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Sample records for abarema cochliacarpos gomes

  1. Abarema cochliacarpos Extract Decreases the Inflammatory Process and Skeletal Muscle Injury Induced by Bothrops leucurus Venom

    PubMed Central

    Saturnino-Oliveira, Jeison; Santos, Daiana Do Carmo; Guimarães, Adriana Gibara; Santos Dias, Antônio; Tomaz, Marcelo Amorim; Monteiro-Machado, Marcos; Estevam, Charles Santos; Lucca Júnior, Waldecy De; Maria, Durvanei Augusto; Melo, Paulo A.; Araújo, Adriano Antunes de Souza; Santos, Márcio Roberto Viana; Almeida, Jackson Roberto Guedes da Silva; Oliveira, Rita de Cássia Meneses; Pereira de Oliveira, Aldeidia; Quintans Júnior, Lucindo José

    2014-01-01

    Snakebites are a public health problem, especially in tropical countries. However, treatment with antivenom has limited effectiveness against venoms' local effects. Here, we investigated the ability of Abarema cochliacarpos hydroethanolic extract (EAc) to protect mice against injection of Bothrops leucurus venom. Swiss mice received perimuscular venom injection and were subsequently treated orally with EAc in different doses. Treatment with EAc 100, 200, and 400 mg/kg reduced the edema induced by B. leucurus in 1%, 13%, and 39%, respectively. Although lower doses showed no antihypernociceptive effect in the Von Frey test, the higher dose significantly reduced hyperalgesia induced by the venom. Antimyotoxic activity of EAc was also observed by microscopy assessment, with treated muscles presenting preserved structures, decreased edema, and inflammatory infiltrate as compared to untreated ones. Finally, on the rotarod test, the treated mice showed better motor function, once muscle fibers were preserved and there were less edema and pain. Treated mice could stand four times more time on the rotating rod than untreated ones. Our results have shown that EAc presented relevant activities against injection of B. leucurus venom in mice, suggesting that it can be considered as an adjuvant in the treatment of envenomation. PMID:25136627

  2. The ESA GOME-Evolution "Climate" water vapor product: a homogenized time series of H2O columns from GOME, SCIAMACHY, and GOME-2

    NASA Astrophysics Data System (ADS)

    Beirle, Steffen; Lampel, Johannes; Wang, Yang; Mies, Kornelia; Dörner, Steffen; Grossi, Margherita; Loyola, Diego; Dehn, Angelika; Danielczok, Anja; Schröder, Marc; Wagner, Thomas

    2018-03-01

    We present time series of the global distribution of water vapor columns over more than 2 decades based on measurements from the satellite instruments GOME, SCIAMACHY, and GOME-2 in the red spectral range. A particular focus is the consistency amongst the different sensors to avoid jumps from one instrument to another. This is reached by applying robust and simple retrieval settings consistently. Potentially systematic effects due to differences in ground pixel size are avoided by merging SCIAMACHY and GOME-2 observations to GOME spatial resolution, which also allows for a consistent treatment of cloud effects. In addition, the GOME-2 swath is reduced to that of GOME and SCIAMACHY to have consistent viewing geometries.Remaining systematic differences between the different sensors are investigated during overlap periods and are corrected for in the homogenized time series. The resulting Climate product v2.2 (GOME-EVL_water_vapor_clim_v2.2" target="_blank">https://doi.org/10.1594/WDCC/GOME-EVL_water_vapor_clim_v2.2) allows the study of the temporal evolution of water vapor over the last 20 years on a global scale.

  3. US Participation in the GOME and SCIAMACHY Projects

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Geary, J. C.; Spurr, R. J. D.

    1998-01-01

    This report summarizes research done under NASA Grant NAGW-2541 through September 30, 1997. The research performed under this grant includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, sensitivity and instrument studies to define GOME and SCIAMACHY instruments, consultation on optical and detector issues for both GOME and SCIAMACHY, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and development of infrared line-by-line atmospheric modeling and retrieval capability for SCIAMACHY. The European Space Agency selected the SAO to participate in GOME validation and science studies, part of the overall ERS AO. This provided access to all GOME data; The SAO activities that are carried out as a result of selection by ESA were funded by the present grant. The Global Ozone Monitoring Experiment was successfully launched on the ERS- 2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY is currently scheduled for launch in early 2000. The first two European ozone monitoring instruments (OMI), to fly on the q series of operational meteorological satellites being planned by Eumetsat, have been selected to be GOME-type instruments (the first, in fact, will be the refurbished GOME flight spare). K. Chance is the U.S. member of the OMI Users Advisory Group.

  4. Tropospheric Chemistry Studies using Observations from GOME and TOMS

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Spurr, Robert J. D.; Kurosu, Thomas P.; Jacob, Daniel J.; Gleason, James F.

    2003-01-01

    Studies to quantitatively determine trace gas and aerosol amounts from the Global Ozone Monitoring Experiment (GOME) and the Total Ozone Monitoring Experiment (TOMS) and to perform chemical modeling studies which utilize these results are given. This includes: 1. Analysis of measurements from the GOME and TOMS instruments for troposphere distributions of O3 and HCHO; troposphere enhancements of SO2, NO2 and aerosols associated with major sources; and springtime events of elevated BrO in the lower Arctic troposphere. 2. Application of a global 3-dimensional model of troposphere chemistry to interpret the GOME observations in terms of the factors controlling the abundances of troposphere ozone and OH.

  5. SAO Participation in the GOME and SCIAMACHY Satellite Instrument Programs

    NASA Technical Reports Server (NTRS)

    Hilsenrath, Ernest (Technical Monitor); Chance, Kelly; Kurosu, Thomas

    2004-01-01

    This report summarizes the progress on our three-year program of research to refine the measurement capability for satellite-based instruments that monitor ozone and other trace species in the Earth's stratosphere and troposphere, to retrieve global distributions of these and other constituents h m the GOME and SCIAMACHY satellite instruments, and to conduct scientific studies for the ILAS instruments. This continues our involvements as a U.S. participant in GOME and SCIAMACHY since their inception, and as a member of the ILAS-II Science Team. These programs have led to the launch of the first satellite instrument specifically designed to measure height-resolved ozone, including the tropospheric component (GOME), and the development of the first satellite instrument that will measure tropospheric ozone simultaneously with NO2, CO, HCHO, N2O, H2O, and CH4 (SCIAMACHY). The GOME program now includes the GOME-2 instruments, to be launched on the Eumetsat Metop satellites, providing long-term continuity in European measurements of global ozone that complement the measurements of the TOMS, SBUV, OMI, OMPS instruments. The research primarily focuses on two areas: Data analysis, including algorithm development and validation studies that will improve the quality of retrieved data products, in support for future field campaigns (to complement in situ and airborne campaigns with satellite measurements), and scientific analyses to be interfaced to atmospheric modeling studies.

  6. SAO Participation in the GOME and SCIAMACHY Satellite Instrument Programs

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Kurosu, Thomas

    2003-01-01

    This report summarizes the progress on our three-year program of research to refine the measurement capability for satellite-based instruments that monitor ozone and other trace species in the Earth's stratosphere and troposphere, to retrieve global distributions of these and other constituents from the GOME and SCIAMACHY satellite instruments, and to conduct scientific studies for the ILAS instruments. This continues our involvements as a U.S. participant in GOME and SCIAMACHY since their inception, and as a member of the ILAS-II Science Team. These programs have led to the launch of the first satellite instrument specifically designed to measure height-resolved ozone, including the tropospheric component (GOME), and the development of the first satellite instrument that will measure tropospheric ozone simultaneously with NO2, CO, HCHO, N2O, H2O, and CH4 (SCIAMACHY). The GOME program now includes the GOME-2 instruments, to be launched on the Eumetsat Metop satellites, providing long-term continuity in European measurements of global ozone that complement the measurements of the TOMS, SBW, OMI, OMPS instruments. The research primarily focuses on two areas: Data analysis, including algorithm development and validation studies that will improve the quality of retrieved data products, in support for future field campaigns (to complement in situ and airborne campaigns with satellite measurements), and scientific analyses to be interfaced to atmospheric modeling studies.

  7. U.S. Participation in the GOME and SCIAMACHY Projects

    NASA Technical Reports Server (NTRS)

    Chance, K. V.

    1996-01-01

    This report summarizes research done under NASA Grant NAGW-2541 from April 1, 1996 through March 31, 1997. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and development of infrared line-by-line atmospheric modeling and retrieval capability for SCIAMACHY. SAO also continues to participate in GOME validation studies, to the limit that can be accomplished at the present level of funding. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY is currently in instrument characterization. The first two European ozone monitoring instruments (OMI), to fly on the Metop series of operational meteorological satellites being planned by Eumetsat, have been selected to be GOME-type instruments (the first, in fact, will be the refurbished GOME flight spare). K. Chance is the U.S. member of the OMI Users Advisory Group.

  8. GOME/ERS-2: New Homogeneous Level 1B Data from an Old Instrument

    NASA Astrophysics Data System (ADS)

    Slijkhuis, S.; Aberle, B.; Coldewey-Egbers, M.; Loyola, D.; Dehn, A.; Fehr, T.

    2015-11-01

    In the framework of ESA's "GOME Evolution Project", a reprocessing will be made of the entire 16 year GOME Level 1 dataset. The GOME Evolution Project further includes the generation of a new GOME water vapour product, and a public outreach programme.In this paper we will describe the reprocessing of the Level 1 data, carried out with the latest version of the GOME Data Processor at DLR. The change most visible to the user will be the new product format in NetCDF, plus supporting documentation (ATBD and PUM). Full-mission reprocessed L1b data are expected to be released in the 4th quarter of 2015.

  9. US Participation in the GOME and SCIAMACHY Projects

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Geary, J. C.

    1996-01-01

    The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, further sensitivity and instrument studies to help finalize the definition of the SCIAMACHY instrument, and consultation on optical and detector issues for both GOME and SCIAMACHY. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, during this reporting period, and is working in the expected fashion. The European Space Agency has made their selections from responses to the Announcement of Opportunity for GOME validation and science studies, part of the overall ERS AO. The Smithsonian Astrophysical Observatory (SAO) proposal has been selected. These proposals are primarily for access to the data; ESA does not provide research funding for the selected investigations. The SAO activities that are carried out as a result of selection by ESA are funded by the present grant, to the limit that can be accomplished at the present level of funding. SCIAMACHY is currently in Phase C/D. Instrument design is almost finalized and selection of infrared detectors from the initial production run has been made.

  10. Quantitative spectroscopy for the analysis of GOME data

    NASA Technical Reports Server (NTRS)

    Chance, K.

    1997-01-01

    Accurate analysis of the global ozone monitoring experiment (GOME) data to obtain atmospheric constituents requires reliable, traceable spectroscopic parameters for atmospheric absorption and scattering. Results are summarized for research that includes: the re-determination of Rayleigh scattering cross sections and phase functions for the 200 nm to 1000 nm range; the analysis of solar spectra to obtain a high-resolution reference spectrum with excellent absolute vacuum wavelength calibration; Ring effect cross sections and phase functions determined directly from accurate molecular parameters of N2 and O2; O2 A band line intensities and pressure broadening coefficients; and the analysis of absolute accuracies for ultraviolet and visible absorption cross sections of O3 and other trace species measurable by GOME.

  11. Operational trace gas column observations from GOME-2 on MetOp

    NASA Astrophysics Data System (ADS)

    Valks, Pieter; Hao, Nan; Pinardi, Gaia; Hedelt, Pascal; Liu, Song; Van Roozendael, Michel; De Smedt, Isabelle; Theys, Nicolas; Koukouli, MariLiza; Balis, Dimitris

    2017-04-01

    This contribution focuses on the operational GOME-2 trace gas column products developed in the framework of EUMETSAT's Satellite Application Facility on Atmospheric Composition Monitoring (AC-SAF). We present an overview of the retrieval algorithms for ozone, OClO, NO2, SO2 and formaldehyde, and we show examples of various applications such as air quality and climate monitoring, using observations from the GOME-2 instruments on MetOp-A and MetOp-B. Total ozone and the minor trace gas columns from GOME-2 are retrieved with the latest version 4.8 of the GOME Data Processor (GDP), which uses an optimized Differential Optical Absorption Spectroscopy (DOAS) algorithm, with air mass factor conversions based on the LIDORT model. Improved total and tropospheric NO2 columns are retrieved in the visible wavelength region between 425 and 497 nm. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 using the UV wavelength region around 320 nm. For formaldehyde, an optimal DOAS fitting window around 335 nm has been determined for GOME-2. The GOME-2 trace gas columns have reached the operational EUMETSAT product status, and are available to the users in near real time (within two hours after sensing by GOME-2). The use of trace gas observations from the GOME-2 instruments on MetOp-A and MetOp-B for air quality purposed will be illustrated, e.g. for South-East Asia and Europe. Furthermore, comparisons of the GOME-2 satellite observations with ground-based measurements will be shown. Finally, the use of GOME-2 trace-gas column data in the Copernicus Atmosphere Monitoring Service (CAMS) will be presented.

  12. Retrieval and Analysis of Stratospheric NO2 from GOME

    NASA Technical Reports Server (NTRS)

    Wenig, M.; Kuehl, S.; Beirle, S.; Wagner, T.; Jaehne, B.; Platt, U.

    2003-01-01

    In this paper we describe the retrieval of stratospheric NO2 from the GOME (Global Ozone Monitoring Experiment) spectrometer. For this retrieval the Differential Optical Absorption Spectroscopy (DOAS) is used and we describe the influence of the instrument s characteristics on this measurement technique. This analysis led to an improved version of the DOAS algorithm resulting in results with lower systematic errors. Subsequently these results were used to separate the tropospheric and stratospheric fraction of the measured NO;! in the atmosphere. This paper is focusing on the annual variations of the stratospheric distribution of nitrogen oxides. For this examination the satellite data from beginning of 1996 to the end of 2001 was used and has been visualized in a plot zonal means versus time of the year, a visualization which proved to be very useful for Ozone. Additionally the so called "Noxon Cliff", a drop of NO2 column densities Noxon measured in 1975-77 while traveling northwards towards the pole in Canada, is shown. Also its southern equivalent could be discovered in the GOME data.

  13. Comparison of GOME-2/Metop total column water vapour with ground-based and in situ measurements

    NASA Astrophysics Data System (ADS)

    Kalakoski, N.; Kujanpää, J.; Sofieva, V.; Tamminen, J.; Grossi, M.; Valks, P.

    2014-12-01

    Total column water vapour product from the Global Ozone Monitoring Experiment-2 on board Metop-A and Metop-B satellites (GOME-2/Metop-A and GOME-2/Metop-B) produced by the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) is compared with co-located radiosonde and Global Positioning System (GPS) observations. The comparisons are performed using recently reprocessed data by the GOME Data Processor (GDP) version 4.7. The comparisons are performed for the period of January 2007-July 2013 (GOME-2A) and from December 2012 to July 2013 (GOME-2B). Radiosonde data are from the Integrated Global Radiosonde Archive (IGRA) maintained by National Climatic Data Center (NCDC) and screened for soundings with incomplete tropospheric column. Ground-based GPS observations from COSMIC/SuomiNet network are used as the second independent data source. Good general agreement between GOME-2 and the ground-based observations is found. The median relative difference of GOME-2 to radiosonde observations is -2.7% for GOME-2A and -0.3% for GOME-2B. Against GPS observations, the median relative differences are 4.9 and 3.2% for GOME-2A and B, respectively. For water vapour total columns below 10 kg m-2, large wet biases are observed, especially against GPS observations. Conversely, at values above 50 kg m-2, GOME-2 generally underestimates both ground-based observations.

  14. Validation of GOME-2/Metop total column water vapour with ground-based and in situ measurements

    NASA Astrophysics Data System (ADS)

    Kalakoski, Niilo; Kujanpää, Jukka; Sofieva, Viktoria; Tamminen, Johanna; Grossi, Margherita; Valks, Pieter

    2016-04-01

    The total column water vapour product from the Global Ozone Monitoring Experiment-2 on board Metop-A and Metop-B satellites (GOME-2/Metop-A and GOME-2/Metop-B) produced by the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) is compared with co-located radiosonde observations and global positioning system (GPS) retrievals. The validation is performed using recently reprocessed data by the GOME Data Processor (GDP) version 4.7. The time periods for the validation are January 2007-July 2013 (GOME-2A) and December 2012-July 2013 (GOME-2B). The radiosonde data are from the Integrated Global Radiosonde Archive (IGRA) maintained by the National Climatic Data Center (NCDC). The ground-based GPS observations from the COSMIC/SuomiNet network are used as the second independent data source. We find a good general agreement between the GOME-2 and the radiosonde/GPS data. The median relative difference of GOME-2 to the radiosonde observations is -2.7 % for GOME-2A and -0.3 % for GOME-2B. Against the GPS, the median relative differences are 4.9 % and 3.2 % for GOME-2A and B, respectively. For water vapour total columns below 10 kg m-2, large wet biases are observed, especially against the GPS retrievals. Conversely, at values above 50 kg m-2, GOME-2 generally underestimates both ground-based observations.

  15. Temperature dependent O3 absorption cross sections for GOME, SCIAMACHY and GOME-2: II. New laboratory measurements

    NASA Astrophysics Data System (ADS)

    Serdyuchenko, Anna; Gorshelev, Victor; Chehade, Wissam; Weber, Mark; Burrows, John P.

    We report on the work devoted to the up-to-date measurements of the ozone absorption cross-sections. The main goal of the project is to produce a consolidated and consistent set of high resolution cross-sections for satellite spectrometers series that allows a derivation of the harmonized long term data set. The generation of long-term datasets of atmospheric trace gases is a major need and prerequisite for climate and air quality related studies. At present there are three atmospheric chemistry instruments (GOME1, SCIAMACHY and GOME2) in operation and two more spectrometers (GOME2) to be launched five years apart in the next decade resulting in a time series covering two or more decades of ozone observations. Information from different sensors has to be com-bined for a consistent long-term data record, since the lifetime of individual satellite missions is limited. The harmonization of cross-sections is carried out by combination of new experimental work with re-evaluation of the existing cross-sections data. New laboratory measurements of ozone cross-section are underway that will improve a) absolute scaling of cross-sections, b) temper-ature dependence of cross-sections (using very low temperatures starting at 190 K and higher sampling of temperatures up to room temperature) and c) improved wavelength calibration. We take advantage of a Fourier transform spectrometer (visible, near IR) and Echelle spectropho-tometer (UV, visible) to extend the dynamic range of the system (covering several orders of magnitude in cross-sections from UV up to the near IR). We plan to cover the spectral range 220 -1000 nm at a spectral resolution of 0.02 nm in UV/VIS with absolute intensity accuracy of at least 2%, and wavelength accuracy better than 0.001 nm in the temperature range 193-293 K in 10 K steps. A lot of attention is paid to the accuracy of determining the temperature of the ozone flow and new methods for absolute calibration of relative spectra. This work is in

  16. Comparison of GOME-2/MetOp total ozone data with Brewer spectroradiometer data over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Antón, M.; Loyola, D.; López, M.; Vilaplana, J. M.; Bañón, M.; Zimmer, W.; Serrano, A.

    2009-04-01

    The main objective of this article is to compare the total ozone data from the new Global Ozone Monitoring Experiment instrument (GOME-2/MetOp) with reliable ground-based measurement recorded by five Brewer spectroradiometers in the Iberian Peninsula. In addition, a similar comparison for the predecessor instrument GOME/ERS-2 is described. The period of study is a whole year from May 2007 to April 2008. The results show that GOME-2/MetOp ozone data already has a very good quality, total ozone columns are on average 3.05% lower than Brewer measurements. This underestimation is higher than that obtained for GOME/ERS-2 (1.46%). However, the relative differences between GOME-2/MetOp and Brewer measurements show significantly lower variability than the differences between GOME/ERS-2 and Brewer data. Dependencies of these relative differences with respect to the satellite solar zenith angle (SZA), the satellite scan angle, the satellite cloud cover fraction (CF), and the ground-based total ozone measurements are analyzed. For both GOME instruments, differences show no significant dependence on SZA. However, GOME-2/MetOp data show a significant dependence on the satellite scan angle (+1.5%). In addition, GOME/ERS-2 differences present a clear dependence with respect to the CF and ground-based total ozone; such differences are minimized for GOME-2/MetOp. The comparison between the daily total ozone values provided by both GOME instruments shows that GOME-2/MetOp ozone data are on average 1.46% lower than GOME/ERS-2 data without any seasonal dependence. Finally, deviations of a priori climatological ozone profile used by the satellite retrieval algorithm from the true ozone profile are analyzed. Although excellent agreement between a priori climatological and measured partial ozone values is found for the middle and high stratosphere, relative differences greater than 15% are common for the troposphere and lower stratosphere.

  17. Sulfur dioxide retrievals from OMI and GOME-2 in preparation of TROPOMI

    NASA Astrophysics Data System (ADS)

    Theys, Nicolas; De Smedt, Isabelle; Danckaert, Thomas; Yu, Huan; van Gent, Jeroen; Van Roozendael, Michel

    2016-04-01

    The TROPOspheric Monitoring Instrument (TROPOMI) will be launched in 2016 onboard the ESA Sentinel-5 Precursor (S5P) platform and will provide global observations of atmospheric trace gases, with unprecedented spatial resolution. Sulfur dioxide (SO2) measurements from S5P will significantly improve the current capabilities for anthropogenic and volcanic emissions monitoring, and will extend the long-term datasets from past and existing UV sensors (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS). This work presents the SO2 retrieval schemes performed at BIRA-IASB as part of level-2 algorithm prototyping activities for S5P and tested on OMI and GOME-2. With a focus on anthropogenic sources, we show comparisons between OMI and GOME-2 as well as ground-based measurements, and discuss the possible reasons for the differences.

  18. Godiva, a European Project for Ozone and Trace Gas Measurements from GOME

    NASA Astrophysics Data System (ADS)

    Goede, A. P. H.; Tanzi, C. P.; Aben, I.; Burrows, J. P.; Weber, M.; Perner, D.; Monks, P. S.; Llewellyn-Jones, D.; Corlett, G. K.; Arlander, D. W.; Platt, U.; Wagner, T.; Pfeilsticker, K.; Taalas, P.; Kelder, H.; Piters, A.

    GODIVA (GOME Data Interpretation, Validation and Application) is a European Commission project aimed at the improvement of GOME (Global Ozone Monitoring Experiment) data products. Existing data products include global ozone, NO2 columns and (ir)radiances. Advanced data products include O3 profiles, BrO, HCHO and OCIO columns. These data are validated by ground-based and balloon borne instruments. Calibration issues are investigated by in-flight monitoring using several complementary calibration sources, as well as an on-ground replica of the GOME instrument. The results will lead to specification of operational processing of the EUMETSAT ozone Satellite Application Facility as well as implementation of the improved and new GOME data products in the NILU database for use in the European THESEO (Third European Stratospheric Experiment on Ozone) campaign of 1999

  19. GOME and Sciamachy data access using the Netherlands Sciamachy Data Center

    NASA Astrophysics Data System (ADS)

    Som de Cerff, Wim; de Vreede, Ernst; van de Vegte, John; van Hees, Ricard; van der Neut, Ian; Stammes, Piet; Pieters, Ankie; van der A, Ronald

    2010-05-01

    The Netherlands Sciamachy Data Center (NL-SCIA-DC) provides access to satellite data from the GOME and Sciamachy instruments for over 10 years now. GOME and Sciamachy both measure trace gases like Ozone, Methane, NO2 and aerosols, which are important for climate and air quality monitoring. Recently (February 2010) a new release of the NL-SCIA-DC provides an improved processing and archiving structure and an improved user interface. This Java Webstart application allows the user to browse, query and download GOME and Sciamachy data products, including KNMI and SRON GOME and Sciamachy products (cloud products, CH4, NO2, CO). Data can be searched on file and pixel level, and can be graphically displayed. The huge database containing all pixel information of GOME and Sciamachy is unique and allows specific selection, e.g., selecting cloud free pixels. Ordered data is delivered by FTP or email. The data available spans the mission times of GOME and Sciamachy, and is constantly updated as new data becomes available. The data services future upgrades include offering additional functionality to end-users of Sciamachy data. One of the functionalities provided will be the possibility to select and process Sciamachy products using different data processors, using Grid technology. This technology was successfully researched and will be made operationally available in the near future.

  20. GOME Total Ozone and Calibration Error Derived Usign Version 8 TOMS Algorithm

    NASA Technical Reports Server (NTRS)

    Gleason, J.; Wellemeyer, C.; Qin, W.; Ahn, C.; Gopalan, A.; Bhartia, P.

    2003-01-01

    The Global Ozone Monitoring Experiment (GOME) is a hyper-spectral satellite instrument measuring the ultraviolet backscatter at relatively high spectral resolution. GOME radiances have been slit averaged to emulate measurements of the Total Ozone Mapping Spectrometer (TOMS) made at discrete wavelengths and processed using the new TOMS Version 8 Ozone Algorithm. Compared to Differential Optical Absorption Spectroscopy (DOAS) techniques based on local structure in the Huggins Bands, the TOMS uses differential absorption between a pair of wavelengths including the local stiucture as well as the background continuum. This makes the TOMS Algorithm more sensitive to ozone, but it also makes the algorithm more sensitive to instrument calibration errors. While calibration adjustments are not needed for the fitting techniques like the DOAS employed in GOME algorithms, some adjustment is necessary when applying the TOMS Algorithm to GOME. Using spectral discrimination at near ultraviolet wavelength channels unabsorbed by ozone, the GOME wavelength dependent calibration drift is estimated and then checked using pair justification. In addition, the day one calibration offset is estimated based on the residuals of the Version 8 TOMS Algorithm. The estimated drift in the 2b detector of GOME is small through the first four years and then increases rapidly to +5% in normalized radiance at 331 nm relative to 385 nm by mid 2000. The lb detector appears to be quite well behaved throughout this time period.

  1. Free-tropospheric BrO investigations based on GOME

    NASA Astrophysics Data System (ADS)

    Post, P.; van Roozendael, M.; Backman, L.; Damski, J.; Thölix, L.; Fayt, C.; Taalas, P.

    2003-04-01

    Bromine compounds contribute significantly to the stratospheric ozone depletion. However measurements of most bromine compounds are sparse or non-existent, and experimental studies essentially rely on BrO observations. The differences between balloon and ground based measurements of stratospheric BrO columns and satellite total column measurements are too large to be explained by measurement uncertainties. Therefore, it has been assumed that there is a concentration of BrO in the free troposphere of about 1-3 ppt. In a previous work, we have calculated the tropospheric BrO abundance as the difference between total BrO and stratospheric BrO columns. The total vertical column densities of BrO are extracted from GOME measurements using IASB-BIRA algorithms. The stratospheric amount has been calculated using chemical transport models (CTM). Results from SLIMCAT and FinROSE simulations are used for this purpose. SLIMCAT is a widely used 3D CTM that has been tested against balloon measurements. FinROSE is a 3D CTM developed at FMI. We have tried several different tropospheric BrO profiles. Our results show that a profile with high BrO concentrations in the boundary layer usually gives unrealistically high tropospheric column values over areas of low albedo (like oceans). This suggests that the tropospheric BrO would be predominantly distributed in the free troposphere. In this work, attempts are made to identify the signature of a free tropospheric BrO content when comparing cloudy and non-cloudy scenes. The possible impact of orography on measured BrO columns is also investigated.

  2. OCRA radiometric cloud fractions for GOME-2 on MetOp-A/B

    NASA Astrophysics Data System (ADS)

    Lutz, R.; Loyola, D.; Gimeno García, S.; Romahn, F.

    2015-12-01

    This paper describes an approach for cloud parameter retrieval (radiometric cloud fraction estimation) using the polarization measurements of the Global Ozone Monitoring Experiment-2 (GOME-2) on-board the MetOp-A/B satellites. The core component of the Optical Cloud Recognition Algorithm (OCRA) is the calculation of monthly cloud-free reflectances for a global grid (resolution of 0.2° in longitude and 0.2° in latitude) and to derive radiometric cloud fractions. These cloud fractions will serve as a priori information for the retrieval of cloud top height (CTH), cloud top pressure (CTP), cloud top albedo (CTA) and cloud optical thickness (COT) with the Retrieval Of Cloud Information using Neural Networks (ROCINN) algorithm. This approach is already being implemented operationally for the GOME/ERS-2 and SCIAMACHY/ENVISAT sensors and here we present version 3.0 of the OCRA algorithm applied to the GOME-2 sensors. Based on more than six years of GOME-2A data (February 2007-June 2013), reflectances are calculated for ≈ 35 000 orbits. For each measurement a degradation correction as well as a viewing angle dependent and latitude dependent correction is applied. In addition, an empirical correction scheme is introduced in order to remove the effect of oceanic sun glint. A comparison of the GOME-2A/B OCRA cloud fractions with co-located AVHRR geometrical cloud fractions shows a general good agreement with a mean difference of -0.15±0.20. From operational point of view, an advantage of the OCRA algorithm is its extremely fast computational time and its straightforward transferability to similar sensors like OMI (Ozone Monitoring Instrument), TROPOMI (TROPOspheric Monitoring Instrument) on Sentinel 5 Precursor, as well as Sentinel 4 and Sentinel 5. In conclusion, it is shown that a robust, accurate and fast radiometric cloud fraction estimation for GOME-2 can be achieved with OCRA by using the polarization measurement devices (PMDs).

  3. Homogenized total ozone data records from the European sensors GOME/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A

    NASA Astrophysics Data System (ADS)

    Lerot, C.; Van Roozendael, M.; Spurr, R.; Loyola, D.; Coldewey-Egbers, M.; Kochenova, S.; van Gent, J.; Koukouli, M.; Balis, D.; Lambert, J.-C.; Granville, J.; Zehner, C.

    2014-02-01

    Within the European Space Agency's Climate Change Initiative, total ozone column records from GOME (Global Ozone Monitoring Experiment), SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CartograpHY), and GOME-2 have been reprocessed with GODFIT version 3 (GOME-type Direct FITting). This algorithm is based on the direct fitting of reflectances simulated in the Huggins bands to the observations. We report on new developments in the algorithm from the version implemented in the operational GOME Data Processor v5. The a priori ozone profile database TOMSv8 is now combined with a recently compiled OMI/MLS tropospheric ozone climatology to improve the representativeness of a priori information. The Ring procedure that corrects simulated radiances for the rotational Raman inelastic scattering signature has been improved using a revised semi-empirical expression. Correction factors are also applied to the simulated spectra to account for atmospheric polarization. In addition, the computational performance has been significantly enhanced through the implementation of new radiative transfer tools based on principal component analysis of the optical properties. Furthermore, a soft-calibration scheme for measured reflectances and based on selected Brewer measurements has been developed in order to reduce the impact of level-1 errors. This soft-calibration corrects not only for possible biases in backscattered reflectances, but also for artificial spectral features interfering with the ozone signature. Intersensor comparisons and ground-based validation indicate that these ozone data sets are of unprecedented quality, with stability better than 1% per decade, a precision of 1.7%, and systematic uncertainties less than 3.6% over a wide range of atmospheric states.

  4. Intercomparison of 4 Years of Global Formaldehyde Observations from the GOME-2 and OMI Sensors

    NASA Astrophysics Data System (ADS)

    De Smedt, Isabelle; Van Roozendael, Michel; Stravrakou, Trissevgeni; Muller, Jean-Francois; Chance, Kelly; Kurosu, Thomas

    2012-11-01

    Formaldehyde (H2CO) tropospheric columns have been retrieved since 2007 from backscattered UV radiance measurements performed by the GOME-2 instrument on the EUMETSAT METOP-A platform. This data set extends the successful time-series of global H2CO observations established with GOME/ ERS-2 (1996-2003), SCIAMACHY/ ENVISAT (2003-2012), and OMI on the NASA AURA platform (2005-now). In this work, we perform an intercomparison of the H2CO tropospheric columns retrieved from GOME-2 and OMI between 2007 and 2010, respectively at BIRA-IASB and at Harvard SAO. We first compare the global formaldehyde data products that are provided by each retrieval group. We then investigate each step of the retrieval procedure: the slant column fitting, the reference sector correction and the air mass factor calculation. New air mass factors are computed for OMI using external parameters consistent with those used for GOME-2. By doing so, the impacts of the different a priori profiles and aerosol corrections are quantified. The remaining differences are evaluated in view of the expected diurnal variations of the formaldehyde concentrations, based on ground-based measurements performed in the Beijing area.

  5. A preliminary comparison between TOVS and GOME level 2 ozone data

    NASA Astrophysics Data System (ADS)

    Rathman, William; Monks, Paul S.; Llewellyn-Jones, David; Burrows, John P.

    1997-09-01

    A preliminary comparison between total column ozone concentration values derived from TIROS Operational Vertical Sounder (TOVS) and Global Ozone Monitoring Experiment (GOME) has been carried out. Two comparisons of ozone datasets have been made: a) TOVS ozone analysis maps vs. GOME level 2 data; b) TOVS data located at Northern Hemisphere Ground Ozone Stations (NHGOS) vs. GOME data. Both analyses consistently showed an offset in the value of the total column ozone between the datasets [for analyses a) 35 Dobson Units (DU); and for analyses b) 10 DU], despite a good correlation between the spatial and temporal features of the datasets. A noticeably poor correlation in the latitudinal bands 10°/20° North and 10°/20° South was observed—the reasons for which are discussed. The smallest region which was statistically representative of the ozone value correlation dataset of TOVS data at NHGOS and GOME level-2 data was determined to be a region that was enclosed by effective radius of 0.75 arc-degrees (83.5km).

