxtaposed rain gauges with different funnel profiles, in addition to a WMO reference pit rain gauge measurement. These data describe the rainfall measurement uncertainty. The sites were selected to represent the prevalent rainfall regimes observed in the UK. Two research stations are on the west coast; which is prone to frontal weather systems and storms swept in from the Atlantic, often enhanced by orography. Two are located in the east. Rural lowland and upland areas are represented, both in the west and the east. Urban sites will also have significant undercatch problems but are outside the scope of this study. Data from the four research stations are analysed for the 2015 winter storms which caused devastating flooding in the west of the UK, particularly Cumbria and the Scottish Borders, where two of the sites are located. An assessment of the effect of wind on the rainfall catch during these large storm events is presented for each research station. Based on a reference pit rain gauge, the undercatch for these events is calculated. The difference in rainfall catch between several types of rain gauge mounted at variable heights is also investigated. This work aims to demonstrate the importance of improving the accuracy of rainfall measurements, and to emphasise the need to provide an assessment of the measurement uncertainty. A knowledge gap exists in the understanding of precisely how physical phenomena are contributing to wind-induced undercatch. For instance, a priori, the effect of the wind on the rainfall catch will change depending upon the dimensions of the rain droplets. Rainfall 'type' and rainfall intensity may be able to inform corrections, but rigorous multi-variate statistical analysis of high resolution measurements will be key to the success of these procedures. As the spatio-temporal distribution of rainfall can be highly variable, and each measurement location is different; it is a challenging undertaking to understand and pin down the fundamental processes responsible for the wind-induced undercatch.

Micrometeorological Technique for Monitoring of Geological Carbon Capture, Utilization and Storage: Methodology, Workflow and Resources

NASA Astrophysics Data System (ADS)

Burba, G. G.; Madsen, R.; Feese, K.

2013-12-01

The eddy covariance (EC) method is a micrometeorological technique for direct high-speed measurements of the transport of gases and energy between land or water surfaces and the atmosphere [1]. This method allows for observations of gas transport scales from 20-40 times per second to multiple years, represents gas exchange integrated over a large area, from hundreds of square meters to tens of square kilometres, and corresponds to gas exchange from the entire surface, including canopy, and soil or water layers. Gas fluxes, emission and exchange rates are characterized from single-point in situ measurements using permanent or mobile towers, or moving platforms such as automobiles, helicopters, airplanes, etc. Presently, over 600 eddy covariance stations are in operation in over 120 countries [1]. EC is now recognized as an effective method in regulatory and industrial applications, including CCUS [2-10]. Emerging projects utilize EC to continuously monitor large areas before and after the injections, to locate and quantify leakages where CO2 may escape from the subsurface, to improve storage efficiency, and for other CCUS characterizations [5-10]. Although EC is one of the most direct and defensible micrometeorological techniques measuring gas emission and transport, and complete automated stations and processing are readily available, the method is mathematically complex, and requires careful setup and execution specific to the site and project. With this in mind, step-by-step instructions were created in [1] to introduce a novice to the EC method, and to assist in further understanding of the method through more advanced references. In this presentation we provide brief highlights of the eddy covariance method, its application to geological carbon capture, utilization and storage, key requirements, instrumentation and software, and review educational resources particularly useful for carbon sequestration research. References: [1] Burba G. Eddy Covariance Method for Scientific, Industrial, Agricultural and Regulatory Applications. LI-COR Biosciences; 2013. [2] International Energy Agency. Quantification techniques for CO2 leakage. IEA-GHG; 2012. [3] US Department of Energy. Best Practices for Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formations. US DOE; 2012. [4] Liu G. (Ed.). Greenhouse Gases: Capturing, Utilization and Reduction. Intech; 2012. [5] Finley R. et al. An Assessment of Geological Carbon Sequestration Options in the Illinois Basin - Phase III. DOE-MGSC; DE-FC26-05NT42588; 2012. [6] LI-COR Biosciences. Surface Monitoring for Geologic Carbon Sequestration. LI-COR, 980-11916, 2011. [7] Lewicki J., Hilley G. Eddy covariance mapping and quantification of surface CO2 leakage fluxes. GRL, 2009; 36: L21802. [8] Finley R. An Assessment of Geological Carbon Sequestration in the Illinois Basin. Overview of the Decatur-Illinois Basin Site. DOE-MGSC; 2009. [9] Eggleston H., et al. (Eds). IPCC Guidelines for National Greenhouse Gas Inventories, IPCC NGGI P, WMO/UNEP; 2006-2011. [10] Burba G., Madsen R., Feese K. Eddy Covariance Method for CO2 Emission Measurements in CCUS Applications: Principles, Instrumentation and Software. Energy Procedia; Submitted: 1-8.

Dissemination of Climate Model Output to the Public and Commercial Sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert Stockwell, PhD

2010-09-23

Climate is defined by the Glossary of Meteorology as the mean of atmospheric variables over a period of time ranging from as short as a few months to multiple years and longer. Although the term climate is often used to refer to long-term weather statistics, the broader definition of climate is the time evolution of a system consisting of the atmosphere, hydrosphere, lithosphere, and biosphere. Physical, chemical, and biological processes are involved in interactions among the components of the climate system. Vegetation, soil moisture, and glaciers are part of the climate system in addition to the usually considered temperature andmore » precipitation (Pielke, 2008). Climate change refers to any systematic change in the long-term statistics of climate elements (such as temperature, pressure, or winds) sustained over several decades or longer. Climate change can be initiated by external forces, such as cyclical variations in the Earth's solar orbit that are thought to have caused glacial and interglacial periods within the last 2 million years (Milankovitch, 1941). However, a linear response to astronomical forcing does not explain many other observed glacial and interglacial cycles (Petit et al., 1999). It is now understood that climate is influenced by the interaction of solar radiation with atmospheric greenhouse gasses (e.g., carbon dioxide, chlorofluorocarbons, methane, nitrous oxide, etc.), aerosols (airborne particles), and Earth's surface. A significant aspect of climate are the interannual cycles, such as the El Nino La Nina cycle which profoundly affects the weather in North America but is outside the scope of weather forecasts. Some of the most significant advances in understanding climate change have evolved from the recognition of the influence of ocean circulations upon the atmosphere (IPCC, 2007). Human activity can affect the climate system through increasing concentrations of atmospheric greenhouse gases, air pollution, increasing concentrations of aerosol, and land alteration. A particular concern is that atmospheric levels of CO{sub 2} may be rising faster than at any time in Earth's history, except possibly following rare events like impacts from large extraterrestrial objects (AMS, 2007). Atmospheric CO{sub 2} concentrations have increased since the mid-1700s through fossil fuel burning and changes in land use, with more than 80% of this increase occurring since 1900. The increased levels of CO{sub 2} will remain in the atmosphere for hundreds to thousands of years. The complexity of the climate system makes it difficult to predict specific aspects of human-induced climate change, such as exactly how and where changes will occur, and their magnitude. The Intergovernmental Panel for Climate Change (IPCC) was established by World Meteorological Organization (WMO) and the United Nations in 1988. The IPCC was tasked with assessing the scientific, technical and socioeconomic information needed to understand the risk of human-induced climate change, its observed and projected impacts, and options for adaptation and mitigation. The IPCC concluded in its Fourth Assessment Report (AR4) that warming of the climate system is unequivocal, and that most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increased in anthropogenic greenhouse gas concentrations (IPCC, 2007).« less

Arctic-HYCOS: a Large Sample observing system for estimating freshwater fluxes in the drainage basin of the Arctic Ocean

NASA Astrophysics Data System (ADS)

Pietroniro, Al; Korhonen, Johanna; Looser, Ulrich; Hardardóttir, Jórunn; Johnsrud, Morten; Vuglinsky, Valery; Gustafsson, David; Lins, Harry F.; Conaway, Jeffrey S.; Lammers, Richard; Stewart, Bruce; Abrate, Tommaso; Pilon, Paul; Sighomnou, Daniel; Arheimer, Berit

2015-04-01

The Arctic region is an important regulating component of the global climate system, and is also experiencing a considerable change during recent decades. More than 10% of world's river-runoff flows to the Arctic Ocean and there is evidence of changes in its fresh-water balance. However, about 30% of the Arctic basin is still ungauged, with differing monitoring practices and data availability from the countries in the region. A consistent system for monitoring and sharing of hydrological information throughout the Arctic region is thus of highest interest for further studies and monitoring of the freshwater flux to the Arctic Ocean. The purpose of the Arctic-HYCOS project is to allow for collection and sharing of hydrological data. Preliminary 616 stations were identified with long-term daily discharge data available, and around 250 of these already provide online available data in near real time. This large sample will be used in the following scientific analysis: 1) to evaluate freshwater flux to the Arctic Ocean and Seas, 2) to monitor changes and enhance understanding of the hydrological regime and 3) to estimate flows in ungauged regions and develop models for enhanced hydrological prediction in the Arctic region. The project is intended as a component of the WMO (World Meteorological Organization) WHYCOS (World Hydrological Cycle Observing System) initiative, covering the area of the expansive transnational Arctic basin with participation from Canada, Denmark, Finland, Iceland, Norway, Russian Federation, Sweden and United States of America. The overall objective is to regularly collect, manage and share high quality data from a defined basic network of hydrological stations in the Arctic basin. The project focus on collecting data on discharge and possibly sediment transport and temperature. Data should be provisional in near-real time if available, whereas time-series of historical data should be provided once quality assurance has been completed. The initial stages of the project will focus on collecting data on discharge and revise station selection criteria. For monitoring freshwater flow to oceans, stations close to the mouths of rivers and immediately inland for back-up purposes will be preferred. For studies of change emphasis is placed on hydrological regime stations located in headwaters small sub-catchments, including pristine basins. Stations outside the Arctic Ocean basin, such as at the mouth of the Yukon River, Baltic Sea and Hudson Bay, can also be considered to allow a better understanding of hydrological processes occurring in the general region. Countries shall facilitate, to the extent possible, access to their data currently published online, and also access to those not yet regularly published on the web. At a later stage data exchange standards such as WaterML2.0 will be implemented. The project will also perform pan-Arctic hydrological modelling (geo-statistical, deterministic and probabilistic methods) for the assessment and integration of observational and modelled data to improve estimates of ungauged discharge and the overall estimates of freshwater flux to the Arctic Ocean, as well as understanding of hydrological processes.

Coupled Data Assimilation for Integrated Earth System Analysis and Prediction: Goals, Challenges, and Recommendations

NASA Technical Reports Server (NTRS)

Penny, Stephen G.; Akella, Santha; Buehner, Mark; Chevallier, Matthieu; Counillon, Francois; Draper, Clara; Frolov, Sergey; Fujii, Yosuke; Karspeck, Alicia; Kumar, Arun

2017-01-01

The purpose of this report is to identify fundamental issues for coupled data assimilation (CDA), such as gaps in science and limitations in forecasting systems, in order to provide guidance to the World Meteorological Organization (WMO) on how to facilitate more rapid progress internationally. Coupled Earth system modeling provides the opportunity to extend skillful atmospheric forecasts beyond the traditional two-week barrier by extracting skill from low-frequency state components such as the land, ocean, and sea ice. More generally, coupled models are needed to support seamless prediction systems that span timescales from weather, subseasonal to seasonal (S2S), multiyear, and decadal. Therefore, initialization methods are needed for coupled Earth system models, either applied to each individual component (called Weakly Coupled Data Assimilation - WCDA) or applied the coupled Earth system model as a whole (called Strongly Coupled Data Assimilation - SCDA). Using CDA, in which model forecasts and potentially the state estimation are performed jointly, each model domain benefits from observations in other domains either directly using error covariance information known at the time of the analysis (SCDA), or indirectly through flux interactions at the model boundaries (WCDA). Because the non-atmospheric domains are generally under-observed compared to the atmosphere, CDA provides a significant advantage over single-domain analyses. Next, we provide a synopsis of goals, challenges, and recommendations to advance CDA: Goals: (a) Extend predictive skill beyond the current capability of NWP (e.g. as demonstrated by improving forecast skill scores), (b) produce physically consistent initial conditions for coupled numerical prediction systems and reanalyses (including consistent fluxes at the domain interfaces), (c) make best use of existing observations by allowing observations from each domain to influence and improve the full earth system analysis, (d) develop a robust observation-based identification and understanding of mechanisms that determine the variability of weather and climate, (e) identify critical weaknesses in coupled models and the earth observing system, (f) generate full-field estimates of unobserved or sparsely observed variables, (g) improve the estimation of the external forcings causing changes to climate, (h) transition successes from idealized CDA experiments to real-world applications. Challenges: (a) Modeling at the interfaces between interacting components of coupled Earth system models may be inadequate for estimating uncertainty or error covariances between domains, (b) current data assimilation methods may be insufficient to simultaneously analyze domains containing multiple spatiotemporal scales of interest, (c) there is no standardization of observation data or their delivery systems across domains, (d) the size and complexity of many large-scale coupled Earth system models makes it is difficult to accurately represent uncertainty due to model parameters and coupling parameters, (e) model errors lead to local biases that can transfer between the different Earth system components and lead to coupled model biases and long-term model drift, (e) information propagation across model components with different spatiotemporal scales is extremely complicated, and must be improved in current coupled modeling frameworks, (h) there is insufficient knowledge on how to represent evolving errors in non-atmospheric model components (e.g. as sea ice, land and ocean) on the timescales of NWP.

Spatial-temporal variations in surface ozone over Ushuaia and the Antarctic region: observations from in situ measurements, satellite data, and global models.

PubMed

Nadzir, Mohd Shahrul Mohd; Ashfold, Matthew J; Khan, Md Firoz; Robinson, Andrew D; Bolas, Conor; Latif, Mohd Talib; Wallis, Benjamin M; Mead, Mohammed Iqbal; Hamid, Haris Hafizal Abdul; Harris, Neil R P; Ramly, Zamzam Tuah Ahmad; Lai, Goh Thian; Liew, Ju Neng; Ahamad, Fatimah; Uning, Royston; Samah, Azizan Abu; Maulud, Khairul Nizam; Suparta, Wayan; Zainudin, Siti Khalijah; Wahab, Muhammad Ikram Abdul; Sahani, Mazrura; Müller, Moritz; Yeok, Foong Swee; Rahman, Nasaruddin Abdul; Mujahid, Aazani; Morris, Kenobi Isima; Sasso, Nicholas Dal

2018-01-01

The Antarctic continent is known to be an unpopulated region due to its extreme weather and climate conditions. However, the air quality over this continent can be affected by long-lived anthropogenic pollutants from the mainland. The Argentinian region of Ushuaia is often the main source area of accumulated hazardous gases over the Antarctic Peninsula. The main objective of this study is to report the first in situ observations yet known of surface ozone (O 3 ) over Ushuaia, the Drake Passage, and Coastal Antarctic Peninsula (CAP) on board the RV Australis during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC'16). Hourly O 3 data was measured continuously for 23 days using an EcoTech O 3 analyzer. To understand more about the distribution of surface O 3 over the Antarctic, we present the spatial and temporal of surface O 3 of long-term data (2009-2015) obtained online from the World Meteorology Organization of World Data Centre for greenhouse gases (WMO WDCGG). Furthermore, surface O 3 satellite data from the free online NOAA-Atmospheric Infrared Sounder (AIRS) database and online data assimilation from the European Centre for Medium-Range Weather Forecasts (ECMWF)-Monitoring Atmospheric Composition and Climate (MACC) were used. The data from both online products are compared to document the data sets and to give an indication of its quality towards in situ data. Finally, we used past carbon monoxide (CO) data as a proxy of surface O 3 formation over Ushuaia and the Antarctic region. Our key findings were that the surface O 3 mixing ratio during MASEC'16 increased from a minimum of 5 ppb to ~ 10-13 ppb approaching the Drake Passage and the Coastal Antarctic Peninsula (CAP) region. The anthropogenic and biogenic O 3 precursors from Ushuaia and the marine region influenced the mixing ratio of surface O 3 over the Drake Passage and CAP region. The past data from WDCGG showed that the annual O 3 cycle has a maximum during the winter of 30 to 35 ppb between June and August and a minimum during the summer (January to February) of 10 to 20 ppb. The surface O 3 mixing ratio during the summer was controlled by photochemical processes in the presence of sunlight, leading to the depletion process. During the winter, the photochemical production of surface O 3 was more dominant. The NOAA-AIRS and ECMWF-MACC analysis agreed well with the MASEC'16 data but twice were higher during the expedition period. Finally, the CO past data showed the surface O 3 mixing ratio was influenced by the CO mixing ratio over both the Ushuaia and Antarctic regions. Peak surface O 3 and CO hourly mixing ratios reached up to ~ 38 ppb (O 3 ) and ~ 500 ppb (CO) over Ushuaia. High CO over Ushuaia led to the depletion process of surface O 3 over the region. Monthly CO mixing ratio over Antarctic (South Pole) were low, leading to the production of surface O 3 over the Antarctic region.

Ninety Years of International Cooperation in Geophysics

NASA Astrophysics Data System (ADS)

Ismail-Zadeh, A.; Beer, T.

2009-05-01

Because applicable physical, chemical, and mathematical studies of the Earth system must be both interdisciplinary and international, the International Union of Geodesy and Geophysics (IUGG) was formed in 1919 as an non-governmental, non-profit organization dedicated to advancing, promoting, and communicating knowledge of the Earth system, its space environment, and the dynamical processes causing change. The Union brings together eight International Associations that address different disciplines of Earth sciences. Through these Associations, IUGG promotes and enables studies in the geosciences by providing a framework for collaborative research and information exchange, by organizing international scientific assemblies worldwide, and via research publications. Resolutions passed by assemblies of IUGG and its International Associations set geophysical standards and promote issues of science policy on which national members agree. IUGG has initiated and/or vigorously supported collaborative international efforts that have led to highly productive worldwide interdisciplinary research programs, such as the International Geophysical Year and subsequent International Years (IPY, IYPE, eGY, and IHY), International Lithosphere Programme, World Climate Research Programme, Geosphere-Biosphere Programme, and Integrated Research on Risk Disaster. IUGG is inherently involved in the projects and programs related to climate change, global warming, and related environmental impacts. One major contribution has been the creation, through the International Council for Science (ICSU), of the World Data Centers and the Federation of Astronomical and Geophysical Data Analysis Services. These are being transformed to the ICSU World Data System, from which the data gathered during the major programs and data products will be available to researchers everywhere. IUGG cooperates with UNESCO, WMO, and some other U.N. and non-governmental organizations in the study of natural catastrophes, climate dynamics, and in geodetic, hydrological, meteorological, oceanographic, seismological, and volcanological research. IUGG also places particular emphasis on the scientific problems of economically less-developed countries by sponsoring activities relevant to their scientific needs (e.g. Geosciences in Africa, Water Resources, Health and Well-Being etc.) The American Geophysical Union was established as the U.S. National Committee for IUGG in 1919 and today has become a distinguished union of individual geoscientists around the world. Several regional geoscience societies also evolved during the last several decades, most prominent being the European Geosciences Union and the Asia Oceania Geosciences Society. These, and some other national and regional geophysical societies, together with IUGG play a strong part in the international cooperation and promotion of geophysical sciences. At the same time the "geosciences" space is getting crowded, and there is a lot of overlap. International linkages between IUGG, AGU, EGU and other geophysical societies as well as their linkage with International Scientific Unions, that comprise the GeoUnions, are going to become more and more important. Working together is going to be more fruitful than territorial disputes. But what mechanisms can be used to encourage relationships between the international, national and regional geophysical and geoscientific bodies? We will discuss some possibilities on how to come together, to develop and to implement joint programs, research meeting, open forums, and policy statements.

Long-term analysis and appropriate metrics of climate change in Mongolia

NASA Astrophysics Data System (ADS)

Jamiyansharav, Khishigbayar

This study addresses three important issues related to long-term climate change study in Mongolia. Mongolia is one of the biggest land-locked countries in Asia and 75--80 percent of the land is rangeland, which is highly vulnerable to climate change. Climate will affect many sectors critical to the country's economic, social, and ecological welfare. Therefore, it is regionally and globally important to evaluate climate change in Mongolia. Chapter 1 discusses the qualitative and descriptive study on exposure characteristics of the 17 Mongolian meteorological stations, which are part of the Global Climate Observing Network (GCON). The global average temperature anomalies are based in part on the GCON stations' meteorological data. To document the possible exposures surrounding the weather stations, the Mongolian meteorological stations were surveyed during July--August 2005. From the total 17 stations, 47 percent were determined strongly influenced by urban character landscape, 41 percent received some anthropogenic influences, and 12 percent had very little to no anthropogenic influences. Even though the Mongolian meteorological stations' exposure characteristics are better than the European and North American stations' the strict adherence in following WMO guidelines is important and urgently needed. Chapter 2 evaluates the long-term (1961--2005) trends in seasonal and annual surface mean, maximum, minimum temperatures and precipitation. Furthermore, this study compares the long-term mean temperature trends with decadal (1998--2007) trends. This chapter also discusses the extreme climate indices on spatial and temporal scales. According to the results, the long-term linear temperature trends show a clear increasing trend whereas the decadal trends show the decreasing trend mostly in winter and spring. The analysis of extreme indices (1961--2001) indicate that most of the stations frost and icing days are decreased and summer days, tropical nights, monthly maximum value of daily minimum, maximum temperatures and growing season length are increased. Precipitation indices varied substantially and there were no unified temporal and spatial pattern. In addition to that, I am suggesting effective temperature as an appropriate metric to evaluate surface heat change because it counts not only air temperature but also surface humidity. Chapter 3 discusses a case study of grazing intensity on surface energy budgets. To evaluate the land atmospheric interactions over the grassland area depending on the different grazing intensity I conducted the case study over the Shortgrass Steppe Long-Term Ecological Research site on Northern Great Plains of US to imply the findings in semiarid shortgrass steppe of Mongolia. The study site has much of similarities with Mongolian shortgrass steppe and has more frequent, high quality data. This study evaluates the impact of grazing on microclimate and energy budgets in a dry (163 mm) and two near-normal (262 and 260 mm) precipitation years based on continuously measured 20 minute interval data. This study helps to describe surface energy partitioning in semi-arid grasslands that has long history of grazing. The main finding of the study is grazing has a potential impact on the energy partitioning under conditions of higher water availability, but not during dry conditions.

Towards a new daily in-situ precipitation data set supporting parameterization of wet-deposition of CTBT relevant radionuclides

NASA Astrophysics Data System (ADS)

Becker, A.; Ceranna, L.; Ross, O.; Schneider, U.; Meyer-Christoffer, A.; Ziese, M.; Lehner, K.; Rudolf, B.

2012-04-01

As contribution to the World Climate Research Program (WCRP) and in support of the Global Climate Observing System (GCOS) of the World Meteorological Organization (WMO), the Deutscher Wetterdienst (DWD) operates the Global Precipitation Climatology Centre (GPCC). The GPCC re-analysis and near-real time monitoring products are recognized world-wide as the most reliable global data set on rain-gauge based (in-situ) precipitation measurements. The GPCC Monitoring Product (Schneider et al, 2011; Becker et al. 2012, Ziese et al, EGU2012-5442) is available two months after the fact based on the data gathered while listening to the GTS to fetch the SYNOP and CLIMAT messages. This product serves also the reference data to calibrate satellite based precipitation measurements yielding the Global Precipitation Climatology Project (GPCP) data set (Huffmann et al., 2009). The quickest GPCC product is the First Guess version of the GPCC Monitoring Product being available already 3-5 days after the month regarded. Both, the GPCC and the GPCP products bear the capability to serve as data base for the computational light-weight post processing of the wet deposition impact on the radionuclide (RN) monitoring capability of the CTBT network (Wotawa et al., 2009) on the regional and global scale, respectively. This is of major importance any time, a reliable quantitative assessment of the source-receptor sensitivity is needed, e.g. for the analysis of isotopic ratios. Actually the wet deposition recognition is a prerequisite if ratios of particulate and noble gas measurements come into play. This is so far a quite unexplored field of investigation, but would alleviate the clearance of several apparently CTBT relevant detections, encountered in the past, as bogus and provide an assessment for the so far overestimation of the RN detection capability of the CTBT network. Besides the climatological kind of wet deposition assessment for threshold monitoring purposes, there are also singular release events like the Fukushima accident that need to be classified as bogus by a properly working RN verification regime. For these kinds of events a higher temporal resolution of the precipitation data sets is needed. In course of the research project 'Global DAily Precipitation Analysis for the validation of medium-range CLImate Predictions (DAPACLIP) within the Framework Research Programme MiKlip (Mittelfristige Klimaprognose), funded by the German ministry for research (BMBF), a new quality controlled and globally gridded daily precipitation data set is built up, where GPCC will serve the land-surface compartment. The data set is primarily constructed to study decadal behaviour of the essential climate variable precipitation, but as a collateral benefit it will also serve RN verification regime needs. The Fukushima accident has also provided impetus to construct even hourly in-situ precipitation data sets as will be presented in the same session by Yatagai (2012). A comprehensive overview on available precipitation data sets based on in-situ (rain gauge), satellite measurements or the combination of both systems is available from the International Precipitation Working Group (IPWG) web pages (http://www.isac.cnr.it/~ipwg/data/datasets.html).

Atmospheric Nitrogen Inputs to the Ocean and their Impact

NASA Astrophysics Data System (ADS)

Jickells, Tim D.