  6. OCRA radiometric cloud fractions for GOME-2 on MetOp-A/B

    NASA Astrophysics Data System (ADS)

    Lutz, Ronny; Loyola, Diego; Gimeno García, Sebastián; Romahn, Fabian

    2016-05-01

    This paper describes an approach for cloud parameter retrieval (radiometric cloud-fraction estimation) using the polarization measurements of the Global Ozone Monitoring Experiment-2 (GOME-2) onboard the MetOp-A/B satellites. The core component of the Optical Cloud Recognition Algorithm (OCRA) is the calculation of monthly cloud-free reflectances for a global grid (resolution of 0.2° in longitude and 0.2° in latitude) to derive radiometric cloud fractions. These cloud fractions will serve as a priori information for the retrieval of cloud-top height (CTH), cloud-top pressure (CTP), cloud-top albedo (CTA) and cloud optical thickness (COT) with the Retrieval Of Cloud Information using Neural Networks (ROCINN) algorithm. This approach is already being implemented operationally for the GOME/ERS-2 and SCIAMACHY/ENVISAT sensors and here we present version 3.0 of the OCRA algorithm applied to the GOME-2 sensors. Based on more than five years of GOME-2A data (April 2008 to June 2013), reflectances are calculated for ≈ 35 000 orbits. For each measurement a degradation correction as well as a viewing-angle-dependent and latitude-dependent correction is applied. In addition, an empirical correction scheme is introduced in order to remove the effect of oceanic sun glint. A comparison of the GOME-2A/B OCRA cloud fractions with colocated AVHRR (Advanced Very High Resolution Radiometer) geometrical cloud fractions shows a general good agreement with a mean difference of -0.15 ± 0.20. From an operational point of view, an advantage of the OCRA algorithm is its very fast computational time and its straightforward transferability to similar sensors like OMI (Ozone Monitoring Instrument), TROPOMI (TROPOspheric Monitoring Instrument) on Sentinel 5 Precursor, as well as Sentinel 4 and Sentinel 5. In conclusion, it is shown that a robust, accurate and fast radiometric cloud-fraction estimation for GOME-2 can be achieved with OCRA using polarization measurement devices (PMDs).

  7. SO2 columns over China: Temporal and spatial variations using OMI and GOME-2 observations

    NASA Astrophysics Data System (ADS)

    Huanhuan, Yan; Liangfu, Chen; Lin, Su; Jinhua, Tao; Chao, Yu

    2014-03-01

    Enhancements of SO2 column amounts due to anthropogenic emission sources over China were shown in this paper by using OMI and GOME-2 observations. The temporal and spatial variations of SO2 columns over China were analyzed for the time period 2005-2010. Beijing and Chongqing showed a high concentration in the SO2 columns, attributable to the use of coal for power generation in China and the characteristic of terrain and meteorology. The reduction of SO2 columns over Beijing and surrounding provinces in 2008 was observed by OMI, which confirms the effectiveness of strict controls on pollutant emissions and motor vehicle traffic before and during 2008 Olympic and Paralympic Games. The SO2 columns over China from GOME-2 (0.2-0.5 DU) were lower than those from OMI (0.6-1 DU), but both showed a decrease in SO2 columns over northern China since 2008 (except an increase in OMI SO2 in 2010).

  8. Combined Characterisation of GOME and TOMS Total Ozone Using Ground-Based Observations from the NDSC

    NASA Technical Reports Server (NTRS)

    Lambert, J.-C.; VanRoozendael, M.; Simon, P. C.; Pommereau, J.-P.; Goutail, F.; Andersen, S. B.; Arlander, D. W.; BuiVan, N. A.; Claude, H.; deLaNoee, J.; hide

    1998-01-01

    Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe Total Ozone Mapping Spectrometer (TOMS), and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network for the Detection of Stratospheric Change (NDSC), over an extended latitude range and a variety of geophysical conditions. The comparisons with each spaceborne sensor are combined altogether for investigating their respective solar zenith angle (SZA) dependence, dispersion, and difference of sensitivity. The space- and ground-based data are found to agree within a few percent on average. However, the analysis highlights for both Global Ozone Monitoring Experiment (GOME) and TOMS several sources of discrepancies, including a dependence on the SZA at high latitudes and internal inconsistencies.

  9. Eleven years of tropospheric NO2 measured by GOME, SCIAMACHY and OMI

    NASA Astrophysics Data System (ADS)

    Eskes, H.; Boersma, F.; Dirksen, R.; van der A, R.; Veefkind, P.; Levelt, P.; Brinksma, E.; van Roozendael, M.; de Smedt, I.; Gleason, J.

    2006-12-01

    Based on measurements of GOME on ESA ERS-2, SCIAMACHY on ESA-ENVISAT, and Ozone Monitoring Instrument (OMI) on the NASA EOS-Aura satellite there is now a unique 11-year dataset of global tropospheric nitrogen dioxide measurements from space. The retrieval approach consists of two steps. The first step is an application of the DOAS (Differential Optical Absorption Spectroscopy) approach which delivers the total absorption optical thickness along the light path (the slant column). For GOME and SCIAMACHY this is based on the DOAS implementation developed by BIRA/IASB. For OMI the DOAS implementation was developed in a collaboration between KNMI and NASA. The second retrieval step, developed at KNMI, estimates the tropospheric vertical column of NO2 based on the slant column, cloud fraction and cloud top height retrieval, stratospheric column estimates derived from a data assimilation approach and vertical profile estimates from space-time collocated profiles from the TM chemistry-transport model. The second step was applied with only minor modifications to all three instruments to generate a uniform 11-year data set. In our talk we will address the following topics: - A short summary of the retrieval approach and results - Comparisons with other retrievals - Comparisons with global and regional-scale models - OMI-SCIAMACHY and SCIAMACHY-GOME comparisons - Validation with independent measurements - Trend studies of NO2 for the past 11 years

  10. Retrieval Of Cloud Pressure And Chlorophyll Content Using Raman Scattering In GOME Ultraviolet Spectra

    NASA Technical Reports Server (NTRS)

    Atlas, Robert (Technical Monitor); Joiner, Joanna; Vasikov, Alexander; Flittner, David; Gleason, James; Bhartia, P. K.

    2002-01-01

    Reliable cloud pressure estimates are needed for accurate retrieval of ozone and other trace gases using satellite-borne backscatter ultraviolet (buv) instruments such as the global ozone monitoring experiment (GOME). Cloud pressure can be derived from buv instruments by utilizing the properties of rotational-Raman scattering (RRS) and absorption by O2-O2. In this paper we estimate cloud pressure from GOME observations in the 355-400 nm spectral range using the concept of a Lambertian-equivalent reflectivity (LER) surface. GOME has full spectral coverage in this range at relatively high spectral resolution with a very high signal-to-noise ratio. This allows for much more accurate estimates of cloud pressure than were possible with its predecessors SBUV and TOMS. We also demonstrate the potential capability to retrieve chlorophyll content with full-spectral buv instruments. We compare our retrieved LER cloud pressure with cloud top pressures derived from the infrared ATSR instrument on the same satellite. The findings confirm results from previous studies that showed retrieved LER cloud pressures from buv observations are systematically higher than IR-derived cloud-top pressure. Simulations using Mie-scattering radiative transfer algorithms that include O2-O2 absorption and RRS show that these differences can be explained by increased photon path length within and below cloud.

  11. Development of an OClO Slant Column Product for the GOME-2 Sensors

    NASA Astrophysics Data System (ADS)

    Richter, Andreas; Wittrock, Folkard; Burrows, John P.

    2016-04-01

    Stratospheric ozone depletion by catalytic reactions involving halogens is one of the most prominent examples of anthropogenic impacts on the atmosphere. In spite of the rapid and successful international action to reduce emissions of CFCs and other ozone depleting substances leading to the Montreal Protocol and its amendments, ozone depletion in polar spring is still observed in both hemispheres on a regular basis. For the coming years, slow ozone recovery is expected but individual years will still see very low ozone columns depending on meteorology and possible interactions with climate change. Monitoring of both ozone and ozone depleting substances in the stratosphere remains a priority to ensure that the predicted reduction in halogen levels and recovery of ozone columns is taking place as predicted. One way to observe stratospheric chlorine activation is by measurements of OClO which can be detected by UV/visible remote sensing from the ground and from satellite. While the link between OClO levels and chlorine activation is complicated by the fact that a) OClO is not directly involved in ozone depletion but is produced by reaction of BrO and ClO and b) is rapidly photolysed at daylight, the long existing data series from both ground-based and satellite observations makes it an interesting tracer of chlorine activation. The GOME-2 instruments on the MetOp series of satellites are nadir viewing UV/vis spectrometers having the spectral coverage and resolution needed for Differential Optical Absorption Spectroscopy retrievals of OClO. With their combined lifetime of more than 15 years, they can provide a long-term data set. However, previous attempts to create an OClO product for GOME-2 suffered from large scatter in the OClO data and time-dependent offsets. Here we present an improved OClO slant column retrieval for the two instruments GOME2-A and GOME2-B. The data is shown to be of similar quality as for earlier instruments such as SCIAMACHY, and is consistent

  12. Evaluating a New Homogeneous Total Ozone Climate Data Record from GOME/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A

    NASA Technical Reports Server (NTRS)

    Koukouli, M.E.; Lerot, C.; Granville, J.; Goutail, F.; Lambert, J.-C.; Pommereau, J.-P.; Balis, D.; Zyrichidou, I.; Van Roozendael, M.; Coldewey-Egbers, M.; hide

    2015-01-01

    The European Space Agency's Ozone Climate Change Initiative (O3-CCI) project aims at producing and validating a number of high-quality ozone data products generated from different satellite sensors. For total ozone, the O3-CCI approach consists of minimizing sources of bias and systematic uncertainties by applying a common retrieval algorithm to all level 1 data sets, in order to enhance the consistency between the level 2 data sets from individual sensors. Here we present the evaluation of the total ozone products from the European sensors Global Ozone Monitoring Experiment (GOME)/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A produced with the GOME-type Direct FITting (GODFIT) algorithm v3. Measurements from the three sensors span more than 16 years, from 1996 to 2012. In this work, we present the latest O3-CCI total ozone validation results using as reference ground-based measurements from Brewer and Dobson spectrophotometers archived at the World Ozone and UV Data Centre of the World Meteorological Organization as well as from UV-visible differential optical absorption spectroscopy (DOAS)/Système D'Analyse par Observations Zénithales (SAOZ) instruments from the Network for the Detection of Atmospheric Composition Change. In particular, we investigate possible dependencies in these new GODFIT v3 total ozone data sets with respect to latitude, season, solar zenith angle, and different cloud parameters, using the most adequate type of ground-based instrument. We show that these three O3-CCI total ozone data products behave very similarly and are less sensitive to instrumental degradation, mainly as a result of the new reflectance soft-calibration scheme. The mean bias to the ground-based observations is found to be within the 1 plus or minus 1 percent level for all three sensors while the near-zero decadal stability of the total ozone columns (TOCs) provided by the three European instruments falls well within the 1-3 percent requirement of the European Space

  13. Chlorophyll induced fluorescence retrieved from GOME2 for improving gross primary productivity estimates of vegetation

    NASA Astrophysics Data System (ADS)

    van Leth, Thomas C.; Verstraeten, Willem W.; Sanders, Abram F. J.

    2014-05-01

    Mapping terrestrial chlorophyll fluorescence is a crucial activity to obtain information on the functional status of vegetation and to improve estimates of light-use efficiency (LUE) and global primary productivity (GPP). GPP quantifies carbon fixation by plant ecosystems and is therefore an important parameter for budgeting terrestrial carbon cycles. Satellite remote sensing offers an excellent tool for investigating GPP in a spatially explicit fashion across different scales of observation. The GPP estimates, however, still remain largely uncertain due to biotic and abiotic factors that influence plant production. Sun-induced fluorescence has the ability to enhance our knowledge on how environmentally induced changes affect the LUE. This can be linked to optical derived remote sensing parameters thereby reducing the uncertainty in GPP estimates. Satellite measurements provide a relatively new perspective on global sun-induced fluorescence, enabling us to quantify spatial distributions and changes over time. Techniques have recently been developed to retrieve fluorescence emissions from hyperspectral satellite measurements. We use data from the Global Ozone Monitoring Instrument 2 (GOME2) to infer terrestrial fluorescence. The spectral signatures of three basic components atmospheric: absorption, surface reflectance, and fluorescence radiance are separated using reference measurements of non-fluorescent surfaces (desserts, deep oceans and ice) to solve for the atmospheric absorption. An empirically based principal component analysis (PCA) approach is applied similar to that of Joiner et al. (2013, ACP). Here we show our first global maps of the GOME2 retrievals of chlorophyll fluorescence. First results indicate fluorescence distributions that are similar with that obtained by GOSAT and GOME2 as reported by Joiner et al. (2013, ACP), although we find slightly higher values. In view of optimizing the fluorescence retrieval, we will show the effect of the references

  14. Variability in Tropospheric Ozone over China Derived from Assimilated GOME-2 Ozone Profiles

    NASA Astrophysics Data System (ADS)

    van Peet, J. C. A.; van der A, R. J.; Kelder, H. M.

    2016-08-01

    A tropospheric ozone dataset is derived from assimilated GOME-2 ozone profiles for 2008. Ozone profiles are retrieved with the OPERA algorithm, using the optimal estimation method. The retrievals are done on a spatial resolution of 160×160 km on 16 layers ranging from the surface up to 0.01 hPa. By using the averaging kernels in the data assimilation, the algorithm maintains the high resolution vertical structures of the model, while being constrained by observations with a lower vertical resolution.

  15. Detection of BrO plumes over various sources using OMI and GOME-2 measurements

    NASA Astrophysics Data System (ADS)

    Seo, Sora; Richter, Andreas; Blechschmidt, Anne-Marlene; Burrows, John P.

    2017-04-01

    Reactive halogen species (RHS) play important roles in the chemistry of the stratosphere and troposphere. They are responsible for ozone depletion through catalytic reaction cycles, changes in the OH/HO2 and NO/NO2 ratios, and oxidation of compounds such as gaseous elemental mercury (GEM) and dimethyl sulphide (DMS). Thus, monitoring of halogen oxides is important for understanding global atmospheric oxidation capacity and climate change. Bromine monoxide (BrO) is one of the most common active halogen oxides. In the troposphere, large amounts of bromine are detected in Polar Regions in spring, over salt lakes, and in volcanic plumes. In this study, we analyse BrO column densities using OMI and GOME-2 observations. The measured spectra from both UV-visible nadir satellites were analyzed using the differential optical absorption spectroscopy (DOAS) method with different settings depending on the instrumental characteristics. Large amounts of volcanic BrO from the Kasatochi eruption in 2008 were detected for 6 days from August 8 to August 13. Especially large BrO amounts were found in the plume center for 3 days from August 9 to 11 with slant column densities (SCD) of up to ˜1.6x1015 molecules cm-2 and ˜5.5x1014 molecules cm-2 in OMI and GOME-2 measurements, respectively. In addition to the volcanic sources, events of widespread BrO enhancements were also observed over the Arctic and Antarctic coastal regions during the spring time by both satellites. As the overpass time of the two instruments is not the same, differences between the two data sets are expected. In this study, the agreement between OMI and GOME-2 BrO data is investigated using both the operational products and different DOAS fits. Systematic differences are found in BrO slant columns and fitting residuals, both being larger in the case of OMI data. In addition, results are sensitive to the choice of fitting window. From a monitoring point of view, due to the higher spatial resolution of OMI compared

  16. Overview of the O3M SAF GOME-2 operational atmospheric composition and UV radiation data products and data availability

    NASA Astrophysics Data System (ADS)

    Hassinen, S.; Balis, D.; Bauer, H.; Begoin, M.; Delcloo, A.; Eleftheratos, K.; Gimeno Garcia, S.; Granville, J.; Grossi, M.; Hao, N.; Hedelt, P.; Hendrick, F.; Hess, M.; Heue, K.-P.; Hovila, J.; Jønch-Sørensen, H.; Kalakoski, N.; Kiemle, S.; Kins, L.; Koukouli, M. E.; Kujanpää, J.; Lambert, J.-C.; Lerot, C.; Loyola, D.; Määttä, A.; Pedergnana, M.; Pinardi, G.; Romahn, F.; van Roozendael, M.; Lutz, R.; De Smedt, I.; Stammes, P.; Steinbrecht, W.; Tamminen, J.; Theys, N.; Tilstra, L. G.; Tuinder, O. N. E.; Valks, P.; Zerefos, C.; Zimmer, W.; Zyrichidou, I.

    2015-07-01

    The three GOME-2 instruments will provide unique and long data sets for atmospheric research and applications. The complete time period will be 2007-2022, including the period of ozone depletion as well as the beginning of ozone layer recovery. Besides ozone chemistry, the GOME-2 products are important e.g. for air quality studies, climate modeling, policy monitoring and hazard warnings. The heritage for GOME-2 is in the ERS/GOME and Envisat/SCIAMACHY instruments. The current Level 2 (L2) data cover a wide range of products such as trace gas columns (NO2, BrO, H2CO, H2O, SO2), tropospheric columns of NO2, total ozone columns and vertical ozone profiles in high and low spatial resolution, absorbing aerosol indices from the main science channels as well as from the polarization channels (AAI, AAI-PMD), Lambertian-equivalent reflectivity database, clear-sky and cloud-corrected UV indices and surface UV fields with different weightings and photolysis rates. The Ozone Monitoring and Atmospheric Composition Satellite Application Facility (O3M SAF) processing and data dissemination is operational and running 24/7. Data quality is quarantined by the detailed review processes for the algorithms, validation of the products as well as by a continuous quality monitoring of the products and processing. This is an overview paper providing the O3M SAF project background, current status and future plans to utilization of the GOME-2 data. An important focus is the provision of summaries of the GOME-2 products including product principles and validation examples together with the product sample images. Furthermore, this paper collects the references to the detailed product algorithm and validation papers.

  17. Global observations of BrO in the troposphere using GOME-2 satellite data

    NASA Astrophysics Data System (ADS)

    Theys, N.; van Roozendael, M.; Hendrick, F.; Xin, Y.; Isabelle, D.; Richter, A.; Mathias, B.; Quentin, E.; Johnston, P. V.; Kreher, K.; Martine, D.

    2010-12-01

    Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and correlative data including ground-based BrO vertical columns and total BrO columns derived from SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables to separate the stratospheric and tropospheric fractions of the measured total BrO columns and allows studying the BrO plumes in polar region in more detail. While several satellite BrO plumes can largely be explained by an influence of stratospheric descending air, we show that numerous tropospheric BrO hotspots are associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this finding is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. Outside the polar region, evidences are provided for a global tropospheric BrO background with columns of 1-3 x 1013 molec/cm2.

  18. Global observations of tropospheric BrO columns using GOME-2 satellite data

    NASA Astrophysics Data System (ADS)

    Theys, N.; van Roozendael, M.; Hendrick, F.; Yang, X.; de Smedt, I.; Richter, A.; Begoin, M.; Errera, Q.; Johnston, P. V.; Kreher, K.; de Mazière, M.

    2011-02-01

    Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and BrO vertical columns derived from correlative ground-based and SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables separation of stratospheric and tropospheric fractions of the measured total BrO columns and allows quantitative study of the BrO plumes in polar regions. While some satellite observed plumes of enhanced BrO can be explained by stratospheric descending air, we show that most BrO hotspots are of tropospheric origin, although they are often associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this result is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. No definitive conclusion can be drawn however on the importance of blowing snow sources in comparison to other bromine release mechanisms. Outside polar regions, evidence is provided for a global tropospheric BrO background with column of 1-3 × 1013 molec cm-2, consistent with previous estimates.

  19. Global observations of tropospheric BrO columns using GOME-2 satellite data

    NASA Astrophysics Data System (ADS)

    Theys, N.; van Roozendael, M.; Hendrick, F.; Yang, X.; de Smedt, I.; Richter, A.; Begoin, M.; Errera, Q.; Johnston, P. V.; Kreher, K.; de Mazière, M.

    2010-11-01

    Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and BrO vertical columns derived from correlative ground-based and SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables separation of stratospheric and tropospheric fractions of the measured total BrO columns and allows quantitative study of the BrO plumes in polar regions. While some satellite observed plumes of enhanced BrO can be explained by stratospheric descending air, we show that most BrO hotspots are of tropospheric origin, although they are often associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this result is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. Outside polar regions, evidence is provided for a global tropospheric BrO background with column of 1-3×1013 molec/cm2, consistent with previous estimates.

  20. The Analysis of Inter-calibration Between FY-3C/TOU, NPP/OMPS and Metop/GOME-2

    NASA Astrophysics Data System (ADS)

    Wang, H.; Hu, X.

    2017-12-01

    Total ozone unit (TOU), one of the main payloads on FY-3C satellite, is the instrument for daily global coverage of total ozone monitoring in China. It has been in-orbit for about four years since October 2013. However, its solar irradiance is not correct because all of three diffuser boards cannot work normally. Therefore, in-orbit inter-calibration of radiance and reflectance are studied for TOU measurement. A method is introduced for inter-calibration between FY-3C/TOU and NPP/OMPS, Metop-B/GOME-2. It includes orbit forecast, temporal concurrent, spatial collocation, geometrical alignement, uniform filtration, and spectral consistent. Then, it is used for TOU data of 3 years from 2014 to 2016. The slopes of radiance inter-calibration equations of 360 nm between TOU (y-axis) and NPP/OMPS (x-axis) decrease gradually from 1 to 0.96. The slopes of radiance inter-calibration equations of 360 nm between TOU (y-axis) and Metop-B/GOME2 (x-axis) increased gradually from 1.12 to 1.72, while the slopes between TOU and Metop-A/GOME2 varied within 2.1-2.3. Most relation coefficients (R2) of them are >0.8. The inter-calibration results, combining with the solar irradiance of OMPS/GOME-2, will be used for the attenuation analysis of TOU measurements.

  1. Total ozone column derived from GOME and SCIAMACHY using KNMI retrieval algorithms: Validation against Brewer measurements at the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Antón, M.; Kroon, M.; López, M.; Vilaplana, J. M.; Bañón, M.; van der A, R.; Veefkind, J. P.; Stammes, P.; Alados-Arboledas, L.

    2011-11-01

    This article focuses on the validation of the total ozone column (TOC) data set acquired by the Global Ozone Monitoring Experiment (GOME) and the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite remote sensing instruments using the Total Ozone Retrieval Scheme for the GOME Instrument Based on the Ozone Monitoring Instrument (TOGOMI) and Total Ozone Retrieval Scheme for the SCIAMACHY Instrument Based on the Ozone Monitoring Instrument (TOSOMI) retrieval algorithms developed by the Royal Netherlands Meteorological Institute. In this analysis, spatially colocated, daily averaged ground-based observations performed by five well-calibrated Brewer spectrophotometers at the Iberian Peninsula are used. The period of study runs from January 2004 to December 2009. The agreement between satellite and ground-based TOC data is excellent (R2 higher than 0.94). Nevertheless, the TOC data derived from both satellite instruments underestimate the ground-based data. On average, this underestimation is 1.1% for GOME and 1.3% for SCIAMACHY. The SCIAMACHY-Brewer TOC differences show a significant solar zenith angle (SZA) dependence which causes a systematic seasonal dependence. By contrast, GOME-Brewer TOC differences show no significant SZA dependence and hence no seasonality although processed with exactly the same algorithm. The satellite-Brewer TOC differences for the two satellite instruments show a clear and similar dependence on the viewing zenith angle under cloudy conditions. In addition, both the GOME-Brewer and SCIAMACHY-Brewer TOC differences reveal a very similar behavior with respect to the satellite cloud properties, being cloud fraction and cloud top pressure, which originate from the same cloud algorithm (Fast Retrieval Scheme for Clouds from the Oxygen A-Band (FRESCO+)) in both the TOSOMI and TOGOMI retrieval algorithms.

  2. GOME-2 Tropospheric Ozone Profile Retrievals from Joint UV/Visible Measurement

    NASA Astrophysics Data System (ADS)

    Liu, X.; Zoogman, P.; Chance, K.; Cai, Z.; Nowlan, C. R.; Huang, G.; Gonzalez Abad, G.

    2016-12-01

    It has been shown from sensitivity studies that adding visible measurements in the Chappuis ozone band to UV measurements in the Hartley/Huggins ozone bands can significantly enhance retrieval sensitivity to lower tropospheric ozone from backscattered solar radiances due to deeper photon penetration in the visible to the surface than in the ultraviolet. The first NASA EVI (Earth Venture Instrument) TEMPO (Tropospheric Emissions: Monitoring of Pollution) instrument is being developed to measure backscattered solar radiation in two channels ( 290-490 and 540-740 nm) and make atmospheric pollution measurements over North America from the Geostationary orbit. However, this retrieval enhancement has yet to be demonstrated from existing measurements due to the weak ozone absorption in the visible and strong interferences from surface reflectance and aerosols and the requirement of accurate radiometric calibration across different spectral channels. We present GOME-2 retrievals from joint UV/visible measurements using the SAO ozone profile retrieval algorithm, to directly explore the retrieval improvement in lower tropospheric ozone from additional visible measurements. To reduce the retrieval interference from surface reflectance, we add characterization of surface spectral reflectance in the visible based on combining EOFs (Empirical Orthogonal Functions) derived from ASTER and other surface reflectance spectra with MODIS BRDF climatology into the ozone profile algorithm. The impacts of various types of aerosols and surface BRDF on the retrievals will be investigated. In addition, we will also perform empirical radiometric calibration of the GOME-2 data based on radiative transfer simulations. We will evaluate the retrieval improvement of joint UV/visible retrieval over the UV retrieval based on fitting quality and validation against ozonesonde observations.

  3. Monitoring the Bardarbunga eruption using GOME-2/Metop-A & -B

    NASA Astrophysics Data System (ADS)

    Hedelt, Pascal; Valks, Pieter; Loyola, Diego

    2015-04-01

    We will present here the results of the Bardarbunga eruption monitored by the GOME-2 instrument aboard MetOp-A & -B. After increased seismic activity in August, the Icelandic volcano Bardarbunga (Bárðarbunga) erupted on 31 August 2014. Since 1 September the GOME-2 instruments aboard the MetOp-A and -B satellites detect a continuous emission of sulphur-dioxide (SO2) emitted from the Holuhraun fissure at the flanks of the Bardarbunga volcano. At the beginning the emitted SO2 was mainly transported to the north-eastern direction over Scandinavia and Russia. However, on September 22 an SO2 cloud was even moving over Europe and could be detected at the Hohenpeissenberg and Schneefernerhaus observatories. SO2 emissions are a good indicator for volcanic activity, since besides weak anthropogenic emissions there are no other known sources for atmospheric SO2, which can cause respiratory problems in the local population and the aircraft passengers. Furthermore in form of acid rain it increases the oxidation of aircraft components. It was found that for some volcanic eruptions SO2 can be a good proxy for the much harder to detect volcanic ash. Volcanic ash can be hazardous not only for the local population but also for aviation since it can cause total engine failure if it melts and then congeals in the engine. Furthermore ash is highly abrasive to engine turbine vanes and propellers. Under the leadership of IMF, DLR-EOC provides operational trace gas measurements, including total SO2 columns, in near-real-time (i.e., within 2 hours of recording) in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF).

  4. Comparison of GOME tropospheric NO2 columns with NO2 profiles deduced from ground-based in situ measurements

    NASA Astrophysics Data System (ADS)

    Schaub, D.; Boersma, K. F.; Kaiser, J. W.; Weiss, A. K.; Folini, D.; Eskes, H. J.; Buchmann, B.

    2006-08-01

    Nitrogen dioxide (NO2) vertical tropospheric column densities (VTCs) retrieved from the Global Ozone Monitoring Experiment (GOME) are compared to coincident ground-based tropospheric NO2 columns. The ground-based columns are deduced from in situ measurements at different altitudes in the Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME NO2 VTC data retrieved by a collaboration of KNMI (Royal Netherlands Meteorological Institute) and BIRA/IASB (Belgian Institute for Space Aeronomy) with independently derived tropospheric NO2 profiles. A first comparison relates the GOME retrieved tropospheric columns to the tropospheric columns obtained by integrating the ground-based NO2 measurements. For a second comparison, the tropospheric profiles constructed from the ground-based measurements are first multiplied with the averaging kernel (AK) of the GOME retrieval. The second approach makes the comparison independent from the a priori NO2 profile used in the GOME retrieval. This allows splitting the total difference between the column data sets into two contributions: one that is due to differences between the a priori and the ground-based NO2 profile shapes, and another that can be attributed to uncertainties in both the remaining retrieval parameters (such as, e.g., surface albedo or aerosol concentration) and the ground-based in situ NO2 profiles. For anticyclonic clear sky conditions the comparison indicates a good agreement between the columns (n=157, R=0.70/0.74 for the first/second comparison approach, respectively). The mean relative difference (with respect to the ground-based columns) is -7% with a standard deviation of 40% and GOME on average slightly underestimating the ground-based columns. Both data sets show a similar seasonal behaviour with a distinct maximum of spring NO2 VTCs. Further analysis indicates small GOME columns being systematically smaller than the ground-based ones. The influence of different shapes in the a priori and

  5. A linear method for the retrieval of sun-induced chlorophyll fluorescence from GOME-2 and SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Guanter, L.; Joiner, J.

    2015-06-01

    Global retrievals of near-infrared sun-induced chlorophyll fluorescence (SIF) have been achieved in the last few years by means of a number of space-borne atmospheric spectrometers. Here, we present a new retrieval method for medium spectral resolution instruments such as the Global Ozone Monitoring Experiment-2 (GOME-2) and the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY). Building upon the previous work by Guanter et al. (2013) and Joiner et al. (2013), our approach provides a solution for the selection of the number of free parameters. In particular, a backward elimination algorithm is applied to optimize the number of coefficients to fit, which reduces also the retrieval noise and selects the number of state vector elements automatically. A sensitivity analysis with simulated spectra has been utilized to evaluate the performance of our retrieval approach. The method has also been applied to estimate SIF at 740 nm from real spectra from GOME-2 and for the first time, from SCIAMACHY. We find a good correspondence of the absolute SIF values and the spatial patterns from the two sensors, which suggests the robustness of the proposed retrieval method. In addition, we compare our results to existing SIF data sets, examine uncertainties and use our GOME-2 retrievals to show empirically the relatively low sensitivity of the SIF retrieval to cloud contamination.

  6. A linear method for the retrieval of sun-induced chlorophyll fluorescence from GOME-2 and SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Guanter, L.; Joiner, J.

    2014-12-01

    Global retrievals of near-infrared sun-induced chlorophyll fluorescence (SIF) have been achieved in the last years by means of a number of space-borne atmospheric spectrometers. Here, we present a new retrieval method for medium spectral resolution instruments such as the Global Ozone Monitoring Experiment (GOME-2) and the SCanning Imaging Absorption SpectroMeter for Atmospheric ChartographY (SCIAMACHY). Building upon the previous work by Joiner et al. (2013), our approach solves existing issues in the retrieval such as the non-linearity of the forward model and the arbitrary selection of the number of free parameters. In particular, we use a backward elimination algorithm to optimize the number of coefficients to fit, which reduces also the retrieval noise and selects the number of state vector elements automatically. A sensitivity analysis with simulated spectra has been utilized to evaluate the performance of our retrieval approach. The method has also been applied to estimate SIF from real spectra from GOME-2 and for the first time, from SCIAMACHY. We find a good correspondence of the absolute SIF values and the spatial patterns from the two sensors, which suggests the robustness of the proposed retrieval method. In addition, we examine uncertainties and use our GOME-2 retrievals to show empirically the low sensitivity of the SIF retrieval to cloud contamination.

  7. A linear method for the retrieval of sun-induced chlorophyll fluorescence from GOME-2 and SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Köhler, Philipp; Guanter, Luis; Joiner, Joanna

    2015-04-01

    Global retrievals of near-infrared sun-induced chlorophyll fluorescence (SIF) have been achieved in the last several years by means of space-borne atmospheric spectrometers. SIF is an electromagnetic signal emitted by the chlorophyll-a of photosynthetically active vegetation in the 650-850 nm spectral range. It represents a part of the excess energy during the process of photosynthesis and provides a measure of photosynthetic activity. The key challenge to retrieve SIF from space is to isolate the signal from the about 100 times more intense reflected solar radiation in the measured top of atmosphere (TOA) radiance spectrum. Nevertheless, it has been demonstrated that a number of satellite sensors provide the necessary spectral and radiometric performance to evaluate the in-filling of solar Fraunhofer lines and/or atmospheric absorption features by SIF. We will present recent developments for the retrieval of SIF from medium spectral resolution space-borne spectrometers such as the Global Ozone Monitoring Experiment (GOME-2) and the Scanning Imaging Absorption SpectroMeter for Atmospheric ChartographY (SCIAMACHY). Building upon the previous work by Joiner et al. 2013, our approach solves existing issues in the retrieval such as the non-linearity of the forward model and the arbitrary selection of the number of free parameters. In particular, we use a backward elimination algorithm to optimize the number of coefficients to fit, which reduces also the retrieval noise and selects the number of state vector elements automatically. A sensitivity analysis with simulated spectra has been utilized to evaluate the performance of our retrieval approach. The method has also been applied to estimate SIF from real spectra from GOME-2 and for the first time, from SCIAMACHY. We are able to present a time series of GOME-2 SIF results covering the 2007-2011 time period and SCIAMACHY SIF results between 2003-2011. This represents an almost one decade long record of global SIF. We

  8. Validation of GOME-2/MetOp-A total water vapour column using reference radiosonde data from the GRUAN network

    NASA Astrophysics Data System (ADS)

    Antón, M.; Loyola, D.; Román, R.; Vömel, H.

    2015-03-01

    The main goal of this paper is to validate the total water vapour column (TWVC) measured by the Global Ozone Monitoring Experiment-2 (GOME-2) satellite sensor and generated using the GOME Data Processor (GDP) retrieval algorithm developed by the German Aerospace Centre (DLR). For this purpose, spatially and temporally collocated TWVC data from highly accurate sounding measurements for the period January 2009-May 2014 at six sites are used. These balloon-borne data are provided by the GCOS Reference Upper-Air Network (GRUAN). The correlation between GOME-2 and sounding TWVC data is reasonably good (determination coefficient, R2, of 0.89) when all available radiosondes (1400) are employed in the inter-comparison. When cloud-free cases (544) are selected by means of the satellite cloud fraction (CF < 5%), the correlation exhibits a remarkable improvement (R2 ~ 0.95). Nevertheless, the analysis of the relative differences between GOME-2 and GRUAN data shows a mean absolute bias error (weighted with the combined uncertainty derived from the estimated errors of both data sets) of 15% for all-sky conditions (9% for cloud-free cases). These results evidence a notable bias in the satellite TWVC data against the reference balloon-borne measurements, partially related to the cloudy conditions during the satellite overpass. The detailed analysis of the influence of cloud properties - CF, cloud top albedo (CTA) and cloud top pressure (CTP) - on the satellite-sounding differences reveals, as expected, a large effect of clouds in the GOME-2 TWVC data. For instance, the relative differences exhibit a large negative dependence on CTA, varying from -6 to -23% when CTA rises from 0.3 to 0.8. Furthermore, the satellite-sounding TWVC differences show a strong dependence on the satellite solar zenith angle (SZA) for values above 50°. Hence the smallest relative differences found in this satellite-sounding comparison are achieved for those cloud-free cases with satellite SZA below 50

  9. Validation of GOME (ERS-2) NO2 vertical column data with ground-based measurements at Issyk-Kul (Kyrgyzstan)

    NASA Astrophysics Data System (ADS)

    Ionov, D.; Sinyakov, V.; Semenov, V.

    Starting from 1995 the global monitoring of atmospheric nitrogen dioxide is carried out by the measurements of nadir-viewing GOME spectrometer aboard ERS-2 satellite. Continuous validation of that data by means of comparisons with well-controlled ground-based measurements is important to ensure the quality of GOME data products and improve related retrieval algorithms. At the station of Issyk-Kul (Kyrgyzstan) the ground-based spectroscopic observations of NO2 vertical column have been started since 1983. The station is located on the northern shore of Issyk-Kul lake, 1650 meters above the sea level (42.6 N, 77.0 E). The site is equipped with grating spectrometer for the twilight measurements of zenith-scattered solar radiation in the visible range, and applies the DOAS technique to retrieve NO2 vertical column. It is included in the list of NDSC stations as a complementary one. The present study is focused on validation of GOME NO2 vertical column data, based on 8-year comparison with correlative ground-based measurements at Issyk-Kul station in 1996-2003. Within the investigation, an agreement of both individual and monthly averaged GOME measurements with corresponding twilight ground-based observations is examined. Such agreement is analyzed with respect to different conditions (season, sun elevation), temporal/spatial criteria choice (actual overpass location, correction for diurnal variation) and data processing (GDP version 2.7, 3.0). In addition, NO2 vertical columns were integrated from simultaneous stratospheric profile measurements by NASA HALOE and SAGE-II/III satellite instruments and introduced to explain the differences with ground-based observations. In particular cases, NO2 vertical profiles retrieved from the twilight ground-based measurements at Issuk-Kul were also included into comparison. Overall, summertime GOME NO2 vertical columns were found to be systematicaly lower than ground-based data. This work was supported by International Association

  10. Weekly cycle of NO2 by GOME measurements: A signature of anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Beirle, S.; Platt, U.; Wenig, M.; Wagner, T.

    2003-07-01

    Nitrogen oxides (NO+NO2=NOx) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50% of the total production of NOx. Since human activity in industrialized countries largely follows an artificial seven-day cycle, fossil fuel combustion is expected to be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of NO2 column densities. Applying sophisticated algorithms, vertical column densities (VCD) of tropospheric NO2 can be determined. We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25-50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD allows the identification of anthropogenic sources. In addition, the fraction of emissions subjected to a weekly cycle (mainly transport, power generation) with respect to a constant background (all kind of natural sources, biomass burning, heavy industry) can be estimated. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle over Germany in detail, obtaining a value of about 12 h.

  11. Weekly cycle of NO2 by GOME measurements: a signature of anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Beirle, S.; Platt, U.; Wenig, M.; Wagner, T.

    2003-12-01

    Nitrogen oxides (NO+NO2=NOx and reservoir species) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50% of the total production of NOx. Since human activity in industrialized countries largely follows a seven-day cycle, fossil fuel combustion is expected to be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of NO2 column densities. By estimating and subtracting the stratospheric column, and considering radiative transfer, vertical column densities (VCD) of tropospheric NO2 can be determined (e.g. Leue et al., 2001). We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25-50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD may help to identify the different anthropogenic source categories. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle exemplarily over Germany, obtaining a value of about 6 h in summer and 18-24 h in winter.

  12. On-ground re-calibration of the GOME-2 satellite spectrometer series

    NASA Astrophysics Data System (ADS)

    Otter, Gerard; Dijkhuizen, Niels; Vosteen, Amir; Brinkers, Sanneke; Gür, Bilgehan; Kenter, Pepijn; Sallusti, Marcello; Tomuta, Dana; Veratti, Rubes; Cappani, Annalisa

    2017-11-01

    The Global Ozone Monitoring Experiment-2[1] (GOME-2) represents one of the European instruments carried on board the MetOp satellite within the ESA's "Living Planet Program". Consisting of three flight models (FM's) it is intended to provide long-term monitoring of atmospheric ozone and other trace gases over a time frame of 15-20 years, thus contributing valuable input towards climate and atmospheric research and providing near real-time data for use in air quality forecasting. The ambition to achieve highly accurate scientific results requires a thorough calibration and characterization of the instrument prior to launch. These calibration campaigns were performed by TNO in Delft in the Netherlands, in the "Thermal Vacuum Calibration Facility" of the institute. Due to refurbishment and / or storage of the instruments over a period of a few years, several re-calibration campaigns were necessary. These re-calibrations provided the unique opportunity to study the effects of long term storage and build up statistics on the instrument as well as the calibration methods used. During the re-calibration of the second flight model a difference was found in the radiometric calibration output, which was not understood initially. In order to understand the anomalies on the radiometry, a deep investigation was performed using numerous variations of the setup and different sources. The major contributor was identified to be a systematic error in the alignment, for which a correction was applied. Apart from this, it was found that the geometry of the sources influenced the results. Based on the calibration results combined with a theoretical geometrical hypothesis inferred that the on-ground calibration should mimic as close as possible the in-orbit geometry.

  13. SO2 plume height retrieval from direct fitting of GOME-2 backscattered radiance measurements

    NASA Astrophysics Data System (ADS)

    van Gent, J.; Spurr, R.; Theys, N.; Lerot, C.; Brenot, H.; Van Roozendael, M.

    2012-04-01

    The use of satellite measurements for SO2 monitoring has become an important aspect in the support of aviation control. Satellite measurements are sometimes the only information available on SO2 concentrations from volcanic eruption events. The detection of SO2 can furthermore serve as a proxy for the presence of volcanic ash that poses a possible hazard to air traffic. In that respect, knowledge of both the total vertical column amount and the effective altitude of the volcanic SO2 plume is valuable information to air traffic control. The Belgian Institute for Space Aeronomy (BIRA-IASB) hosts the ESA-funded Support to Aviation Control Service (SACS). This system provides Volcanic Ash Advisory Centers (VAACs) worldwide with near real-time SO2 and volcanic ash data, derived from measurements from space. We present results from our algorithm for the simultaneous retrieval of total vertical columns of O3 and SO2 and effective SO2 plume height from GOME-2 backscattered radiance measurements. The algorithm is an extension to the GODFIT direct fitting algorithm, initially developed at BIRA-IASB for the derivation of improved total ozone columns from satellite data. The algorithm uses parameterized vertical SO2 profiles which allow for the derivation of the peak height of the SO2 plume, along with the trace gas total column amounts. To illustrate the applicability of the method, we present three case studies on recent volcanic eruptions: Merapi (2010), Grímsvotn (2011), and Nabro (2011). The derived SO2 plume altitude values are validated with the trajectory model FLEXPART and with aerosol altitude estimations from the CALIOP instrument on-board the NASA A-train CALIPSO platform. We find that the effective plume height can be obtained with a precision as fine as 1 km for moderate and strong volcanic events. Since this is valuable information for air traffic, we aim at incorporating the plume height information in the SACS system.

  14. Operational Monitoring of GOME-2 and IASI Level 1 Product Processing at EUMETSAT

    NASA Astrophysics Data System (ADS)

    Livschitz, Yakov; Munro, Rosemary; Lang, Rüdiger; Fiedler, Lars; Dyer, Richard; Eisinger, Michael

    2010-05-01

    The growing complexity of operational level 1 radiance products from Low Earth Orbiting (LEO) platforms like EUMETSATs Metop series makes near-real-time monitoring of product quality a challenging task. The main challenge is to provide a monitoring system which is flexible and robust enough to identify and to react to anomalies which may be previously unknown to the system, as well as to provide all means and parameters necessary in order to support efficient ad-hoc analysis of the incident. The operational monitoring system developed at EUMETSAT for monitoring of GOME-2 and IASI level 1 data allows to perform near-real-time monitoring of operational products and instrument's health in a robust and flexible fashion. For effective information management, the system is based on a relational database (Oracle). An Extract, Transform, Load (ETL) process transforms products in EUMETSAT Polar System (EPS) format into relational data structures. The identification of commonalities between products and instruments allows for a database structure design in such a way that different data can be analyzed using the same business intelligence functionality. An interactive analysis software implementing modern data mining techniques is also provided for a detailed look into the data. The system is effectively used for day-to-day monitoring, long-term reporting, instrument's degradation analysis as well as for ad-hoc queries in case of an unexpected instrument or processing behaviour. Having data from different sources on a single instrument and even from different instruments, platforms or numerical weather prediction within the same database allows effective cross-comparison and looking for correlated parameters. Automatic alarms raised by checking for deviation of certain parameters, for data losses and other events significantly reduce time, necessary to monitor the processing on a day-to-day basis.

  15. Operational Monitoring of GOME-2 and IASI Level 1 Product Processing at EUMETSAT

    NASA Astrophysics Data System (ADS)

    Livschitz, Y.; Munro, R.; Lang, R.; Fiedler, L.; Dyer, R.; Eisinger, M.

    2009-12-01

    The growing complexity of operational level 1 radiance products from Low Earth Orbiting (LEO) platforms like EUMETSATs Metop series makes near-real-time monitoring of product quality a challenging task. The main challenge is to provide a monitoring system which is flexible and robust enough to identify and to react to anomalies which may be previously unknown to the system, as well as to provide all means and parameters necessary in order to support efficient ad-hoc analysis of the incident. The operational monitoring system developed at EUMETSAT for monitoring of GOME-2 and IASI level 1 data allows to perform near-real-time monitoring of operational products and instrument’s health in a robust and flexible fashion. For effective information management, the system is based on a relational database (Oracle). An Extract, Transform, Load (ETL) process transforms products in EUMETSAT Polar System (EPS) format into relational data structures. The identification of commonalities between products and instruments allows for a database structure design in such a way that different data can be analyzed using the same business intelligence functionality. An interactive analysis software implementing modern data mining techniques is also provided for a detailed look into the data. The system is effectively used for day-to-day monitoring, long-term reporting, instrument’s degradation analysis as well as for ad-hoc queries in case of an unexpected instrument or processing behaviour. Having data from different sources on a single instrument and even from different instruments, platforms or numerical weather prediction within the same database allows effective cross-comparison and looking for correlated parameters. Automatic alarms raised by checking for deviation of certain parameters, for data losses and other events significantly reduce time, necessary to monitor the processing on a day-to-day basis.

  16. Macrophytobenthic flora of the Abrolhos Archipelago and the Sebastião Gomes Reef, Brazil

    NASA Astrophysics Data System (ADS)

    Torrano-Silva, Beatriz N.; Oliveira, Eurico C.

    2013-11-01

    The Abrolhos Bank, located on the coast of Bahia, Brazil, harbors the largest coral reef system in the South Atlantic. This area has attracted the attention of biologists because of its peculiar mushroom-shaped structures, locally known as "chapeirões", and endemic species of corals and other organisms. The macrophytobenthos compartment plays an important ecological role in the functioning of the bank, and some reports on the presence of seaweeds and seagrasses have been published; however, the data are fragmentary, and a more detailed survey of the macrophytobenthos compartment is lacking. Here we consolidate the information available and add new data obtained from two expeditions focused on seaweed and seagrass diversity from two sectors of the bank: the islands of the Abrolhos archipelago (AA) and the Sebastião Gomes Reef (SG). These sites were selected for their contrasting characteristics. Specifically, SG (15 km off the mouth of the Caravelas River) is subjected to a broader range of anthropogenic impacts and to input of terrigenous sediments, while the AA (54 km offshore) is surrounded by calcareous biogenic sediments, has clearer water and is less affected by human activities. Macrophytobenthic species richness on both reference areas is larger than previously thought. Considering previous records, there are 164 species of macrophytes in AA and 111 species in SG, of which 59 and 74 species are first records for each respective location. The higher species richness at the AA may result from a higher habitat complexity and lower turbidity, but a potential negative effect of enhanced human impacts at SG cannot be ruled out. Considering that macroalgae are relevant components of the benthic community, as producers and structurer organisms, the data presented herein provide a reliable baseline for future environmental studies, and thus may contribute to improve management policies within the unique ecosystem of Abrolhos.

  17. Trends in formaldehyde columns over the Amazon rainforest, as observed from space with SCIAMACHY, OMI and GOME-2 spectrometers.

    NASA Astrophysics Data System (ADS)

    De Smedt, Isabelle; Stavrakou, Trissevgeni; Lerot, Christophe; Yu, Huan; François, Hendrick; Gielen, Clio; Pinardi, Gaia; Muller, Jean-François; Van Roozendael, Michel

    2015-04-01

    Atmospheric formaldehyde (H2CO) is a central carbonyl compound of tropospheric chemistry. It is produced by the oxidation of a large variety of volatile organic compounds (VOCs), from biogenic, pyrogenic or anthropogenic emission sources. Tropical vegetation, in particular the Amazon forest that represents over half of the planet's remaining rainforests, emit a wide range of highly reactive biogenic volatile organic compounds (BVOCs). Those play a critical role in atmospheric chemistry and climate, by changing the oxidation capacity of the atmosphere and thus the lifetimes of other key trace gases such as CO and CH4, and by producing organic aerosols. Satellite observations of H2CO, bringing information at the global scale and over decades, are essential to trace and understand the nature and the spatio-temporal evolution of VOC emissions. We have been developing algorithms to retrieve formaldehyde columns from satellite nadir UV spectral measurements, and we have processed the full level-1 datasets of GOME/ERS-2, SCIAMACHY/ENVISAT, GOME-2/METOPA&B and OMI/AURA (De Smedt et al., 2008; 2012; 2015). Resulting H2CO products are openly distributed via the TEMIS website (http://h2co.aeronomie.be). In this work, we use the morning and afternoon H2CO columns between 2004 and 2014, respectively composed by the SCIAMACHY and GOME2 A&B datasets, and from the OMI observations, to study the diurnal, seasonal and long-term variations of H2CO over the Amazon rainforest. The highest H2CO columns worldwide are observed, with morning columns markedly higher than early afternoon. Very large variations between the dry and the wet seasons occur each year. Importantly, in some areas of the forest, mainly in the Rondonia Brazilian State, we observe a net decrease of the H2CO columns. We find very high correlation coefficients between the satellite H2CO columns and the reported deforestation fires that have significantly decreased in Rondonia since 2004 [INPE].

  18. Application of OMI, SCIAMACHY and GOME-2 Satellite SO2 Retrievals for Detection of Large Emission Sources

    NASA Technical Reports Server (NTRS)

    Fioletov, V.E.; McLinden, C. A.; Krotkov, N.; Yang, K.; Loyola, D. G.; Valks, P.; Theys, N.; Van Roozendael, M.; Nowlan, C. R.; Chance, K.; hide

    2013-01-01

    Retrievals of sulfur dioxide (SO2) from space-based spectrometers are in a relatively early stage of development. Factors such as interference between ozone and SO2 in the retrieval algorithms often lead to errors in the retrieved values. Measurements from the Ozone Monitoring Instrument (OMI), Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and Global Ozone Monitoring Experiment-2 (GOME-2) satellite sensors, averaged over a period of several years, were used to identify locations with elevated SO2 values and estimate their emission levels. About 30 such locations, detectable by all three sensors and linked to volcanic and anthropogenic sources, were found after applying low and high spatial frequency filtration designed to reduce noise and bias and to enhance weak signals to SO2 data from each instrument. Quantitatively, the mean amount of SO2 in the vicinity of the sources, estimated from the three instruments, is in general agreement. However, its better spatial resolution makes it possible for OMI to detect smaller sources and with additional detail as compared to the other two instruments. Over some regions of China, SCIAMACHY and GOME-2 data show mean SO2 values that are almost 1.5 times higher than those from OMI, but the suggested spatial filtration technique largely reconciles these differences.

  19. GOME-2A retrievals of tropospheric NO2 in different spectral ranges - influence of penetration depth

    NASA Astrophysics Data System (ADS)

    Behrens, Lisa K.; Hilboll, Andreas; Richter, Andreas; Peters, Enno; Eskes, Henk; Burrows, John P.

    2018-05-01

    In this study, we present a novel nitrogen dioxide (NO2) differential optical absorption spectroscopy (DOAS) retrieval in the ultraviolet (UV) spectral range for observations from the Global Ozone Monitoring Instrument 2 on board EUMETSAT's MetOp-A (GOME-2A) satellite. We compare the results to those from an established NO2 retrieval in the visible (vis) spectral range from the same instrument and investigate how differences between the two are linked to the NO2 vertical profile shape in the troposphere. As expected, radiative transfer calculations for satellite geometries show that the sensitivity close to the ground is higher in the vis than in the UV spectral range. Consequently, NO2 slant column densities (SCDs) in the vis are usually higher than in the UV if the NO2 is close to the surface. Therefore, these differences in NO2 SCDs between the two spectral ranges contain information on the vertical distribution of NO2 in the troposphere. We combine these results with radiative transfer calculations and simulated NO2 fields from the TM5-MP chemistry transport model to evaluate the simulated NO2 vertical distribution. We investigate regions representative of both anthropogenic and biomass burning NO2 pollution. Anthropogenic air pollution is mostly located in the boundary layer close to the surface, which is reflected by large differences between UV and vis SCDs of ˜ 60 %. Biomass burning NO2 in contrast is often uplifted into elevated layers above the boundary layer. This is best seen in tropical Africa south of the Equator, where the biomass burning NO2 is well observed in the UV, and the SCD difference between the two spectral ranges is only ˜ 36 %. In tropical Africa north of the Equator, however, the biomass burning NO2 is located closer to the ground, reducing its visibility in the UV. While not enabling a full retrieval of the vertical NO2 profile shape in the troposphere, our results can help to constrain the vertical profile of NO2 in the lower

  20. Operational surface UV radiation product from GOME-2 and AVHRR/3 data

    NASA Astrophysics Data System (ADS)

    Kujanpää, J.; Kalakoski, N.

    2015-05-01

    The surface ultraviolet (UV) radiation product, version 1.20, generated operationally in the framework of the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) is described. The product is based on the total ozone column derived from the measurements of the second Global Ozone Monitoring Experiment (GOME-2) instrument aboard EUMETSAT's polar orbiting meteorological operational (Metop) satellites. The input total ozone product is generated by the German Aerospace Center (DLR) also within the O3M SAF framework. Polar orbiting satellites provide global coverage but infrequent sampling of the diurnal cloud cover. The diurnal variation of the surface UV radiation is extremely strong due to modulation by solar elevation and rapidly changing cloud cover. At the minimum, one sample of the cloud cover in the morning and another in the afternoon are needed to derive daily maximum and daily integrated surface UV radiation quantities. This is achieved by retrieving cloud optical depth from the channel 1 reflectance of the third Advanced Very High Resolution Radiometer (AVHRR/3) instrument aboard both Metop in the morning orbit (daytime descending node around 09:30 LT) and Polar Orbiting Environmental Satellites (POES) of the National Oceanic and Atmospheric Administration (NOAA) in the afternoon orbit (daytime ascending node around 14:30 LT). In addition, more overpasses are used at high latitudes where the swaths of consecutive orbits overlap. The input satellite data are received from EUMETSAT's Multicast Distribution System (EUMETCast) using commercial telecommunication satellites for broadcasting the data to the user community. The surface UV product includes daily maximum dose rates and integrated daily doses with different biological weighting functions, integrated UVB and UVA radiation, solar noon UV Index and daily maximum photolysis

  1. How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; De Mazière, M.; Vigouroux, C.; Hendrick, F.; George, M.; Clerbaux, C.; Coheur, P.-F.; Guenther, A.

    2015-10-01

    The vertical columns of formaldehyde (HCHO) retrieved from two satellite instruments, the Global Ozone Monitoring Instrument-2 (GOME-2) on Metop-A and the Ozone Monitoring Instrument (OMI) on Aura, are used to constrain global emissions of HCHO precursors from open fires, vegetation and human activities in the year 2010. To this end, the emissions are varied and optimized using the adjoint model technique in the IMAGESv2 global CTM (chemical transport model) on a monthly basis and at the model resolution. Given the different local overpass times of GOME-2 (09:30 LT) and OMI (13:30 LT), the simulated diurnal cycle of HCHO columns is investigated and evaluated against ground-based optical measurements at seven sites in Europe, China and Africa. The modeled diurnal cycle exhibits large variability, reflecting competition between photochemistry and emission variations, with noon or early afternoon maxima at remote locations (oceans) and in regions dominated by anthropogenic emissions, late afternoon or evening maxima over fire scenes, and midday minima in isoprene-rich regions. The agreement between simulated and ground-based columns is generally better in summer (with a clear afternoon maximum at mid-latitude sites) than in winter, and the annually averaged ratio of afternoon to morning columns is slightly higher in the model (1.126) than in the ground-based measurements (1.043). The anthropogenic VOC (volatile organic compound) sources are found to be weakly constrained by the inversions on the global scale, mainly owing to their generally minor contribution to the HCHO columns, except over strongly polluted regions, like China. The OMI-based inversion yields total flux estimates over China close to the bottom-up inventory (24.6 vs. 25.5 TgVOC yr-1 in the a priori) with, however, pronounced increases in the northeast of China and reductions in the south. Lower fluxes are estimated based on GOME-2 HCHO columns (20.6 TgVOC yr-1), in particular over the northeast

  2. How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; De Mazière, M.; Vigouroux, C.; Hendrick, F.; George, M.; Clerbaux, C.; Coheur, P.-F.; Guenther, A.

    2015-04-01

    The vertical columns of formaldehyde (HCHO) retrieved from two satellite instruments, the Global Ozone Monitoring Instrument-2 (GOME-2) on Metop-A and the Ozone Monitoring Instrument (OMI) on Aura, are used to constrain global emissions of HCHO precursors from open fires, vegetation and human activities in the year 2010. To this end, the emissions are varied and optimized using the adjoint model technique in the IMAGESv2 global CTM (chemistry-transport model) on a monthly basis and at the model resolution. Given the different local overpass times of GOME-2 (09:30 LT) and OMI (13:30 LT), the simulated diurnal cycle of HCHO columns is investigated and evaluated against ground-based optical measurements at 7 sites in Europe, China and Africa. The modelled diurnal cycle exhibits large variability, reflecting competition between photochemistry and emission variations, with noon or early afternoon maxima at remote locations (oceans) and in regions dominated by anthropogenic emissions, late afternoon or evening maxima over fire scenes, and midday minima in isoprene-rich regions. The agreement between simulated and ground-based columns is found to be generally better in summer (with a clear afternoon maximum at mid-latitude sites) than in winter, and the annually averaged ratio of afternoon to morning columns is slightly higher in the model (1.126) than in the ground-based measurements (1.043). The anthropogenic VOC (volatile organic compound) sources are found to be weakly constrained by the inversions on the global scale, mainly owing to their generally minor contribution to the HCHO columns, except over strongly polluted regions, like China. The OMI-based inversion yields total flux estimates over China close to the bottom-up inventory (24.6 vs. 25.5 in the a priori) with, however, pronounced increases in the Northeast China and reductions in the south. Lower fluxes are estimated based on GOME-2 HCHO columns (20.6 TgVOC), in particular over the Northeast, likely

  3. Diurnal, seasonal and long-term variations of global formaldehyde columns inferred from combined OMI and GOME-2 observations

    NASA Astrophysics Data System (ADS)

    De Smedt, I.; Stavrakou, T.; Hendrick, F.; Danckaert, T.; Vlemmix, T.; Pinardi, G.; Theys, N.; Lerot, C.; Gielen, C.; Vigouroux, C.; Hermans, C.; Fayt, C.; Veefkind, P.; Müller, J.-F.; Van Roozendael, M.

    2015-11-01

    We present the new version (v14) of the BIRA-IASB algorithm for the retrieval of formaldehyde (H2CO) columns from spaceborne UV-visible sensors. Applied to OMI measurements from Aura and to GOME-2 measurements from MetOp-A and MetOp-B, this algorithm is used to produce global distributions of H2CO representative of mid-morning and early afternoon conditions. Its main features include (1) a new iterative DOAS scheme involving three fitting intervals to better account for the O2-O2 absorption, (2) the use of earthshine radiances averaged in the equatorial Pacific as reference spectra, and (3) a destriping correction and background normalisation resolved in the across-swath position. For the air mass factor calculation, a priori vertical profiles calculated by the IMAGES chemistry transport model at 09:30 and 13:30 LT are used. Although the resulting GOME-2 and OMI H2CO vertical columns are found to be highly correlated, some systematic differences are observed. Afternoon columns are generally larger than morning ones, especially in mid-latitude regions. In contrast, over tropical rainforests, morning H2CO columns significantly exceed those observed in the afternoon. These differences are discussed in terms of the H2CO column variation between mid-morning and early afternoon, using ground-based MAX-DOAS measurements available from seven stations in Europe, China and Africa. Validation results confirm the capacity of the combined satellite measurements to resolve diurnal variations in H2CO columns. Furthermore, vertical profiles derived from MAX-DOAS measurements in the Beijing area and in Bujumbura are used for a more detailed validation exercise. In both regions, we find an agreement better than 15 % when MAX-DOAS profiles are used as a priori for the satellite retrievals. Finally, regional trends in H2CO columns are estimated for the 2004-2014 period using SCIAMACHY and GOME-2 data for morning conditions, and OMI for early afternoon conditions. Consistent features

  4. Diurnal, seasonal and long-term variations of global formaldehyde columns inferred from combined OMI and GOME-2 observations

    NASA Astrophysics Data System (ADS)

    De Smedt, I.; Stavrakou, T.; Hendrick, F.; Danckaert, T.; Vlemmix, T.; Pinardi, G.; Theys, N.; Lerot, C.; Gielen, C.; Vigouroux, C.; Hermans, C.; Fayt, C.; Veefkind, P.; Müller, J.-F.; Van Roozendael, M.

    2015-04-01

    We present the new version (v14) of the BIRA-IASB algorithm for the retrieval of formaldehyde (H2CO) columns from spaceborne UV-Visible sensors. Applied to OMI measurements from Aura and to GOME-2 measurements from MetOp-A and B, this algorithm is used to produce global distributions of H2CO representative of mid-morning and early afternoon conditions. Its main features include (1) a new iterative DOAS scheme involving three fitting intervals to better account for the O2-O2 absorption, (2) the use of earthshine radiances averaged in the equatorial Pacific as reference spectra, (3) a destriping correction and background normalisation resolved in the along-swath position. For the air mass factor calculation, a priori vertical profiles calculated by the IMAGES chemistry transport model at 9.30 a.m. and 13.30 p.m. are used. Although the resulting GOME-2 and OMI H2CO vertical columns are found to be highly correlated, some systematic differences are observed. Afternoon columns are generally larger than morning ones, especially in mid-latitude regions. In contrast, over tropical rainforests, morning H2CO columns significantly exceed those observed in the afternoon. These differences are discussed in terms of the H2CO column variation between mid-morning and early afternoon, using ground-based MAX-DOAS measurements available from seven stations in Europe, China and Africa. Validation results confirm the capacity of the combined satellite measurements to resolve diurnal variations in H2CO columns. Furthermore, vertical profiles derived from MAX-DOAS measurements in the Beijing area and in Bujumbura are used for a more detailed validation exercise. In both regions, we find an agreement better than 15% when MAX-DOAS profiles are used as a priori for the satellite retrievals. Finally regional trends in H2CO columns are estimated for the 2004-2014 period using SCIAMACHY and GOME-2 data for morning conditions, and OMI for early afternoon conditions. Consistent features are

  5. How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?

    SciTech Connect

    Stavrakou, T.; Muller, J. F.; Bauwens, M.

    2015-10-26

    The vertical columns of formaldehyde (HCHO) retrieved from two satellite instruments, the Global Ozone Monitoring Instrument-2 (GOME-2) on Metop-A and the Ozone Monitoring Instrument (OMI) on Aura, are used to constrain global emissions of HCHO precursors from open fires, vegetation and human activities in the year 2010. To this end, the emissions are varied and optimized using the ad-joint model technique in the IMAGESv2 global CTM (chem-ical transport model) on a monthly basis and at the model res-olution. Given the different local overpass times of GOME- 2 (09:30 LT) and OMI (13:30 LT), the simulated diurnal cy-cle of HCHO columnsmore » is investigated and evaluated against ground-based optical measurements at seven sites in Europe, China and Africa. The modeled diurnal cycle exhibits large variability, reflecting competition between photochemistry and emission variations, with noon or early afternoon max-ima at remote locations (oceans) and in regions dominated by anthropogenic emissions, late afternoon or evening max-ima over fire scenes, and midday minima in isoprene-rich re-gions. The agreement between simulated and ground-based columns is generally better in summer (with a clear after-noon maximum at mid-latitude sites) than in winter, and the annually averaged ratio of afternoon to morning columns is slightly higher in the model (1.126) than in the ground-based measurements (1.043).The anthropogenic VOC (volatile organic compound) sources are found to be weakly constrained by the inversions on the global scale, mainly owing to their generally minor contribution to the HCHO columns, except over strongly pol-luted regions, like China. The OMI-based inversion yields total flux estimates over China close to the bottom-up inven-tory (24.6 vs. 25.5 TgVOC yr -1 in the a priori) with, how-ever, pronounced increases in the northeast of China and re-ductions in the south. Lower fluxes are estimated based on GOME-2 HCHO columns (20.6 TgVOC yr -1), in particular

  6. Observing atmospheric formaldehyde (HCHO) from space: validation and intercomparison of six retrievals from four satellites (OMI, GOME2A, GOME2B, OMPS) with SEAC4RS aircraft observations over the Southeast US

    PubMed Central

    Zhu, Lei; Jacob, Daniel J.; Kim, Patrick S.; Fisher, Jenny A.; Yu, Karen; Travis, Katherine R.; Mickley, Loretta J.; Yantosca, Robert M.; Sulprizio, Melissa P.; De Smedt, Isabelle; Abad, Gonzalo Gonzalez; Chance, Kelly; Li, Can; Ferrare, Richard; Fried, Alan; Hair, Johnathan W.; Hanisco, Thomas F.; Richter, Dirk; Scarino, Amy Jo; Walega, James; Weibring, Petter; Wolfe, Glenn M.

    2018-01-01

    Formaldehyde (HCHO) column data from satellites are widely used as a proxy for emissions of volatile organic compounds (VOCs) but validation of the data has been extremely limited. Here we use highly accurate HCHO aircraft observations from the NASA SEAC4RS campaign over the Southeast US in August–September 2013 to validate and intercompare six retrievals of HCHO columns from four different satellite instruments (OMI, GOME2A, GOME2B and OMPS) and three different research groups. The GEOS-Chem chemical transport model is used as a common intercomparison platform. All retrievals feature a HCHO maximum over Arkansas and Louisiana, consistent with the aircraft observations and reflecting high emissions of biogenic isoprene. The retrievals are also interconsistent in their spatial variability over the Southeast US (r=0.4–0.8 on a 0.5°×0.5° grid) and in their day-to-day variability (r=0.5–0.8). However, all retrievals are biased low in the mean by 20–51%, which would lead to corresponding bias in estimates of isoprene emissions from the satellite data. The smallest bias is for OMI-BIRA, which has high corrected slant columns relative to the other retrievals and low scattering weights in its air mass factor (AMF) calculation. OMI-BIRA has systematic error in its assumed vertical HCHO shape profiles for the AMF calculation and correcting this would eliminate its bias relative to the SEAC4RS data. Our results support the use of satellite HCHO data as a quantitative proxy for isoprene emission after correction of the low mean bias. There is no evident pattern in the bias, suggesting that a uniform correction factor may be applied to the data until better understanding is achieved. PMID:29619044

  7. The GOME-2 instrument on the Metop series of satellites: instrument design, calibration, and level 1 data processing - an overview

    NASA Astrophysics Data System (ADS)

    Munro, Rosemary; Lang, Rüdiger; Klaes, Dieter; Poli, Gabriele; Retscher, Christian; Lindstrot, Rasmus; Huckle, Roger; Lacan, Antoine; Grzegorski, Michael; Holdak, Andriy; Kokhanovsky, Alexander; Livschitz, Jakob; Eisinger, Michael

    2016-03-01

    The Global Ozone Monitoring Experiment-2 (GOME-2) flies on the Metop series of satellites, the space component of the EUMETSAT Polar System. In this paper we will provide an overview of the instrument design, the on-ground calibration and characterization activities, in-flight calibration, and level 0 to 1 data processing. The current status of the level 1 data is presented and points of specific relevance to users are highlighted. Long-term level 1 data consistency is also discussed and plans for future work are outlined. The information contained in this paper summarizes a large number of technical reports and related documents containing information that is not currently available in the published literature. These reports and documents are however made available on the EUMETSAT web pages and readers requiring more details than can be provided in this overview paper will find appropriate references at relevant points in the text.

  8. The GOME-2 instrument on the Metop series of satellites: instrument design, calibration, and level 1 data processing - an overview

    NASA Astrophysics Data System (ADS)

    Munro, R.; Lang, R.; Klaes, D.; Poli, G.; Retscher, C.; Lindstrot, R.; Huckle, R.; Lacan, A.; Grzegorski, M.; Holdak, A.; Kokhanovsky, A.; Livschitz, J.; Eisinger, M.

    2015-08-01

    The Global Ozone Monitoring Experiment-2 (GOME-2) flies on the Metop series of satellites, the space component of the EUMETSAT Polar System. In this paper we will provide an overview of the instrument design, the on-ground calibration and characterisation activities, in-flight calibration, and level 0 to 1 data processing. The quality of the level 1 data is presented and points of specific relevance to users are highlighted. Long-term level 1 data consistency is also discussed and plans for future work are outlined. The information contained in this paper summarises a large number of technical reports and related documents containing information that is not currently available in the published literature. These reports and documents are however made available on the EUMETSAT web pages (http://www.eumetsat.int) and readers requiring more details than can be provided in this overview paper will find appropriate references at relevant points in the text.