2016-04-01

Atmospheric Nitrogen Inputs to the Ocean and their Impact T Jickells (1), K. Altieri (2), D. Capone (3), E. Buitenhuis (1), R. Duce (4), F. Dentener (5), K. Fennel (6), J. Galloway (7), M. Kanakidou (8), J. LaRoche (9), K. Lee (10), P. Liss (1), J. Middleburg (11), K. Moore (12), S. Nickovic (13), G. Okin (14), A. Oschilies (15), J. Prospero (16), M. Sarin (17), S. Seitzinger (18), J. Scharples (19), P. Suntharalingram (1), M. Uematsu (20), L. Zamora (21) Atmospheric nitrogen inputs to the ocean have been identified as an important source of nitrogen to the oceans which has increased greatly as a result of human activity. The significance of atmospheric inputs for ocean biogeochemistry were evaluated in a seminal paper by Duce et al., 2008 (Science 320, 893-7). In this presentation we will update the Duce et al 2008 study estimating the impact of atmospheric deposition on the oceans. We will summarise the latest model estimates of total atmospheric nitrogen deposition to the ocean, their chemical form (nitrate, ammonium and organic nitrogen) and spatial distribution from the TM4 model. The model estimates are somewhat smaller than the Duce et al estimate, but with similar spatial distributions. We will compare these flux estimates with a new estimate of the impact of fluvial nitrogen inputs on the open ocean (Sharples submitted) which estimates some transfer of fluvial nitrogen to the open ocean, particularly at low latitudes, compared to the complete trapping of fluvial inputs on the continental shelf assumed by Duce et al. We will then estimate the impact of atmospheric deposition on ocean primary productivity and N2O emissions from the oceans using the PlankTOM10 model. The impacts of atmospheric deposition we estimate on ocean productivity here are smaller than those predicted by Duce et al impacts, consistent with the smaller atmospheric deposition estimates. However, the atmospheric input is still larger than the estimated fluvial inputs to the open ocean, even with the increased transport across shelf to the open ocean from low latitude fluvial systems identified. 1. School of Environmental Science University of East Anglia UK 2. Energy Research Centre University of Cape Town SA 3. Department of Biological Sciences University of S California USA 4. Departments of Oceanography and Atmospheric Sciences Texas A&M University USA 5. JRC Ispra Italy 6. Department of Oceanography Dalhousie University Canada 7. Department of Environmental Sciences U. Virginia USA 8. Department of Chemistry, University of Crete, Greece 9. Department of Biology Dalhousie University, Canada 10. School of Environmental Science and Engineering Pohang University S Korea. 11. Faculty of Geosciences University of Utrecht Netherlands 12. Department of Earth System Science University of California at Irvine USA 13. WMO Geneva 14. Department of Geography University of California USA 15. GEOMAR Keil Germany 16. Department of Atmospheric Sciences, University of Miami, USA 17. Geosciences Division at Physical Research Laboratory, Ahmedabad, India 18. Department of Environmental Studies, University of Victoria, Canada 19. School of Environmentak Sciences, U Liverpool UK 20. Center for International Collaboration, Atmosphere and Ocean Research Institute, The University of Tokyo Japan 21. Oak Ridge Associated Universities USA

Continuous atmospheric monitoring of the injected CO2 behavior over geological storage sites using flux stations: latest technologies and resources

NASA Astrophysics Data System (ADS)

Burba, George; Madsen, Rodney; Feese, Kristin

2014-05-01

Flux stations have been widely used to monitor emission rates of CO2 from various ecosystems for climate research for over 30 years [1]. The stations provide accurate and continuous measurements of CO2 emissions with high temporal resolution. Time scales range from 20 times per second for gas concentrations, to 15-minute, hourly, daily, and multi-year periods. The emissions are measured from the upwind area ranging from thousands of square meters to multiple square kilometers, depending on the measurement height. The stations can nearly instantaneously detect rapid changes in emissions due to weather events, as well as changes caused by variations in human-triggered events (pressure leaks, control releases, etc.). Stations can also detect any slow changes related to seasonal dynamics and human-triggered low-frequency processes (leakage diffusion, etc.). In the past, station configuration, data collection and processing were highly-customized, site-specific and greatly dependent on "school-of-thought" practiced by a particular research group. In the last 3-5 years, due to significant efforts of global and regional CO2 monitoring networks (e.g., FluxNet, Ameriflux, Carbo-Europe, ICOS, etc.) and technological developments, the flux station methodology became fairly standardized and processing protocols became quite uniform [1]. A majority of current stations compute CO2 emission rates using the eddy covariance method, one of the most direct and defensible micrometeorological techniques [1]. Presently, over 600 such flux stations are in operation in over 120 countries, using permanent and mobile towers or moving platforms (e.g., automobiles, helicopters, and airplanes). Atmospheric monitoring of emission rates using such stations is now recognized as an effective method in regulatory and industrial applications, including carbon storage [2-8]. Emerging projects utilize flux stations to continuously monitor large areas before and after the injections, to locate and quantify leakages from the subsurface, to improve storage efficiency, and for other storage characterizations [5-8]. In this presentation, the latest regulatory and methodological updates are provided regarding atmospheric monitoring of the injected CO2 behavior using flux stations. These include 2013 improvements in methodology, as well as the latest literature, including regulatory documents for using the method and step-by-step instructions on implementing it in the field. Updates also include 2013 development of a fully automated remote unattended flux station capable of processing data on-the-go to continuously output final CO2 emission rates in a similar manner as a standard weather station outputs weather parameters. References: [1] Burba G. Eddy Covariance Method for Scientific, Industrial, Agricultural and Regulatory Applications. LI-COR Biosciences; 2013. [2] International Energy Agency. Quantification techniques for CO2 leakage. IEA-GHG; 2012. [3] US Department of Energy. Best Practices for Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formations. US DOE; 2012. [4] Liu G. (Ed.). Greenhouse Gases: Capturing, Utilization and Reduction. Intech; 2012. [5] Finley R. et al. An Assessment of Geological Carbon Sequestration Options in the Illinois Basin - Phase III. DOE-MGSC; DE-FC26-05NT42588; 2012. [6] LI-COR Biosciences. Surface Monitoring for Geologic Carbon Sequestration. LI-COR, 980-11916, 2011. [7] Eggleston H., et al. (Eds). IPCC Guidelines for National Greenhouse Gas Inventories, IPCC NGGI P, WMO/UNEP; 2006-2011. [8] Burba G., Madsen R., Feese K. Eddy Covariance Method for CO2 Emission Measurements in CCUS Applications: Principles, Instrumentation and Software. Energy Procedia, 40C: 329-336; 2013.

Effect of metal opaquer on the final color of 3 ceramic crown types on 3 abutment configurations.

PubMed

Arif, Rabia; Yilmaz, Burak; Mortazavi, Aras; Ozcelik, Tuncer B; Johnston, William M

2018-04-30

The effect of a recently introduced metal opaquer when used to mask the color of a titanium abutment under ceramic crown systems is unknown. The purpose of this study was to compare the color coordinates of 3 ceramic crown types-characterized monolithic lithium disilicate (LDC) (IPS e.max; Ivoclar Vivadent AG), layered lithium disilicate (LDL) (IPS e.max; Ivoclar Vivadent AG), and layered zirconia (ZL) (H.C. Starck)-on 3 abutment configurations, nonopaqued titanium (Ti), resin opaqued titanium (Op), and zirconia (Zir). In addition, the color differences (CIEDE2000) were evaluated among the 3 crown types on 3 different abutment substrates. Ten Ti disks (10×1 mm) were fabricated with computer-aided design and computer-aided manufacturing (CAD-CAM) to represent the Ti abutments. Five Ti specimens were opaqued (Op) (whiteMetal Opaquer wMO; Blue Sky Bio), and 5 were not opaqued (Ti). Ten zirconia disks were fabricated with CAD-CAM and sintered (10×1.2 mm). Five disks were used as backings to represent Zir abutments, and 5 disks were layered with 1 mm of porcelain (B1, IPS e.Max Ceram; Ivoclar Vivadent AG) to represent layered zirconia crowns (ZL). Ten lithium disilicate plates (14×14×1.2 mm) were sectioned from CAD blocks (B1 IPS e.Max CAD; Ivoclar Vivadent AG). Five plates were layered with the same porcelain (B1, 1 mm), and 5 plates were surface characterized and glazed. An LDL crown on a Zir abutment configuration was used as the control. The 3 simulated crown types (n=5) were optically connected to each of the 3 abutment types, and the color of the 9 groups was measured using a spectroradiometer. Measured data were reported in CIELab coordinates. CIELab data were used to calculate color differences between the control and the 8 experimental groups. Color data were summarized for each group, and analyzed by repeated-measures ANOVA. For pairwise comparisons, a Bonferroni correction of t tests was used, and for interpretive analysis of resulting color difference data, a 1-way ANOVA and subsequent Tukey testing for pairwise comparisons were used. The statistical significance of the analysis of color coordinates was found to be P≤.002. Although 3-way interaction was not found to be significant (P=.335), all three 2-way interactions of the main effects were found to be significant (P≤.002). All crown types on the Zir abutment revealed color differences from the control group. The color differences of the crown types on the Op and Zir abutment configurations compared with the control (LDL/Zir) were not (P>.05) statistically different. Colors of tested crown systems on Ti backing were each unacceptably different from the control group. Colors of these systems on zirconia backing were not perceivably different. Use of opaquer on titanium backing resulted in a small color difference from the control group (P>.05) for each crown system, demonstrating that it may be used to prevent the unfavorable metal show-through that can influence the final color of all ceramic crown systems tested. Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Improved method for sea ice age computation based on combination of sea ice drift and concentration

NASA Astrophysics Data System (ADS)

Korosov, Anton; Rampal, Pierre; Lavergne, Thomas; Aaboe, Signe

2017-04-01

Sea Ice Age is one of the components of the Sea Ice ECV as defined by the Global Climate Observing System (GCOS) [WMO, 2015]. It is an important climate indicator describing the sea ice state in addition to sea ice concentration (SIC) and thickness (SIT). The amount of old/thick ice in the Arctic Ocean has been decreasing dramatically [Perovich et al. 2015]. Kwok et al. [2009] reported significant decline in the MYI share and consequent loss of thickness and therefore volume. Today, there is only one acknowledged sea ice age climate data record [Tschudi, et al. 2015], based on Maslanik et al. [2011] provided by National Snow and Ice Data Center (NSIDC) [http://nsidc.org/data/docs/daac/nsidc0611-sea-ice-age/]. The sea ice age algorithm [Fowler et al., 2004] is using satellite-derived ice drift for Lagrangian tracking of individual ice parcels (12-km grid cells) defined by areas of sea ice concentration > 15% [Maslanik et al., 2011], i.e. sea ice extent, according to the NASA Team algorithm [Cavalieri et al., 1984]. This approach has several drawbacks. (1) Using sea ice extent instead of sea ice concentration leads to overestimation of the amount of older ice. (2) The individual ice parcels are not advected uniformly over (long) time. This leads to undersampling in areas of consistent ice divergence. (3) The end product grid cells are assigned the age of the oldest ice parcel within that cell, and the frequency distribution of the ice age is not taken into account. In addition, the base sea ice drift product (https://nsidc.org/data/docs/daac/nsidc0116_icemotion.gd.html) is known to exhibit greatly reduced accuracy during the summer season [Sumata et al 2014, Szanyi, 2016] as it only relies on a combination of sea ice drifter trajectories and wind-driven "free-drift" motion during summer. This results in a significant overestimate of old-ice content, incorrect shape of the old-ice pack, and lack of information about the ice age distribution within the grid cells. We propose an improved algorithm for sea ice age computation based on combination of sea ice drift and concentration, both derived from satellite measurements. The base sea ice drift product is from the Ocean and Sea Ice Satellite Application Facility (EUMETSAT OSI-SAF, Lavergne et al., 2011). This operational product was recently upgraded to also process ice drift during the summer season [http://osisaf.met.no/]. . The Sea Ice Concentration product from the ESA Sea Ice Climate Change Initiative (ESA SI CCI) project is used to adjust the partial concentrations at every advection step [http://esa-cci.nersc.no/]. Each grid cell is characterised by its partial concentration of water and ice of different ages. Also, sea ice convergence and divergence are used to realistically adjust the ratio of young ice / multi year ice. Comparison of results from this new algorithm with results derived from drifting ice buoys deployed in 2013 - 2016 demonstrates clear improvement in the ice age estimation. The spatial distribution of sea ice age in the new product compares better to the Sea Ice Type derived from satellite passive microwave and scatterometer measurements, both with regard to the decreased patchiness and the shape. The new ice age algorithm is developed in the context of the ESA CCI, and is designed for production of more accurate sea ice age climate data records in the future.

The new Mediterranean background monitoring station of Ersa, Cape Corsica: A long term Observatory component of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx)

NASA Astrophysics Data System (ADS)

Dulac, Francois

2013-04-01

The Chemistry-Aerosol Mediterranean Experiment (ChArMEx, http://charmex.lsce.ipsl.fr/) is a French initiative supported by the MISTRALS program (Mediterranean Integrated Studies at Regional And Locals Scales, http://www.mistrals-home.org). It aims at a scientific assessment of the present and future state of the atmospheric environment in the Mediterranean Basin, and of its impacts on the regional climate, air quality, and marine biogeochemistry. The major stake is an understanding of the future of the Mediterranean region in a context of strong regional anthropogenic and climatic pressures. The target of ChArMEx is short-lived particulate and gaseous tropospheric trace species which are the cause of poor air quality events, have two-way interactions with climate, or impact the marine biogeochemistry. In order to fulfill these objectives, important efforts have been put in 2012 in order to implement the infrastructure and instrumentation for a fully equipped background monitoring station at Ersa, Cape Corsica, a key location at the crossroads of dusty southerly air masses and polluted outflows from the European continent. The observations at this station began in June 2012 (in the context of the EMEP / ACTRIS / PEGASOS / ChArMEx campaigns). A broad spectrum of aerosol properties is also measured at the station, from the chemical composition (off-line daily filter sampling in PM2.5/PM10, on-line Aerosol Chemical Speciation Monitor), ground optical properties (extinction/absorption/light scattering coeff. with 1-? CAPS PMex monitor, 7-? Aethalometer, 3-? Nephelometer), integrated and vertically resolved optical properties (4-? Cimel sunphotometer and LIDAR, respective), size distribution properties (N-AIS, SMPS, APS, and OPS instruments), mass (PM1/PM10 by TEOM/TEOM-FDMS), hygroscopicity (CCN), as well as total insoluble deposition. So far, real-time measurement of reactive gases (O3, CO, NO, NO2), and off-line VOC measurements (cylinders, cartridges) are also performed. A Kipp and Zonen system for monitoring direct and diffuse broadband radiative fluxes will also be in operation soon, as well as an ICOS/RAMCES CO2 and CH4 monitoring instrument. Through this unprecedented effort and with the support from ChArMEx, ADEME, and CORSiCA programs (http://www.obs-mip.fr/corsica), this observatory represents so far the most achieved French atmospheric station having the best set of instruments for measuring in-situ reactive gases and aerosols. It stands out as the station of not one laboratory but of a large number (see list of co-authors). It provides "real time" information useful to the local air quality network (Qualitair Corse, http://www.qualitaircorse.org/) concerning EU regulated parameters (O3, PMx). This station aims providing quality controlled climatically relevant gas/aerosol database following the recommendations of the EU-FP7 ACTRIS infrastructure, EMEP and WMO-GAW programs. Atmospheric datasets are currently available at the MISTRALS database (http://mistrals.sedoo.fr/ChArMEx/) and soon at the ACTRIS & GAW databases. After a brief presentation of the Cape Corsica Station (location, climatology, instrumental settings ...), we present here the first months of aerosols properties (optical / chemical / particle size) obtained at this station. Acknowledgements: the station is mainly supported by ADEME, CNRS-INSU, CEA, CTC, EMD, FEDER, and Météo-France.