  9. First Directly Retrieved Global Distribution of Tropospheric Column Ozone from GOME: Comparison with the GEOS-CHEM Model

    NASA Technical Reports Server (NTRS)

    Liu, Xiong; Chance, Kelly; Sioris, Christopher E.; Kurosu, Thomas P.; Spurr, Robert J. D.; Martin, Randall V.; Fu, Tzung-May; Logan, Jennifer A.; Jacob, Daniel J.; Palmer, Paul I.; hide

    2006-01-01

    We present the first directly retrieved global distribution of tropospheric column ozone from Global Ozone Monitoring Experiment (GOME) ultraviolet measurements during December 1996 to November 1997. The retrievals clearly show signals due to convection, biomass burning, stratospheric influence, pollution, and transport. They are capable of capturing the spatiotemporal evolution of tropospheric column ozone in response to regional or short time-scale events such as the 1997-1998 El Nino event and a 10-20 DU change within a few days. The global distribution of tropospheric column ozone displays the well-known wave-1 pattern in the tropics, nearly zonal bands of enhanced tropospheric column ozone of 36-48 DU at 20degS-30degS during the austral spring and at 25degN-45degN during the boreal spring and summer, low tropospheric column ozone of <30 DU uniformly distributed south of 35 S during all seasons, and relatively high tropospheric column ozone of >33 DU at some northern high-latitudes during the spring. Simulation from a chemical transport model corroborates most of the above structures, with small biases of <+/-5 DU and consistent seasonal cycles in most regions, especially in the southern hemisphere. However, significant positive biases of 5-20 DU occur in some northern tropical and subtropical regions such as the Middle East during summer. Comparison of GOME with monthly-averaged Measurement of Ozone and Water Vapor by Airbus in-service Aircraft (MOZAIC) tropospheric column ozone for these regions usually shows good consistency within 1 a standard deviations and retrieval uncertainties. Some biases can be accounted for by inadequate sensitivity to lower tropospheric ozone, the different spatiotemporal sampling and the spatiotemporal variations in tropospheric column ozone.

  10. Anti-inflammatory activity of aqueous extract and bioactive compounds identified from the fruits of Hancornia speciosa Gomes (Apocynaceae).

    PubMed

    Torres-Rêgo, Manoela; Furtado, Allanny Alves; Bitencourt, Mariana Angélica Oliveira; Lima, Maira Conceição Jerônimo de Souza; Andrade, Rafael Caetano Lisbôa Castro de; Azevedo, Eduardo Pereira de; Soares, Thaciane da Cunha; Tomaz, José Carlos; Lopes, Norberto Peporine; da Silva-Júnior, Arnóbio Antônio; Zucolotto, Silvana Maria; Fernandes-Pedrosa, Matheus de Freitas

    2016-08-05

    Hancornia speciosa Gomes (Apocynaceae), popularly known as "mangabeira," has been used in folk medicine to treat inflammatory disorders, hypertension, dermatitis, diabetes, liver diseases and gastric disorders. Although the ethnobotany indicates that its fruits can be used for the treatment of ulcers and inflammatory disorders, only few studies have been conducted to prove such biological activities. This study investigated the anti-inflammatory properties of the aqueous extract of the fruits of H. speciosa Gomes as well as its bioactive compounds using in vivo experimental models. The bioactive compounds were identified by High Performance Liquid Chromatography coupled with diode array detector (HPLC-DAD) and Liquid Chromatography coupled with Mass Spectrometry (LC-MS). The anti-inflammatory properties were investigated through in vivo tests, which comprised xylene-induced ear edema, carrageenan-induced peritonitis and zymosan-induced air pouch. The levels of IL-1β, IL-6, IL-12 and TNF-α were determined using ELISA. Rutin and chlorogenic acid were identified in the extract as the main secondary metabolites. In addition, the extract as well as rutin and chlorogenic acid significantly inhibited the xilol-induced ear edema and also reduced the cell migration in both carrageenan-induced peritonitis and zymosan-induced air pouch models. Reduced levels of cytokines were also observed. This is the first study that demonstrated the anti-inflammatory activity of the extract of H. speciosa fruits against different inflammatory agents in animal models, suggesting that its bioactive molecules, especially rutin and chlorogenic acid are, at least in part, responsible for such activity. These findings support the widespread use of Hancornia speciosa in popular medicine and demonstrate that its aqueous extract has therapeutical potential for the development of herbal drugs with anti-inflammatory properties.

  11. Observing Atmospheric Formaldehyde (HCHO) from Space: Validation and Intercomparison of Six Retrievals from Four Satellites (OMI, GOME2A, GOME2B, OMPS) with SEAC4RS Aircraft Observations over the Southeast US

    NASA Technical Reports Server (NTRS)

    Zhu, Lei; Jacob, Daniel J.; Kim, Patrick S.; Fisher, Jenny A.; Yu, Karen; Travis, Katherine R.; Mickley, Loretta J.; Yantosca, Robert M.; Sulprizio, Melissa P.; De Smedt, Isabelle; hide

    2016-01-01

    Formaldehyde (HCHO) column data from satellites are widely used as a proxy for emissions of volatile organic compounds (VOCs), but validation of the data has been extremely limited. Here we use highly accurate HCHO aircraft observations from the NASA SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) campaign over the southeast US in August-September 2013 to validate and intercompare six retrievals of HCHO columns from four different satellite instruments (OMI (Ozone Monitoring Instrument), GOME (Global Ozone Monitoring Experiment) 2A, GOME (Global Ozone Monitoring Experiment) 2B and OMPS (Ozone Mapping and Profiler Suite)) and three different research groups. The GEOS (Goddard Earth Observing System)-Chem chemical transport model is used as a common intercomparison platform. All retrievals feature a HCHO maximum over Arkansas and Louisiana, consistent with the aircraft observations and reflecting high emissions of biogenic isoprene. The retrievals are also interconsistent in their spatial variability over the southeast US (r equals 0.4 to 0.8 on a 0.5 degree by 0.5 degree grid) and in their day-to-day variability (r equals 0.5 to 0.8). However, all retrievals are biased low in the mean by 20 to 51 percent, which would lead to corresponding bias in estimates of isoprene emissions from the satellite data. The smallest bias is for OMI-BIRA (Ozone Monitoring Instrument - Belgian Institute for Space Aeronomy), which has high corrected slant columns relative to the other retrievals and low scattering weights in its air mass factor (AMF) calculation. OMI-BIRA has systematic error in its assumed vertical HCHO shape profiles for the AMF calculation, and correcting this would eliminate its bias relative to the SEAC (sup 4) RS data. Our results support the use of satellite HCHO data as a quantitative proxy for isoprene emission after correction of the low mean bias. There is no evident pattern in the bias, suggesting that

  12. [Luís Gomes Ferreira reports on the health of slaves in his work entitled Erário mineral (1735)].

    PubMed

    Eugênio, Alisson

    2015-01-01

    The article analyzes the reports of Luís Gomes Ferreira published in his manual on practical medicine entitled Erário mineral, of 1735, on the most common illnesses in captivity. It is shown that such reports can be interpreted as a criticism of the social relations of the slave era by issuing some warnings to the landowners who failed to look after the health of their slaves.

  13. New Methods for Retrieval of Chlorophyll Red Fluorescence from Hyperspectral Satellite Instruments: Simulations and Application to GOME-2 and SCIAMACHY

    NASA Technical Reports Server (NTRS)

    Joiner, Joanna; Yoshida, Yasuko; Guanter, Luis; Middleton, Elizabeth M.

    2016-01-01

    Global satellite measurements of solar-induced fluorescence (SIF) from chlorophyll over land and ocean have proven useful for a number of different applications related to physiology, phenology, and productivity of plants and phytoplankton. Terrestrial chlorophyll fluorescence is emitted throughout the red and far-red spectrum, producing two broad peaks near 683 and 736nm. From ocean surfaces, phytoplankton fluorescence emissions are entirely from the red region (683nm peak). Studies using satellite-derived SIF over land have focused almost exclusively on measurements in the far red (wavelengths greater than 712nm), since those are the most easily obtained with existing instrumentation. Here, we examine new ways to use existing hyperspectral satellite data sets to retrieve red SIF (wavelengths less than 712nm) over both land and ocean. Red SIF is thought to provide complementary information to that from the far red for terrestrial vegetation. The satellite instruments that we use were designed to make atmospheric trace-gas measurements and are therefore not optimal for observing SIF; they have coarse spatial resolution and only moderate spectral resolution (0.5nm). Nevertheless, these instruments, the Global Ozone Monitoring Instrument 2 (GOME-2) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), offer a unique opportunity to compare red and far-red terrestrial SIF at regional spatial scales. Terrestrial SIF has been estimated with ground-, aircraft-, or satellite-based instruments by measuring the filling-in of atmospheric andor solar absorption spectral features by SIF. Our approach makes use of the oxygen (O2) gamma band that is not affected by SIF. The SIF-free O2 gamma band helps to estimate absorption within the spectrally variable O2 B band, which is filled in by red SIF. SIF also fills in the spectrally stable solar Fraunhofer lines (SFLs) at wavelengths both inside and just outside the O2 B band, which further helps

  14. A method to generate surface UV radiation maps over Europe using GOME, Meteosat, and ancillary geophysical data

    NASA Astrophysics Data System (ADS)

    Verdebout, Jean

    2000-02-01

    This paper presents a method for generating surface ultraviolet (UV) radiation maps over Europe, with a spatial resolution of 0.05°, and potentially on a half-hour basis. The UV irradiance is obtained by interpolation in a look-up table (LUT), the entries of which are solar zenith angle, total column ozone amount, cloud liquid water thickness, near-surface horizontal visibility, surface elevation, and UV albedo. Both satellite (Meteosat, GOME) and nonsatellite (synoptic observations, meteorological model results, digital elevation model) data are exploited to assign values to the influencing factors. With the help of another LUT simulating the visible signal, Meteosat data are processed to retrieve the cloud liquid water thickness. The radiative transfer calculations are performed with the UVspec code. A preliminary step consists in generating an effective surface Meteosat albedo map from a series of 10 consecutive days. In this process the well-known difficulty of distinguishing clouds from snow-covered surfaces is encountered. An attempt is made to partially resolve the ambiguity by using the Meteosat infrared channel and modeled snow cover data. After additional empirical cloud filtering, the effective albedo map is used as a baseline to estimate the cloud liquid water thickness. The UV surface albedo is assigned uniform values for land and sea/ocean, except in the presence of snow. In this case it is given a value proportional to the Meteosat effective albedo. The total column ozone is extracted from the level 3 GOME products. The aerosol optical thickness is mapped by gridding the daily measurements performed by ˜1000 ground stations. The digital elevation model is the GTOPO30 data set from the U.S. Geological Survey. European wide UV dose rate maps are presented for one day in April 1997, and the influence of the various factors is illustrated. A daily integrated dose map was also generated using 27 Meteosat acquisitions at half-hour intervals on the same

  15. Surface NO2 fields derived from joint use of OMI and GOME-2A observations with EMEP model output

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Svendby, Tove; Stebel, Kerstin

    2016-04-01

    Nitrogen dioxide (NO2) is one of the most prominent air pollutants. Emitted primarily by transport and industry, NO2 has a major impact on health and economy. In contrast to the very sparse network of air quality monitoring stations, satellite data of NO2 is ubiquitous and allows for quantifying the NO2 levels worldwide. However, one drawback of satellite-derived NO2 products is that they provide solely an estimate of the entire tropospheric column, whereas what is generally needed for air quality applications are the concentrations of NO2 near the surface. Here we derive surface NO2 concentration fields from OMI and GOME-2A tropospheric column products using the EMEP chemical transport model as auxiliary information. The model is used for providing information of the boundary layer contribution to the total tropospheric column. For preparation of deriving the surface product, a comprehensive model-based analysis of the spatial and temporal patterns of the NO2 surface-to-column ratio in Europe was carried out for the year 2011. The results from this analysis indicate that the spatial patterns of the surface-to-column ratio vary only slightly. While the highest ratio values can be found in some shipping lanes, the spatial variability of the ratio in some of the most polluted areas of Europe is not very high. Some but not all urban agglomeration shows high ratio values. Focusing on the temporal behavior, the analysis showed that the European-wide average ratio varies throughout the year. The surface-to-column ratio increases from January all the way through April when it reaches its maximum, then decreases relatively rapidly to average levels and then stays mostly constant throughout the summer. The minimum ratio is observed in December. The knowledge gained from analyzing the spatial and temporal patterns of the surface-to-column ratio was then used to produce surface NO2 products from the daily NO2 data for OMI and GOME-2A. This was carried out using two methods

  16. Antioxidant, Antimicrobial and Cytotoxic Properties as Well as the Phenolic Content of the Extract from Hancornia speciosa Gomes

    PubMed Central

    Santos, Uilson P.; Campos, Jaqueline F.; Torquato, Heron Fernandes V.; Paredes-Gamero, Edgar Julian; Carollo, Carlos Alexandre; Estevinho, Leticia M.; de Picoli Souza, Kely

    2016-01-01

    Hancornia speciosa Gomes (Apocynaceae) is a fruit tree, popularly known as mangabeira, and it is widely distributed throughout Brazil. Several parts of the plant are used in folk medicine, and the leaf and bark extracts have anti-inflammatory, antihypertensive, antidiabetic, and antimicrobial properties. In this study, we investigated the chemical composition of the ethanolic extract of Hancornia speciosa leaves (EEHS) and its antioxidant, antimicrobial, and cytotoxic activities as well as the mechanisms involved in cell death. The chemical compounds were identified by liquid chromatography coupled to mass spectrometry (LC-MS/MS). The antioxidant activity of the EEHS was investigated using the method that involves the scavenging of 2,2-diphenyl-1-picrylhydrazyl free radicals as well as the inhibition of oxidative hemolysis and lipid peroxidation induced by 2,2’-azobis (2-amidinopropane) in human erythrocytes. The antimicrobial activity was determined by calculating the minimum inhibitory concentration, minimum bactericidal concentration, minimum fungicidal concentration, and zone of inhibition. Kasumi-1 leukemic cells were used to assess the cytotoxic activity and mechanisms involved in cell death promoted by the EEHS. The chemical compounds identified were quinic acid, chlorogenic acid, catechin, rutin, isoquercitrin, kaempferol-rutinoside, and catechin-pentoside. The EEHS demonstrated antioxidant activity via the sequestration of free radicals, inhibition of hemolysis, and inhibition of lipid peroxidation in human erythrocytes incubated with an oxidizing agent. The antimicrobial activity was observed against American Type Culture Collection (ATCC) and hospital strains of bacteria and fungi, filamentous fungi and dermatophytes. The cytotoxic activity of the EEHS was induced by apoptosis, reduction of the mitochondrial membrane potential, and activation of cathepsins. Together, these results indicate the presence of phenolic compounds and flavonoids in the EEHS

  17. Global Monitoring of Terrestrial Chlorophyll Fluorescence from Moderate-spectral-resolution Near-infrared Satellite Measurements: Methodology, Simulations, and Application to GOME-2

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Gaunter, L.; Lindstrot, R.; Voigt, M.; Vasilkov, A. P.; Middleton, E. M.; Huemmrich, K. F.; Yoshida, Y.; Frankenberg, C.

    2013-01-01

    Globally mapped terrestrial chlorophyll fluorescence retrievals are of high interest because they can provide information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling and agricultural applications. Previous satellite retrievals of fluorescence have relied solely upon the filling-in of solar Fraunhofer lines that are not significantly affected by atmospheric absorption. Although these measurements provide near-global coverage on a monthly basis, they suffer from relatively low precision and sparse spatial sampling. Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data with a simplified radiative transfer model to disentangle the spectral signatures of three basic components: atmospheric absorption, surface reflectance, and fluorescence radiance. An empirically based principal component analysis approach is employed, primarily using cloudy data over ocean, to model and solve for the atmospheric absorption. Through detailed simulations, we demonstrate the feasibility of the approach and show that moderate-spectral-resolution measurements with a relatively high signal-to-noise ratio can be used to retrieve far-red fluorescence information with good precision and accuracy. The method is then applied to data from the Global Ozone Monitoring Instrument 2 (GOME-2). The GOME-2 fluorescence retrievals display similar spatial structure as compared with those from a simpler technique applied to the Greenhouse gases Observing SATellite (GOSAT). GOME-2 enables global mapping of far-red fluorescence with higher precision over smaller spatial and temporal scales than is possible with GOSAT. Near-global coverage is provided within a few days. We are able to show clearly for the first time physically plausible variations in fluorescence over the course of a single month at a spatial resolution of 0.5 deg × 0.5 deg

  18. Global Monitoring of Terrestrial Chlorophyll Fluorescence from Moderate-Spectral-Resolution Near-Infrared Satellite Measurements: Methodology, Simulations, and Application to GOME-2

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Guanter, L.; Lindstrot, R.; Voigt, M.; Vasilkov, A. P.; Middleton, E. M.; Huemmrich, K. F.; Yoshida, Y.; Frankenberg, C.

    2013-01-01

    Globally mapped terrestrial chlorophyll fluorescence retrievals are of high interest because they can provide information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling and agricultural applications. Previous satellite retrievals of fluorescence have relied solely upon the filling-in of solar Fraunhofer lines that are not significantly affected by atmospheric absorption. Although these measurements provide near-global coverage on a monthly basis, they suffer from relatively low precision and sparse spatial sampling. Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data with a simplified radiative transfer model to disentangle the spectral signatures of three basic components: atmospheric absorption, surface reflectance, and fluorescence radiance. An empirically based principal component analysis approach is employed, primarily using cloudy data over ocean, to model and solve for the atmospheric absorption. Through detailed simulations, we demonstrate the feasibility of the approach and show that moderate-spectral-resolution measurements with a relatively high signal-to-noise ratio can be used to retrieve far-red fluorescence information with good precision and accuracy. The method is then applied to data from the Global Ozone Monitoring Instrument 2 (GOME-2). The GOME-2 fluorescence retrievals display similar spatial structure as compared with those from a simpler technique applied to the Greenhouse gases Observing SATellite (GOSAT). GOME-2 enables global mapping of far-red fluorescence with higher precision over smaller spatial and temporal scales than is possible with GOSAT. Near-global coverage is provided within a few days. We are able to show clearly for the first time physically plausible variations in fluorescence over the course of a single month at a spatial resolution of 0.5 0.5. We also show

  19. Global observations of glyoxal columns from OMI/Aura and GOME-2/Metop-A sensors and comparison with multi-year simulations by the IMAGES model

    NASA Astrophysics Data System (ADS)

    Lerot, Christophe; Stavrakou, Trissevgeni; Hendrick, François; De Smedt, Isabelle; Müller, Jean-François; Volkamer, Rainer; Van Roozendael, Michel

    2015-04-01

    Volatile organic compounds (VOCs) originating from both natural and human activities play a key role in air quality. Information on their atmospheric concentrations can be derived using remote sensing techniques for a limited number of species, including formaldehyde (HCHO) and glyoxal (CHOCHO). The latter is mostly produced in the atmosphere as an intermediate product in the oxidation of other non-methane VOCs. It is also directly emitted from fire events and combustion processes. Owing to its short lifetime, elevated glyoxal concentrations are observed near emission sources. Measurements of atmospheric glyoxal concentrations therefore provide quantitative information on the different types of VOC emission and can help to better assess the quality of current inventories. In addition, glyoxal is also known to significantly contribute to the total budget of secondary organic aerosols. Global observations of glyoxal columns have been realized from different space-borne spectrometers using the well-known DOAS retrieval technique. In the past, we developed an algorithm to retrieve glyoxal columns from spectra measured by the GOME-2 instrument aboard METOP-A (Lerot et al., 2010). Specificities of this algorithm were an original two-step approach in the DOAS fit to minimize the impact of spectral interferences with the liquid water absorption as well as the use of a priori information from the Chemical Transport Model IMAGES in the air mass factor calculation. In this work, we present the adaptation of this algorithm to the OMI sensor on the AURA platform. The time series of glyoxal columns derived from OMI and GOME-2 are compared in different parts of the world and a high level of consistency is found. The OMI glyoxal data product is found to be very stable over the entire duration of the mission, in contrast to the GOME-2 product which is affected by instrumental degradation. We present validation results using several years of MAX-DOAS glyoxal measurements

  20. Retrieval of Ozone Column Content from Airborne Sun Photometer Measurements During SOLVE II: Comparison with SAGE III, POAM III,THOMAS and GOME Measurements. Comparison with SAGE 111, POAM 111, TOMS and GOME Measurements

    NASA Technical Reports Server (NTRS)

    Livingston, J.; Schmid, B.; Russell, P.; Eilers, J.; Kolyer, R.; Redemann, J.; Yee, J.-H.; Trepte, C.; Thomason, L.; Pitts, M.

    2003-01-01

    retrievals during selected DC-8 latitudinal and longitudinal transects with total column ozone data acquired by the Total Ozone Mapping Spectrometer (TOMS) and the Global Ozone Monitoring Experiment (GOME) satellite sensors. To enable this comparison, the amount of ozone in the column below the aircraft is estimated by combining SAGE and/or POAM data with high resolution, fast response in-situ ozone measurements acquired during the DC-8 ascent at the start of each science flight.

  1. Tropospheric O3 over Indonesia during biomass burning events measured with GOME (Global Ozone Monitoring Experiment) and compared with backtrajectory calculation

    NASA Astrophysics Data System (ADS)

    Ladstaetter-Weissenmayer, A.; Meyer-Arnek, J.; Burrows, J. P.

    During the dry season, biomass burning is an important source of ozone precursors for the tropical troposphere, and ozone formation can occur in biomass burning plumes originating in Indonesia and northern Australia. Satellite based GOME (Global Ozone Measuring experiment) data are used to characterize the amount of tropospheric ozone production over this region during the El Niño event in September 1997 compared to a so called "normal" year 1998. Large scale biomass burning occurred over Kalimantan in 1997 caused by the absence of the northern monsoon rains, leading to significant increases in tropospheric ozone. Tropospheric ozone was determined from GOME data using the Tropospheric Excess Method (TEM). Backtrajectory calculations show that Indonesia is influenced every summer by the emissions of trace gases from biomass buring over northern Australia. But in 1997 over Indonesia an increasing of tropospheric ozone amounts can be observed caused by the fires over Indonesia itself as well as by northern Australia. The analysis of the measurements of BIBLE-A (Biomass Burning and Lightning Experiment) and using ATSR (Along the Track Scanning Radiometer) data show differences in the view to the intensity of fire counts and therefore in the amount of the emission of precursors of tropospheric ozone comparing September 1997 to September 1998.

  2. A Model-Data Fusion Approach for Constraining Modeled GPP at Global Scales Using GOME2 SIF Data

    NASA Astrophysics Data System (ADS)

    MacBean, N.; Maignan, F.; Lewis, P.; Guanter, L.; Koehler, P.; Bacour, C.; Peylin, P.; Gomez-Dans, J.; Disney, M.; Chevallier, F.

    2015-12-01

    Predicting the fate of the ecosystem carbon, C, stocks and their sensitivity to climate change relies heavily on our ability to accurately model the gross carbon fluxes, i.e. photosynthesis and respiration. However, there are large differences in the Gross Primary Productivity (GPP) simulated by different land surface models (LSMs), not only in terms of mean value, but also in terms of phase and amplitude when compared to independent data-based estimates. This strongly limits our ability to provide accurate predictions of carbon-climate feedbacks. One possible source of this uncertainty is from inaccurate parameter values resulting from incomplete model calibration. Solar Induced Fluorescence (SIF) has been shown to have a linear relationship with GPP at the typical spatio-temporal scales used in LSMs (Guanter et al., 2011). New satellite-derived SIF datasets have the potential to constrain LSM parameters related to C uptake at global scales due to their coverage. Here we use SIF data derived from the GOME2 instrument (Köhler et al., 2014) to optimize parameters related to photosynthesis and leaf phenology of the ORCHIDEE LSM, as well as the linear relationship between SIF and GPP. We use a multi-site approach that combines many model grid cells covering a wide spatial distribution within the same optimization (e.g. Kuppel et al., 2014). The parameters are constrained per Plant Functional type as the linear relationship described above varies depending on vegetation structural properties. The relative skill of the optimization is compared to a case where only satellite-derived vegetation index data are used to constrain the model, and to a case where both data streams are used. We evaluate the results using an independent data-driven estimate derived from FLUXNET data (Jung et al., 2011) and with a new atmospheric tracer, Carbonyl sulphide (OCS) following the approach of Launois et al. (ACPD, in review). We show that the optimization reduces the strong positive

  3. Reconstructed Solar-Induced Fluorescence: A Machine Learning Vegetation Product Based on MODIS Surface Reflectance to Reproduce GOME-2 Solar-Induced Fluorescence

    NASA Astrophysics Data System (ADS)

    Gentine, P.; Alemohammad, S. H.

    2018-04-01

    Solar-induced fluorescence (SIF) observations from space have resulted in major advancements in estimating gross primary productivity (GPP). However, current SIF observations remain spatially coarse, infrequent, and noisy. Here we develop a machine learning approach using surface reflectances from Moderate Resolution Imaging Spectroradiometer (MODIS) channels to reproduce SIF normalized by clear sky surface irradiance from the Global Ozone Monitoring Experiment-2 (GOME-2). The resulting product is a proxy for ecosystem photosynthetically active radiation absorbed by chlorophyll (fAPARCh). Multiplying this new product with a MODIS estimate of photosynthetically active radiation provides a new MODIS-only reconstruction of SIF called Reconstructed SIF (RSIF). RSIF exhibits much higher seasonal and interannual correlation than the original SIF when compared with eddy covariance estimates of GPP and two reference global GPP products, especially in dry and cold regions. RSIF also reproduces intense productivity regions such as the U.S. Corn Belt contrary to typical vegetation indices and similarly to SIF.

  4. Evaluation of the operational Aerosol Layer Height retrieval algorithm for Sentinel-5 Precursor: application to O2 A band observations from GOME-2A

    NASA Astrophysics Data System (ADS)

    Sanders, A. F. J.; de Haan, J. F.; Sneep, M.; Apituley, A.; Stammes, P.; Vieitez, M. O.; Tilstra, L. G.; Tuinder, O. N. E.; Koning, C. E.; Veefkind, J. P.

    2015-06-01

    An algorithm setup for the operational Aerosol Layer Height product for TROPOMI on the Sentinel-5 Precursor mission is described and discussed, applied to GOME-2A data, and evaluated with lidar measurements. The algorithm makes a spectral fit of reflectance at the O2 A band in the near-infrared and the fit window runs from 758 to 770 nm. The aerosol profile is parameterized by a scattering layer with constant aerosol volume extinction coefficient and aerosol single scattering albedo and with a fixed pressure thickness. The algorithm's target parameter is the height of this layer. In this paper, we apply the algorithm to observations from GOME-2A in a number of systematic and extensive case studies and we compare retrieved aerosol layer heights with lidar measurements. Aerosol scenes cover various aerosol types, both elevated and boundary layer aerosols, and land and sea surfaces. The aerosol optical thicknesses for these scenes are relatively moderate. Retrieval experiments with GOME-2A spectra are used to investigate various sensitivities, in which particular attention is given to the role of the surface albedo. From retrieval simulations with the single-layer model, we learn that the surface albedo should be a fit parameter when retrieving aerosol layer height from the O2 A band. Current uncertainties in surface albedo climatologies cause biases and non-convergences when the surface albedo is fixed in the retrieval. Biases disappear and convergence improves when the surface albedo is fitted, while precision of retrieved aerosol layer pressure is still largely within requirement levels. Moreover, we show that fitting the surface albedo helps to ameliorate biases in retrieved aerosol layer height when the assumed aerosol model is inaccurate. Subsequent retrievals with GOME-2A spectra confirm that convergence is better when the surface albedo is retrieved simultaneously with aerosol parameters. However, retrieved aerosol layer pressures are systematically low (i

  5. Evaluation of the operational Aerosol Layer Height retrieval algorithm for Sentinel-5 Precursor: application to O2 A band observations from GOME-2A

    NASA Astrophysics Data System (ADS)

    Sanders, A. F. J.; de Haan, J. F.; Sneep, M.; Apituley, A.; Stammes, P.; Vieitez, M. O.; Tilstra, L. G.; Tuinder, O. N. E.; Koning, C. E.; Veefkind, J. P.

    2015-11-01

    An algorithm setup for the operational Aerosol Layer Height product for TROPOMI on the Sentinel-5 Precursor mission is described and discussed, applied to GOME-2A data, and evaluated with lidar measurements. The algorithm makes a spectral fit of reflectance at the O2 A band in the near-infrared and the fit window runs from 758 to 770 nm. The aerosol profile is parameterised by a scattering layer with constant aerosol volume extinction coefficient and aerosol single scattering albedo and with a fixed pressure thickness. The algorithm's target parameter is the height of this layer. In this paper, we apply the algorithm to observations from GOME-2A in a number of systematic and extensive case studies, and we compare retrieved aerosol layer heights with lidar measurements. Aerosol scenes cover various aerosol types, both elevated and boundary layer aerosols, and land and sea surfaces. The aerosol optical thicknesses for these scenes are relatively moderate. Retrieval experiments with GOME-2A spectra are used to investigate various sensitivities, in which particular attention is given to the role of the surface albedo. From retrieval simulations with the single-layer model, we learn that the surface albedo should be a fit parameter when retrieving aerosol layer height from the O2 A band. Current uncertainties in surface albedo climatologies cause biases and non-convergences when the surface albedo is fixed in the retrieval. Biases disappear and convergence improves when the surface albedo is fitted, while precision of retrieved aerosol layer pressure is still largely within requirement levels. Moreover, we show that fitting the surface albedo helps to ameliorate biases in retrieved aerosol layer height when the assumed aerosol model is inaccurate. Subsequent retrievals with GOME-2A spectra confirm that convergence is better when the surface albedo is retrieved simultaneously with aerosol parameters. However, retrieved aerosol layer pressures are systematically low (i

  6. Dynamical contibution of Mean Potential Vorticity pseudo-observations derived from MetOp/GOME2 Ozone data into weather forecast, a Mediterranean High Precipitation Event study.

    NASA Astrophysics Data System (ADS)

    Sbii, Siham; Zazoui, Mimoun; Semane, Noureddine

    2015-04-01

    In the absence of observations covering the upper troposphere - lower stratophere, headquarters of several disturbances, and knowing that satellites are uniquely capable of providing uniform data coverage globally, a methodology is followed [1] to convert Total Column Ozone, observed by MetOp/GOME2, into pseudo-observations of Mean Potential Vorticity (MPV). The aim is to study the dynamical impact of Ozone data in the prediction of a Mediterranean Heavy Precipitation Event observed during 28-29 September 2012 in the context of HYMEX1. This study builds on a previously described methodology [2] that generates numerical weather prediction model initial conditions from ozone data. Indeed, the assimilation of MPV in a 3D-var framework is based on a linear regression between observed Ozone and vertical integrated Ertel PV. The latter is calculated using dynamical fields from the moroccan operational limited area model ALADIN-MAROC according to [3]: δθ fp p0 -R δU δV P V = - gξaδp- g-R-(p )Cp [(δp-)2 + (δp-)2] (1) Where ξa is the vertical component of the absolute vorticity, U and V the horizontal wind components, θ the potential temperature, R gas constant, Cp specific heat at constant pressure, p the pressure, p0 a reference pressure, g the gravity and f is the Coriolis parameter. The MPV is estimated using the following expression: --1--∫ P2 M PV = P1 - P2 P P V.δp 1 (2) With P1 = 500hPa and P2 = 100hPa In the present study, the linear regression is performed over September 2012 with a correlation coefficient of 0.8265 and is described as follows: M P V = 5.314610- 2 *O3 - 13.445 (3) where O3 and MPV are given in Dobson Unit (DU) and PVU (1 PV U = 10-6 m2 K kg-1 s-1), respectively. It is found that the ozone-influenced upper-level initializing fields affect the precipitation forecast, as diagnosed by a comparison with the ECMWF model. References [1] S. Sbii, N. Semane, Y. Michel, P. Arbogast and M. Zazoui (2012). Using METOP/GOME-2 data and MSG ozone

  7. New methods for the retrieval of chlorophyll red fluorescence from hyperspectral satellite instruments: simulations and application to GOME-2 and SCIAMACHY

    NASA Astrophysics Data System (ADS)

    Joiner, Joanna; Yoshida, Yasuko; Guanter, Luis; Middleton, Elizabeth M.

    2016-08-01

    Global satellite measurements of solar-induced fluorescence (SIF) from chlorophyll over land and ocean have proven useful for a number of different applications related to physiology, phenology, and productivity of plants and phytoplankton. Terrestrial chlorophyll fluorescence is emitted throughout the red and far-red spectrum, producing two broad peaks near 683 and 736 nm. From ocean surfaces, phytoplankton fluorescence emissions are entirely from the red region (683 nm peak). Studies using satellite-derived SIF over land have focused almost exclusively on measurements in the far red (wavelengths > 712 nm), since those are the most easily obtained with existing instrumentation. Here, we examine new ways to use existing hyperspectral satellite data sets to retrieve red SIF (wavelengths < 712 nm) over both land and ocean. Red SIF is thought to provide complementary information to that from the far red for terrestrial vegetation. The satellite instruments that we use were designed to make atmospheric trace-gas measurements and are therefore not optimal for observing SIF; they have coarse spatial resolution and only moderate spectral resolution (0.5 nm). Nevertheless, these instruments, the Global Ozone Monitoring Instrument 2 (GOME-2) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), offer a unique opportunity to compare red and far-red terrestrial SIF at regional spatial scales. Terrestrial SIF has been estimated with ground-, aircraft-, or satellite-based instruments by measuring the filling-in of atmospheric and/or solar absorption spectral features by SIF. Our approach makes use of the oxygen (O2) γ band that is not affected by SIF. The SIF-free O2 γ band helps to estimate absorption within the spectrally variable O2 B band, which is filled in by red SIF. SIF also fills in the spectrally stable solar Fraunhofer lines (SFLs) at wavelengths both inside and just outside the O2 B band, which further helps to estimate red SIF

  8. Glyoxal Vertical Column Retrievals from the GOME-2/METOP-A European Spaceborne Sensor and Comparisons with the IMAGESv2 CT Model

    NASA Astrophysics Data System (ADS)

    Lerot, C.; Stavrakou, T.; de Smedt, I.; Muller, J. J.; van Roozendael, M.

    2010-12-01

    Glyoxal is mostly formed in our atmosphere as an intermediate product in the oxidation of non-methane volatile organic compounds (NMVOC). To a lesser extent, it is also directly emitted from biomass burning events and from fossil- and bio-fuel combustion processes. Several studies have estimated its atmospheric lifetime to 2-3 hours, which makes of glyoxal a good indicator for short-lived NMVOC emissions. Glyoxal is also known to be a precursor for secondary organic aerosols and could help to reduce the gap between observations and models for organic aerosol abundances. The three absorption bands of glyoxal in the visible region allow applying the DOAS (Differential Optical Absorption Spectroscopy) technique to retrieve its vertical column densities from the nadir backscattered light measurements performed by the GOME-2 satellite sensor. This instrument has been launched in October 2006 on board of the METOP-A platform and is characterized by a spatial resolution of 80 km x 40 km and by a large scan-width (1920 km) leading to a global coverage reached in 1.5 day. The GOME-2 glyoxal retrieval algorithm developed at BIRA-IASB accounts for the liquid water absorption and provides geophysically sound column measurements not only over lands but also over oceanic regions where spectral interferences between glyoxal and liquid water have been shown to be significant. The a-priori glyoxal vertical distribution required for the slant to vertical column conversion is provided by the global chemical transport model IMAGESv2. The highest glyoxal vertical column densities are mainly observed in continental tropical regions, while the mid-latitude columns strongly depend on the season with maximum values during warm months. An anthropogenic signature is also observed in highly populated regions of Asia. Comparisons with glyoxal columns simulated with IMAGESv2 in different regions of the world generally point to a missing glyoxal source in current models. As already reported from

  9. Can One Satellite Data Set Validation Another? Validation of Envisat SCIAMACHY Data by Comparisons with NOAA-16 SBUV/2 and ERS-2 GOME

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Bojkov, B. R.; Labow, G.; Weber, M.; Burrows, J.

    2004-01-01

    Validation of satellite data remains a high priority for the construction of climate data sets. Traditionally ground based measurements have provided the primary comparison data for validation. For some atmospheric parameters such as ozone, a thoroughly validated satellite data record can be used to validate a new instrument s data product in addition to using ground based data. Comparing validated data with new satellite data has several advantages; availability of much more data, which will improve precision, larger geographical coverage, and the footprints are closer in size, which removes uncertainty due to different observed atmospheric volumes. To demonstrate the applicability and some limitations of this technique, observations from the newly launched SCIAMACHY instrument were compared with the NOM-16 SBW/2 and ERS-2 GOME instruments. The SBW/2 data had all ready undergone validation by comparing to the total ozone ground network. Overall the SCIAMACHY data were found to low by 3% with respect to satellite data and 1% low with respect to ground station data. There appears to be seasonal and or solar zenith angle dependences in the comparisons with SBW/2 where differences increase with higher solar zenith angles. It is known that accuracies in both satellite and ground based total ozone algorithms decrease at high solar zenith angles. There is a strong need for more accurate measurement from and the ground under these conditions. At the present time SCIAMACHY data are limited and longer data set with more coverage in both hemispheres is needed to unravel the cause of these differences.

  10. Tropospheric NO2 retrieved from OMI, GOME(-2), and SCIAMACHY within the Quality Assurance For Essential Climate Variables (QA4ECV) project: retrieval improvement, harmonization, and quality assurance

    NASA Astrophysics Data System (ADS)

    Folkert Boersma, K.

    2017-04-01

    One of the prime targets of the EU-project Quality Assurance for Essential Climate Variables (QA4ECV, www.qa4ecv.eu) is the generation and subsequent quality assurance of harmonized, long-term data records of ECVs or precursors thereof. Here we report on a new harmonized and improved retrieval algorithm for NO2 columns and its application to spectra measured by the GOME, SCIAMACHY, OMI, and GOME-2(A) sensors over the period 1996-2016. Our community 'best practices' algorithm is based on the classical 3-step DOAS method. It benefits from a thorough comparison and iteration of spectral fitting and air mass factor calculation approaches between IUP Bremen, BIRA, Max Planck Institute for Chemistry, KNMI, WUR, and a number of external partners. For step 1 of the retrieval, we show that improved spectral calibration and the inclusion of liquid water and intensity-offset correction terms in the fitting procedure, lead to 10-30% smaller NO2 slant columns, in better agreement with independent measurements. Moreover, the QA4ECV NO2 slant columns show 15-35% lower uncertainties relative to earlier versions of the spectral fitting algorithm. For step 2, the stratospheric correction, the algorithm relies on the assimilation of NO2 slant columns over remote regions in the Tracer Model 5 (TM5-MP) chemistry transport model. The representation of stratospheric NOy in the model is improved by nudging towards ODIN HNO3:O3 ratios, leading to more realistic NO2 concentrations in the free-running mode, which is relevant at high latitudes near the terminator. The coupling to TM5-Mass Parallel also allows the calculation of air mass factors (AMFs, step 3) from a priori NO2 vertical profiles simulated at a spatial resolution of 1°×1°, so that hotspot gradients are better resolved in the a priori profile shapes. Other AMF improvements include the use of improved cloud information, and a correction for photon scattering in a spherical atmosphere. Preliminary comparisons indicate that the

  11. On the use of harmonized HCHO and NO2 MAXDOAS measurements for the validation of GOME-2 and OMI satellite sensors

    NASA Astrophysics Data System (ADS)

    Pinardi, Gaia; Hendrick, François; Gielen, Clio; Van Roozendael, Michel; De Smedt, Isabelle; Lambert, Jean-Christopher; Granville, José; Compernolle, Steven; Richter, Andreas; Peters, Enno; Piters, Ankie; Wagner, Thomas; Wang, Yang; Drosoglou, Theano; Bais, Alkis; Wang, Shanshan; Saiz-Lopez, Alfonso

    2017-04-01

    During the last decade, the MAXDOAS technique has been increasingly recognized as a source of Fiducial Reference Measurements (FRM) suitable for the validation of satellite nadir observations of species relevant for climate and air quality like NO2 and HCHO. As part of the EU FP7 QA4ECV (Quality Assurance for Essential Climate Variables; see http://www.qa4ecv.eu/) project, efforts have been recently made to harmonize a network of a dozen of MAXDOAS spectrometers in view of their use to assess the quality of satellite climate data records generated within the same project. Harmonization tasks have addressed both retrieval steps involved in MAXDOAS retrievals, i.e. the DOAS spectral fit providing the differential slant column densities (DSCDs) and the conversion of the retrieved DSCDs into vertical profiles and/or vertical column densities (VCDs). In this work, we illustrate the successive harmonization steps and present the resulting QA4ECV MAXDOAS database v2. The approach adopted for the conversion of slant to vertical columns is based on a simplified look-up-table approach. The strength and limitation of this approach are discussed using reference data retrieved using an optimal estimation scheme. The QA4ECV MAXDOAS database is then used to validate satellite data sets of NO2 and HCHO columns derived from the Aura/OMI and MetOp/GOME-2 sensors. The methodology of comparison, which is also a subject of the QA4ECV project, is reviewed with respect to co-location criteria, impact of vertical and horizontal smoothing and representativeness of validation sites. We conclude by assessing the current strengths and limitations of the existing MAXDOAS datasets for NO2 and HCHO satellite validation.

  12. A weighted least squares approach to retrieve aerosol layer height over bright surfaces applied to GOME-2 measurements of the oxygen A band for forest fire cases over Europe

    NASA Astrophysics Data System (ADS)

    Nanda, Swadhin; Pepijn Veefkind, J.; de Graaf, Martin; Sneep, Maarten; Stammes, Piet; de Haan, Johan F.; Sanders, Abram F. J.; Apituley, Arnoud; Tuinder, Olaf; Levelt, Pieternel F.

    2018-06-01

    This paper presents a weighted least squares approach to retrieve aerosol layer height from top-of-atmosphere reflectance measurements in the oxygen A band (758-770 nm) over bright surfaces. A property of the measurement error covariance matrix is discussed, due to which photons travelling from the surface are given a higher preference over photons that scatter back from the aerosol layer. This is a potential source of biases in the estimation of aerosol properties over land, which can be mitigated by revisiting the design of the measurement error covariance matrix. The alternative proposed in this paper, which we call the dynamic scaling method, introduces a scene-dependent and wavelength-dependent modification in the measurement signal-to-noise ratio in order to influence this matrix. This method is generally applicable to other retrieval algorithms using weighted least squares. To test this method, synthetic experiments are done in addition to application to GOME-2A and GOME-2B measurements of the oxygen A band over the August 2010 Russian wildfires and the October 2017 Portugal wildfire plume over western Europe.

  13. Comparison of Profile Total Ozone from SBUV (v8.6) with GOME-Type and Ground-Based Total Ozone for a 16-Year Period (1996 to 2011)

    NASA Technical Reports Server (NTRS)

    Chiou, E. W.; Bhartia, P. K.; McPeters, R. D.; Loyola, D. G.; Coldewey-Egbers, M.; Fioletov, V. E.; Van Roozendael, M.; Spurr, R.; Lerot, C.; Frith, S. M.

    2014-01-01

    This paper describes the comparison of the variability of total column ozone inferred from the three independent multi-year data records, namely, (i) Solar Backscatter Ultraviolet Instrument (SBUV) v8.6 profile total ozone, (ii) GTO (GOME-type total ozone), and (iii) ground-based total ozone data records covering the 16-year overlap period (March 1996 through June 2011). Analyses are conducted based on area-weighted zonal means for 0-30degS, 0-30degN, 50-30degS, and 30-60degN. It has been found that, on average, the differences in monthly zonal mean total ozone vary between -0.3 and 0.8% and are well within 1 %. For GTO minus SBUV, the standard deviations and ranges (maximum minus minimum) of the differences regarding monthly zonal mean total ozone vary between 0.6-0.7% and 2.8-3.8% respectively, depending on the latitude band. The corresponding standard deviations and ranges regarding the differences in monthly zonal mean anomalies show values between 0.4-0.6% and 2.2-3.5 %. The standard deviations and ranges of the differences ground-based minus SBUV regarding both monthly zonal means and anomalies are larger by a factor of 1.4-2.9 in comparison to GTO minus SBUV. The ground-based zonal means demonstrate larger scattering of monthly data compared to satellite-based records. The differences in the scattering are significantly reduced if seasonal zonal averages are analyzed. The trends of the differences GTO minus SBUV and ground-based minus SBUV are found to vary between -0.04 and 0.1%/yr (-0.1 and 0.3DU/yr). These negligibly small trends have provided strong evidence that there are no significant time-dependent differences among these multiyear total ozone data records. Analyses of the annual deviations from pre-1980 level indicate that, for the 15-year period of 1996 to 2010, all three data records show a gradual increase at 30-60degN from -5% in 1996 to -2% in 2010. In contrast, at 50-30degS and 30degS- 30degN there has been a leveling off in the 15 years after

  14. VizieR Online Data Catalog: FADO code (Gomes+, 2017)

    NASA Astrophysics Data System (ADS)

    Gomes, J. M.; Papaderos, P.

    2017-03-01

    FADO comes from the Latin word "fatum" that means fate or destiny. It is also a well known genre of Portuguese music, and by choosing this acronym for this spectral synthesis tool we would like to pay tribute to Portugal. The main goal of FADO is to explore the star-formation and chemical enrichment history (the "Fado") of galaxies based on two hitherto unique elements in spectral fitting models: a) self-consistency between the best-fitting star formation history (SFH) and the nebular characteristics of a galaxy (e.g., hydrogen Balmer-line luminosities and equivalent widths; shape of the nebular continuum, including the Balmer and Paschen discontinuity) and b) genetic optimization and artificial intelligence algorithms. This document is part of the FADO v.1 distribution package, which contains two different ascii files, ReadMe and Read_F, and one tarball archive FADOv1.tar.gz. FADOv1.tar.gz contains the binary (executable) compiled in both OpenSuSE 13.2 64bit LINUX (FADO) and MAC OS X (FADO_MACOSX). The former is compatible with most LINUX distributions, while the latter was only tested for Yosemite 10.10.3. It contains the configuration files for running FADO: FADO.config and PLOT.config, as well as the "Simple Stellar Population" (SSP) base library with the base file list Base.BC03.L, the FADO v.1 short manual Read_F and this file (in the ReadMe directory) and, for testing purposes, three characteristic de-redshifted spectra from SDSS-DR7 in ascii format, corresponding to a star-forming (spec1.txt), composite (spec2.txt) and LINER (spec3.txt) galaxy. Auxiliary files needed for execution of FADO (.HIfboundem.ascii, .HeIIfbound.ascii, .HeIfboundem.ascii, grfont.dat and grfont.txt) are also included in the tarball. By decompressing the tarball the following six directories are created: input, output, plots, ReadMe, SSPs and tables (see below for a brief explanation). (2 data files).

  15. VizieR Online Data Catalog: Outer satellites occultation predictions (Gomes-Junior+, 2016)

    NASA Astrophysics Data System (ADS)

    Gomes-Junior, A. R.; Assafin, M.; Beauvalet, L.; Desmars, J.; Vieira-Martins, R.; Camargo, J. I. B.; Morgado, B. E.; Braga-Ribas, F.

    2016-07-01

    Tables contain the day of the year and UTC central instant of the prediction; right ascension and declination of the occulted star - at the central instant of the occultation (corrected by proper motions); C/A: apparent geocentric distance between the satellite and the star (a.k.a. the distance between the shadow and the center of the Earth) at the moment of the geocentric closest approach, in arcseconds; P/A: the satellite position angle with respect to the occulted star at C/A, in degrees (zero at north of the star, increasing clockwise); v: relative velocity of event in km/s: positive = prograde, negative = retrograde; D: Geocentric distance to the occulting object in AU; R*: normalized UCAC4 magnitude in the R-band to a common shadow of 20km/s by the relationship R*=RUCAC4+2.5xlog(velocity/(20km/s)), the value 20km/s is typical of events around the opposition; long: east longitude of subplanet point in degrees, positive towards east, at the instant of the geocentric closest approach; LST: UT + long: local solar time at subplanet point, hh:mm; pmra and pmdec: proper motions in right ascension and declination, respectively (mas/year). For more detailed information about the definition and use of these stellar occultation geometric elements see Assafin et al. (2010, Cat. J/A+A/515/A32). (2 data files).

  16. Reduced solar-induced chlorophyll fluorescence from GOME-2 during Amazon drought caused by dataset artifacts.

    PubMed

    Zhang, Yao; Joiner, Joana; Gentine, Pierre; Zhou, Sha

    2018-06-01

    Recently, Yang et al. () reported a decrease in solar-induced chlorophyll fluorescence (SIF) during 2015/2016 El Niño event albeit the increase in enhanced vegetation index (EVI). They interpreted the reduced SIF as a signal of reduced ecosystem photosynthesis. However, we argue that the reduced SIF during 2015/2016 is caused by a decreasing trend of SIF due to sensor degradation and the satellite overpass time is critical for drought impact assessment. © 2018 John Wiley & Sons Ltd.

  17. Unravelling the genetic differentiation among varieties of the Neotropical savanna tree Hancornia speciosa Gomes.

    PubMed

    Collevatti, Rosane G; Rodrigues, Eduardo E; Vitorino, Luciana C; Lima-Ribeiro, Matheus S; Chaves, Lázaro J; Telles, Mariana P C

    2018-04-20

    Spatial distribution of species genetic diversity is often driven by geographical distance (isolation by distance) or environmental conditions (isolation by environment), especially under climate change scenarios such as Quaternary glaciations. Here, we used coalescent analyses coupled with ecological niche modelling (ENM), spatially explicit quantile regression analyses and the multiple matrix regression with randomization (MMRR) approach to unravel the patterns of genetic differentiation in the widely distributed Neotropical savanna tree, Hancornia speciosa (Apocynaceae). Due to its high morphological differentiation, the species was originally classified into six botanical varieties by Monachino, and has recently been recognized as only two varieties by Flora do Brasil 2020. Thus, H. speciosa is a good biological model for learning about evolution of phenotypic plasticity under genetic and ecological effects, and predicting their responses to changing environmental conditions. We sampled 28 populations (777 individuals) of Monachino's four varieties of H. speciosa and used seven microsatellite loci to genotype them. Bayesian clustering showed five distinct genetic groups (K = 5) with high admixture among Monachino's varieties, mainly among populations in the central area of the species geographical range. Genetic differentiation among Monachino's varieties was lower than the genetic differentiation among populations within varieties, with higher within-population inbreeding. A high historical connectivity among populations of the central Cerrado shown by coalescent analyses may explain the high admixture among varieties. In addition, areas of higher climatic suitability also presented higher genetic diversity in such a way that the wide historical refugium across central Brazil might have promoted the long-term connectivity among populations. Yet, FST was significantly related to geographic distances, but not to environmental distances, and coalescent analyses and ENM predicted a demographical scenario of quasi-stability through time. Our findings show that demographical history and isolation by distance, but not isolation by environment, drove genetic differentiation of populations. Finally, the genetic clusters do not support the two recently recognized botanical varieties of H. speciosa, but partially support Monachino's classification at least for the four sampled varieties, similar to morphological variation.

  18. Bacterial community associated with the trunk latex of Hancornia speciosa Gomes (Apocynaceae) grown in the northeast of Brazil.

    PubMed

    Silva, Thais Freitas da; Coelho, Marcia Reed Rodrigues; Vollú, Renata Estebanez; de Vasconcelos Goulart, Fátima Regina; Alviano, Daniela Sales; Alviano, Celuta Sales; Seldin, Lucy

    2011-03-01

    Prevention or cure of different illnesses through the use of plant latex is a worldwide known concept. The antifungal activity of Hancornia speciosa latex has been observed against Candida albicans. However, H. speciosa latex is not a sterile plant exudate and secondary metabolites produced by bacteria could be involved in fungal inhibition. In the present study, the bacterial communities of the latex from three H. speciosa trees were characterized using traditional plating and molecular methods. Twelve strains isolated from the latex samples were clustered into four groups by amplified ribosomal DNA restriction analysis (ARDRA). One representative of each group was sequenced and they were identified as belonging to the genera Bacillus, Klebsiella, Enterobacter and Escherichia. None of the 12 isolates showed antifungal activity against C. albicans. A lack of a microbial origin for the antifungal properties of latex was noted. DGGE profiles generated from each of the three latex samples showed unique patterns. Sequencing of the DGGE bands demonstrated the affiliation with the genera Klebsiella, Pantoea, Enterobacter and Burkholderia. In addition, clone libraries were generated and the phylogenetic distribution of the 50 analyzed clones was similar to that obtained using DGGE. The presence of some potential pathogens should be considered before using H. speciosa latex in folk medicine.

  19. The Impact of Global Climate Change on the Geographic Distribution and Sustainable Harvest of Hancornia speciosa Gomes (Apocynaceae) in Brazil

    NASA Astrophysics Data System (ADS)

    Nabout, João Carlos; Magalhães, Mara Rúbia; de Amorim Gomes, Marcos Aurélio; da Cunha, Hélida Ferreira

    2016-04-01

    The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy.

  20. Variational Assimilation of GOME Total-Column Ozone Satellite Data in a 2D Latitude-Longitude Tracer-Transport Model.

    NASA Astrophysics Data System (ADS)

    Eskes, H. J.; Piters, A. J. M.; Levelt, P. F.; Allaart, M. A. F.; Kelder, H. M.

    1999-10-01

    A four-dimensional data-assimilation method is described to derive synoptic ozone fields from total-column ozone satellite measurements. The ozone columns are advected by a 2D tracer-transport model, using ECMWF wind fields at a single pressure level. Special attention is paid to the modeling of the forecast error covariance and quality control. The temporal and spatial dependence of the forecast error is taken into account, resulting in a global error field at any instant in time that provides a local estimate of the accuracy of the assimilated field. The authors discuss the advantages of the 4D-variational (4D-Var) approach over sequential assimilation schemes. One of the attractive features of the 4D-Var technique is its ability to incorporate measurements at later times t > t0 in the analysis at time t0, in a way consistent with the time evolution as described by the model. This significantly improves the offline analyzed ozone fields.

  1. Satellite-Based Stratospheric and Tropospheric Measurements: Determination of Global Ozone and other Trace Species

    NASA Technical Reports Server (NTRS)

    Chance, K. V.

    2001-01-01

    This report summarizes research done under NASA Grant NAG5-3461 from November 1, 1996 through December 31, 2000. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, sensitivity and instrument studies to help finalize the definition of the SCIAMACHY instrument, leading the development of the SCIAMACHY Scientific Requirements Document for Data and Algorithm Development, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, radiative transfer model development for utilization in GOME, SCIAMACHY and other programs, development of infrared line-by-line atmospheric modeling and retrieval capability for SCIAMACHY, and participation in GOME and SCIAMACHY validation studies. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY is currently planned for launch in late 2001 on the ESA Envisat satellite. Three GOME-2 instruments are now scheduled to fly on the Metop series of operational meteorological satellites (Eumetsat). K. Chance is a member of the reconstituted GOME Scientific Advisory Group, which will guide the GOME-2 program as well as the continuing ERS-2 GOME program.

  2. Satellite-Based Stratospheric and Tropospheric Measurements: Determination of Global Ozone and Other Trace Species

    NASA Astrophysics Data System (ADS)

    Chance, Kelly

    2003-02-01

    This grant is an extension to our previous NASA Grant NAG5-3461, providing incremental funding to continue GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) studies. This report summarizes research done under these grants through December 31, 2002. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and participation in initial SCIAMACHY validation studies. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY was launched March 1, 2002 on the ESA Envisat satellite. Three GOME-2 instruments are now scheduled to fly on the Metop series of operational meteorological satellites (Eumetsat). K. Chance is a member of the reconstituted GOME Scientific Advisory Group, which will guide the GOME-2 program as well as the continuing ERS-2 GOME program.

  3. Satellite-Based Stratospheric and Tropospheric Measurements: Determination of Global Ozone and Other Trace Species

    NASA Technical Reports Server (NTRS)

    Chance, Kelly

    2003-01-01

    This grant is an extension to our previous NASA Grant NAG5-3461, providing incremental funding to continue GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) studies. This report summarizes research done under these grants through December 31, 2002. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and participation in initial SCIAMACHY validation studies. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY was launched March 1, 2002 on the ESA Envisat satellite. Three GOME-2 instruments are now scheduled to fly on the Metop series of operational meteorological satellites (Eumetsat). K. Chance is a member of the reconstituted GOME Scientific Advisory Group, which will guide the GOME-2 program as well as the continuing ERS-2 GOME program.

  4. Quantifying the Seasonal and Interannual Variability of North American Isoprene Emissions Using Satellite Observations of the Formaldehyde Column

    NASA Technical Reports Server (NTRS)

    Palmer, Paul I.; Abbot, Dorian S.; Fu, Tzung-May; Jacob, Daniel J.; Chance, Kelly; Kurosu, Thomas P.; Guenther, Alex; Wiedinmyer, Christine; Stanton, Jenny C.; Pilling, Michael J.; hide

    2006-01-01

    Quantifying isoprene emissions using satellite observations of the formaldehyde (HCHO) columns is subject to errors involving the column retrieval and the assumed relationship between HCHO columns and isoprene emissions, taken here from the GEOS-CHEM chemical transport model. Here we use a 6-year (1996-2001) HCHO column data set from the Global Ozone Monitoring Experiment (GOME) satellite instrument to (1) quantify these errors, (2) evaluate GOME-derived isoprene emissions with in situ flux measurements and a process-based emission inventory (Model of Emissions of Gases and Aerosols from Nature, MEGAN), and (3) investigate the factors driving the seasonal and interannual variability of North American isoprene emissions. The error in the GOME HCHO column retrieval is estimated to be 40%. We use the Master Chemical Mechanism (MCM) to quantify the time-dependent HCHO production from isoprene, alpha- and beta-pinenes, and methylbutenol and show that only emissions of isoprene are detectable by GOME. The time-dependent HCHO yield from isoprene oxidation calculated by MCM is 20-30% larger than in GEOS-CHEM. GOME-derived isoprene fluxes track the observed seasonal variation of in situ measurements at a Michigan forest site with a -30% bias. The seasonal variation of North American isoprene emissions during 2001 inferred from GOME is similar to MEGAN, with GOME emissions typically 25% higher (lower) at the beginning (end) of the growing season. GOME and MEGAN both show a maximum over the southeastern United States, but they differ in the precise location. The observed interannual variability of this maximum is 20-30%, depending on month. The MEGAN isoprene emission dependence on surface air temperature explains 75% of the month-to-month variability in GOME-derived isoprene emissions over the southeastern United States during May-September 1996-2001.

  5. Retrieval and molecule sensitivity studies for the global ozone monitoring experiment and the scanning imaging absorption spectrometer for atmospheric chartography

    NASA Technical Reports Server (NTRS)

    Chance, Kelly V.; Burrows, John P.; Schneider, Wolfgang

    1991-01-01

    The Global Ozone Monitoring Experiment (GOME) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) are diode based spectrometers that will make atmospheric constituent and aerosol measurements from European satellite platforms beginning in the mid 1990's. GOME measures the atmosphere in the UV and visible in nadir scanning, while SCIAMACHY performs a combination of nadir, limb, and occultation measurements in the UV, visible, and infrared. A summary is presented of the sensitivity studies that were performed for SCIAMACHY measurements. As the GOME measurement capability is a subset of the SCIAMACHY measurement capability, the nadir, UV, and visible portion of the studies is shown to apply to GOME as well.

  6. Drivers of Water Column Calcium Carbonate Fluxes and Dissolution in the Gulf of Maine: Impacts on the Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Pilskaln, C. H.; Wang, A. Z.; Lawson, G. L.; Hayashi, K.; Salisbury, J.

    2016-02-01

    Recent studies indicate that the U.S. Northeast coastal region, particularly the Gulf of Maine (GoME), may be more susceptible to ocean acidification (OA) than previously thought due to the low buffer capacity, low pH, and low calcium carbonate saturation measured in the region. In particular, sub-surface waters of the GoME already experience under-saturation with respect to aragonite in spring and summer and recent data suggest that water-column aragonite dissolution may occur throughout the year, even when aragonite is slightly over-saturated. This dissolution process appears associated with organic carbon remineralization in the extensive benthic nepheloid layers and may thus represent a major control over the calcium carbonate (CaCO3) budget of deep, near-bottom waters of the GoME. These findings are surprising for shallow, non-upwelling shelf systems and have important implications for the CaCO3 cycle, shell-building organisms, and the GoME planktonic ecosystem. Additionally, freshening of the GoME over the past several decades due to an increase in low-salinity water input originating in the Labrador Sea may further decrease seawater pH and aragonite saturation in the gulf. We present a variety of biogeochemical data that suggest linkages between potential water column CaCO3 dissolution and their impacts on the GoME carbon cycle.

  7. Mapping Isoprene Emissions over North America using Formaldehyde Column Observations from Space

    NASA Technical Reports Server (NTRS)

    Palmer, Paul I.; Jacob, Daniel J.; Fiore, Arlene M.; Martin, Randall V.; Chance, Kelly; Kurosu, Thomas P.

    2004-01-01

    I] We present a methodology for deriving emissions of volatile organic compounds (VOC) using space-based column observations of formaldehyde (HCHO) and apply it to data from the Global Ozone Monitoring Experiment (GOME) satellite instrument over North America during July 1996. The HCHO column is related to local VOC emissions, with a spatial smearing that increases with the VOC lifetime. lsoprene is the dominant HCHO precursor over North America in summer, and its lifetime (approx. = 1 hour) is sufficiently short that the smearing can be neglected. We use the Goddard Earth Observing System global 3-D model of tropospheric chemistry (GEOS-CHEM) to derive the relationship between isoprene emissions and HCHO columns over North America and use these relationships to convert the GOME HCHO columns to isoprene emissions. We also use the GEOS-CHEM model as an intermediary to validate the GOME HCHO column measurements by comparison with in situ observations. The GEOS-CHEM model including the Global Emissions Inventory Activity (GEIA) isoprene emission inventory provides a good simulation of both the GOME data (r(sup 2) = 0.69, n = 756, bias = +l1 %) and the in situ summertime HCHO measurements over North America (r(sup 2) = 0.47, n = 10, bias = -3%). The GOME observations show high values over regions of known high isoprene emissions and a day-to-day variability that is consistent with the temperature dependence of isoprene emission. Isoprene emissions inferred from the GOME data are 20% less than GEIA on average over North America and twice those from the U S . EPA Biogenic Emissions Inventory System (BEIS2) inventory. The GOME isoprene inventory when implemented in the GEOS-CHEM model provides a better simulation of the HCHO in situ measurements thaneitherGEIAorBEIS2 (r(sup 2) = 0.71,n= 10, bias = -10 %).

  8. Evaluation of the antioxidant system and neurotoxic effects observed in Rhamdia branneri (Teleostei: Heptapteridae) sampled from streams of the lower Iguazu River basin.

    PubMed

    Sobjak, Thaís Maylin; Romão, Silvia; Cazarolli, Luisa Helena; Sampaio, Silvio César; Remor, Marcelo Bevilacqua; Guimarães, Ana Tereza Bittencourt

    2018-07-15

    The use of multiple biomarkers has been shown to be an efficient method for evaluating environmental contamination. In this work, we evaluate neurotoxic effects and the antioxidant system responses of the R. branneri collected in two streams of lower Iguazu River basin, relating them with different percentage of vegetation coverture, presence of pesticides and fall and winter seasons. The biological samples were collected in March and August of 2015, from two streams that belong to the lower Iguazu River basin (Brazil): the Manoel Gomes River and the Arquimedes Stream. Soil analyses were performed, and the results showed the presence of the following organophosphates in the Manoel Gomes River and the Arquimedes Stream: disulfoton, methyl parathion, and ronnel. The present study detected inhibition of cholinesterase activity in the brain and muscle of fish samples during the fall from the Manoel Gomes River and the Arquimedes Stream. In the Manoel Gomes River, elevated lipoperoxidation was also observed during the fall. It was observed that the increase or decrease of biomarkers was related to temporal variation and, possibly, to the exposure of animals to agrochemicals. Although the Manoel Gomes River and the Arquimedes Stream are located in regions with large areas of vegetation, the soil analyses show that agrochemical residues are able to reach these locations, which suggests that the fauna are in contact with oxidant and anti-cholinesterase agents during the fall, in addition to respond differently during each season. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. NASA's Experience with UV Remote Using SBUV and TOMS Instruments

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K.

    1999-01-01

    This paper will discuss key features of the NASA algorithm that has been used to produce several highly popular geophysical products from the Solar Backscatter Ultraviolet (SBUV) and Total Ozone Mapping Spectrometer (TOMS) series of instruments. Since these instruments have a limited number of wavelengths, many innovative algorithmic approaches have been developed over the years to derive maximum information from these sensors. We will use Global Ozone Monitoring Experiment (GOME) data to test the assumptions made in these algorithms and show what additional information is contained in the GOME hyperspectral data. At NASA we are using this information to improve the SBUV and TOMS algorithms, as well as to develop more efficient algorithms to process GOME data.

  10. Estrogen and Thyroid Hormone Receptor Activation by Medicinal Plants from Bahia, Brazil

    PubMed Central

    da Silva, Magnus Régios Dias; Costa, Silvia Lima; Velozo, Eudes da Silva

    2018-01-01

    Background: A number of medicinal plants are traditionally used for metabolic disorders in Bahia state, Brazil. The aim of this study was to evaluate the estrogen receptor (ER) and thyroid receptor (TR) activation of crude extracts prepared from 20 plants. Methods: Species were extracted and assayed for receptor activation through both ER and TR gene-reporter assays, using 17β-estradiol and triiodothyronine (T3), respectively, as the positive controls. Results: Cajanus cajan (Fabaceae), Abarema cochliacarpus (Fabaceae), and Borreria verticillata (Rubiaceae) were able to activate ER as much as the positive control (17β-estradiol). These three plant species were also assayed for TR activation. At the concentration of 50 µg/mL, C. cajans exerted the highest positive modulation on TR, causing an activation of 59.9%, while B. verticillata and A. cochliacarpus caused 30.8% and 23.3%, respectively. Conclusions: Our results contribute towards the validation of the traditional use of C. cajans, B. verticillata, and A. cochliacarpus in the treatment of metabolic disorders related to ER and TR functions. The gene-reporter assay was proven effective in screening crude plant extracts for ER/TR activation, endorsing this methodology as an important tool for future bioprospection studies focused on identifying novel starting molecules for the development of estrogen and thyroid agonists. PMID:29342924

  11. Participation in the TOMS Science Team

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Hilsenrath, Ernest (Technical Monitor)

    2002-01-01

    Because of the nominal funding provided by this grant, some of the relevant research is partially funded by other sources. Research performed for this funding period included the following items: We have investigated errors in TOMS ozone measurements caused by the uncertainty in wavelength calibration, coupled with the ozone cross sections in the Huggins bands and their temperature dependence. Preliminary results show that 0.1 nm uncertainty in TOMS wavelength calibration at the ozone active wavelengths corresponds to approx. 1% systematic error in O3, and thus potential 1% biases among ozone trends from the various TOMS instruments. This conclusion will be revised for absolute O3 Measurements as cross sections are further investigated for inclusion in the HITRAN database at the SAO, but the potential for relative errors remains. In order to aid further comparisons among TOMS and GOME ozone measurements, we have implemented our method of direct fitting of GOME radiances (BOAS) for O3, and now obtain the best fitting precision to date for GOME O3 Columns. This will aid in future comparisons of the actual quantities measured and fitted for the two instrument types. We have made comparisons between GOME ICFA cloud fraction and cloud fraction determined from GOME data using the Ring effect in the Ca II lines. There is a strong correlation, as expected, but there are substantial systematic biases between the determinations. This study will be refined in the near future using the recently-developed GOME Cloud Retrieval Algorithm (GOMECAT). We have improved the SAO Ring effect determination to include better convolution with instrument transfer functions and inclusion of interferences by atmospheric absorbers (e.g., O3). This has been made available to the general community.

  12. Improvement of OMI Ozone Profile Retrievals in the Troposphere and Lower Troposphere by the Use of the Tropopause-Based Ozone Profile Climatology

    NASA Technical Reports Server (NTRS)

    Bak, Juseon; Liu, X.; Wei, J.; Kim, J. H.; Chance, K.; Barnet, C.

    2011-01-01

    An advance algorithm based on the optimal estimation technique has beeen developed to derive ozone profile from GOME UV radiances and have adapted it to OMI UV radiances. OMI vertical resolution : 7-11 km in the troposphere and 10-14 km in the stratosphere. Satellite ultraviolet measurements (GOME, OMI) contain little vertical information for the small scale of ozone, especially in the upper troposphere (UT) and lower stratosphere (LS) where the sharp O3 gradient across the tropopause and large ozone variability are observed. Therefore, retrievals depend greatly on the a-priori knowledge in the UTLS

  13. Aplectana nordestina n. sp. (Nematoda: Cosmocercidae) parasitizing Leposternon polystegum (Squamata: Amphisbaenidae) from Northeastern, Brazil.

    PubMed

    Amorim, Darciane Maria DE; Silva, Lidiane Aparecida Firmino DA; Morais, Drausio Honorio; Silva, Reinaldo José DA; Ávila, Robson Waldemar

    2017-03-23

    There are currently 760 reptile species known in Brazil, from which about 70 are amphisbaenians with 25 species recorded in the Brazilian northeast (Vanzolini 2002; Gomes & Maciel 2012; Costa & Bérnils, 2014; Roberto et al., 2014). Leposternon polystegum Duméril, is a widespread species distributed in the Amazon, Atlantic Forest, Cerrado, and Caatinga biomes (Porto et al., 2000; Ribeiro et al., 2011). The diet is composed mainly by ants, termites, and coleopteran larvae (Barros-Filho & Valverde, 1996; Gomes et al., 2009).