Operational Use of OGC Web Services at the Met Office

NASA Astrophysics Data System (ADS)

Wright, Bruce

2010-05-01

The Met Office has adopted the Service-Orientated Architecture paradigm to deliver services to a range of customers through Rich Internet Applications (RIAs). The approach uses standard Open Geospatial Consortium (OGC) web services to provide information to web-based applications through a range of generic data services. "Invent", the Met Office beta site, is used to showcase Met Office future plans for presenting web-based weather forecasts, product and information to the public. This currently hosts a freely accessible Weather Map Viewer, written in JavaScript, which accesses a Web Map Service (WMS), to deliver innovative web-based visualizations of weather and its potential impacts to the public. The intention is to engage the public in the development of new web-based services that more accurately meet their needs. As the service is intended for public use within the UK, it has been designed to support a user base of 5 million, the analysed level of UK web traffic reaching the Met Office's public weather information site. The required scalability has been realised through the use of multi-tier tile caching: - WMS requests are made for 256x256 tiles for fixed areas and zoom levels; - a Tile Cache, developed in house, efficiently serves tiles on demand, managing WMS request for the new tiles; - Edge Servers, externally hosted by Akamai, provide a highly scalable (UK-centric) service for pre-cached tiles, passing new requests to the Tile Cache; - the Invent Weather Map Viewer uses the Google Maps API to request tiles from Edge Servers. (We would expect to make use of the Web Map Tiling Service, when it becomes an OGC standard.) The Met Office delivers specialist commercial products to market sectors such as transport, utilities and defence, which exploit a Web Feature Service (WFS) for data relating forecasts and observations to specific geographic features, and a Web Coverage Service (WCS) for sub-selections of gridded data. These are locally rendered as maps or graphs, and combined with the WMS pre-rendered images and text, in a FLEX application, to provide sophisticated, user impact-based view of the weather. The OGC web services supporting these applications have been developed in collaboration with commercial companies. Visual Weather was originally a desktop application for forecasters, but IBL have developed it to expose the full range of forecast and observation data through standard web services (WCS and WMS). Forecasts and observations relating to specific locations and geographic features are held in an Oracle Database, and exposed as a WFS using Snowflake Software's GO-Publisher application. The Met Office has worked closely with both IBL and Snowflake Software to ensure that the web services provided strike a balance between conformance to the standards and performance in an operational environment. This has proved challenging in areas where the standards are rapidly evolving (e.g. WCS) or do not allow adequate description of the Met-Ocean domain (e.g. multiple time coordinates and parametric vertical coordinates). It has also become clear that careful selection of the features to expose, based on the way in which you expect users to query those features, in necessary in order to deliver adequate performance. These experiences are providing useful 'real-world' input in to the recently launched OGC MetOcean Domain Working Group and World Meteorological Organisation (WMO) initiatives in this area.

Atmospheric aerosol brown carbon in the high Himalayas

NASA Astrophysics Data System (ADS)

Kirillova, Elena; Decesari, Stefano; Marinoni, Angela; Bonasoni, Paolo; Vuillermoz, Elisa; Facchini, M. Cristina; Fuzzi, Sandro

2016-04-01

Anthropogenic light-absorbing atmospheric aerosol can reach very high concentrations in the planetary boundary layer in South-East Asia ("brown clouds"), affecting atmospheric transparency and generating spatial gradients of temperature over land with a possible impact on atmospheric dynamics and monsoon circulation. Besides black carbon (BC), an important light-absorbing component of anthropogenic aerosols is the organic carbon component known as 'brown carbon' (BrC). In this research, we provided first measurements of atmospheric aerosol BrC in the high Himalayas during different seasons. Aerosol sampling was conducted at the GAW-WMO Global station "Nepal Climate Observatory-Pyramid" (NCO-P) located in the high Khumbu valley at 5079 m a.s.l. in the foothills of Mt. Everest. PM10 aerosol samples were collected from July 2013 to November 2014. The sampling strategy was set up in order to discriminate the daytime valley breeze bringing polluted air masses up to the observatory and free tropospheric air during nighttime. Water-soluble BrC (WS-BrC) and methanol-soluble BrC (MeS-BrC) were extracted and analyzed using a UV/VIS spectrophotometer equipped with a 50 cm liquid waveguide capillary cell. In the polluted air masses, the highest levels of the BrC light absorption coefficient at 365 nm (babs365) were observed during the pre-monsoon season (1.83±1.46 Mm-1 for WS-BrC and 2.86±2.49 Mm-1 for MeS-BrC) and the lowest during the monsoon season (0.21±0.22 Mm-1 for WS-BrC and 0.32±0.29 Mm-1 for MeS-BrC). The pre-monsoon season is the most frequently influenced by a strong atmospheric brown cloud (ABC) transport to NCO-P due to increased convection and mixing layer height over South Asia combined with the highest up-valley wind speed and the increase of the emissions from open fires due to the agricultural practice along the Himalayas foothills and the Indo-Gangetic Plain. In contrast, the monsoon season is characterized by a weakened valley wind regime and an efficient removal of aerosols by wet scavenging. The wavelength dependence of the light absorption by BrC expressed as Ångström Exponent (AAE) within 330-500 nm was on average lower for MeS-BrC (3.9±1.1) compared to WS-BrC (4.8±0.8) and exhibited no diurnal or seasonal trend. The light absorption coefficient of BrC at 365 nm was about 13-17% (WS-BrC) and about 21-29% (MeS-BrC) of that of BC (AAEBC=1). Relative light absorption of BrC and BC considering the whole solar spectrum showed that at NCO-P WS-BrC absorbs 5±2% and MeS-BrC absorbs 12±7% compared to equivalent BC, as measured by Absorption Photometer (MAAP). These results are in line with previous in situ measurements at low altitude stations in South-East Asia, and do not support the strong enhancements of brown carbon absorption contribution in the upper part of the boundary layer and in the free troposphere suggested by remote sensing observations.

Intraregional links between the trends in air pollutants observed at the EANET network sites for 2000-2014

NASA Astrophysics Data System (ADS)

Gromov, Sergey A.; Trifonova-Yakovleva, Alisa; Gromov, Sergey S.

2016-04-01

Recent changes in economic development tendencies and environmental protection policies in the East Asian countries raise hopes for improvement of regional air quality in this vast region populated by more than 3 billion people. To recognize anticipated changes in atmospheric pollutants levels, deposition rates and impact on the environment, the Acid Deposition Monitoring Network in East Asia (EANET, http://www.eanet.asia/) is regularly operating region-wide since 2000 in 13 countries. The network provides continuous monitoring data on the air quality and precipitation (including gas-phase and particulate chemistry) at 55 monitoring sites, including 20 remote and 14 rural sites. Observation of soil and inland water environments are performed at more than 30 monitoring sites [1]. In this study we focus on 1) the data quality assessment and preparation and 2) analysis of temporal trends of compositions observed at selected 26 non-urban EANET stations. Speciation includes gas-phase (SO2, HNO3, HCl, NH3) and particulate matter (SO42-, NO3-, Cl-, NH4+, Na+, K+, Mg2+, Ca2+) abundances analysed in samples collected using filterpack technique with sampling duration/frequency of one-two weeks. Data quality assessment (distribution test and manual inspection) allowed us to remove/repair random and operator errors. Wrong sample timing was found for 0.37% (severe) and 34% (mild inconsistency) of the total of 7630 samples regarded. Erroneous data flagging (e.g. missing or below the detection limit) was repaired for 9.3%, respectively. Some 1.8% of severely affected data were corrected (where possible) or removed. Thus refined 15-year dataset is made available for the scientific community. For convenience, we also provide data in netCDF format (per station or in an assembly). Based on this refined dataset, we performed trend analysis using several statistical approaches including quantile regression which provides robust results against outliers and better understanding of trend origins. Our calculations indicate that about half of the median trends at EANET stations are significant, derived either for the entire observational period or for a given season, however not for the same species. The proportions of decreasing and increasing trends are comparable. The latter is the case for SO2, HCl, Cl-, NO3 (except for Russia), while marked decrease in K+ abundances is prevailing at all stations. Most unsystematic trends are seen for nitrogenated compounds, particularly HNO3, which calls for deeper data quality analysis. Interestingly, about the same statistic (half of significant trends) is obtained for the upper (0.9) quantile of the dataset, suggesting that trends pertain to the upper part of the data distribution usually linked to emission dynamics (i.e. bearing winter/spring compositions). We further apply an ad hoc cluster analysis to infer spatial patterns and colocation of the trends across the East Asian region. Finally, we provide a brief comparison of results with an evaluation of changes in major acidic compounds over EMEP region for the 1990-2012 provided by EMEP in its trend assessment for the UN ECE CLRTAP earlier this year [2]. References: 1. EANET: Data Report 2014. Network Center for EANET (ACAP), November 2015, 314 p. (http://www.eanet.asia/product/datarep/datarep14/datarep14.pdf) 2. EMEP: Air Pollution Trends in the EMEP region between 1990 and 2012. WMO/EMEP TFMM Trend Assessment Report. UN ECE Convention on LRTAP, 2016, 54 p.

HOAPS precipitation validation with ship-borne rain and snow measurements over the Ocean

NASA Astrophysics Data System (ADS)

Bumke, Karl; Schröder, Marc; Fennig, Karsten

2013-04-01

Measuring precipitation over the oceans is still a challenging task. The main reason for a lack of such data can be attributed to the difficulty of measuring precipitation on moving platforms under high wind speeds. The progress in satellite technology has provided the possibility to retrieve global data sets from space, including precipitation. Levizzani et al. (2007) showed that precipitation over the oceans can be derived with sufficient accuracy from passive microwave radiometry. On the other hand, Andersson et al. (2011) pointed out that even state-of-the-art satellite retrievals and reanalysis data sets still disagree on global precipitation with respect to amounts, patterns, variability and temporal behaviour. This creates the need for ship-based precipitation validation data using instruments capable of accurately measuring rain rates even under high wind speed conditions. In the present study we use ship rain gauges (Hasse et al., 1998) and optical disdrometers (Großklaus et al., 1998), the latter is also capable to measure snow (Lempio et al., 2007). Measurements are point-to-area collocated against Hamburg Ocean Atmosphere Parameters and fluxes from Satellite (HOAPS) data (Andersson et al., 2011). The used HOAPS-S data subset contains all retrieved physical parameters at the native SSM/I (Special Sensor Microwave Imager) pixel-level resolution of approximately 50 km for each individual satellite. The algorithm does not discriminate between rain and snowfall. The satellite data is compared to the in situ measurement by the nearest neighbour approach. Therefore, it must be ensured that both observations are related to each other, which can be determined by the decorrelation length. At least a number of 660 precipitation events are at our disposal including 127 snow events. The statistical analysis follows the recommendations given by the World Meteorological Organization (WMO) for dichotomous or binary forecasts (WWRP/WGNE: http://www.cawcr.gov.au/projects/verification/#Methods_for_dichotomous_forecasts). Taking into account that precipitation has to be regarded as a rare event, a better estimate of the performance is the so-called threat score or critical success index (CSI) instead of the proportion correct. The CSI reaches values up to 0.71 for all events and 0.65 taking only snow measurements into account. From accumulated precipitation rates can be concluded that the HOAPS precipitation rates are in a good agreement to measurements. References Andersson, A., Klepp, C., Fennig, K., Bakan, S., Graßl, H. and 495 co-authors. 2011. Evaluation of HOAPS-3 ocean surface freshwater flux components. J. Appl. Meteorol. Climatol. 50, 379-398, doi:10.1175/2010JAMC2341.1. Großklaus, M., Uhlig, K. and Hasse, L. 1998: An optical disdrometer for use in high wind speeds. J. Atmos. Oceanic Technol. 15, 1051-1059. Hasse, L., Großklaus, M., Uhlig, K. and Timm, P. 1998: A ship rain gauge for use under high wind speeds. J. Atmos. Oceanic Technol. 15, 380-386. Lempio, G. E., Bumke, K. and Macke, A., 2007: Measurements of solid precipitation with an optical disdrometer Advances in Space Research, 19 (3). 527-531. Levizzani, V., Bauer, P. and Turk, F. J., 2007: Measuring Precipitation from Space,EURAINSAT and the Future, Advances in Global Change Research, Vol. 28, Springer, 724 p.