  14. Comment on ''Equivalence between the Thirring model and a derivative-coupling model''

    SciTech Connect

    Banerjee, R.

    1988-06-15

    An operator equivalence between the Thirring model and the fermionic sector of a Dirac field interacting via derivative coupling with two scalar fields is established in the path-integral framework. Relations between the coupling parameters of the two models, as found by Gomes and da Silva, can be reproduced.

  15. Operacion FRATERNIDAD. Tegucigalpa, Honduras, 3-6 Septiembre 1962. Exercise Directive Number 1

    DTIC Science & Technology

    1962-08-01

    Jacques MATTOS, Mike LUiMEG, Jorge GOMES , Cesare HCOSTA, Jose PENA, Luis Position Commander Deputy Operations Officer Intelligence Officer...Tte Cnel Federico Poujol, General Staff, b. Staff: Tte Cnel Jorge Robledo, Army of Colombia Mayor Julio Ricardo Zepeda, Army of El Salvador

  16. More than Just Hot Air: How Hairdryers and Role Models Inspire Girls in Engineering

    ERIC Educational Resources Information Center

    Kekelis, Linda; Larkin, Molly; Gomes, Lyn

    2014-01-01

    This article describes a reverse-engineering project where female students take a part a hair dryer--giving them an opportunity to see the many different kinds of engineering disciplines involved in making a hairdryer and that they work together. Mechanical Engineer, Lyn Gome, describes her experience leading a group of middle school girls through…

  17. Document-Based and Message-Centric Security Using XML Authentication and Encryption for Coalition and Interagency Operations

    DTIC Science & Technology

    2009-09-01

    Peruvian Navy Peru X X X X VADM Andrzej Karweta Commander-in-Chief, Polish Navy Poland X X ADM Fernando Jose Ribeiro de Melo Gomes...Chief of Naval Staff, Portuguese Navy Portugal X X X X X VADM J. Mudimu Chief, South African Navy South Africa X X X X X ADM Manuel Rebollo

  18. The Validation of Cloud Retrieval Algorithms Using Synthetic Datasets

    NASA Astrophysics Data System (ADS)

    Kokhanovsky, Alexander; Fischer, Jurgen; Linstrot, Rasmus; Meirink, Jan Fokke; Poulsen, Caroline; Preusker, Rene; Siddans, Richard; Thomas, Gareth; Arnold, Chris; Grainger, Roy; Lilli, Luca; Rozanov, Vladimir

    2012-11-01

    We have performed the inter-comparison study of cloud property retrievals using algorithms initially developed for AATSR (ORAC, RAL-Oxford University), AVHRR and SEVIRI (CPP, KNMI), SCIAMACHY/GOME (SACURA, University of Bremen), and MERIS (ANNA, Free University of Berlin). The accuracy of retrievals of cloud optical thickness (COT), effective radius (ER) of droplets, and cloud top height (CTH) is discussed.

  19. Observation of Atmospheric Constituents From Space

    NASA Astrophysics Data System (ADS)

    Burrows, J. P.

    Remote sensing of the atmosphere from space is a growing research field. Surprisingly but for good physical reasons, the mesosphere and stratosphere are easier to probe from space than the troposphere. GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (Scanning Imaging absorption spectroMeter for Atmospheric CHartographY) are related European instruments, which were proposed and been designed to measure atmospheric constituents (gases, aerosols and clouds) by passive remote sensing of the up-welling solar radiation leaving atmosphere. GOME is a smaller version of SCIAMACHY and was launched as part of the core payload of the second European research satellite (ERS-2) on the 20th April 1995. GOME comprises four spectral channels and measures simultaneously the earthshine radiance or solar extra terrestrial irradiance between 240 and 790 nm. Inversion of GOME measurements using the DOAS (Differential Optical Absorption Spectroscopy) yields the total column of trace gases (e.g. O3, NO2, HCHO, BrO and OClO). Application of the FURM (Full Retrieval Method) enables the profiles of O3 to be retrieved. One of the important achievements of GOME has been the separation of tropopsheirc columns of trace gases using TEM (Tropospheric Excess Method). SCIAMACHY has been developed as Germa n, Dutch and Belgian contribution to ENVISAT. It has significantly enhanced capability compared to GOME, measuring a larger spectral range, 220-2380 nm, and observing in alternate nadir and limb modes as well as solar and lunar occultation. ENVISAT is to be launched into a sun synchronous polar orbit, having an equator crossing time of 10.00 a.m. at the beginning of March 2002. SCIAMACHY is thereby able to measure many more species and vertical profiles than GOME. This facilitates improved tropospheric retrievals. Finally GeoTROPE (Geostationary TROPospheric Explorer) is a new mission, which is proposed for launch within the ESA Earth Explorer Opportunity Mission. It comprises two national

  20. Dormancy as exaptation to protect mimetic seeds against deterioration before dispersal

    PubMed Central

    Brancalion, Pedro H. S.; Novembre, Ana D. L. C.; Rodrigues, Ricardo R.; Marcos Filho, Júlio

    2010-01-01

    Background and Aims Mimetic seeds simulate the appearance of fleshy fruits and arilled seeds without producing nutritive tissues as a reward for seed dispersers. In this strategy of seed dispersal, seeds may remain attached to the mother plant for long periods after maturity, increasing their availability to naïve seed dispersers. The hypothesis that seed coat impermeability in many tropical Fabaceae with mimetic seeds serves as an exaptation to protect the seeds from deterioration and rotting while awaiting dispersal was investigated. Methods Seed coat impermeability was evaluated in five mimetic-seeded species of tropical Fabaceae in south-eastern Brazil (Abarema langsdorffii, Abrus precatorius, Adenanthera pavonina, Erythrina velutina and Ormosia arborea) and in Erythrina speciosa, a ‘basal’ species in its genus, which has monochromatic brown seeds and no mimetic displays. Seed hardness was evaluated as a defence against accelerated ageing (humid chamber at 41 °C for 144 h). Seed development and physiological potential of O. arborea was evaluated and the effect of holding mature seeds in pods on the mother plant in the field for a period of 1 year under humid tropical conditions was compared with seeds stored under controlled conditions (15 °C and 40 % relative air humidity). Key Results All five mimetic-seeded species, and E. speciosa, showed strong coat impermeability, which protected the seeds against deterioration in accelerated ageing. Most O. arborea seeds only became dormant 2 months after pod dehiscence. Germination of seeds after 1 year on the plant in a humid tropical climate was 56 %, compared with 80 % for seeds stored in controlled conditions (15 °C, 45 % relative humidity). Seedling shoot length after 1 year did not differ between seed sources. Conclusions Dormancy acts in mimetic-seeded species as an exaptation to reduce seed deterioration, allowing an increase in their effective dispersal period and mitigating the losses incurred by low

  1. MAX-DOAS NO2 observations over Guangzhou, China; ground-based and satellite comparisons

    NASA Astrophysics Data System (ADS)

    Drosoglou, Theano; Elissavet Koukouli, Maria; Kouremeti, Natalia; Bais, Alkiviadis F.; Zyrichidou, Irene; Balis, Dimitris; van der A, Ronald J.; Xu, Jin; Li, Ang

    2018-04-01

    In this study, the tropospheric NO2 vertical column density (VCD) over an urban site in Guangzhou megacity in China is investigated by means of MAX-DOAS measurements during a campaign from late March 2015 to mid-March 2016. A MAX-DOAS system was deployed at the Guangzhou Institute of Geochemistry of the Chinese Academy of Sciences and operated there for about 1 year, during the spring and summer months. The tropospheric NO2 VCDs retrieved by the MAX-DOAS are presented and compared with space-borne observations from GOME-2/MetOp-A, GOME-2/MetOp-B and OMI/Aura satellite sensors. The comparisons reveal good agreement between satellite and MAX-DOAS observations over Guangzhou, with correlation coefficients ranging between 0.795 for GOME-2B and 0.996 for OMI. However, the tropospheric NO2 loadings are underestimated by the satellite sensors on average by 25.1, 10.3 and 5.7 %, respectively, for OMI, GOME-2A and GOME-2B. Our results indicate that GOME-2B retrievals are closer to those of the MAX-DOAS instrument due to the lower tropospheric NO2 concentrations during the days with valid GOME-2B observations. In addition, the effect of the main coincidence criteria is investigated, namely the cloud fraction (CF), the distance (d) between the satellite pixel center and the ground-based measurement site, as well as the time period within which the MAX-DOAS data are averaged around the satellite overpass time. The effect of CF and time window criteria is more profound on the selection of OMI overpass data, probably due to its smaller pixel size. The available data pairs are reduced to half and about one-third for CF ≤ 0.3 and CF ≤ 0.2, respectively, while, compared to larger CF thresholds, the correlation coefficient is improved to 0.996 from about 0.86, the slope value is very close to unity ( ˜ 0.98) and the mean satellite underestimation is reduced to about half (from ˜ 7 to ˜ 3.5 × 1015 molecules cm-2). On the other hand, the distance criterion affects mostly GOME

  2. Operational Production of the Total Ozone Essential Climate Variable as Part of the Copernicus Climate Change Service (C3S)

    NASA Astrophysics Data System (ADS)

    Lerot, C.; Danckaert, T.; van Gent, J.; Coldewey-Egbers, M.; Loyola, D. G.; Errera, Q.; Spurr, R. J. D.; Garane, K.; Koukouli, M.; Balis, D.; Verhoelst, T.; Granville, J.; Lambert, J. C.; Van Roozendael, M.

    2017-12-01

    Total ozone is one of the Essential Climate Variables (ECV) operationally produced within the European Copernicus Climate Change Service (C3S), which aims at providing the geophysical information needed to monitor and study our climate system. The C3S total ozone processing chain relies on algorithmic developments realized for the last six years as part of the ESA's Ozone Climate Change Initiative (Ozone_cci) project. The C3S Climate Data Store currently contains a total ozone record based on observations from the nadir UV-Vis hyperspectral spectrometers GOME/ERS-2, SCIAMACHY/Envisat, GOME-2/Metop-A, GOME-2/Metop-B and OMI/Aura, spanning more than 23 years.Individual level-2 datasets were generated with the retrieval algorithm GODFIT (GOME-type Direct FITting). The retrievals are based on a non-linear least squares adjustment of reflectances simulated with radiative transfer tools from the LIDORT suite, to the measured spectra in the Huggins bands (325-335 nm). The inter-sensor consistency and the time stability of those data sets is significantly enhanced with the application of a soft-calibration procedure to the level-1 reflectances, in which GOME and OMI are used together as a long-term reference. Level-2 data sets are then combined to produce the level-3 GOME-type Total Ozone (GTO-ECV) record consisting of homogenized 1°x1° monthly mean grids. The merging procedure corrects for subsisting inter-satellite biases and temporal drifts. Some developments for minimizing sampling errors have also been recently investigated and will be discussed. Total ozone level-2 and level-3 data sets are regularly verified and validated by independent measurements both from space (independent algorithms and/or instruments) and ground (Brewer/Dobson/SAOZ) and their excellent quality and stability, as well as their consistency with other long-term total ozone data sets will be illustrated here. In future, in addition to be continuously extended in time, the C3S total ozone record

  3. Satellite Investigation of Atmospheric Metal Deposition During Meteor Showers

    NASA Astrophysics Data System (ADS)

    Correira, J.; Aikin, A. C.; Grebowsky, J. M.

    2008-12-01

    Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the magnesium column densities and any connection to possible enhanced mass deposition during a meteor shower. We derive a time dependent mass flux rate due to meteor showers using published estimates of mass density and activity profiles of meteor showers. An average daily mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal column densities from the years 1996 - 2001.There appears to be little correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.

  4. Satellite Observations of NO2 Trend over Romania

    PubMed Central

    Voiculescu, Mirela; Georgescu, Lucian

    2013-01-01

    Satellite-based measurements of atmospheric trace gases loading give a realistic image of atmospheric pollution at global, regional, and urban level. The aim of this paper is to investigate the trend of atmospheric NO2 content over Romania for the period 1996–2010 for several regions which are generally characterized by different pollutant loadings, resulting from GOME-1, SCIAMACHY, OMI, and GOME-2 instruments. Satellite results are then compared with ground-based in situ measurements made in industrial and relatively clean areas of one major city in Romania. This twofold approach will help in estimating whether the trend of NO2 obtained by means of data satellite retrievals can be connected with the evolution of national industry and transportation. PMID:24453819

  5. Validation of space-based polarization measurements by use of a single-scattering approximation, with application to the global ozone monitoring experiment.

    PubMed

    Aben, Ilse; Tanzi, Cristina P; Hartmann, Wouter; Stam, Daphne M; Stammes, Piet

    2003-06-20

    A method is presented for in-flight validation of space-based polarization measurements based on approximation of the direction of polarization of scattered sunlight by the Rayleigh single-scattering value. This approximation is verified by simulations of radiative transfer calculations for various atmospheric conditions. The simulations show locations along an orbit where the scattering geometries are such that the intensities of the parallel and orthogonal polarization components of the light are equal, regardless of the observed atmosphere and surface. The method can be applied to any space-based instrument that measures the polarization of reflected solar light. We successfully applied the method to validate the Global Ozone Monitoring Experiment (GOME) polarization measurements. The error in the GOME's three broadband polarization measurements appears to be approximately 1%.

  6. Predicting ozone profile shape from satellite UV spectra

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Loyola, Diego; Romahn, Fabian; Doicu, Adrian

    2017-04-01

    Identifying ozone profile shape is a critical yet challenging job for the accurate reconstruction of vertical distributions of atmospheric ozone that is relevant to climate change and air quality. Motivated by the need to develop an approach to reliably and efficiently estimate vertical information of ozone and inspired by the success of machine learning techniques, this work proposes a new algorithm for deriving ozone profile shapes from ultraviolet (UV) absorption spectra that are recorded by satellite instruments, e.g. GOME series and the future Sentinel missions. The proposed algorithm formulates this particular inverse problem in a classification framework rather than a conventional inversion one and places an emphasis on effectively characterizing various profile shapes based on machine learning techniques. Furthermore, a comparison of the ozone profiles from real GOME-2 data estimated by our algorithm and the classical retrieval algorithm (Optimal Estimation Method) is performed.

  7. Combating WMD Journal. Issue 1

    DTIC Science & Technology

    2007-01-01

    Design /Layout CW5 Stephen A. Gomes Ms. Helen M. Stewart DISTRIBUTION STATEMENtI A Approved for Public Release Distribution Unlimited FRO THE DIECO...forming to assist Echelon Above Corps Army elements NBC Defence Factors in the Design , Testing and Accep- with CWMD planning capability. Their initial...Counterproliferation (CP) and Con- with smaller number of officers (-160 designers of the current Officer Pro- sequence Management (CM) arenas FA52s and 275 EOD

  8. West Europe Report

    DTIC Science & Technology

    1986-04-14

    PORTUGAL NEW PROVISIONS IN INTERNAL SECURITY LAW Coordination, Cooperation Targets Lisbon EXPRESSO in Portuguese 8 Feb 86 pi [Text] Eurico de Melo ...Minister of Internal Administration, and Jose Manuel Durao Barroso, State Secretary for that area, have finished the final draft of the new...new law—which was drafted by a committee com- posed of Prof Barbosa de Melo , the auditor of the Ministry of Internal Administration, Gomes Dias, and

  9. NATO Regional Capacity Building: The Foundation for Success in the Counter-Piracy Campaign

    DTIC Science & Technology

    2011-04-16

    could best tailor 68 Nana K. Poku, Neil Renwick, and Joao Gomes Porto, “Human Security and...be established for 79 Alberto Bin, “NATO’s Mediterranean dialogue,” in The Future of the...nations. 81 Alberto Bin, “NATO’s Mediterranean dialogue,” in The Future of the Euro-Mediterranean Security Dialogue, ed. Martin Ortega (Paris

  10. SOLAR OBLIQUITY INDUCED BY PLANET NINE: SIMPLE CALCULATION

    SciTech Connect

    Lai, Dong

    2016-12-01

    Bailey et al. and Gomes et al. recently suggested that the 6° misalignment between the Sun’s rotational equator and the orbital plane of the major planets may be produced by forcing from the hypothetical Planet Nine on an inclined orbit. Here, we present a simple yet accurate calculation of the effect, which provides a clear description of how the Sun’s spin orientation depends on the property of Planet Nine in this scenario.

  11. Ultraviolet Satellite Measurements of Volcanic Ash. Chapter 12

    NASA Technical Reports Server (NTRS)

    Carn, S. A.; Krotkov, N. A.

    2016-01-01

    Ultraviolet (UV) remote sensing of volcanic ash and other absorbing aerosols from space began with the launch of the first Total Ozone Mapping Spectrometer (TOMS) instrument in 1978. Subsequent UV satellite missions (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS) have extended UV ash measurements to the present, generating a unique multidecadal record. A UV Aerosol Index (UVAI) based on two near-UV wavelengths, equally applicable to multispectral (TOMS, DSCOVR) or hyperspectral (GOME, SCIAMACHY, OMI, GOME-2, OMPS) instruments, has been used to derive a unique absorbing aerosol climatology across multiple UV satellite missions. Advantages of UV ash measurements relative to infrared (IR) techniques include the ability to detect ash at any altitude (assuming no clouds), above clouds, and over bright surfaces, where visible and IR techniques may fail. Disadvantages include the daytime-only restriction and nonspecificity to silicate ash, since UV measurements are sensitive to any UV-absorbing aerosol, including smoke, desert dust, and pollution. However, simultaneous retrieval of sulfur dioxide (SO2) abundance and UVAI provides robust discrimination of volcanic clouds. Although the UVAI is only semiquantitative, it has proved successful at detecting and tracking volcanic ash clouds from many volcanic eruptions since 1978. NASA A-Train measurements since 2006 (eg, CALIOP) have provided much improved constraints on volcanic ash altitude, and also permit identification of aerosol type through sensor synergy. Quantitative UV retrievals of ash optical depth, effective particle size, and ash column mass are possible and require assumptions of ash refractive index, particle size distribution, and ash layer altitude. The lack of extensive ash refractive index data in the UV-visible and the effects of ash particle shape on retrievals introduce significant uncertainty in the retrieved parameters, although limited validation against IR ash retrievals has been successful. In this

  12. Tunable far infrared studies of molecular parameters in support of stratospheric measurements

    NASA Technical Reports Server (NTRS)

    Chance, Kelly V.; Evenson, K. M.; Park, K.; Radostitz, J. V.; Jennings, D. A.; Nolt, I. G.; Vanek, M. D.

    1991-01-01

    Lab studies were made in support of far infrared spectroscopy of the stratosphere using the Tunable Far InfraRed (TuFIR) method of ultrahigh resolution spectroscopy and, more recently, spectroscopic and retrieval calculations performed in support of satellite-based atmospheric measurement programs: the Global Ozone Monitoring Experiment (GOME), and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY).

  13. Genetic diversity in natural populations of mangaba in Sergipe, the largest producer State in Brazil.

    PubMed

    Soares, A N R; Vitória, M F; Nascimento, A L S; Ledo, A S; Rabbani, A R C; Silva, A V C

    2016-08-19

    Mangaba (Hancornia speciosa Gomes) is found in areas of coastal tablelands in the Brazilian Northeast and Cerrado regions. This species has been subjected to habitat fragmentation that is mainly due to human activity, and requires conservation strategies. The aim of this study was to analyze the structure and inter- and intrapopulation genetic diversity of natural populations of H. speciosa Gomes using inter-simple sequence repeat (ISSR) molecular markers. A total of 155 individuals were sampled in 10 natural populations (ITA, PAC, IND, EST, BC, PIR, JAP, BG, NEO, and SANT) in the State of Sergipe, Brazil. Fifteen primers were used to generate 162 fragments with 100% polymorphism. Genetic analysis showed that the variability between populations (77%) was higher than within populations (23%). It was possible to identify five different groups by the unweighted pair group method with arithmetic mean and principal coordinate analysis, and only one individual (E10) remained isolated. Using ISSR markers it was possible to obtain a molecular profile of the populations evaluated, showing that these markers were effective and exhibited sufficient polymorphism to estimate the genetic variability of natural populations of H. speciosa Gomes.

  14. Simultaneous assimilation of ozone profiles from multiple UV-VIS satellite instruments

    NASA Astrophysics Data System (ADS)

    van Peet, Jacob C. A.; van der A, Ronald J.; Kelder, Hennie M.; Levelt, Pieternel F.

    2018-02-01

    A three-dimensional global ozone distribution has been derived from assimilation of ozone profiles that were observed by satellites. By simultaneous assimilation of ozone profiles retrieved from the nadir looking satellite instruments Global Ozone Monitoring Experiment 2 (GOME-2) and Ozone Monitoring Instrument (OMI), which measure the atmosphere at different times of the day, the quality of the derived atmospheric ozone field has been improved. The assimilation is using an extended Kalman filter in which chemical transport model TM5 has been used for the forecast. The combined assimilation of both GOME-2 and OMI improves upon the assimilation results of a single sensor. The new assimilation system has been demonstrated by processing 4 years of data from 2008 to 2011. Validation of the assimilation output by comparison with sondes shows that biases vary between -5 and +10 % between the surface and 100 hPa. The biases for the combined assimilation vary between -3 and +3 % in the region between 100 and 10 hPa where GOME-2 and OMI are most sensitive. This is a strong improvement compared to direct retrievals of ozone profiles from satellite observations.

  15. Six years of total ozone column measurements from SCIAMACHY nadir observations

    NASA Astrophysics Data System (ADS)

    Lerot, C.; van Roozendael, M.; van Geffen, J.; van Gent, J.; Fayt, C.; Spurr, R.; Lichtenberg, G.; von Bargen, A.

    2009-04-01

    Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR) in the version 4 of the GOME Data Processor (GDP) and in version 3 of the SCIAMACHY Ground Processor (SGP), respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA). We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2-0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.

  16. Six years of total ozone column measurements from SCIAMACHY nadir observations

    NASA Astrophysics Data System (ADS)

    Lerot, C.; van Roozendael, M.; van Geffen, J.; van Gent, J.; Fayt, C.; Spurr, R.; Lichtenberg, G.; von Bargen, A.

    2008-11-01

    Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR) in the version 4 of the GOME Data Processor (GDP) and in version 3 of the SCIAMACHY Ground Processor (SGP), respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA). We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2-0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.

  17. Toward Quantitative Estimation of the Effect of Aerosol Particles in the Global Climate Model and Cloud Resolving Model

    NASA Astrophysics Data System (ADS)

    Eskes, H.; Boersma, F.; Dirksen, R.; van der A, R.; Veefkind, P.; Levelt, P.; Brinksma, E.; van Roozendael, M.; de Smedt, I.; Gleason, J.

    2005-05-01

    Based on measurements of GOME on ESA ERS-2, SCIAMACHY on ESA-ENVISAT, and Ozone Monitoring Instrument (OMI) on the NASA EOS-Aura satellite there is now a unique 11-year dataset of global tropospheric nitrogen dioxide measurements from space. The retrieval approach consists of two steps. The first step is an application of the DOAS (Differential Optical Absorption Spectroscopy) approach which delivers the total absorption optical thickness along the light path (the slant column). For GOME and SCIAMACHY this is based on the DOAS implementation developed by BIRA/IASB. For OMI the DOAS implementation was developed in a collaboration between KNMI and NASA. The second retrieval step, developed at KNMI, estimates the tropospheric vertical column of NO2 based on the slant column, cloud fraction and cloud top height retrieval, stratospheric column estimates derived from a data assimilation approach and vertical profile estimates from space-time collocated profiles from the TM chemistry-transport model. The second step was applied with only minor modifications to all three instruments to generate a uniform 11-year data set. In our talk we will address the following topics: - A short summary of the retrieval approach and results - Comparisons with other retrievals - Comparisons with global and regional-scale models - OMI-SCIAMACHY and SCIAMACHY-GOME comparisons - Validation with independent measurements - Trend studies of NO2 for the past 11 years

  18. Satellite Mapping of Rain-Induced Nitric Oxide Emissions from Soils

    NASA Technical Reports Server (NTRS)

    Jaegle, L.; Martin, R. V.; Chance, K.; Steinberger, L.; Kurosu, T. P.; Jacob, D. J.; Modi, A. I.; Yoboue, V.; Sigha-Nkamdjou, L.; Galy-Lacaux, C.

    2004-01-01

    We use space-based observations of NO2 columns from the Global Ozone Monitoring Experiment (GOME) to map the spatial and seasonal variations of NOx emissions over Africa during 2000. The GOME observations show not only enhanced tropospheric NO2 columns from biomass burning during the dry season but also comparable enhancements from soil emissions during the rainy season over the Sahel. These soil emissions occur in strong pulses lasting 1-3 weeks following the onset of rain, and affect 3 million sq km of semiarid sub-Saharan savanna. Surface observations of NO2 from the International Global Atmospheric Chemistry (IGAC)/Deposition of Biochemically Important Trace Species (DEBITS)/Africa (IDAF) network over West Africa provide further evidence for a strong role for microbial soil sources. By combining inverse modeling of GOME NO2 columns with space-based observations of fires, we estimate that soils contribute 3.3+/-1.8 TgN/year, similar to the biomass burning source (3.8+/-2.1 TgN/year), and thus account for 40% of surface NO(x) emissions over Africa. Extrapolating to all the tropics, we estimate a 7.3 TgN/year biogenic soil source, which is a factor of 2 larger compared to model-based inventories but agrees with observation-based inventories. These large soil NO(x) emissions are likely to significantly contribute to the ozone enhancement originating from tropical Africa.

  19. MERIS albedo climatology and its effect on the FRESCO+ O2 A-band cloud retrieval from SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Popp, Christoph; Wang, Ping; Brunner, Dominik; Stammes, Piet; Zhou, Yipin

    2010-05-01

    Accurate cloud information is an important prerequisite for the retrieval of atmospheric trace gases from spaceborne UV/VIS sensors. Errors in the estimated cloud fraction and cloud height (pressure) result in an erroneous air mass factor and thus can lead to inaccuracies in the vertical column densities of the retrieved trace gas. In ESA's TEMIS (Tropospheric Emission Monitoring Internet Service) project, the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band) cloud retrieval is applied to, amongst others, SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CartograpHY) data to determine these quantities. Effective cloud fraction and pressure are inverted by (i) radiative transfer simulations of top-of-atmosphere reflectance based on O2 absorption, single Rayleigh scattering, surface and cloud albedo in three spectral windows covering the O2 A-band and (ii) a subsequent fitting of the simulated to the measured spectrum. However, FRESCO+ relies on a relatively coarse resolution surface albedo climatology (1° x 1°) compiled from GOME (Global Ozone Monitoring Experiment) measurements in the 1990's which introduces several artifacts, e.g. an overestimation of cloud fraction at coastlines or over some mountainous regions. Therefore, we test the substitution of the GOME climatology with a new land surface albedo climatology compiled for every month from MEdium Resolution Imaging Spectrometer (MERIS) Albedomap data (0.05° x 0.05°) covering the period January 2003 to October 2006. The MERIS channels at 754nm and 775nm are located spectrally close to the corresponding GOME channels (758nm and 772nm) on both sides of the O2 A-band. Further, the increased spatial resolution of the MERIS product allows to better account for SCIAMACHY's pixel size of approximately 30x60km. The aim of this study is to describe and assess (i) the compilation and quality of the MERIS climatology (ii) the differences to the GOME climatology, and (iii) possible

  20. 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

  1. 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

  2. Quality assessment of the Ozone_cci Climate Research Data Package (release 2017) - Part 1: Ground-based validation of total ozone column data products

    NASA Astrophysics Data System (ADS)

    Garane, Katerina; Lerot, Christophe; Coldewey-Egbers, Melanie; Verhoelst, Tijl; Elissavet Koukouli, Maria; Zyrichidou, Irene; Balis, Dimitris S.; Danckaert, Thomas; Goutail, Florence; Granville, Jose; Hubert, Daan; Keppens, Arno; Lambert, Jean-Christopher; Loyola, Diego; Pommereau, Jean-Pierre; Van Roozendael, Michel; Zehner, Claus

    2018-03-01

    The GOME-type Total Ozone Essential Climate Variable (GTO-ECV) is a level-3 data record, which combines individual sensor products into one single cohesive record covering the 22-year period from 1995 to 2016, generated in the frame of the European Space Agency's Climate Change Initiative Phase II. It is based on level-2 total ozone data produced by the GODFIT (GOME-type Direct FITting) v4 algorithm as applied to the GOME/ERS-2, OMI/Aura, SCIAMACHY/Envisat and GOME-2/Metop-A and Metop-B observations. In this paper we examine whether GTO-ECV meets the specific requirements set by the international climate-chemistry modelling community for decadal stability long-term and short-term accuracy. In the following, we present the validation of the 2017 release of the Climate Research Data Package Total Ozone Column (CRDP TOC) at both level 2 and level 3. The inter-sensor consistency of the individual level-2 data sets has mean differences generally within 0.5 % at moderate latitudes (±50°), whereas the level-3 data sets show mean differences with respect to the OMI reference data record that span between -0.2 ± 0.9 % (for GOME-2B) and 1.0 ± 1.4 % (for SCIAMACHY). Very similar findings are reported for the level-2 validation against independent ground-based TOC observations reported by Brewer, Dobson and SAOZ instruments: the mean bias between GODFIT v4 satellite TOC and the ground instrument is well within 1.0 ± 1.0 % for all sensors, the drift per decade spans between -0.5 % and 1.0 ± 1.0 % depending on the sensor, and the peak-to-peak seasonality of the differences ranges from ˜ 1 % for GOME and OMI to ˜ 2 % for SCIAMACHY. For the level-3 validation, our first goal was to show that the level-3 CRDP produces findings consistent with the level-2 individual sensor comparisons. We show a very good agreement with 0.5 to 2 % peak-to-peak amplitude for the monthly mean difference time series and a negligible drift per decade of the differences in the Northern Hemisphere

  3. Multi-sensor satellite monitoring of ash and SO2 volcanic plume in support to aviation control

    NASA Astrophysics Data System (ADS)

    Brenot, Hugues; Theys, Nicolas; Clarisse, Lieven; van Geffen, Jos; van Gent, Jeroen; Van Roozendael, Michel; van der A, Ronald; Hurtmans, Daniel; Coheur, Pierre-Francois; Clerbaux, Cathy; Valks, Pieter; Hedelt, Pascal; Prata, Fred; Rasson, Olivier; Sievers, Klaus; Zehner, Claus

    2014-05-01

    The 'Support to Aviation Control Service' (SACS; http://sacs.aeronomie.be) is an ESA-funded project hosted by the Belgian Institute for Space Aeronomy since 2007. The service provides near real-time (NRT) global volcanic ash and SO2 observations, as well as notifications in case of volcanic eruptions (success rate >95% for ash and SO2). SACS is based on the combined use of UV-visible (OMI, GOME-2 MetOp-A, GOME-2 MetOp-B) and infrared (AIRS, IASI MetOp-A, IASI MetOp-B) satellite instruments. The SACS service is primarily designed to support the Volcanic Ash Advisory Centers (VAACs) in their mandate to gather information on volcanic clouds and give advice to airline and air traffic control organisations. SACS also serves other users that subscribe to the service, in particular local volcano observatories, research scientists and airliner pilots. When a volcanic eruption is detected, SACS issues a warning that takes the form of a notification sent by e-mail to users. The SACS notification points to a dedicated web page where all relevant information is available and can be visualised with user-friendly tools. Information about the volcanic plume height from GOME-2 (MetOp-A and MetOp-B) are also available. The strength of a multi-sensor approach relies in the use of satellite data with different overpasses times, minimising the time-lag for detection and enhancing the reliability of such alerts. This presentation will give an overview of the SACS service, and of the different techniques used to detect volcanic plumes (ash, SO2 and plume height). It will also highlight the strengths and limitations of the service and measurements, and some perspectives.

  4. 20 Years of Total and Tropical Ozone Time Series Based on European Satellite Observations

    NASA Astrophysics Data System (ADS)

    Loyola, D. G.; Heue, K. P.; Coldewey-Egbers, M.

    2016-12-01

    Ozone is an important trace gas in the atmosphere, while the stratospheric ozone layer protects the earth surface from the incident UV radiation, the tropospheric ozone acts as green house gas and causes health damages as well as crop loss. The total ozone column is dominated by the stratospheric column, the tropospheric columns only contributes about 10% to the total column.The ozone column data from the European satellite instruments GOME, SCIAMACHY, OMI, GOME-2A and GOME-2B are available within the ESA Climate Change Initiative project with a high degree of inter-sensor consistency. The tropospheric ozone columns are based on the convective cloud differential algorithm. The datasets encompass a period of more than 20 years between 1995 and 2015, for the trend analysis the data sets were harmonized relative to one of the instruments. For the tropics we found an increase in the tropospheric ozone column of 0.75 ± 0.12 DU decade^{-1} with local variations between 1.8 and -0.8. The largest trends were observed over southern Africa and the Atlantic Ocean. A seasonal trend analysis led to the assumption that the increase is caused by additional forest fires.The trend for the total column was not that certain, based on model predicted trend data and the measurement uncertainty we estimated that another 10 to 15 years of observations will be required to observe a statistical significant trend. In the mid latitudes the trends are currently hidden in the large variability and for the tropics the modelled trends are low. Also the possibility of diverging trends at different altitudes must be considered; an increase in the tropospheric ozone might be accompanied by decreasing stratospheric ozone.The European satellite data record will be extended over the next two decades with the atmospheric satellite missions Sentinel 5 Precursor (launch end of 2016), Sentinel 4 and Sentinel 5.

  5. The Seasonal Cycle of Satellite Chlorophyll Fluorescence Observations and its Relationship to Vegetation Phenology and Ecosystem Atmosphere Carbon Exchange

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Yoshida, Y.; Vasilkov, A. P.; Schaefer, K.; Jung, M.; Guanter, L.; Zhang, Y; Garrity, S.; Middleton, E. M.; Huemmrich, K. F.; hide

    2014-01-01

    Mapping of terrestrial chlorophyll uorescence from space has shown potentialfor providing global measurements related to gross primary productivity(GPP). In particular, space-based fluorescence may provide information onthe length of the carbon uptake period that can be of use for global carboncycle modeling. Here, we examine the seasonal cycle of photosynthesis asestimated from satellite fluorescence retrievals at wavelengths surroundingthe 740nm emission feature. These retrievals are from the Global OzoneMonitoring Experiment 2 (GOME-2) flying on the MetOp A satellite. Wecompare the fluorescence seasonal cycle with that of GPP as estimated froma diverse set of North American tower gas exchange measurements. Because the GOME-2 has a large ground footprint (40 x 80km2) as compared with that of the flux towers and requires averaging to reduce random errors, we additionally compare with seasonal cycles of upscaled GPP in the satellite averaging area surrounding the tower locations estimated from the Max Planck Institute for Biogeochemistry (MPI-BGC) machine learning algorithm. We also examine the seasonality of absorbed photosynthetically-active radiation(APAR) derived with reflectances from the MODerate-resolution Imaging Spectroradiometer (MODIS). Finally, we examine seasonal cycles of GPP as produced from an ensemble of vegetation models. Several of the data-driven models rely on satellite reflectance-based vegetation parameters to derive estimates of APAR that are used to compute GPP. For forested sites(particularly deciduous broadleaf and mixed forests), the GOME-2 fluorescence captures the spring onset and autumn shutoff of photosynthesis as delineated by the tower-based GPP estimates. In contrast, the reflectance-based indicators and many of the models tend to overestimate the length of the photosynthetically-active period for these and other biomes as has been noted previously in the literature. Satellite fluorescence measurements therefore show potential for

  6. Assessing the potential of Sun-Induced Fluorescence and the Canopy Scattering Coefficient to track large-scale vegetation dynamics in Amazon forests

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Guanter, L.; Kobayashi, H.; Walther, S.

    2016-12-01

    Two new remote sensing vegetation parameters derived from spaceborne spectrometers and simulated with a three dimensional radiative transfer model have been evaluated in terms of their prospects and drawbacks for the monitoring of dense vegetation canopies: (i) sun-induced chlorophyll fluorescence (SIF), a unique signal emitted by photosynthetically active vegetation and (ii) the canopy scattering coefficient (CSC), a vegetation parameter derived along with the directional area scattering factor (DASF) and expected to be particularly sensitive to leaf optical properties. Here, we present the first global data set of DASF/CSC and examine the potential of CSC and SIF for providing complementary information on the controversially discussed vegetation seasonality in the Amazon rainforest. A comparison between near-infrared SIF derived from the Global Ozone Monitoring Experiment-2 (GOME-2) instrument and the Orbiting Carbon Observatory-2 (OCO-2) (overpass time in the morning and noon, respectively) reveals the response of SIF to instantaneous photosynthetically active radiation (PAR) and the response of SIF to changing pigment concentrations ('green-up'). The observed seasonality of SIF largely depends on the satellite overpass time which is due to changing temporal trajectories of (instantaneous) PAR with daytime. Therefore, GOME-2 SIF reaches its seasonal maximum in October and around February, while OCO-2 SIF peaks in February and November. We further examine anisotropic reflectance characteristics with the finding that the hot spot effect significantly impacts observed GOME-2 SIF values. On the contrary, our sensitivity analysis suggests that CSC is highly independent of sun-sensor geometry as well as atmospheric effects. The slight annual variability of CSC shows a seasonal cycle attributable to variations in leaf area and/or the amount of precipitation, rather supporting the 'green-up' hypothesis for periods of less intense precipitation.

  7. Satellite-observed NO2, SO2, and HCHO Vertical Column Densities in East Asia: Recent Changes and Comparisons with Regional Model

    NASA Astrophysics Data System (ADS)

    Kim, H. C.; Lee, P.; Kim, S.; Mok, J.; Yoo, H. L.; Bae, C.; Kim, B. U.; Lim, Y. K.; Woo, J. H.; Park, R.

    2015-12-01

    This study reports the recent changes in tropospheric NO2, SO2, and HCHO vertical column densities (VCD) in East Asia observed from multiple satellites, highlighting especially the annual trend changes of NO2 and SO2 over Beijing-Tianjin-Hebei (BTH) region of China since 2010. Tropospheric VCD data from Global Ozone Monitoring Experiment (GOME), SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), Ozone Monitoring Instrument (OMI) and GOME-2, retrieved from the Royal Netherlands Meteorological Institute (KNMI) and OMI National Aeronautics and Space Administration (NASA) standard products, are utilized to investigate the annual trends of NO2, SO2, and HCHO VCDs from 2001 to 2015. They are also compared with simulations from Community Multi-scale Air Quality Model (CMAQ) based forecast system by the Integrated Multi-scale Air Quality System for Korea (IMAQS-K) of Ajou University. Until 2011, the changes in NO2 VCD over East Asian countries agree well with the findings of previous research, including the impact of the economic downturn during 2008-2009 and the subsequent quick recovery in China. After peaking in 2011, the NO2 VCD observations from active instruments (OMI and GOME-2) over China started to show a slower decreasing trend, mostly led by the rapid changes in the BTH region in northern China. On the other hand, SO2 started to decline earlier, from 2007, but inclined back from 2010 to 2012, and then back to declining trend since 2012. While satellite observations show dramatic recent changes, the model could not reproduce those changes mostly due to its use of fixed emission inventory. We conclude that rapid update of latest emission inventory is necessary for an accurate forecast of regional air quality in east Asia, especially for upcoming international sports events in PyeongChang (Korea), Tokyo (Japan) and Beijing (China) in 2018, 2020 and 2022, respectively.

  8. Development of a harmonised multi sensor retrieval scheme for HCHO within the Quality Assurance For Essential Climate Variables (QA4ECV) project

    NASA Astrophysics Data System (ADS)

    De Smedt, Isabelle; Richter, Andreas; Beirle, Steffen; Danckaert, Thomas; Van Roozendael, Michel; Yu, Huan; Bösch, Tim; Hilboll, Andreas; Peters, Enno; Doerner, Steffen; Wagner, Thomas; Wang, Yang; Lorente, Alba; Eskes, Henk; Van Geffen, Jos; Boersma, Folkert

    2016-04-01

    One of the main goals of the QA4ECV project is to define community best-practices for the generation of multi-decadal ECV data records from satellite instruments. QA4ECV will develop retrieval algorithms for the Land ECVs surface albedo, leaf area index (LAI), and fraction of active photosynthetic radiation (fAPAR), as well as for the Atmosphere ECV ozone and aerosol precursors nitrogen dioxide (NO2), formaldehyde (HCHO), and carbon monoxide (CO). Here we assess best practices and provide recommendations for the retrieval of HCHO. Best practices are established based on (1) a detailed intercomparison exercise between the QA4ECV partner's for each specific algorithm processing steps, (2) the feasibility of implementation, and (3) the requirement to generate consistent multi-sensor multi-decadal data records. We propose a fitting window covering the 328.5-346 nm spectral interval for the morning sensors (GOME, SCIAMACHY and GOME-2) and an extension to 328.5-359 nm for OMI and GOME-2, allowed by improved quality of the recorded spectra. A high level of consistency between group algorithms is found when the retrieval settings are carefully aligned. However, the retrieval of slant columns is highly sensitive to any change in the selected settings. The use of a mean background radiance as DOAS reference spectrum allows for a stabilization of the retrievals. A background correction based on the reference sector method is recommended for implementation in the QA4ECV HCHO algorithm as it further reduces retrieval uncertainties. HCHO AMFs using different radiative transfer codes show a good overall consistency when harmonized settings are used. As for NO2, it is proposed to use a priori HCHO profiles from the TM5 model. These are provided on a 1°x1° latitude-longitude grid.

  9. Total Ozone from the Ozone Monitoring System (OMI) using TOMS and DOAS Methods

    NASA Technical Reports Server (NTRS)

    Veefkind, J. P.; Bhartia, P. K.; Gleason, J.; deHaan, J. F.; Wellemeyer, C.; Levelt, P. F.

    2003-01-01

    The Ozone Monitoring Instrument (OMI) is the Dutch-Finnish contribution to NASA's EOS-Aura satellite scheduled for launch in January 2004. OMI is an imaging spectrometer that will measure the back-scattered Solar radiance in the wavelength range of 270 to 500 nm. The instrument provides near global coverage in one day with a spatial resolution of 13x24 square kilometers. OMI is a new instrument, with a heritage from TOMS, SBW, GOME, GOMOS and SCIAMACHY. OMI'S unique capabilities for measuring important trace gases and aerosols with a small footprint and daily global coverage, in conjunction with the other Aura instruments, will make a major contribution to our understanding of stratospheric and tropospheric chemistry and climate change. OMI will provide data continuity with the 23-year ozone record of TOMS. There are three ozone products planned for OMI: total column ozone, ozone profile and tropospheric column ozone. We are developing two different algorithms for total column ozone: one similar to the algorithm currently being used to process the TOMS data, and the other an improved version of the differential optical absorption spectroscopy (DOAS) method, which has been applied to GOME and SCIAMACHY data. The main reasons for starting with two algorithms for total ozone have to do with heritage and past experience; our long-term goal is to combine the two to develop a more accurate and reliable total ozone product for OMI. We will compare the performance of these two algorithms by applying both of them to the GOME data. We will examine where and how the results differ, and use the extensive TOMS-Dobson comparison studies to assess the performance of the DOAS algorithm.

  10. Consistency Between Sun-Induced Chlorophyll Fluorescence and Gross Primary Production of Vegetation in North America

    NASA Technical Reports Server (NTRS)

    Zhang, Yao; Xiao, Xiangming; Jin, Cui; Dong, Jinwei; Zhou, Sha; Wagle, Pradeep; Joiner, Joanna; Guanter, Luis; Zhang, Yongguang; Zhang , Geli; hide

    2016-01-01

    Accurate estimation of the gross primary production (GPP) of terrestrial ecosystems is vital for a better understanding of the spatial-temporal patterns of the global carbon cycle. In this study,we estimate GPP in North America (NA) using the satellite-based Vegetation Photosynthesis Model (VPM), MODIS (Moderate Resolution Imaging Spectrometer) images at 8-day temporal and 500 meter spatial resolutions, and NCEP-NARR (National Center for Environmental Prediction-North America Regional Reanalysis) climate data. The simulated GPP (GPP (sub VPM)) agrees well with the flux tower derived GPP (GPPEC) at 39 AmeriFlux sites (155 site-years). The GPP (sub VPM) in 2010 is spatially aggregated to 0.5 by 0.5-degree grid cells and then compared with sun-induced chlorophyll fluorescence (SIF) data from Global Ozone Monitoring Instrument 2 (GOME-2), which is directly related to vegetation photosynthesis. Spatial distribution and seasonal dynamics of GPP (sub VPM) and GOME-2 SIF show good consistency. At the biome scale, GPP (sub VPM) and SIF shows strong linear relationships (R (sup 2) is greater than 0.95) and small variations in regression slopes ((4.60-5.55 grams Carbon per square meter per day) divided by (milliwatts per square meter per nanometer per square radian)). The total annual GPP (sub VPM) in NA in 2010 is approximately 13.53 petagrams Carbon per year, which accounts for approximately 11.0 percent of the global terrestrial GPP and is within the range of annual GPP estimates from six other process-based and data-driven models (11.35-22.23 petagrams Carbon per year). Among the seven models, some models did not capture the spatial pattern of GOME-2 SIF data at annual scale, especially in Midwest cropland region. The results from this study demonstrate the reliable performance of VPM at the continental scale, and the potential of SIF data being used as a benchmark to compare with GPP models.

  11. Spatial-temporal consistency between gross primary productivity and solar-induced chlorophyll fluorescence of vegetation in China during 2007-2014.

    PubMed

    Ma, Jun; Xiao, Xiangming; Zhang, Yao; Doughty, Russell; Chen, Bangqian; Zhao, Bin

    2018-10-15

    Accurately estimating spatial-temporal patterns of gross primary production (GPP) is important for the global carbon cycle. Satellite-based light use efficiency (LUE) models are regarded as an efficient tool in simulating spatial-temporal dynamics of GPP. However, the accuracy assessment of GPP simulations from LUE models at both spatial and temporal scales remains a challenge. In this study, we simulated GPP of vegetation in China during 2007-2014 using a LUE model (Vegetation Photosynthesis Model, VPM) based on MODIS (moderate-resolution imaging spectroradiometer) images with 8-day temporal and 500-m spatial resolutions and NCEP (National Center for Environmental Prediction) climate data. Global Ozone Monitoring Instrument 2 (GOME-2) solar-induced chlorophyll fluorescence (SIF) data were used to compare with VPM simulated GPP (GPP VPM ) temporally and spatially using linear correlation analysis. Significant positive linear correlations exist between monthly GPP VPM and SIF data over a single year (2010) and multiple years (2007-2014) in most areas of China. GPP VPM is also significantly positive correlated with GOME-2 SIF (R 2  > 0.43) spatially for seasonal scales. However, poor consistency was detected between GPP VPM and SIF data at yearly scale. GPP dynamic trends have high spatial-temporal variation in China during 2007-2014. Temperature, leaf area index (LAI), and precipitation are the most important factors influence GPP VPM in the regions of East Qinghai-Tibet Plateau, Loss Plateau, and Southwestern China, respectively. The results of this study indicate that GPP VPM is temporally and spatially in line with GOME-2 SIF data, and space-borne SIF data have great potential for evaluating LUE-based GPP models. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Solar Spectral Irradiance Variability in Cycle 24: Model Predictions and OMI Observations

    NASA Technical Reports Server (NTRS)

    Marchenko, S.; DeLand, M.; Lean, J.

    2016-01-01

    Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265-500 nanometers during the ongoing Cycle 24. We supplement the OMI data with concurrent observations from the GOME-2 (Global Ozone Monitoring Experiment - 2) and SORCE (Solar Radiation and Climate Experiment) instruments and find fair-to-excellent agreement between the observations and predictions of the NRLSSI2 (Naval Research Laboratory Solar Spectral Irradiance - post SORCE) and SATIRE-S (the Naval Research Laboratory's Spectral And Total Irradiance REconstruction for the Satellite era) models.

  13. Magnetic susceptibilities of actinide 3d-metal intermetallic compounds

    SciTech Connect

    Muniz, R.B.; d'Albuquerque e Castro, J.; Troper, A.

    1988-04-15

    We have numerically calculated the magnetic susceptibilities which appear in the Hartree--Fock instability criterion for actinide 3d transition-metal intermetallic compounds. This calculation is based on a previous tight-binding description of these actinide-based compounds (A. Troper and A. A. Gomes, Phys. Rev. B 34, 6487 (1986)). The parameters of the calculation, which starts from simple tight-binding d and f bands are (i) occupation numbers, (ii) ratio of d-f hybridization to d bandwidth, and (iii) electron-electron Coulomb-type interactions.

  14. Reply to 'Comment on 'Quantum time-of-flight distribution for cold trapped atoms''

    SciTech Connect

    Ali, Md. Manirul; Home, Dipankar; Pan, Alok K.

    2008-02-15

    In their comment Gomes et al. [Phys. Rev. A 77, 026101 (2008)] have questioned the possibility of empirically testable differences existing between the semiclassical time of flight distribution for cold trapped atoms and a quantum distribution discussed by us recently [Ali et al., Phys. Rev. A 75, 042110 (2007).]. We argue that their criticism is based on a semiclassical treatment having restricted applicability for a particular trapping potential. Their claim does not preclude, in general, the possibility of differences between the semiclassical calculations and fully quantum results for the arrival time distribution of freely falling atoms.

  15. Solar spectral irradiance variability in cycle 24: observations and models

    NASA Astrophysics Data System (ADS)

    Marchenko, Sergey V.; DeLand, Matthew T.; Lean, Judith L.

    2016-12-01

    Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265 and 500 nm during the ongoing cycle 24. We supplement the OMI data with concurrent observations from the Global Ozone Monitoring Experiment-2 (GOME-2) and Solar Radiation and Climate Experiment (SORCE) instruments and find fair-to-excellent, depending on wavelength, agreement among the observations, and predictions of the Naval Research Laboratory Solar Spectral Irradiance (NRLSSI2) and Spectral And Total Irradiance REconstruction for the Satellite era (SATIRE-S) models.

  16. Reply to ``Comment on `Quantum time-of-flight distribution for cold trapped atoms' ''

    NASA Astrophysics Data System (ADS)

    Ali, Md. Manirul; Home, Dipankar; Majumdar, A. S.; Pan, Alok K.

    2008-02-01

    In their comment Gomes [Phys. Rev. A 77, 026101 (2008)] have questioned the possibility of empirically testable differences existing between the semiclassical time of flight distribution for cold trapped atoms and a quantum distribution discussed by us recently [Ali , Phys. Rev. A 75, 042110 (2007).]. We argue that their criticism is based on a semiclassical treatment having restricted applicability for a particular trapping potential. Their claim does not preclude, in general, the possibility of differences between the semiclassical calculations and fully quantum results for the arrival time distribution of freely falling atoms.

  17. Potential of the multispectral synergism for observing ozone pollution combining measurements of IASI-NG and UVNS onboard EPS-SG

    NASA Astrophysics Data System (ADS)

    Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

    2016-04-01

    Current and future satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit sensors offer a limited capacity to probe surface concentrations of gaseous pollutants such as tropospheric ozone. Using single-band approaches based on IASI spaceborne thermal infrared measurements, only ozone down to the lower troposphere (3-4 km of altitude at lowest) may be observed (Eremenko et al., 2008). A recent multispectral method combining IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the IR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere, but with maximum sensitivity around 2 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years, such as EPS-SG, carrying new generation sensors like IASI-NG and UVNS that will enhance the capacity to observe ozone pollution, and particularly when combining them through a multispectral synergism. This work presents an analysis of the potential of the multispectral synergism of IASI-NG and UVNS future spaceborne measurements for observing ozone pollution, performed in the framework of SURVEYOZON project (funded by the French Space Agency, CNES). For this, we develop a simulator of synthetic multispectral retrievals or pseudo-observations (referred as OSSE, Observing System Simulation Experiment) derived from IASI-NG+UVNS that will be compared to those from IASI+GOME2. In the first step of the OSSE, we create a pseudo-reality with simulations from the chemical-transport model MOCAGE (provided by CERFACS laboratory), where real O3 data from IASI and surface network stations have been assimilated for a realistic representation of ozone variability at the surface and the free troposphere. We focus on the high pollution event occurred in Europe on 10 July 2010. We use the coupled algorithms KOPRA+VLIDORT to simulate the spectra emitted, scattered and

  18. Remote sensing of tropospheric constituents by OMI on the EOS Aura satellite

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2006-01-01

    The Ozone Monitoring Instrument (OMI) was launched on NASA's EOS Aura satellite in July 2004. This instrument was built in the Netherlands with collaboration with Finland. The science data products are being developed jointly by scientists from the three countries. OMI is the first instrument to combine the high spatial resolution daily global mapping capability of TOMS with high spectral resolution measurements necessary for retrieving a number of trace gases of relevance to atmospheric chemistry, using techniques pioneered by GOME. In this talk I will show what our planet looks like at UV wavelengths and what these data can tell us about the effects of human activities on global air quality and climate.

  19. Reductions of NO2 detected from space during the 2008 Beijing Olympic Games

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R. J.; Boersma, K. F.; Van Roozendael, M.; De Smedt, I.; Kelder, H. M.

    2009-07-01

    During the 2008 Olympic and Paralympic Games in Beijing (from 8 August to 17 September), local authorities enforced strong measures to reduce air pollution during the events. To evaluate the direct effect of these measures, we use the tropospheric NO2 column observations from the satellite instruments GOME-2 and OMI. We interpret these data against simulations from the regional chemistry transport model CHIMERE, based on a 2006 emission inventory, and find a reduction of NO2 concentrations of approximately 60% above Beijing during the Olympic period. The air quality measures were especially effective in the Beijing area, but also noticeable in surrounding cities of Tianjin (30% reduction) and Shijiazhuang (20% reduction).

  20. Innovative T Cell-Targeted Therapy for Ovarian Cancer

    DTIC Science & Technology

    2014-10-01

    cell effector functions: a blend of innate programming and acquired plasticity. Nat Rev Immunol 2010; 10(7): 467-78. 22. Gomes AQ, Martins DS...costimulator (ICOS) is critical for the development of human T(H)17 cells . Sci Transl Med 2010; 2(55): 55ra78. 36. Cua DJ, Tato CM. Innate IL-17...intestinal epithelial lympho- cytes (17, 18). In contrast, circulating γδ T cells can be found in the blood and lymphoid organs, and are dominated by γδ

  1. The Contribution of TOMS and UARS Data to Our Understanding of Ozone Change

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Both TOMS (Total Ozone Mapping Spectrometer) and UARS (Upper Atmosphere Research Satellite) have operated over an extended period, and generated data sets of sufficient accuracy to be of use in determining ozone change (TOMS) and some of the underlying causes (UARS). The basic scientific products have been used for model validation and assimilation to extend our understanding of stratospheric processes. TOMS on Nimbus-7, Earth-Probe, and QuikTOMS, and UARS have led to the next generation of instruments onboard the EOS platforms. Algorithms used for TOMS and UARS are being applied to the new data sets and extended to analysis of European satellite data (e.g., GOME)

  2. Group engagement in persons with dementia: The concept and its measurement.

    PubMed

    Cohen-Mansfield, Jiska; Hai, Tasmia; Comishen, Michael

    2017-05-01

    Although a few papers documented benefits of group therapeutic activities for individuals with dementia, there is a dearth of studies that have investigated the effects of group activities on persons with dementia. This paper introduces a theoretical framework of studying group therapeutic recreational activity, the Comprehensive Process Model of Group Engagement, and an assessment tool, the Group Observational Measurement of Engagement (GOME). We also report the psychometric properties of this assessment. One hundred and four persons with dementia took part in ten different group activities, with each activity conducted twice at random order so that 20 activities were observed for each group of participants. Following each group activity, research and therapeutic recreation staff members used the GOME assessment to independently rate participants on individual-level measures of attendance duration and engagement, and group level measures (e.g., positive and negative interactions among group members). Reliability and validity analyses comparing observer ratings for each group activity on the individual-level measures of attendance and engagement showed good psychometric properties. Different measures collected on a group level differed with respect to their psychometric quality. We present a theoretical framework to understand group engagement and present measures that could be used in future research and practice. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  3. Observation of Pollution from Space

    NASA Astrophysics Data System (ADS)

    Burrows, J. P.; Richter, A.; Bovensmann, H.; Buchwitz, M.; Andrés Hernández, M. D.; Hilboll, A.; Schoenhardt, A.; Blechschmidt, A.; Alvarado, L.; Wittrock, F.

    2016-12-01

    The rapid growth of population since the industrial revolution has led to large changes in surface emissions and land use change. It is now over 30 years since the SCIAMACHY project was initiated. This project has led to the GOME (ESA ERS-2 1995-2011), SCIAMACHY (ESA Envisat 2002 to 2011) GOME-2 (EUMETSAT/ESA Metop A, 2006 to present, Metop B 2012 to present, Metop C planned launch 2018) and the spin offs OMI (NASA AURA 2004-present) . This presentation addresses observations of tropospheric trace gas pollutants retrieved these instruments with a focus on recent studies of the ozone precursors NO2, HCHO and CHO.CHO, the halogen oxides BrO, IO and CH4 and CO2. It will discuss the objectives of the DLR HALO EMeRGe mission. The latter is research mission combining satelltie and aircraft observations, whihc aims to study pollution from major pollution centers in Europe and Asia, and is planned to take palce in 2017 and 2018.

  4. The Copernicus Sentinel 4 mission: a geostationary imaging UVN spectrometer for air quality monitoring

    NASA Astrophysics Data System (ADS)

    Bazalgette Courrèges-Lacoste, G.; Sallusti, M.; Bulsa, G.; Bagnasco, G.; Veihelmann, Ben; Riedl, S.; Smith, D. J.; Maurer, R.

    2017-09-01

    Sentinel-4 is an imaging UVN (UV-VIS-NIR) spectrometer, developed by Airbus Defence and Space under ESA contract in the frame of the joint EU/ESA COPERNICUS program. The mission objective is the operational monitoring of trace gas concentrations for atmospheric chemistry and climate applications - hence the motto of Sentinel-4 "Knowing what we breathe". Sentinel-4 will provide accurate measurements of key atmospheric constituents such as ozone, nitrogen dioxide, sulfur dioxide, methane, and aerosol properties over Europe and adjacent regions from a geostationary orbit (see Fig. 1). In the family of already flown UVN spectrometers (SCIAMACHY, OMI, GOME and GOME 2) and of those spectrometers currently under development (Sentinel-5p and Sentinel-5), Sentinel-4 is unique in being the first geostationary UVN mission. Furthermore, thanks to its 60-minutes repeat cycle measurements and high spatial resolution (8x8 km2), Sentinel-4 will increase the frequency of cloud-free observations, which is necessary to assess troposphere variability. Two identical Sentinel-4 instruments (PFM and FM-2) will be embarked, as Customer Furnished Item (CFI), fully verified, qualified and calibrated respectively onto two EUMETSAT satellites: Meteosat Third Generation-Sounder 1 and 2 (MTG-S1 and MTG-S2), whose Flight Acceptance Reviews are presently planned respectively in Q4 2021 and Q1 2030. This paper gives an overview of the Sentinel-4 system1 architecture, its design and development status, current performances and the key technological challenges.

  5. Metal concentrations in the upper atmosphere during meteor showers

    NASA Astrophysics Data System (ADS)

    Correira, J.; Aikin, A. C.; Grebowsky, J. M.; Burrows, J. P.

    2010-02-01

    Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996-2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.

  6. Metal concentrations in the upper atmosphere during meteor showers

    NASA Astrophysics Data System (ADS)

    Correira, J.; Aikin, A. C.; Grebowsky, J. M.; Burrows, J. P.

    2009-09-01

    Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996-2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.

  7. SO2 plume height retrieval from UV satellite measurements in support to aviation control

    NASA Astrophysics Data System (ADS)

    van Gent, Jeroen; Brenot, Hugues; Lerot, Christophe; Theys, Nicolas; Van Roozendael, Michel

    2014-05-01

    The Support to Aviation Control Service (SACS), operated at our institute, uses multi-sensor UV-visible and infrared satellite measurements to provide near real-time information on volcanic ash and SO2 concentrations. In case of enhanced SO2 concentrations, notifications are send out to subscribing organisations and individuals, with details regarding the volcanic event. This information may be used by aviation control organisations to judge the risc to air traffic and provide possible alternative routing. One of the latest additions to the system is information on the altitude of SO2 plumes, based on UV measurements of the GOME-2 sensors on the platforms METOP-A and METOP-B. Further improvement of this system is ongoing. This poster shows examples of plume height retrieval from GOME-2 (METOP-A and -B) and OMI (EOS-AURA). Results are shown for a number of recent major volcanic eruptions, each with different characteristics. The applied technique to retrieve altitude information will be discussed, as well as the applicability, quality and limitations of the method.

  8. Trend analysis of tropospheric NO2 column density over East Asia during 2000-2010: multi-satellite observations and model simulations with the updated REAS emission inventory

    NASA Astrophysics Data System (ADS)

    Itahashi, S.; Uno, I.; Irie, H.; Kurokawa, J.; Ohara, T.

    2013-04-01

    Satellite observations of the tropospheric NO2 vertical column density (VCD) are closely correlated to surface NOx emissions and can thus be used to estimate the latter. In this study, the NO2 VCDs simulated by a regional chemical transport model with data from the updated Regional Emission inventory in ASia (REAS) version 2.1 were validated by comparison with multi-satellite observations (GOME, SCIAMACHY, GOME-2, and OMI) between 2000 and 2010. Rapid growth in NO2 VCD driven by expansion of anthropogenic NOx emissions was revealed above the central eastern China region, except during the economic downturn. In contrast, slightly decreasing trends were captured above Japan. The modeled NO2 VCDs using the updated REAS emissions reasonably reproduced the annual trends observed by multi-satellites, suggesting that the NOx emissions growth rate estimated by the updated inventory is robust. On the basis of the close linear relationship of modeled NO2 VCD, observed NO2 VCD, and anthropogenic NOx emissions, the NOx emissions in 2009 and 2010 were estimated. It was estimated that the NOx emissions from anthropogenic sources in China beyond doubled between 2000 and 2010, reflecting the strong growth of anthropogenic emissions in China with the rapid recovery from the economic downturn during late 2008 and mid-2009.

  9. Mini MAX-DOAS Measurements of Air Pollutants over China

    NASA Astrophysics Data System (ADS)

    Staadt, Steffen; Hao, Nan; Trautmann, Thomas

    2016-08-01

    This study continues the work of Clémer et al., (2010) and is aimed to improve trace gas retrievals with mini MAX-DOAS measurements in Nanjing. Based on that work, aerosol extinction vertical profiles are retrieved using the bePRO inversion algorithm developed by the Royal Belgian Institute for Space Aeronomy (BIRA- IASB). Afterwards, the tropospheric trace gas vertical profiles and vertical column densities (VCDs) are retrieved by applying the optimal estimation method to the O4 MAX-DOAS measurements. The Profiles for N O2 , S O2 , glyoxal, formaldehyde and nitrous acid are obtained with different results and different settings for the DOAS measurement. The AODs show small positive correlation against the AERONET values. For NO2, the retrieval shows reasonable concentrations in winter as opposed to summer and has small positive correlations with GOME-2 data. The SO2 VCDs are not correlated with the GOME-2 data, due to high uncertainties from MAX-DOAS and satellite retrievals, while the vertical mixing ratios (VMR) show good agreement with in-situ data (SORPES) at Nanjing. Nitrous acid shows a maximum in winter and a minimum in summer, while glyoxal has its maximum in August and September.

  10. Global long-term ozone trends derived from different observed and modelled data sets

    NASA Astrophysics Data System (ADS)

    Coldewey-Egbers, M.; Loyola, D.; Zimmer, W.; van Roozendael, M.; Lerot, C.; Dameris, M.; Garny, H.; Braesicke, P.; Koukouli, M.; Balis, D.

    2012-04-01

    The long-term behaviour of stratospheric ozone amounts during the past three decades is investigated on a global scale using different observed and modelled data sets. Three European satellite sensors GOME/ERS-2, SCIAMACHY/ENVISAT, and GOME-2/METOP are combined and a merged global monthly mean total ozone product has been prepared using an inter-satellite calibration approach. The data set covers the 16-years period from June 1995 to June 2011 and it exhibits an excellent long-term stability, which is required for such trend studies. A multiple linear least-squares regression algorithm using different explanatory variables is applied to the time series and statistically significant positive trends are detected in the northern mid latitudes and subtropics. Global trends are also estimated using a second satellite-based Merged Ozone Data set (MOD) provided by NASA. For few selected geographical regions ozone trends are additionally calculated using well-maintained measurements of individual Dobson/Brewer ground-based instruments. A reasonable agreement in the spatial patterns of the trends is found amongst the European satellite, the NASA satellite, and the ground-based observations. Furthermore, two long-term simulations obtained with the Chemistry-Climate Models E39C-A provided by German Aerospace Center and UMUKCA-UCAM provided by University of Cambridge are analysed.

  11. The operational cloud retrieval algorithms from TROPOMI on board Sentinel-5 Precursor

    NASA Astrophysics Data System (ADS)

    Loyola, Diego G.; Gimeno García, Sebastián; Lutz, Ronny; Argyrouli, Athina; Romahn, Fabian; Spurr, Robert J. D.; Pedergnana, Mattia; Doicu, Adrian; Molina García, Víctor; Schüssler, Olena

    2018-01-01

    This paper presents the operational cloud retrieval algorithms for the TROPOspheric Monitoring Instrument (TROPOMI) on board the European Space Agency Sentinel-5 Precursor (S5P) mission scheduled for launch in 2017. Two algorithms working in tandem are used for retrieving cloud properties: OCRA (Optical Cloud Recognition Algorithm) and ROCINN (Retrieval of Cloud Information using Neural Networks). OCRA retrieves the cloud fraction using TROPOMI measurements in the ultraviolet (UV) and visible (VIS) spectral regions, and ROCINN retrieves the cloud top height (pressure) and optical thickness (albedo) using TROPOMI measurements in and around the oxygen A-band in the near infrared (NIR). Cloud parameters from TROPOMI/S5P will be used not only for enhancing the accuracy of trace gas retrievals but also for extending the satellite data record of cloud information derived from oxygen A-band measurements, a record initiated with the Global Ozone Monitoring Experiment (GOME) on board the second European Remote-Sensing Satellite (ERS-2) over 20 years ago. The OCRA and ROCINN algorithms are integrated in the S5P operational processor UPAS (Universal Processor for UV/VIS/NIR Atmospheric Spectrometers), and we present here UPAS cloud results using the Ozone Monitoring Instrument (OMI) and GOME-2 measurements. In addition, we examine anticipated challenges for the TROPOMI/S5P cloud retrieval algorithms, and we discuss the future validation needs for OCRA and ROCINN.

  12. Full-Physics Inverse Learning Machine for Satellite Remote Sensing of Ozone Profile Shapes and Tropospheric Columns

    NASA Astrophysics Data System (ADS)

    Xu, J.; Heue, K.-P.; Coldewey-Egbers, M.; Romahn, F.; Doicu, A.; Loyola, D.

    2018-04-01

    Characterizing vertical distributions of ozone from nadir-viewing satellite measurements is known to be challenging, particularly the ozone information in the troposphere. A novel retrieval algorithm called Full-Physics Inverse Learning Machine (FP-ILM), has been developed at DLR in order to estimate ozone profile shapes based on machine learning techniques. In contrast to traditional inversion methods, the FP-ILM algorithm formulates the profile shape retrieval as a classification problem. Its implementation comprises a training phase to derive an inverse function from synthetic measurements, and an operational phase in which the inverse function is applied to real measurements. This paper extends the ability of the FP-ILM retrieval to derive tropospheric ozone columns from GOME- 2 measurements. Results of total and tropical tropospheric ozone columns are compared with the ones using the official GOME Data Processing (GDP) product and the convective-cloud-differential (CCD) method, respectively. Furthermore, the FP-ILM framework will be used for the near-real-time processing of the new European Sentinel sensors with their unprecedented spectral and spatial resolution and corresponding large increases in the amount of data.

  13. Increase in NOx emissions from Indian thermal power plants during 1996-2010: unit-based inventories and multisatellite observations.