Ground Based, Millimeter Wave Measurement of Ozone in the Middle Atmosphere

NASA Technical Reports Server (NTRS)

Parrish, Alan

2000-01-01

There is a need for highly reliable measurements of stratospheric ozone. Policy makers worldwide concerned with public health rely oil a clear consensus from the scientific community as a basis for ozone-related environmental policy that has a significant impact oil national economies. Tile latest Such consensus was presented in WMO, and used in a 1999 meeting of the parties considering amendments to the Montreal Protocol oil Substances that Deplete the Ozone Layer. Tile scientific community, in turn, needs highly precise and accurate measurements of ozone levels, and small time derivatives of these levels, both in continued - development of its understanding of the physical and chemical processes involved and as clear evidence that these processes are occurring as stated. Over most of the world, changes in ozone levels are small. For example, over the heavily populated northern midlatitudes, the linearized rate of ozone decline is between 0.2% per year and 0.7% per year, depending on altitude. These values are small enough to make measurement requirements technically challenging. Data quality may suffer from imperfections in individual instruments. In one instance, early results from a satellite-borne ozone sensor were later found to be invalid because of calibration drift. Even in the absence of drift, tile absolute calibration of a new sensor may differ slightly from that of its predecessor in service. Most ozone remote sensing instruments operate at ultraviolet or infrared wavelengths where scattering from dust and aerosols must be taken into account; results from these systems may be or are affected following a major volcanic eruption, such as tile one at Mt. Pinatubo in 1991. Given these difficulties, a consensus of measurements from several independent systems is required to insure a reliable understanding of stratospheric ozone levels. Because of the above-described need for highly precise and accurate ozone measurements using several independent techniques, there was interest in developing several techniques which were known but not highly developed in the 1980's into systems capable of being used in ail operational manner to make measurements with the level of quality needed to-detect small trends in ozone levels. A ground-based microwave instrument capable of remotely sensing stratospheric ozone had been designed by tile Principal Investigator of the present project. This instrument was built at tile Millitech Corporation in South Deerfield, Massachusetts before tile present work began. (Funding for design and construction of the instrument came from sources other than the present grant.) Tile instrument measured the spectrum of one of the many emission lines produced by purely rotational transitions of ozone, one at a frequency of 110.8 GHz. The altitude distribution of ozone can. in principle, be retrieved from the details of the pressure-broadened spectrum of the ozone transition. However, the level of contamination of the spectral measurement by instrumentally induced artifacts must be very low in order to retrieve a ozone profile of useful quality from it. The Millitech instrument demonstrated spectral purity at ail adequate level, and there were promising ideas for instrumental improvements and for further development of the technique. The initial objectives of the present project, then, were to develop techniques for calibrating the Millitech instrument, to minimize artifacts in tile spectra it produces, to optimally retrieve ozone profiles from tile spectra, to test tile quality of the microwave profiles by comparing them with profiles obtained using several other, independent techniques over both short and periods of time, and to perform research using the ozone data gathered with the instrument.

A multi-model intercomparison of halogenated very short-lived substances (TransCom-VSLS): linking oceanic emissions and tropospheric transport for a reconciled estimate of the stratospheric source gas injection of bromine

NASA Astrophysics Data System (ADS)

Hossaini, R.; Patra, P. K.; Leeson, A. A.; Krysztofiak, G.; Abraham, N. L.; Andrews, S. J.; Archibald, A. T.; Aschmann, J.; Atlas, E. L.; Belikov, D. A.; Bönisch, H.; Carpenter, L. J.; Dhomse, S.; Dorf, M.; Engel, A.; Feng, W.; Fuhlbrügge, S.; Griffiths, P. T.; Harris, N. R. P.; Hommel, R.; Keber, T.; Krüger, K.; Lennartz, S. T.; Maksyutov, S.; Mantle, H.; Mills, G. P.; Miller, B.; Montzka, S. A.; Moore, F.; Navarro, M. A.; Oram, D. E.; Pfeilsticker, K.; Pyle, J. A.; Quack, B.; Robinson, A. D.; Saikawa, E.; Saiz-Lopez, A.; Sala, S.; Sinnhuber, B.-M.; Taguchi, S.; Tegtmeier, S.; Lidster, R. T.; Wilson, C.; Ziska, F.

2016-07-01

The first concerted multi-model intercomparison of halogenated very short-lived substances (VSLS) has been performed, within the framework of the ongoing Atmospheric Tracer Transport Model Intercomparison Project (TransCom). Eleven global models or model variants participated (nine chemical transport models and two chemistry-climate models) by simulating the major natural bromine VSLS, bromoform (CHBr3) and dibromomethane (CH2Br2), over a 20-year period (1993-2012). Except for three model simulations, all others were driven offline by (or nudged to) reanalysed meteorology. The overarching goal of TransCom-VSLS was to provide a reconciled model estimate of the stratospheric source gas injection (SGI) of bromine from these gases, to constrain the current measurement-derived range, and to investigate inter-model differences due to emissions and transport processes. Models ran with standardised idealised chemistry, to isolate differences due to transport, and we investigated the sensitivity of results to a range of VSLS emission inventories. Models were tested in their ability to reproduce the observed seasonal and spatial distribution of VSLS at the surface, using measurements from NOAA's long-term global monitoring network, and in the tropical troposphere, using recent aircraft measurements - including high-altitude observations from the NASA Global Hawk platform. The models generally capture the observed seasonal cycle of surface CHBr3 and CH2Br2 well, with a strong model-measurement correlation (r ≥ 0.7) at most sites. In a given model, the absolute model-measurement agreement at the surface is highly sensitive to the choice of emissions. Large inter-model differences are apparent when using the same emission inventory, highlighting the challenges faced in evaluating such inventories at the global scale. Across the ensemble, most consistency is found within the tropics where most of the models (8 out of 11) achieve best agreement to surface CHBr3 observations using the lowest of the three CHBr3 emission inventories tested (similarly, 8 out of 11 models for CH2Br2). In general, the models reproduce observations of CHBr3 and CH2Br2 obtained in the tropical tropopause layer (TTL) at various locations throughout the Pacific well. Zonal variability in VSLS loading in the TTL is generally consistent among models, with CHBr3 (and to a lesser extent CH2Br2) most elevated over the tropical western Pacific during boreal winter. The models also indicate the Asian monsoon during boreal summer to be an important pathway for VSLS reaching the stratosphere, though the strength of this signal varies considerably among models. We derive an ensemble climatological mean estimate of the stratospheric bromine SGI from CHBr3 and CH2Br2 of 2.0 (1.2-2.5) ppt, ˜ 57 % larger than the best estimate from the most recent World Meteorological Organization (WMO) Ozone Assessment Report. We find no evidence for a long-term, transport-driven trend in the stratospheric SGI of bromine over the simulation period. The transport-driven interannual variability in the annual mean bromine SGI is of the order of ±5 %, with SGI exhibiting a strong positive correlation with the El Niño-Southern Oscillation (ENSO) in the eastern Pacific. Overall, our results do not show systematic differences between models specific to the choice of reanalysis meteorology, rather clear differences are seen related to differences in the implementation of transport processes in the models.

Vertical distribution of aerosol optical properties in the Po Valley during the 2012 summer campaigns

NASA Astrophysics Data System (ADS)

Bucci, Silvia; Cristofanelli, Paolo; Decesari, Stefano; Marinoni, Angela; Sandrini, Silvia; Größ, Johannes; Wiedensohler, Alfred; Di Marco, Chiara F.; Nemitz, Eiko; Cairo, Francesco; Di Liberto, Luca; Fierli, Federico

2018-04-01

Studying the vertical distribution of aerosol particle physical and chemical properties in the troposphere is essential to understand the relative importance of local emission processes vs. long-range transport for column-integrated aerosol properties (e.g. the aerosol optical depth, AOD, affecting regional climate) as well as for the aerosol burden and its impacts on air quality at the ground. The main objective of this paper is to investigate the transport of desert dust in the middle troposphere and its intrusion into the planetary boundary layer (PBL) over the Po Valley (Italy), a region considered one of the greatest European pollution hotspots for the frequency that particulate matter (PM) limit values are exceeded. Events of mineral aerosol uplift from local (soil) sources and phenomena of hygroscopic growth at the ground are also investigated, possibly affecting the PM concentration in the region as well. During the PEGASOS 2012 field campaign, an integrated observing-modelling system was set up based on near-surface measurements (particle concentration and chemistry), vertical profiling (backscatter coefficient profiles from lidar and radiosoundings) and Lagrangian air mass transport simulations by FLEXPART model. Measurements were taken at the San Pietro Capofiume supersite (44°39' N, 11°37' E; 11 m a.s.l.), located in a rural area relatively close to some major urban and industrial emissive areas in the Po Valley. Mt. Cimone (44°12' N, 10°42' E; 2165 m a.s.l.) WMO/GAW station observations are also included in the study to characterize regional-scale variability. Results show that, in the Po Valley, aerosol is detected mainly below 2000 m a.s.l. with a prevalent occurrence of non-depolarizing particles ( > 50 % throughout the campaign) and a vertical distribution modulated by the PBL daily evolution. Two intense events of mineral dust transport from northern Africa (19-21 and 29 June to 2 July) are observed, with layers advected mainly above 2000 m, but subsequently sinking and mixing in the PBL. As a consequence, a non-negligible occurrence of mineral dust is observed close to the ground ( ˜ 7 % of occurrence during a 1-month campaign). The observations unambiguously show Saharan dust layers intruding the Po Valley mixing layer and directly affecting the aerosol concentrations near the surface. Finally, lidar observations also indicate strong variability in aerosol on shorter timescales (hourly). Firstly, these highlight events of hygroscopic growth of anthropogenic aerosol, visible as shallow layers of low depolarization near the ground. Such events are identified during early morning hours at high relative humidity (RH) conditions (RH > 80 %). The process is observed concurrently with high PM1 nitrate concentration (up to 15 µg cm-3) and hence mainly explicable by deliquescence of fine anthropogenic particles, and during mineral dust intrusion episodes, when water condensation on dust particles could instead represent the dominant contribution. Secondly, lidar images show frequent events (mean daily occurrence of ˜ 22 % during the whole campaign) of rapid uplift of mineral depolarizing particles in afternoon-evening hours up to 2000 m a.s.l. height. The origin of such particles cannot be directly related to long-range transport events, being instead likely linked to processes of soil particle resuspension from agricultural lands.

The state of the art of flood forecasting - Hydrological Ensemble Prediction Systems

NASA Astrophysics Data System (ADS)

Thielen-Del Pozo, J.; Pappenberger, F.; Salamon, P.; Bogner, K.; Burek, P.; de Roo, A.

2010-09-01

Flood forecasting systems form a key part of ‘preparedness' strategies for disastrous floods and provide hydrological services, civil protection authorities and the public with information of upcoming events. Provided the warning leadtime is sufficiently long, adequate preparatory actions can be taken to efficiently reduce the impacts of the flooding. Because of the specific characteristics of each catchment, varying data availability and end-user demands, the design of the best flood forecasting system may differ from catchment to catchment. However, despite the differences in concept and data needs, there is one underlying issue that spans across all systems. There has been an growing awareness and acceptance that uncertainty is a fundamental issue of flood forecasting and needs to be dealt with at the different spatial and temporal scales as well as the different stages of the flood generating processes. Today, operational flood forecasting centres change increasingly from single deterministic forecasts to probabilistic forecasts with various representations of the different contributions of uncertainty. The move towards these so-called Hydrological Ensemble Prediction Systems (HEPS) in flood forecasting represents the state of the art in forecasting science, following on the success of the use of ensembles for weather forecasting (Buizza et al., 2005) and paralleling the move towards ensemble forecasting in other related disciplines such as climate change predictions. The use of HEPS has been internationally fostered by initiatives such as "The Hydrologic Ensemble Prediction Experiment" (HEPEX), created with the aim to investigate how best to produce, communicate and use hydrologic ensemble forecasts in hydrological short-, medium- und long term prediction of hydrological processes. The advantages of quantifying the different contributions of uncertainty as well as the overall uncertainty to obtain reliable and useful flood forecasts also for extreme events, has become evident. However, despite the demonstrated advantages, worldwide the incorporation of HEPS in operational flood forecasting is still limited. The applicability of HEPS for smaller river basins was tested in MAP D-Phase, an acronym for "Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region" which was launched in 2005 as a Forecast Demonstration Project of World Weather Research Programme of WMO, and entered a pre-operational and still active testing phase in 2007. In Europe, a comparatively high number of EPS driven systems for medium-large rivers exist. National flood forecasting centres of Sweden, Finland and the Netherlands, have already implemented HEPS in their operational forecasting chain, while in other countries including France, Germany, Czech Republic and Hungary, hybrids or experimental chains have been installed. As an example of HEPS, the European Flood Alert System (EFAS) is being presented. EFAS provides medium-range probabilistic flood forecasting information for large trans-national river basins. It incorporates multiple sets of weather forecast including different types of EPS and deterministic forecasts from different providers. EFAS products are evaluated and visualised as exceedance of critical levels only - both in forms of maps and time series. Different sources of uncertainty and its impact on the flood forecasting performance for every grid cell has been tested offline but not yet incorporated operationally into the forecasting chain for computational reasons. However, at stations where real-time discharges are available, a hydrological uncertainty processor is being applied to estimate the total predictive uncertainty from the hydrological and input uncertainties. Research on long-term EFAS results has shown the need for complementing statistical analysis with case studies for which examples will be shown.

Effects of UV radiation on phytoplankton

NASA Astrophysics Data System (ADS)

Smith, Raymond C.; Cullen, John J.

1995-07-01

It is now widely documented that reduced ozone will result in increased levels of ultraviolet (UV) radiation, especially UV-B (280-320nm), incident at the surface of the earth [Watson, 1988; Anderson et al., 1991; Schoeberl and Hartmann, 1991; Frederick and Alberts, 1991; WMO, 1991; Madronich, 1993; Kerr and McElroy, 1993], and there is considerable and increasing evidence that these higher levels of UV-B radiation may be detrimental to various forms of marine life in the upper layers of the ocean. With respect to aquatic ecosystems, we also know that this biologically- damaging mid-ultraviolet radiation can penetrate to ecologically- significant depths in marine and freshwater systems [Jerlov, 1950; Lenoble, 1956; Smith and Baker, 1979; Smith and Baker, 1980; Smith and Baker, 1981; Kirk et al., 1994]. This knowledge, plus the dramatic decline in stratospheric ozone over the Antarctic continent each spring, now known to be caused by anthropogenically released chemicals [Solomon, 1990; Booth et al., 1994], has resulted in increased UV-environmental research and a number of summary reports. The United Nations Environmental Program (UNEP) has provided recent updates with respect to the effects of ozone depletion on aquatic ecosystems (Hader, Worrest, Kumar in UNEP 1989, 1991, Hader, Worrest, Kumar and Smith UNEP 1994) and the Scientific Committee on Problems of the Environment (SCOPE) has provided [SCOPE, 1992] a summary of the effects of increased UV radiation on biological systems. SCOPE has also reported [SCOPE, 1993] on the effects of increased UV on the biosphere. In addition, several books have recently been published reviewing various aspects of environmental UV photobiology [Young et al., 1993], UV effects on humans, animals and plants [Tevini, 1993], the biological effects of UV radiation in Antarctica [Weiler and Penhale, 1994], and UV research in freshwater ecosystems [Williamson and Zagarese, 1994]. Several other reviews are relevant [NAS, 1984; Caldwell et al., 1986; Worrest, 1986; NOAA, 1987; Smith, 1989; Smith and Baker, 1989; Voytek, 1990; Häder, 1993; Acevedo and Nolan, 1993; Holm-Hansen et al., 1993; Vincent and Roy, 1993; Biggs and Joyner, 1994; Williamson and Zagarese, 1994; Karentz, 1994; Cullen and Neale, 1993; Cullen and Neale, 1994]. As Hader et al. have summarized [UNEP, 1989; UNEP, 1991], "UV-B radiation in aquatic systems: 1) affects adaptive strategies (e.g., motility, orientation); 2) impairs important physiological functions (e.g., photosynthesis and enzymatic reactions); and 3) threatens marine organisms during their developmental stages (e.g., the young of finfish, shrimp larvae, crab larvae)". Possible consequences to aquatic systems include: reduced biomass production; changes in species composition and biodiversity; and alterations of aquatic ecosystems and biogeochemical cycles associated with the above changes. Within the past four years, our knowledge with respect to the environmental effects of ozone-related increased levels of UV-B has increased significantly, and numerous efforts have been directed toward process-oriented studies of UV responses in plants and animals. Consensus is building toward the view that current levels of UV play a major role as an ecological determinant, influencing both survival and distribution, and are thus deserving of increased study independent of ozone-related UV-B increases. This review outlines U.S. research subsequent to 1991 and emphasizes studies concerned with phytoplankton.

Physico-chemical properties of aerosols in Sao Paulo, Brazil and mechanisms of secondary organic aerosol formation.

NASA Astrophysics Data System (ADS)

Artaxo, Paulo; Ferreira de Brito, Joel; Varanda Rizzo, Luciana; Luiza Godoy, Maria; Godoy, Jose Marcus

2013-04-01

Megacities emissions are increasingly becoming a global issue, where emissions from the transportation sector play an increasingly important role. Sao Paulo is a megacity with a population of about 18 million people, 7 million cars and large-scale industrial emissions. As a result of the vehicular and industrial emissions, the air quality in Sao Paulo is bellow WMO standards for aerosol particles and ozone. Many uncertainties are found on gas- and particulate matter vehicular emission factors and their following atmospheric processes, e.g. secondary organic aerosol formation. Due to the uniqueness of the vehicular fuel in Brazil, largely based on ethanol use, such characterization currently holds further uncertainties. To improve the understanding of the role of this unique emission characteristics, we are running a source apportionment study in Sao Paulo focused on the mechanisms of organic aerosol formation. One of the goals of this study is a quantitative aerosol source apportionment focused on vehicular emissions, including ethanol and gasohol (both fuels used by light-duty vehicles). This study comprises four sampling sites with continuous measurements for one year, where trace elements and organic aerosol are being measured for PM2.5 and PM10 along with real-time NOx, O3, PM10 and CO measurements. Aerosol optical properties and size distribution are being measured on a rotation basis between sampling stations. Furthermore, a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) and an Aerosol Chemical Speciation Monitor (ACSM) are used to measure in real time VOCs and aerosol composition, respectively. Trace elements were measured using XRF and OC/EC analysis was determined with a Sunset OC/EC instrument. A TSI Nephelometer with 3 wavelengths measure light scattering and a MAAP measure black carbon. Results show aerosol number concentrations ranging between 10,000 and 35,000 cm-3, mostly concentrated in the nucleation and Aitken modes, with a peak in size at 80-120 nm. Average mass concentrations were measured at 11.5 ug/m3 and 30.7 ug/m3 for fine and coarse mode, respectively. The elemental analysis shows that Fe, Si and Al dominate the coarse mode indicating strong contribution from soil dust resuspension whereas sulfur dominates the fine mode (0.8 micrograms/m3). Scattering coefficients typically range between 20 and 150 Mm-1 at 637 nm, and absorption varied between 10 to 60 Mm-1 at 637 nm, respectively, both of them peaking at 7:00 local time, the morning rush hour. The corresponding single scattering albedo varies between 0.50 and 0.80, indicating a significant contribution of primary soot particles to the aerosol population. Organic aerosol accounts for 70% of the aerosol mass, with nitrates accounting for 11.7%, ammonia 8.4%, sulfate 8.2% and chlorine 1.6% pf PM1 measured by AMS techniques. Most of the organic aerosol were oxygenated. Several new particle formation events were observed, with a clear increase in organic aerosol and VOCs amounts associated with new particle formation. The study allows the characterization of a unique fueled fleet emissions and its impact on atmospheric chemistry, particle formation and other atmospheric dynamic processes. This work was funded by Petrobras S/A

Neutron Scattering Studies on Correlated Transition-Metal Oxides

NASA Astrophysics Data System (ADS)

Zhu, Mengze

We have explored the collective phenomena of correlated electrons in two different transition-metal oxides, Ruddlesden-Popper type ruthenates (Sr,Ca) n+1RunO3n+1 and inverse-trirutile chromates Cr2MO6 (M = Te, Mo and W), using neutron scattering in combination with various material characterization methods. (Sr,Ca)n+1RunO 3n+1 are 4d transition-metal oxides exhibiting competing magnetic and electronic tendencies. The delicate balance among the competing states can be readily tuned by perturbations, such as chemical doping and magnetic field, which gives rise to emergent phenomena. We have investigated the effects of 3d transition-metal doping on the magnetic and electronic properties of layered ruthenates. For instance, the single-layer (n = 1) Sr2RuO4 is an unconventional superconductor possessing an incommensurate spin density wave instability with a wave vector qic= (0.3 0.3 L) driven by Fermi surface nesting. Upon Fe substitution, we have unveiled an unexpected commensurate spin density wave order with a propagation vector qc= (0.25 0.25 0) in Sr2Ru1-xFexO 4 (x = 0.03 and 0.05), despite the magnetic fluctuations persisting at qic. The latter feature is corroborated by the first principles calculations, which show that Fe doping barely changes the nesting vector of the Fermi surface. These results suggest that in addition to the known incommensurate magnetic instability, Sr2RuO4 is also in proximity to a commensurate magnetic tendency that can be stabilized via Fe doping. We have also studied the effects of a magnetic field. For example, the bilayer (n = 2) Ca3(Ru1-xTi x)2O7 (x = 0.03) is a G-type antiferromagnetic Mott insulator. We have revealed that a modest magnetic field can lead to colossal magnetoresistance arising from an anomalous collapse of the Mott insulating state. Such an insulator-to-metal transition is accompanied by magnetic and structural transitions. These findings call for deeper theoretical studies to reexamine the magnetic field tuning of Mott systems with magnetic and electronic instabilities, as a magnetic field usually stabilizes the insulating ground state in Mott-Hubbard systems. Cr2MO6 (M = Te, W and Mo) are spin dimer systems with the magnetic ions Cr3+ structurally dimerized favoring a singlet ground state. However, all three compounds investigated exhibit long-range antiferromagnetic orders at low temperature owing to the inter-dimer interactions. We have shown that the inter-dimer exchange coupling can be tuned from antiferromagnetic in Cr2TeO6 to ferromagnetic in Cr2WO6 and Cr2MoO6, by altering the degree of d-p orbital hybridization between W(Mo) and O atoms. The tunability of the inter-dimer interactions without introducing additional complexities such as structural distortions and carrier doping offers a rare opportunity to drive the system toward the quantum critical point (QCP) separating the dimer-based quantum disordered state and the classical long-range antiferromagnetic order. Moreover, we have unraveled Higgs amplitude modes in the magnetic excitation spectra of Cr2TeO6 and Cr2WO6, which are generally believed to survive only in systems close to the QCP where the ordered moment is suppressed significantly from its fully saturated value by quantum fluctuations. However, these two compounds are away from the QCP with the ordered moment reduced only by 24%. This study suggests that Higgs amplitude modes are not the privilege of ordered systems in the vicinity of the QCP, but may be common excitation modes in ordered spin dimer systems.

Optimized approach to retrieve information on the tropospheric and stratospheric carbonyl sulfide (OCS) vertical distributions above Jungfraujoch from high-resolution FTIR solar spectra.

NASA Astrophysics Data System (ADS)

Lejeune, Bernard; Mahieu, Emmanuel; Servais, Christian; Duchatelet, Pierre; Demoulin, Philippe

2010-05-01

Carbonyl sulfide (OCS), which is produced in the troposphere from both biogenic and anthropogenic sources, is the most abundant gaseous sulfur species in the unpolluted atmosphere. Due to its low chemical reactivity and water solubility, a significant fraction of OCS is able to reach the stratosphere where it is converted to SO2 and ultimately to H2SO4 aerosols (Junge layer). These aerosols have the potential to amplify stratospheric ozone destruction on a global scale and may influence Earth's radiation budget and climate through increasing solar scattering. The transport of OCS from troposphere to stratosphere is thought to be the primary mechanism by which the Junge layer is sustained during nonvolcanic periods. Because of this, long-term trends in atmospheric OCS concentration, not only in the troposphere but also in the stratosphere, are of great interest. A new approach has been developed and optimized to retrieve atmospheric abundance of OCS from high-resolution ground-based infrared solar spectra by using the SFIT-2 (v3.91) algorithm, including a new model for solar lines simulation (solar lines often produce significant interferences in the OCS microwindows). The strongest lines of the ν3 fundamental band of OCS at 2062 cm-1 have been systematically evaluated with objective criteria to select a new set of microwindows, assuming the HITRAN 2004 spectroscopic parameters with an increase in the OCS line intensities of the ν3band main isotopologue 16O12C32S by 15.79% as compared to HITRAN 2000 (Rothman et al., 2008, and references therein). Two regularization schemes have further been compared (deducted from ATMOS and ACE-FTS measurements or based on a Tikhonov approach), in order to select the one which optimizes the information content while minimizing the error budget. The selected approach has allowed us to determine updated OCS long-term trend from 1988 to 2009 in both the troposphere and the stratosphere, using spectra recorded on a regular basis with Fourier Transform Infrared spectrometers (FTIRs), under clear-sky conditions, at the NDACC site (Network for the Detection of Atmospheric Composition Change, visit http://www.ndacc.org) of the International Scientific Station of the Jungfraujoch (Swiss Alps, 46.5° N, 8.0° E, 3580m asl). Trends and seasonal cycles deduced from our results will be compared to values published in the literature and critically discussed. In particular, we will confirm the recent change in the OCS total column trend, which has become positive since 2002 before undergoing a slowing down over the last years. References Brasseur, G.P., J.J. Orlando and G.S. Tyndall (Eds.), Atmospheric Chemistry and Global Change, 654 pp., Oxford University Press, New York, 1999. Mahieu E., R. Zander, P. Demoulin, P. Duchatelet, C. Servais, C.P. Rinsland and M. De Mazière, Recent evolution of atmospheric OCS above the Jungfraujoch station : implications for the stratospheric aerosol layer. In: Proceedings of atmospheric spectroscopic applications, ASA Reims 2005, September 6-8, 2005. Rinsland, C.P., L. Chiou, E. Mahieu, R. Zander, C.D. Boone, and P.F. Bernath, Measurements of long-term changes in atmospheric OCS (carbonyl sulfide) from infrared solar observations, Journal of Quantitative Spectroscopy & Radiative Transfer, 109, 2679-2686, 2008. Rothman, L.S., I.E. Gordon, A. Barbe and al., The HITRAN 2008 molecular spectroscopic database, Journal of Quantitative Spectroscopy & Radiative Transfer, 110, 533-572, 2008. SPARC Assessment of Stratospheric Aerosol Properties, L. Thomason and Th. Peter (Eds.), WCRP 124, WMO/TD- No. 1295, SPARC Report No. 4, 2006.

OceanSITES format and Ocean Observatory Output harmonisation: past, present and future

NASA Astrophysics Data System (ADS)

Pagnani, Maureen; Galbraith, Nan; Diggs, Stephen; Lankhorst, Matthias; Hidas, Marton; Lampitt, Richard

2015-04-01

The Global Ocean Observing System (GOOS) initiative was launched in 1991, and was the first step in creating a global view of ocean observations. In 1999 oceanographers at the OceanObs conference envisioned a 'global system of eulerian observatories' which evolved into the OceanSITES project. OceanSITES has been generously supported by individual oceanographic institutes and agencies across the globe, as well as by the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology (under JCOMMOPS). The project is directed by the needs of research scientists, but has a strong data management component, with an international team developing content standards, metadata specifications, and NetCDF templates for many types of in situ oceanographic data. The OceanSITES NetCDF format specification is intended as a robust data exchange and archive format specifically for time-series observatory data from the deep ocean. First released in February 2006, it has evolved to build on and extend internationally recognised standards such as the Climate and Forecast (CF) standard, BODC vocabularies, ISO formats and vocabularies, and in version 1.3, released in 2014, ACDD (Attribute Convention for Dataset Discovery). The success of the OceanSITES format has inspired other observational groups, such as autonomous vehicles and ships of opportunity, to also use the format and today it is fulfilling the original concept of providing a coherent set of data from eurerian observatories. Data in the OceanSITES format is served by 2 Global Data Assembly Centres (GDACs), one at Coriolis, in France, at ftp://ftp.ifremer.fr/ifremer/oceansites/ and one at the US NDBC, at ftp://data.ndbc.noaa.gov/data/oceansites/. These two centres serve over 26,800 OceanSITES format data files from 93 moorings. The use of standardised and controlled features enables the files held at the OceanSITES GDACs to be electronically discoverable and ensures the widest access to the data. The OceanSITES initiative has always been truly international, and in Europe the first project to include OceanSITES as part of its outputs was ANIMATE(2002-2005), where 3 moorings and 5 partners shared equipment, methods and analysis effort and produced their final outputs in OceanSITES format. Subsequent European projects, MERSEA(2004-2008) and EuroSITES (2008-2011) built on that early success and the current European project FixO3 encompasses 23 moorings and 29 partners, all of whom are committed to producing data in OceanSITES format. The global OceanSITES partnership continues to grow; in 2014 the Australian Integrated Marine Observing System ( IMOS) started delivering data to the OceanSITES FTP, and files and India, South Korea and Japan are also active members of the OceanSITES community. As illustrated in figure 1 the OceanSITES sites cover the entire globe, and the format has now matured enough to be taken up by other user groups. GO-SHIP, a global, ship-based hydrographic program, shares technical management with OceanSITES through JCOMMOPS, and has its roots in WOCE Hydrography. This program complements OceanSITES and directly contributes to the mooring data holdings by providing repeated CTD and bottle profiles at specific locations. GO-SHIP hydrographic data adds a source of timeseries profiles and are provided in the OceanSITES file structure to facilitate full data interoperability. GO-SHIP has worked closely with the OceanSITES program, and this interaction has produced an unexpected side benefit - all data in the GO-SHIP database will be offered the robust and CF-compliant OceanSITES format beginning in 2015. The MyOcean European ocean monitoring and forecasting project has been in existence since 2009, and has successfully used the OceanSITES format as a unifying paradigm. MyOcean daily receives hundreds of data files from across Europe, and distributes the data from drifter buoys, moorings and tide gauges in OceanSITES format. These in-situ data are essential for both model verification points and for assimilation into the models. The use of the OceanSITES format now exceeds the hopes and expectations of the original OceanObs vision in 1999 and the stewardship of the format development, extension and documentation is in the expert care of the international OceanSITES Data Management Team. PIC Figure 1

Uncertainties in modelling Mt. Pinatubo eruption with 2-D AER model and CCM SOCOL

NASA Astrophysics Data System (ADS)

Kenzelmann, P.; Weisenstein, D.; Peter, T.; Luo, B. P.; Rozanov, E.; Fueglistaler, S.; Thomason, L. W.

2009-04-01

Large volcanic eruptions may introduce a strong forcing on climate. They challenge the skills of climate models. In addition to the short time attenuation of solar light by ashes the formation of stratospheric sulphate aerosols, due to volcanic sulphur dioxide injection into the lower stratosphere, may lead to a significant enhancement of the global albedo. The sulphate aerosols have a residence time of about 2 years. As a consequence of the enhanced sulphate aerosol concentration both the stratospheric chemistry and dynamics are strongly affected. Due to absorption of longwave and near infrared radiation the temperature in the lower stratosphere increases. So far chemistry climate models overestimate this warming [Eyring et al. 2006]. We present an extensive validation of extinction measurements and model runs of the eruption of Mt. Pinatubo in 1991. Even if Mt. Pinatubo eruption has been the best quantified volcanic eruption of this magnitude, the measurements show considerable uncertainties. For instance the total amount of sulphur emitted to the stratosphere ranges from 5-12 Mt sulphur [e.g. Guo et al. 2004, McCormick, 1992]. The largest uncertainties are in the specification of the main aerosol cloud. SAGE II, for instance, could not measure the peak of the aerosol extinction for about 1.5 years, because optical termination was reached. The gap-filling of the SAGE II [Thomason and Peter, 2006] using lidar measurements underestimates the total extinctions in the tropics for the first half year after the eruption by 30% compared to AVHRR [Rusell et. al 1992]. The same applies to the optical dataset described by Stenchikov et al. [1998]. We compare these extinction data derived from measurements with extinctions derived from AER 2D aerosol model calculations [Weisenstein et al., 2007]. Full microphysical calculations with injections of 14, 17, 20 and 26 Mt SO2 in the lower stratosphere were performed. The optical aerosol properties derived from SAGE II measurements and from AER model calculation serve as input for the 3D chemistry climate model (CCM) SOCOL [Schraner et al., 2008]. The heating rates, calculated with SOCOL, are compared with a reference radiative transfer model LibRadtran [Mayer and Kylling, 2005]. This comparison suggests that SOCOL underestimates the net heating rate by 10-20%. In stark contrast, the temperature increase in the lower stratosphere due to absorption of longwave and near infrared radiation is overestimated by all SOCOL scenarios. This lets us conclude that SOCOL, and similarly other state-of-the-art CCMs, misrepresent processes required to model the effect of volcanic eruptions on the lower stratosphere and tropopause region. Possible reasons for model deficiencies could be too coarse vertical resolution or missing dynamical feedbacks near the tropopause and in the lower stratosphere. Another important feature is the warming of the tropical troposphere, which is present in the model simulation but was not observed with comparable amplitude in reality. The heating of the lower stratosphere in the models leads to an increase of stratospheric water vapour and influences the radiative and chemical properties of the stratosphere. Eyring, V. et al (2006), Assessment of temperature, trace species, and ozone in chemistry-climate model simulations of the recent past, Journal of Geophysical Research-Atmospheres, 111, D22,308. Guo, S., G. J. S. Bluth, W. I. Rose, I. M. Watson, and A. J. Prata (2004), Re-evaluation of SO2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared satellite sensors, Geochemistry Geophysics Geosystems, 5. Mayer, B., and A. Kylling (2005), Technical note: The libRadtran software package for radiative transfer calculations - description and examples of use, Atmos. Chem. Phys, 5, 1855-1877. McCormick, M. P. (1992), Initial assessment of the stratospheric and climatic impact of the 1991 Mount- Pinatubo eruption - prologue, Geophysical Research Letters, 19 (2), 149-149. Russell, P. B. et al. (1996), Global to microscale evolution of the Pinatubo volcanic aerosol derived from diverse measurements and analyses, Journal of Geophysical Research-Atmospheres, 101 (D13), 18,745- 18,763. Schraner, M. et al (2008), Technical note: Chemistry-climate model SOCOL: version 2.0 with improved transport and chemistry/microphysics schemes, Atmos. Chem. Phys., 8, 5957-5974. Stenchikov, G. L. et al (1998), Radiative forcing from the 1991 Mount Pinatubo volcanic eruption, Journal Of Geophysical Research-Atmospheres, 103 (D12), 13,837-13,857. Thomason, L., and T. Peter (2006), (eds.), SPARC Report No. 4, World Climate Research Programme WCRP- 124, WMO/TD No. 1295. Weisenstein, D. K. et al., Global 2-D intercomparison of sectional and modal aerosol modules, Atmos. Chem. Phys, 7 (9), 2339-2355.

Precipitation Indices Low Countries

NASA Astrophysics Data System (ADS)

van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

2009-09-01

Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period (+2): Wide scale river flooding, marshy acres and meadows.-Farmers cope with poor harvests of hay, grains, fruit etc. resulting in famines.-Late grape harvests, poor yield quantity and quality of wine. Wet period (+1): High water levels cq discharges of major rivers, tributaries and brooks, local river floodings, marshy acres and meadows in the low lying areas.-Wearisome and hampered agriculture. Normal (0) Dry period (-1): Low water levels cq discharges of major rivers, tributaries and brooks. Some brooks may dry up.-Summer half year: local short of yield of grass, hay and other forage.-Summer half year: moor-, peat- and forest fires. Very dry period (-2): Very low water levels cq discharges of major rivers and tributaries. Brooks and wells dry up. Serious shortage of drinking water; especially in summer.-Major agricultural damage, shortage of water, mortality stock of cattle. Shortage of grain. Flour can not be produced due to water mills running out of water, shortage of bread, bread riots, famines.-Large scale forest and peat areas, resulting in serious air pollution. Town fires. By verifying the historical evidence on these criterions, a series of 5 step indices ranging from very dry to very wet for summer and winter half year of the Low Countries was obtained. Subsequently these indices series were compared with the instrumentally observed seasonal precipitation sums for De Bilt (1735-2008), which is considered to be representative for the Central Netherlands. For winter (Oct-March) and summer half year (Apr.-Sept.) the accumulated precipitation amounts are calculated; these amounts are approximately normally distributed. Based on this distribution, the cumulative frequency distribution is calculated. By tabulating the number of summers in the pre-instrumental period 1201-1750 for each of the drought classes, a distribution is calculated which is then related to the modern accumulated precipitation distribution. Assuming that the accumulated precipitation amount has not been below (above) the mean precipitation minus (plus) three standard deviations for the corresponding season, an accumulated precipitation amount which relates to each of the five drought classes in the classification can be estimated. (1) Buisman, J. , Van Engelen, A.F.V. (editor), Duizend jaar weer wind en water in de Lage Landen, Van Wijnen, Franeker (Netherlands), Vol. I763-1300, 1995, Vol. II, 1300-1450, 1996, Vol. III, 1450-1575, 1998, Vol. IV, 1575-1675, 2000, Vol. V, 1675-1750, 2006. (2) Shabalova, M.V., Van Engelen, A.F.V., Evaluation of a reconstruction of winter and summer temperatures in the Low Countries, AD 764-1998, Climatic Change 58: 219-242, 2003

First retrievals of methane isotopologues from FTIR ground-based observations

NASA Astrophysics Data System (ADS)

Bader, Whitney; Strong, Kimberly; Walker, Kaley; Buzan, Eric

2017-04-01

Atmospheric methane concentrations have reached a new high at 1845 ± 2 ppb, accounting for an increase of 256 % since pre-industrial times (WMO, 2016). In the last ten years, methane has been on the rise again at rates of ˜0.3%/year (e.g., Bader et al., 2016), after a period of stabilization of about 5 years. This recent increase is not fully understood due to remaining uncertainties in the methane budget, influenced by numerous anthropogenic and natural emission sources. In order to examine the cause(s) of this increase, we focus on the two main methane isotopologues, i.e. CH3D and 13CH4. Both CH3D and 13CH4 are emitted in the atmosphere with different ratio depending on the emission processes involved. As heavier isotopologues will react more slowly than 12CH4, each isotopologue will be depleted from the atmosphere at a specific rate depending on the removal process. Methane isotopologues are therefore good tracers of the methane budget. In this contribution, the first development and optimization of the retrieval strategy of CH3D as well as the preliminary tests for 13CH4 will be presented and discussed , using FTIR (Fourier Transform infrared) solar spectra collected at the Eureka (80.05 ˚ N, -86.42 ˚ E, 610 m a.s.l.) and Toronto (43.66˚ N, -79.4˚ E, 174 m a.s.l.) ground-based sites. Mixing ratio vertical profiles from a Whole Atmosphere Community Climate Model (WACCM v.4, Marsh et al., 2013) simulation developed by Buzan et al. (2016) are used as a priori inputs. A discussion on the type of regularization constraints used for the retrievals will be presented as well as an evaluation of available spectroscopy (primarily the different editions of the HITRAN database, see Rothman et al., 2013 and references therein). The uncertainties affecting the retrieved columns as well as information content evaluation will be discussed in order to assess the best strategy to be employed based on its altitude sensitivity range and complete error budget. Acknowledgments Whitney Bader has received funding from the European Union's Horizon2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement n˚ 704951, and from the University of Toronto through a Faculty of Arts & Science Postdoctoral Fellowship Award. References Bader, W., Bovy, B., Conway, S., Strong, K., Smale, D., Turner, A. J., Blumenstock, T., Boone, C., Coulon, A., Garcia, O., Griffith, D. W. T., Hase, F., Hausmann, P., Jones, N., Krummel, P., Murata, I., Morino, I., Nakajima, H., O&apos;Doherty, S., Paton-Walsh, C., Robinson, J., Sandrin, R., Schneider, M., Servais, C., Sussmann, R. and Mahieu, E.: Ten years of atmospheric methane from ground-based NDACC FTIR observations, Atmos. Chem. Phys. Discuss., 1-31, doi:10.5194/acp-2016-699, 2016. Buzan, E. M., Beale, C. A., Boone, C. D. and Bernath, P. F.: Global stratospheric measurements of the isotopologues of methane from the Atmospheric Chemistry Experiment Fourier transform spectrometer, Atmos. Meas. Tech., 9(3), 1095-1111, doi:10.5194/amt-9-1095-2016, 2016. Marsh, D. R., Mills, M. J., Kinnison, D. E., Lamarque, J.-F., Calvo, N. and Polvani, L. M.: Climate Change from 1850 to 2005 Simulated in CESM1(WACCM), J. Clim., 26(19), 7372-7391, doi:10.1175/JCLI-D-12-00558.1, 2013. Rothman, L. S., Gordon, I. E., Babikov, Y., Barbe, A., Chris Benner, D., Bernath, P. F., Birk, M., Bizzocchi, L., Boudon, V., Brown, L. R., Campargue, A., Chance, K., Cohen, E. A., Coudert, L. H., Devi, V. M., Drouin, B. J., Fayt, A., Flaud, J.-M., Gamache, R. R., Harrison, J. J., Hartmann, J.-M., Hill, C., Hodges, J. T., Jacquemart, D., Jolly, A., Lamouroux, J., Le Roy, R. J., Li, G., Long, D. A., Lyulin, O. M., Mackie, C. J., Massie, S. T., Mikhailenko, S., Müller, H. S. P., Naumenko, O. V., Nikitin, A. V., Orphal, J., Perevalov, V., Perrin, A., Polovtseva, E. R., Richard, C., Smith, M. A. H., Starikova, E., Sung, K., Tashkun, S., Tennyson, J., Toon, G. C., Tyuterev, V. G. and Wagner, G.: The HITRAN2012 molecular spectroscopic database, J. Quant. Spectrosc. Radiat. Transf., 130, 4-50, doi:10.1016/j.jqsrt.2013.07.002, 2013. World Meteorological Organization, Greenhouse gas bulletin, N˚ 12, October 2016.

Observation and modelling of stable isotopes in precipitation for midlatitude weather systems in Melbourne, Australia

NASA Astrophysics Data System (ADS)

Barras, Vaughan; Simmonds, Ian

2010-05-01

The application of stable water isotopes as tracers of moisture throughout the hydrological cycle is often hindered by the relatively coarse temporal and spatial resolution of observational data. Intensive observation periods (IOPs) of isotopes in precipitation have been valuable in this regard enabling the quantification of the effects of vapour recycling, convection, cloud top height and droplet reevaporation (Dansgaard, 1953; Miyake et al., 1968; Gedzelman and Lawrence, 1982; 1990; Pionke and DeWalle, 1992; Risi et al., 2008; 2009) and have been used as a basis to develop isotope models of varying complexity (Lee and Fung, 2008; Bony et al., 2008). This study took a unified approach combining observation and modelling of stable isotopes in precipitation in an investigation of three key circulation types that typically bring rainfall to southeastern Australia. The observational component of this study involved the establishment of the Melbourne University Network of Isotopes in Precipitation (MUNIP). MUNIP was devised to sample rainwater simultaneously at a number of collection sites across greater Melbourne to record the spatial and temporal isotopic variability of precipitation during the passage of particular events. Samples were collected at half-hourly intervals for three specific rain events referred to as (1) mixed-frontal, (2) convective, and (3) stratiform. It was found that the isotopic content for each event varied over both high and low frequencies due to influences from local changes in rain intensity and large scale rainout respectively. Of particular note was a positive relationship between deuterium excess and rainfall amount under convective conditions. This association was less well defined for stratiform rainfall. As a supplement to the data coverage of the observations, the events were simulated using a version of NCAR CAM3 running with an isotope hydrology scheme. This was done by periodically nudging the model dynamics with data from the NCEP Reanalysis (Noone, 2006). Results from the simulations showed that the model represented well the large scale evolution of vapour profiles of deuterium excess and 18O for the mixed-frontal and stratiform events. Reconstruction of air mass trajectories provided further detail of the evolution and structure of the vapour profiles revealing a convergence of air masses from different source regions for the mixed-frontal event. By combining observations and modelling in this way, much detail of the structure and isotope moisture history of the observed events was provided that would be unavailable from the sampling of precipitation alone. References Bony, S., C. Risi, and F. Vimeux (2008), Influence of convective processes on the isotopic composition (?18O and ?D) of precipitation and water vapor in the tropics: 1. Radiative-convective equilibrium and Tropical Ocean-Global Atmosphere-Coupled Ocean-Atmosphere Response (TOGA-COARE) simulations, J. Geophys. Res., 113, D19305, doi:10.1029/2008JD009942. Dansgaard, W. (1953), The abundance of 18O in atmospheric water and water vapor. Tellus, 5, 461-469. Gedzelman, S. D., and J. R. Lawrence (1982), The isotopic composition of cyclonic precipitation. J. App. Met., 21, 1385-1404. Gedzelman, S. D., and J. R. Lawrence (1990), The isotopic composition of precipitation from two extratropical cyclones, Mon. Weather Rev., 118 , 495-509. Lee, J., and I. Fung (2008), 'Amount effect' of water isotopes and quantitative analysis of post-condensation processes, Hydrol. Process., 22, 1-8. Miyake, Y., O. Matsubaya, and C. Nishihara (1968), An isotopic study on meteoric precipitation, Pap. Meteorol. Geophys., 19, 243-266. Noone, D. (2006), Isotopic composition of water vapor modeled by constraining global climate simulations with reanalyses, in Research activities in atmospheric and oceanic modeling, J. Côté (ed.), Report No. 36, WMO/TD-No. 1347, p. 2.37-2.38. Pionke, H. B., and D. R. DeWalle (1992), Intra- and inter-storm 18O trends for selected rainstorms in Pennsylvania. J. Hydrol., 138, 131-143. Risi, C., S. Bony, and F. Vimeux (2008), Influence of convective processes on the isotopic composition (?18O and ?D) of precipitation and water vapor in the tropics: 2. Physical interpretation of the amount effect. J. Geophys. Res., 113, D19306, doi:10.1029/2008JD009943. Risi, C., S. Bony, F. Vimeux, M. Chong, and L. Descroix (2009), Evolution of the water stable isotopic composition of the rain sampled along Sahelian squall lines, Q. J. Roy. Meteor. Soc., doi:10.1002/qj.485, (in press).

Further development of the EUMETNET Composite Observing System (EUCOS)

NASA Astrophysics Data System (ADS)

Klink, S.; Dibbern, J.

2009-09-01

EUCOS, which stands for EUMETNET Composite Observing System, is a EUMETNET programme whose main objective is a central management of surface based operational observations on a European-wide scale serving the needs of regional scale NWP. EUMETNET is a consortium of currently 26 national meteorological services in Europe that provides a framework for different operational and developmental co-operative programmes between the services. The work content of the EUCOS Programme includes the management of the operational observing networks, through the E-AMDAR, E-ASAP, E-SURFMAR and E-WINPROF programmes. The coordination of NMSs owned territorial networks (e.g. radiosonde stations and synoptic stations), data quality monitoring, fault reporting and recovery, a studies programme for the evolution of the observing networks and liaison with other organisations like WMO are among the tasks of the programme. The current period of the EUCOS programme has a five year duration (2007-2011) and a two stage approach was proposed in the programme definition. During the transition phase 2007-2008 no new programmatic objectives had been set because amongst others the Space-Terrestrial (S-T) study which investigated the relative contributions of selected space based and ground based observing systems to the forecast skill of global and regional NWP models had to be finalised first. Based on the findings of this study EUCOS currently prepares a redesign of its upper-air network. The original EUCOS upper-air network design was prepared in 2000 in order to define a set of stations serving the common general NWP requirement. Additional considerations were to make it possible to supply a common set of performance standards across the territory of EUMETNET Members and to ensure that the radiosonde network interleaved with AMDAR airports. The EUCOS upper-air network now requires a redesign because of several reasons. There is a need to take into account the significant evolution of the AMDAR network. Member states were not able to install the proposed EUCOS radiosonde network design with 4 ascents per day at most of the sites. The results from the S-T study are available with recommendations for the network design. Data assimilation of NWP models has improved significantly with advanced capability to make use of high time resolution data. The guidelines for the redesign of the EUCOS upper-air network will be derived from a study which is currently organised by EUCOS and conducted by ECMWF and several national Met. services. They contribute by running OSEs for different observation network setups with their model suites. The S-T study has shown that despite of all the additional new satellite observations, the degrading of the current terrestrial observing system to a basic (GUAN+GSN) network would have a significant negative impact on the forecast skill. The expected result from the envisaged OSEs is to find an optimum setting of upper-air measurements in space and time which maintains forecast skill. Throughout the second phase of the programme (2009-2011) the revised EUCOS design will be implemented. In the field of observation targeting EUCOS supported the PREVIEW Data Targeting (DTS) project. The main goal of this project was to develop and to assess the feasibility of an operational adaptive control of the operational observing system. The DTS project was lead by Met Office and co-funded by EUCOS and the European Commission (within the PREVIEW project). The main software, an interactive web-based tool, was developed by ECMWF and ran on their computer system during the trial phase which lasted from February until December 2008. During the trial the focus was on improving short range (1-3 days) forecasts of potentially high-impact and/or high-uncertainty weather events in Europe. Forecasters from all EUMETNET members had had the chance to submit sensitive area prediction requests on a daily basis. Afterwards the DTS displayed the sensitive areas calculated by ECMWF, Météo-France and Met Office and the lead user (an experienced forecaster) could then use the system to issue requests for additional, unscheduled observations. The trial has shown that a data targeting system can be routinely used. Targeted observations were successfully deployed from E-ASAP units, by the E-AMDAR programme and in 21 countries. 88% of the additionally requested radiosondes from land stations have been launched. Furthermore, the DTS was used to support research field campaigns like THORPEX-IPY, THORPEX-PARC and MEDEX. During the envisaged MEDEX Phase 2 campaign in autumn 2009, the DTS will be used as an operational tool to aid research. Further tasks for EUCOS will be the proposal and implementation of a new E-programme responsible for running a central data hub and centralised monitoring, setting of new objectives for the programme components E-ASAP, E-AMDAR, E-SURFMAR and E-WINPROF, and an extension of quality monitoring activities. An example for new programme objectives is the introduction of a humidity sensor on commercial aircraft within the E-AMDAR programme.

Splash erosion in recently-burnt area in North-West Spain

NASA Astrophysics Data System (ADS)

Fernández Raga, María

2013-04-01

Splash erosion is generally acknowledged as the main erosive agent, because it represents the first step in water erosion (Ellison, 1944, Sempere Torres et al., 1994). The impact of raindrops not only modifies the structure of the earth's surface, (Moss, 1991) but also breaks down and emits soil fragments which are later transported over long distances in the case of additional surface runoff processes (Moss and Green, 1983). In the whole process we need to take into account not only the specific kinetic energy associated to each rain event, but also the type of soil and the size of the particles released (Sharma et al 1991), as well as the characteristics of the layer of water formed on the surface (Moss and Green, 1983, Kinnell, 1991, Leguédois et al., 2005). The erosion process is more obvious when it affects vulnerable areas that have recently been devastated by a wildfire. This study has computed the raindrop size, its volume, the fall velocity, and its kinetic energy by means of an optical disdrometer. The data have subsequently been compared with the mass of soil that was splashed and collected in a particular area devastated by an important wildfire on the 17th of May 2012. The splash erosion produced in 6 months has been analyzed. 2. Study Site The data were gathered in the period between the 29th May and the 30th November 2012, in the area of Congosto, in the province of León, Spain. The study zone is part of a transition area between the plain and the mountainous regions. The dominant climate is the continentalized Mediterranean climate, although with more moderate temperatures. In general, in this area we find a wide temperature range (from 12 to 20°C), long and cold winters, short springs and autumns, and short and warm summers. Precipitation is irregularly scattered along the year, and may reach, depending on the area, up to 1,500 mm per year. Intense precipitation events may occur. The area presents a coarse-grained siliceous lithology, that is, quartzite with sandstone and slate, with a soil cover of inceptisol of franc-sandy texture. The vegetation, which is the first defense line against erosion in the area, is limited to holm oaks and pine trees, all of which were virtually eliminated by the virulence of the wildfire in May 2012. 3. Materials and Methods Precipitation was measured using a Thies optical disdrometer which registers raindrop size spectra every minute. This device is described in detail in Bloemink and Lanzinger (2005). The instruments used to carry out this study on splash erosion have been the funnels described in Fernández-Raga 2010. The area affected by the wildfire was divided into 2 sections, one former pine tree area, and another former scrubland area. Five sampling points were installed in each area. Similar control areas were established in the part of land not affected by the fire, with the same type of vegetation, and with another 5 sampling points in each case. In addition, control devices were installed to collect airborne soil. 4. The kinetic energy of rain The kinetic energy of rain was assessed using data obtained by the disdrometer: raindrop size distribution (DSD). This information enables us to compute the mass of the raindrop and its fall velocity (Ryzhkov et al 1999). To compute the mass, we need to know the shape of the drop. The shape of raindrops has been the object of many previous studies (Brandes, 2002, Sansom, 2004). The main conclusion is that drops smaller than 1 mm are spherical, but raindrops with diameters larger than 1 mm take on a shape that resembles more an ellipsoid. Considering that size, we adopt a polynomial equation of degree 12 (Fernández-Raga 2010). 5. Evolution of splash erosion The study has assessed the amount of splash erosion as well as its composition. In addition, the erosion caused has been compared with the regeneration of the vegetation in the area. The results reveal a very slow recovery of the vegetation in the study zone, and a halt in the amount of soil affected by splash erosion until now. 5. Results and Conclusions It was found that the precipitation in Congosto has a nearly exponential drop size distribution (DSD), except for large sizes. It can also be noted that drops between the sizes of 2 and 2.5 mm are the ones that contribute more to the kinetic energy hitting the ground. The comparison between the splash erosion registered and the total kinetic energy in each rain event has led to the following conclusions: • The DSD of precipitation in Congosto follows an exponential or gamma distribution. The energy distribution, on the other hand, is a gamma distribution. • Splash erosion has been found to be very important in the area devastated by the wildfire in the 2 months immediately after the fire. Later, splash erosion decreases, though it remains relatively high despite fewer rain events during the summer. • The vegetation has not recovered at all in the 6 months that followed the wildfire. • The soil analysis reveals a high degree of degradation caused by the wildfire. 6. References Angulo-Martínez, M., Beguería, S., Navas, A. Machín, J. 2012. Splash erosion under natural rainfall on three soil types in NE Spain Geomorphology, 175-176, 38-44. Bloemink, HI and Lanzinger, E., 2005.precipitation type from the thies disdrometer. Wmo technical conference on meteorological and environmental instruments and methods of observations (teco-2005) Bucharest, Romania, 4-7 may, 3. Brandes, e. A., g. Zhang, and j. 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