    PubMed

    Lu, Zifeng; Streets, David G

    2012-07-17

    Driven by rapid economic development and growing electricity demand, NO(x) emissions (E) from the power sector in India have increased dramatically since the mid-1990s. In this study, we present the NO(x) emissions from Indian public thermal power plants for the period 1996-2010 using a unit-based methodology and compare the emission estimates with the satellite observations of NO(2) tropospheric vertical column densities (TVCDs) from four spaceborne instruments: GOME, SCIAMACHY, OMI, and GOME-2. Results show that NO(x) emissions from Indian power plants increased by at least 70% during 1996-2010. Coal-fired power plants, NO(x) emissions from which are not regulated in India, contribute ∼96% to the total power sector emissions, followed by gas-fired (∼4%) and oil-fired (<1%) ones. A number of isolated NO(2) hot spots are observed over the power plant areas, and good agreement between NO(2) TVCDs and NO(x) emissions is found for areas dominated by power plant emissions. Average NO(2) TVCDs over power plant areas were continuously increasing during the study period. We find that the ratio of ΔE/E to ΔTVCD/TVCD changed from greater than one to less than one around 2005-2008, implying that a transition of the overall NO(x) chemistry occurred over the power plant areas, which may cause significant impact on the atmospheric environment.

  14. Rapid economic growth leads to boost in NO2 pollution over India, as seen from space

    NASA Astrophysics Data System (ADS)

    Hilboll, Andreas; Richter, Andreas; Burrows, John P.

    2016-04-01

    Over the past decades, the Indian economy has been growing at an exceptional pace. This growth was induced and accompanied by a strong increase of the Indian population. Consequently, traffic, electricity consumption, and industrial production have soared over the past decades, leading to a strong increase in fuel consumption and thus pollutant emissions. Nitrogen oxides (NO+NO2) are a major component of anthropogenic air pollution, playing key part in reaction cycles leading to the formation of tropospheric ozone. They are mainly emitted by the combustion of fossil fuels; other sources include production by lightning, biomass burning, and microbial activity in soils. Since the mid-1990s, space-borne measurements of tropospheric nitrogen dioxide (NO2) have been conducted by the GOME, SCIAMACHY, GOME-2, and OMI instruments. These instruments perform hyperspectral measurements of scattered and reflected sunlight. Their measurements are then analyzed using differential optical absorption spectroscopy (DOAS) to yield vertically integrated columnar trace gas abundances. Here, we will present the results of 20 years of NO2 measurements over the Indian subcontinent. After showing the spatial distribution of NO2 pollution over India, we will present time series for individual states and urban agglomerations. These time series will then be related to various indicators of economic development. Finally, we will highlight several instances where single industrial pollution sources and their development can clearly be identified from the NO2 maps and estimate their NO2 emissions.

  15. Validation of SCIAMACHY and TOMS UV Radiances Using Ground and Space Observations

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Bhartia, P. K.; Bojkov, B. R.; Kowalewski, M.; Labow, G.; Ahmad, Z.

    2004-01-01

    Verification of a stratospheric ozone recovery remains a high priority for environmental research and policy definition. Models predict an ozone recovery at a much lower rate than the measured depletion rate observed to date. Therefore improved precision of the satellite and ground ozone observing systems are required over the long term to verify its recovery. We show that validation of satellite radiances from space and from the ground can be a very effective means for correcting long term drifts of backscatter type satellite measurements and can be used to cross calibrate all B W instruments in orbit (TOMS, SBW/2, GOME, SCIAMACHY, OM, GOME-2, OMPS). This method bypasses the retrieval algorithms used for both satellite and ground based measurements that are normally used to validate and correct the satellite data. Radiance comparisons employ forward models and are inherently more accurate than inverse (retrieval) algorithms. This approach however requires well calibrated instruments and an accurate radiative transfer model that accounts for aerosols. TOMS and SCIAMACHY calibrations are checked to demonstrate this method and to demonstrate applicability for long term trends.

  16. A climatology of visible surface reflectance spectra

    NASA Astrophysics Data System (ADS)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-09-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290-740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment-2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes.

  17. NILU-UV multi-filter radiometer total ozone columns: Comparison with satellite observations over Thessaloniki, Greece.

    PubMed

    Zempila, Melina Maria; Taylor, Michael; Koukouli, Maria Elissavet; Lerot, Christophe; Fragkos, Konstantinos; Fountoulakis, Ilias; Bais, Alkiviadis; Balis, Dimitrios; van Roozendael, Michel

    2017-07-15

    This study aims to construct and validate a neural network (NN) model for the production of high frequency (~1min) ground-based estimates of total ozone column (TOC) at a mid-latitude UV and ozone monitoring station in the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki (LAP/AUTh) for the years 2005-2014. In the first stage of model development, ~30,000 records of coincident solar UV spectral irradiance measurements from a Norsk Institutt for Luftforskning (NILU)-UV multi-filter radiometer and TOC measurements from a co-located Brewer spectroradiometer are used to train a NN to learn the nonlinear functional relation between the irradiances and TOC. The model is then subjected to sensitivity analysis and validation. Close agreement is obtained (R 2 =0.94, RMSE=8.21 DU and bias=-0.15 DU relative to the Brewer) for the training data in the correlation of NN estimates on Brewer derived TOC with 95% of the coincident data differing by less than 13 DU. In the second stage of development, a long time series (≥1 million records) of high frequency (~1min) NILU-UV ground-based measurements are presented as inputs to the NN model to generate high frequency TOC estimates. The advantage of the NN model is that it is not site dependent and is applicable to any NILU input data lying within the range of the training data. GOME/ERS-2, SCIAMACHY/Envisat, OMI/Aura and GOME2/MetOp-A TOC records are then used to perform a precise cross-validation analysis and comparison with the NILU TOC estimates over Thessaloniki. All 4 satellite TOC dataset are retrieved using the GOME Direct Fitting algorithm, version 3 (GODFIT_v3), for reasons of consistency. The NILU TOC estimates within ±30min of the overpass times agree well with the satellite TOC retrievals with coefficient of determination in the range 0.88≤R 2 ≤0.90 for all sky conditions and 0.95≤R 2 ≤0.96 for clear sky conditions. The mean fractional differences are found to be -0.67%±2.15%, -1

  18. Observing the Impact of the Anthropocene from Space: the Evolution of Atmospheric Observation

    NASA Astrophysics Data System (ADS)

    Burrows, John P.

    2016-04-01

    From the Neolithic revolution to the industrial revolution over ~ 10 000 years, the earth's population rose from several millions to 1 Billion powered by energy from a mixture of biofuels, water and solar power and a limited amount of the combustion of coal. The industrial revolution began in the UK in the late 18th century, and has been fuelled by the combustion of fossil fuels, initially coal but then oil and gas. This has led to a dramatic rise in both the human population, now comprising over 7 Billion with more than 50% living in urban areas, and its standard of living. The expectation is that by 2050 population will be of the order of 10 Billion with 75% dwelling in urban areas. Anthropogenic activity has resulted in pollution from the local to the global scale, changes in land use, the destruction of stratospheric ozone, the modification of biogeochemical cycling, the destruction of species, ecosystems and ecosystem services and climate change. The earth has entered a new geological epoch the anthropocene. The observation of atmospheric composition provides a unique early warning of the natural and anthropogenic origins of change. Consistent and consolidated measurements from the local to the global scale are required to test our knowledge of the biogeochemical cycles, which determine atmospheric composition, and to assess and attribute accurately their modification by anthropogenic activity. To achieve global measurements of atmospheric constituents (trace gases, aerosol and cloud parameters) the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY), Project was initiated in the early 1980s. This was the first passive remote sensing space based instrumentation, designed to make simultaneous contiguous measurements of the solar upwelling radiation at the top of the atmosphere from the ultraviolet to the shortwave infrared. The SCIAMACHY project resulted in measurements of the instruments GOME, originally called SCIA-mini, on ESA

  19. Potential of multispectral synergism for observing tropospheric ozone by combining IR and UV measurements from incoming LEO (EPS-SG) and GEO (MTG) satellite sensors

    NASA Astrophysics Data System (ADS)

    Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Coman, Adriana; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

    2017-04-01

    Satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit sensors do not allow to probe surface concentrations of gaseous pollutants such as tropospheric ozone (Liu et al., 2010). Using single-band approaches based on spaceborne measurements of either thermal infrared radiance (TIR, Eremenko et al., 2008) or ultraviolet reflectance (UV, Liu et al., 2010) only ozone down to the lower troposphere (3 km) may be observed. A recent multispectral method (referred to as IASI+GOME-2) combining the information of IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the TIR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere (LMT, below 3 km of altitude) with maximum sensitivity down to 2.20 km a.s.l. over land, while sensitivity for IASI or GOME-2 only peaks at 3 to 4 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years on both low and geostationary orbits, such as EPS-SG (EUMETSAT Polar System Second Generation) and MTG (Meteosat Third Generation), carrying respectively IASI-NG (for IR) and UVNS (for UV), and IRS (for IR) and UVN (Sentinel 4, for UV). This new-generation sensors will enhance the capacity to observe ozone pollution and particularly by synergism of multispectral measurements. In this work we develop a pseudo-observation simulator and evaluate the potential of future EPS-SG and MTG satellite observations, through IASI-NG+UVNS and IRS+UVN multispectral methods to observe near-surface O3. The pseudo-real state of atmosphere (nature run) is provided by MOCAGE (MOdèle de Chimie Atmosphérique à Grande Échelle) chemical transport model. Simulations are calibrated by careful comparisons with real data, to ensure the best coherence between pseudo-reality and reality, as well as between the pseudo-observation simulator and existing satellite products. We perform full and

  20. Potential of multispectral synergism for observing ozone pollution by combining IASI-NG and UVNS measurements from the EPS-SG satellite

    NASA Astrophysics Data System (ADS)

    Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Coman, Adriana; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

    2017-04-01

    Present and future satellite observations offer great potential for monitoring air quality on a daily and global basis. However, measurements from currently orbiting satellites do not allow a single sensor to accurately probe surface concentrations of gaseous pollutants such as tropospheric ozone. Combining information from IASI (Infrared Atmospheric Sounding Interferometer) and GOME-2 (Global Ozone Monitoring Experiment-2) respectively in the TIR and UV spectra, a recent multispectral method (referred to as IASI+GOME-2) has shown enhanced sensitivity for probing ozone in the lowermost troposphere (LMT, below 3 km altitude) with maximum sensitivity down to 2.20 km a.s.l. over land, while sensitivity for IASI or GOME-2 alone only peaks at 3 to 4 km at the lowest.In this work we develop a pseudo-observation simulator and evaluate the potential of future EPS-SG (EUMETSAT Polar System - Second Generation) satellite observations, from new-generation sensors IASI-NG (Infrared Atmospheric Sounding Interferometer - New Generation) and UVNS (Ultraviolet Visible Near-infrared Shortwave-infrared), to observe near-surface O3 through the IASI-NG+UVNS multispectral method. The pseudo-real state of the atmosphere is provided by the MOCAGE (MOdèle de Chimie Atmosphérique à Grande Échelle) chemical transport model. We perform full and accurate forward and inverse radiative transfer calculations for a period of 4 days (8-11 July 2010) over Europe.In the LMT, there is a remarkable agreement in the geographical distribution of O3 partial columns between IASI-NG+UVNS pseudo-observations and the corresponding MOCAGE pseudo-reality. With respect to synthetic IASI+GOME-2 products, IASI-NG+UVNS shows a higher correlation between pseudo-observations and pseudo-reality, which is enhanced by about 12 %. The bias on high ozone retrieval is reduced and the average accuracy increases by 22 %. The sensitivity to LMT ozone is also enhanced. On average, the degree of freedom for signal is

  1. Assessing potential changes of chestnut productivity in Europe under future climate conditions

    NASA Astrophysics Data System (ADS)

    Calheiros, T.; Pereira, M. G.; Pinto, J. G.; Caramelo, L.; Gomes-Laranjo, J.; Dacamara, C. C.

    2012-04-01

    The European chestnut is cultivated for its nuts and wood. Several studies point to the dependency of chestnut productivity on specific soil and climate characteristics. For instance, this species dislikes chalky and poorly drained soils, appreciates sedimentary, siliceous and acidic to neutral soils. Chestnut trees also seems to appreciate annual mean values of sunlight spanning between 2400 and 2600 h, rainfall ranging between 600 and 1500 mm, mean annual temperature between 9 and 13°C, 27°C being the mean of the maximum temperature (Heiniger and Conedera, 1992; Gomes-Laranjo et al.,2008). The amount of heat between May and October must range between 1800°D and 2400°D (Dinis et al., 2011) . In Poland, the growing season is defined as the period of time when the mean 24-h temperature is greater than 5°C (Wilczynski and Podalski, 2007). In Portugal, maximum photosynthetic activity occurs at 24-28°C for adult trees, but exhibits more than 50% of termoinhibition when the air temperature is above 32°C, which is frequent during summer (Gomes- Laranjo et al., 2006, 2008). Recently Pereira et al (2011) identified a set of meteorological variables/parameters with high impact on chestnut productivity. The main purpose of this work is to assess the potential impacts of future climate change on chestnut productivity in Portugal as well as on European chestnut orchards. First, observed data from the European Climate assessment (ECA) and simulations with the Regional Circulation Model (RCM) COSMO-CLM for recent climate conditions are used to assess the ability of the RCM to model the actual meteorological conditions. Then, ensemble projections from the ECHAM5/COSMO-CLM model chain for two climate scenarios (A1B and B1) are used to estimate the values of relevant meteorological variables and parameters und future climate conditions. Simulated values are then compared with those obtained for present climate. Results point to changes in the spatial and temporal

  2. Evaluation of biogenic emission flux and its impact on oxidants and inorganic aerosols in East Asia

    NASA Astrophysics Data System (ADS)

    Han, K. M.; Song, C. H.; Park, R. S.; Woo, J.; Kim, H.

    2010-12-01

    As a major precursor during the summer season, biogenic species are of primary importance in the ozone and SOAs (secondary organic aerosols) formations. Isoprene and mono-terpene also influence the level of inorganic aerosols (i.e. sulfate and nitrate) by controlling OH radicals. However, biogenic emission fluxes are highly uncertain in East Asia. While isoprene emission fluxes from the GEIA (Global Emissions Inventory Activity) and POET (Precursors of Ozone and their Effects in the Troposphere) inventories estimate approximately 20 Tg yr-1 in East Asia, those from the MEGAN (Model of Emissions of Gases and Aerosols from Nature) and MOHYCAN (MOdel for Hydrocarbon emissions by the CANopy) estimate approximately 10 Tg yr-1 and 5 Tg yr-1, respectively. In order to evaluate and/or quantify the magnitude of biogenic emission fluxes over East Asia, the tropospheric HCHO columns obtained from the GOME (Global Ozone Monitoring Experiment) observations were compared with the HCHO columns from the CMAQ (Community Multi-scale Air Quality) simulations over East Asia. In this study, US EPA Models-3/CMAQ v4.5.1 model simulation using the ACE-ASIA (Asia Pacific Regional Aerosol Characterization Experiment) emission inventory for anthropogenic pollutants and GEIA, POET, MEGAN, and MOHYCAN emission inventories for biogenic species was carried out in conjunction with the Meteorological fields generated from the PSU/NCAR MM5 (Pennsylvania state University/National Center for Atmospheric Research Meso-scale Model 5) model for the summer episodes of the year 2002. In addition to an evaluation of the biogenic emission flux, we investigated the impact of the uncertainty in biogenic emission inventory on inorganic aerosol formations and variations of oxidants (OH, O3, and H2O2) in East Asia. In this study, when the GEIA and POET emission inventories are used, the CMAQ-derived HCHO columns are highly overestimated over East Asia, particularly South China compared with GOME-derived HCHO

  3. The CEOS Atmospheric Composition Constellation (ACC), an Integrated Observing System

    NASA Astrophysics Data System (ADS)

    Hilsenrath, E.; Langen, J.; Zehner, C.

    2008-05-01

    participating space agencies. These include 1) Time of day changes in NO2 using Aura/OMI and Metop/GOME-2. 2) Near-real-time fire detection and smoke forecasts using multiple satellites (A-Train, GOES, GOME-2, MSG, etc) and trajectory model, and 3) Improved volcanic ash alerts for aviation hazard avoidance from satellite SO2 and ash data from SCIAMACHY, OMI, GOME-2, AIRS and SEVIRI. Each of the three projects will address the GEO SBAs with consideration to discovery and interoperability of their data products. The status of the ACC studies will be reviewed with a progress report on the above three projects.

  4. Overview of Global Monitoring of Terrestrial Chlorophyll Fluorescence from Space

    NASA Technical Reports Server (NTRS)

    Guanter, Luis; Zhang, Yongguang; Kohler, Philipp; Walther, Sophia; Frankenberg, Christian; Joiner, Joanna

    2016-01-01

    Despite the critical importance of photosynthesis for the Earth system, understanding how it is influenced by factors such as climate variability, disturbance history, and water or nutrient availability remains a challenge because of the complex interactions and the lack of GPP measurements at various temporal and spatial scales. Space observations of the sun-induced chlorophyll fluorescence (SIF) electromagnetic signal emitted by plants in the 650-850nm spectral range hold the promise of providing a new view of vegetation photosynthesis on a global basis. Global retrievals of SIF from space have recently been achieved from a number of spaceborne spectrometers originally intended for atmospheric research. Despite not having been designed for land applications, such instruments have turned out to provide the necessary spectral and radiometric sensitivity for SIF retrieval from space. The first global measurements of SIF were achieved in 2011 from spectra acquired by the Japanese GOSAT mission launched in 2009. The retrieval takes advantage of the high spectral resolution provided by GOSATs Fourier Transform Spectrometer (FTS) which allows the evaluation of the in-filling of solar Fraunhofer lines by SIF. Unfortunately, GOSAT only provides a sparse spatial sampling with individual soundings separated by several hundred kilometers. Complementary, the Global Ozone Monitoring Experiment-2 (GOME-2) instruments onboard MetOp-A and MetOp-B enable SIF retrievals since 2007 with a continuous and global spatial coverage. GOME-2 measures in the red and near-infrared (NIR) spectral regions with a spectral resolution of 0.5 nm and a pixel size of up to 40x40 km2. Most recently, another global and spatially continuous data set of SIF retrievals at 740 nm spanning the 2003-2012 time frame has been produced from ENVISATSCIAMACHY. This observational scenario has been completed by the first fluorescence data from the NASA-JPL OCO-2 mission (launched in July 2014) and the upcoming

  5. Potentials of satellite derived SIF products to constrain GPP simulated by the new ORCHIDEE-FluOR terrestrial model at the global scale

    NASA Astrophysics Data System (ADS)

    Bacour, C.; Maignan, F.; Porcar-Castell, A.; MacBean, N.; Goulas, Y.; Flexas, J.; Guanter, L.; Joiner, J.; Peylin, P.

    2016-12-01

    A new era for improving our knowledge of the terrestrial carbon cycle at the global scale has begun with recent studies on the relationships between remotely sensed Sun Induce Fluorescence (SIF) and plant photosynthetic activity (GPP), and the availability of such satellite-derived products now "routinely" produced from GOSAT, GOME-2, or OCO-2 observations. Assimilating SIF data into terrestrial ecosystem models (TEMs) represents a novel opportunity to reduce the uncertainty of their prediction with respect to carbon-climate feedbacks, in particular the uncertainties resulting from inaccurate parameter values. A prerequisite is a correct representation in TEMs of the several drivers of plant fluorescence from the leaf to the canopy scale, and in particular the competing processes of photochemistry and non photochemical quenching (NPQ).In this study, we present the first results of a global scale assimilation of GOME-2 SIF products within a new version of the ORCHIDEE land surface model including a physical module of plant fluorescence. At the leaf level, the regulation of fluorescence yield is simulated both by the photosynthesis module of ORCHIDEE to calculate the photochemical yield and by a parametric model to estimate NPQ. The latter has been calibrated on leaf fluorescence measurements performed for boreal coniferous and Mediterranean vegetation species. A parametric representation of the SCOPE radiative transfer model is used to model the plant fluorescence fluxes for PSI and PSII and the scaling up to the canopy level. The ORCHIDEE-FluOR model is firstly evaluated with respect to in situ measurements of plant fluorescence flux and photochemical yield for scots pine and wheat. The potentials of SIF data to constrain the modelled GPP are evaluated by assimilating one year of GOME-2-SIF products within ORCHIDEE-FluOR. We investigate in particular the changes in the spatial patterns of GPP following the optimization of the photosynthesis and phenology parameters

  6. Rain-induced emission pulses of NOx and HCHO from soils in African regions after dry spells as viewed by satellite sensors

    NASA Astrophysics Data System (ADS)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Veres, Patrick; Williams, Jonathan; Wagner, Thomas

    2014-05-01

    Outside industrial areas, soil emissions of NOx (stemming from bacterial emissions of NO) represent a considerable fraction of total NOx emissions, and may even dominate in remote tropical and agricultural areas. NOx fluxes from soils are controlled by abiotic and microbiological processes which depend on ambient environmental conditions. Rain-induced spikes in NOx have been observed by in-situ measurements and also satellite observations. However, the estimation of soil emissions over broad geographic regions remains uncertain using bottom-up approaches. Independent, global satellite measurements can help constrain emissions used in chemical models. Laboratory experiments on soil fluxes suggest that significant HCHO emissions from soil can occur. However, it has not been previously attempted to detect HCHO emissions from wetted soils by using satellite observations. This study investigates the evolution of tropospheric NO2 (as a proxy for NOx) and HCHO column densities before and after the first rain fall event following a prolonged dry period in semi-arid regions, deserts as well as tropical regions in Africa. Tropospheric NO2 and HCHO columns retrieved from OMI aboard the AURA satellite, GOME-2 aboard METOP and SCIAMACHY aboard ENVISAT are used to study and inter-compare the observed responses of the trace gases with multiple space-based instruments. The observed responses are prone to be affected by other sources like lightning, fire, influx from polluted air masses, as well measurement errors in the satellite retrieval caused by manifold reasons such as an increased cloud contamination. Thus, much care is taken verify that the observed spikes reflect enhancements in soil emissions. Total column measurements of H2O from GOME-2 give further insight into the atmospheric state and help to explain the increase in humidity before the first precipitation event. The analysis is not only conducted for averages of distinct geographic regions, i.e. the Sahel, but also

  7. Comparison of several satellite-derived Sun-Induced Fluorescence products

    NASA Astrophysics Data System (ADS)

    Bacour, C.; Maignan, F.; MacBean, N.; Köhler, P.; Vountas, M.; Khosravi, N.; Guanter, L.; Joiner, J.; Frankenberg, C.; Somkuti, P.; Peylin, P.

    2017-12-01

    Large uncertainties remain in our representation of the global carbon budget, in particular regarding the spatial and temporal dynamics of the net land surface CO2 fluxes along with its two constitutive components, photosynthesis and respiration. Bolstered by the evidenced linear relationship between remotely sensed sun-induced fluorescence (SIF) and plant gross carbon uptake (GPP - gross primary productivity) at broad spatial and temporal scales, satellite SIF products are foreseen to provide significant constraint on one of the key component of the terrestrial carbon cycle, and ultimately to help reducing the uncertainties in the projections of the fate of carbon sinks and sources under a changing climate.Global SIF estimates are now "routinely" produced from observations of space-borne spectrometers having sufficient spectral resolution/sampling in solar Fraunhofer lines or atmospheric absorption bands in the visible - near-infrared domain. Differences between SIF products derived from different instruments are expected depending on evaluated wavelengths (SIF has a spectral signature with maxima around 685 and 740 nm) and their own observation characteristics (time of satellite overpass, spatial resolution, revisit frequency, spectral resolution, etc.). For instance, SIF products estimated at 760 nm (GOSAT, OCO-2) are about 1.5 times lower than estimates at 740 nm (GOME-2, SCIAMACHY). However, as highlighted by Köhler et al. (2015), strong discrepancies in SIF absolute values may arise for products derived from the same set of observations (GOME-2) but using different estimation algorithms. In the view of using satellite SIF products to calibrate terrestrial biosphere models (e.g. through data assimilation), this is highly problematic, especially for evergreen ecosystems where SIF magnitude is the only observational constraint that can be made use of.In this study, we compare several gridded satellite SIF products and quantify their similarities

  8. New Developments in the SCIAMACHY Level 2 Ground Processor Towards Version 7

    NASA Astrophysics Data System (ADS)

    Meringer, Markus; Noël, Stefan; Lichtenberg, Günter; Lerot, Christophe; Theys, Nicolas; Fehr, Thorsten; Dehn, Angelika; Liebing, Patricia; Gretschany, Sergei

    2016-07-01

    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002. SCIAMACHY doubled its originally planned in-orbit lifetime of five years before the communication to ENVISAT was severed in April 2012, and the mission entered its post-operational phase. In order to preserve the best quality of the outstanding data recorded by SCIAMACHY, data processors are still being updated. This presentation will highlight three new developments that are currently being incorporated into the forthcoming version 7 of ESA's operational level 2 processor: 1. Tropospheric BrO, a new retrieval based on the scientific algorithm of (Theys et al., 2011). This algorithm had originally been developed for the GOME-2 sensor and was later adapted for SCIAMACHY. The main principle of the new algorithm is to split BrO total columns, which are already an operational product, into stratospheric VCD_{strat} and tropospheric VCD_{trop} fractions. BrO VCD_{strat} is determined from a climatological approach, driven by SCIAMACHY O_3 and NO_2 observations. Tropospheric vertical column densities are then determined as difference VCD_{trop}=VCD_{total}-VCD_{strat}. 2. Improved cloud flagging using limb measurements (Liebing, 2015). Limb cloud flags are already part of the SCIAMACHY L2 product. They are currently calculated employing the scientific algorithm developed by (Eichmann et al., 2015). Clouds are categorized into four types: water, ice, polar stratospheric and noctilucent clouds. High atmospheric aerosol loadings, however, often lead to spurious cloud flags, when aerosols had been misidentified as clouds. The new algorithm will better discriminate between aerosol and clouds. It will also have a higher

  9. Measurements of tropospheric NO2 in Romania using a zenith-sky mobile DOAS system and comparisons with satellite observations.

    PubMed

    Constantin, Daniel-Eduard; Merlaud, Alexis; Van Roozendael, Michel; Voiculescu, Mirela; Fayt, Caroline; Hendrick, François; Pinardi, Gaia; Georgescu, Lucian

    2013-03-20

    In this paper we present a new method for retrieving tropospheric NO2 Vertical Column Density (VCD) from zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements using mobile observations. This method was used during three days in the summer of 2011 in Romania, being to our knowledge the first mobile DOAS measurements peformed in this country. The measurements were carried out over large and different areas using a mobile DOAS system installed in a car. We present here a step-by-step retrieval of tropospheric VCD using complementary observations from ground and space which take into account the stratospheric contribution, which is a step forward compared to other similar studies. The detailed error budget indicates that the typical uncertainty on the retrieved NO2tropospheric VCD is less than 25%. The resulting ground-based data set is compared to satellite measurements from the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment-2 (GOME-2). For instance, on 18 July 2011, in an industrial area located at 47.03°N, 22.45°E, GOME-2 observes a tropospheric VCD value of (3.4 ± 1.9) × 1015 molec./cm2, while average mobile measurements in the same area give a value of (3.4 ± 0.7) × 10(15) molec./cm2. On 22 August 2011, around Ploiesti city (44.99°N, 26.1°E), the tropospheric VCD observed by satellites is (3.3 ± 1.9) × 10(15) molec./cm2 (GOME-2) and (3.2 ± 3.2) × 10(15) molec./cm2 (OMI), while average mobile measurements give (3.8 ± 0.8) × 10(15) molec./cm2. Average ground measurements over "clean areas", on 18 July 2011, give (2.5 ± 0.6) × 10(15) molec./cm2 while the satellite observes a value of (1.8 ± 1.3) × 10(15) molec./cm2.

  10. Measurements of Tropospheric NO2 in Romania Using a Zenith-Sky Mobile DOAS System and Comparisons with Satellite Observations

    PubMed Central

    Constantin, Daniel-Eduard; Merlaud, Alexis; Van Roozendael, Michel; Voiculescu, Mirela; Fayt, Caroline; Hendrick, François; Pinardi, Gaia; Georgescu, Lucian

    2013-01-01

    In this paper we present a new method for retrieving tropospheric NO2 Vertical Column Density (VCD) from zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements using mobile observations. This method was used during three days in the summer of 2011 in Romania, being to our knowledge the first mobile DOAS measurements peformed in this country. The measurements were carried out over large and different areas using a mobile DOAS system installed in a car. We present here a step-by-step retrieval of tropospheric VCD using complementary observations from ground and space which take into account the stratospheric contribution, which is a step forward compared to other similar studies. The detailed error budget indicates that the typical uncertainty on the retrieved NO2tropospheric VCD is less than 25%. The resulting ground-based data set is compared to satellite measurements from the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment-2 (GOME-2). For instance, on 18 July 2011, in an industrial area located at 47.03°N, 22.45°E, GOME-2 observes a tropospheric VCD value of (3.4 ± 1.9) × 1015 molec./cm2, while average mobile measurements in the same area give a value of (3.4 ± 0.7) × 1015 molec./cm2. On 22 August 2011, around Ploiesti city (44.99°N, 26.1°E), the tropospheric VCD observed by satellites is (3.3 ± 1.9) × 1015 molec./cm2 (GOME-2) and (3.2 ± 3.2) × 1015 molec./cm2 (OMI), while average mobile measurements give (3.8 ± 0.8) × 1015 molec./cm2. Average ground measurements over “clean areas”, on 18 July 2011, give (2.5 ± 0.6) × 1015 molec./cm2 while the satellite observes a value of (1.8 ± 1.3) × 1015 molec./cm2. PMID:23519349

  11. Comparison of dust-layer heights from active and passive satellite sensors

    NASA Astrophysics Data System (ADS)

    Kylling, Arve; Vandenbussche, Sophie; Capelle, Virginie; Cuesta, Juan; Klüser, Lars; Lelli, Luca; Popp, Thomas; Stebel, Kerstin; Veefkind, Pepijn

    2018-05-01

    Aerosol-layer height is essential for understanding the impact of aerosols on the climate system. As part of the European Space Agency Aerosol_cci project, aerosol-layer height as derived from passive thermal and solar satellite sensors measurements have been compared with aerosol-layer heights estimated from CALIOP measurements. The Aerosol_cci project targeted dust-type aerosol for this study. This ensures relatively unambiguous aerosol identification by the CALIOP processing chain. Dust-layer height was estimated from thermal IASI measurements using four different algorithms (from BIRA-IASB, DLR, LMD, LISA) and from solar GOME-2 (KNMI) and SCIAMACHY (IUP) measurements. Due to differences in overpass time of the various satellites, a trajectory model was used to move the CALIOP-derived dust heights in space and time to the IASI, GOME-2 and SCIAMACHY dust height pixels. It is not possible to construct a unique dust-layer height from the CALIOP data. Thus two CALIOP-derived layer heights were used: the cumulative extinction height defined as the height where the CALIOP extinction column is half of the total extinction column, and the geometric mean height, which is defined as the geometrical mean of the top and bottom heights of the dust layer. In statistical average over all IASI data there is a general tendency to a positive bias of 0.5-0.8 km against CALIOP extinction-weighted height for three of the four algorithms assessed, while the fourth algorithm has almost no bias. When comparing geometric mean height there is a shift of -0.5 km for all algorithms (getting close to zero for the three algorithms and turning negative for the fourth). The standard deviation of all algorithms is quite similar and ranges between 1.0 and 1.3 km. When looking at different conditions (day, night, land, ocean), there is more detail in variabilities (e.g. all algorithms overestimate more at night than during the day). For the solar sensors it is found that on average SCIAMACHY data

  12. Evolution of NO2 levels in Spain from 1996 to 2012

    PubMed Central

    Cuevas, Carlos A.; Notario, Alberto; Adame, José Antonio; Hilboll, Andreas; Richter, Andreas; Burrows, John P.; Saiz-Lopez, Alfonso

    2014-01-01

    We report on the evolution of tropospheric nitrogen dioxide (NO2) over Spain, focusing on the densely populated cities of Barcelona, Bilbao, Madrid, Sevilla and Valencia, during 17 years, from 1996 to 2012. This data series combines observations from in-situ air quality monitoring networks and the satellite-based instruments GOME and SCIAMACHY. The results in these five cities show a smooth decrease in the NO2 concentrations of ~2% per year in the period 1996–2008, due to the implementation of emissions control environmental legislation, and a more abrupt descend of ~7% per year from 2008 to 2012 as a consequence of the economic recession. In the whole Spanish territory the NO2 levels have decreased by ~22% from 1996 to 2012. Statistical analysis of several economic indicators is used to investigate the different factors driving the NO2 concentration trends over Spain during the last two decades. PMID:25074028

  13. CIE, Vitamin D and DNA Damage: A Synergetic Study in Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Zempila, Melina Maria; Taylor, Michael; Fountoulakis, Ilias; Koukouli, Maria Elissavet; Bais, Alkiviadis; Arola, Antii; van Geffen, Jos; van Weele, Michiel; van der A, Ronald; Kouremeti, Natalia; Kazadzis, Stelios; Meleti, Chariklia; Balis, Dimitrios

    2016-08-01

    The present study aims to validate different approaches for the estimation of three photobiological effective doses: the erythemal UV, the vitamin D and that for DNA damage, using high temporal resolution surface- based measurements of solar UV from 2005-2015. Data from a UV spectrophotometer, a multi-filter radiometer, and a UV radiation pyranometer that are located in Thessaloniki, Greece are used together with empirical relations, algorithms and models in order to calculate the desired quantities. In addition to the surface-based dose retrievals, OMI/Aura and the combined SCIAMACHY/Envisat and GOME/MetopA satellite products are also used in order to assess the accuracy of each method for deriving the photobiological doses.

  14. Fabrication of Photothermal Stable Gold Nanosphere/Mesoporous Silica Hybrid Nanoparticle Responsive to Near-Infrared Light.

    PubMed

    Cheng, Bei; Xu, Peisheng

    2017-01-01

    Various gold nanoparticles have been explored in biomedical systems and proven to be promising in photothermal therapy and drug delivery. Among them, nanoshells were regarded as traditionally strong near infrared absorbers that have been widely used to generate photothermal effect for cancer therapy. However, the nanoshell is not photo-thermal stable and thus is not suitable for repeated irradiation. Here, we describe a novel discrete gold nanostructure by mimicking the continuous gold nanoshell-gold/mesoporous silica hybrid nanoparticle (GoMe). It possesses the best characteristics of both conventional gold nanoparticles and mesoporous silica nanoparticles, such as excellent photothermal converting ability as well as high drug loading capacity and triggerable drug release.

  15. Flux Calculation Using CARIBIC DOAS Aircraft Measurements: SO2 Emission of Norilsk

    NASA Technical Reports Server (NTRS)

    Walter, D.; Heue, K.-P.; Rauthe-Schoech, A.; Brenninkmeijer, C. A. M.; Lamsal, L. N.; Krotkov, N. A.; Platt, U.

    2012-01-01

    Based on a case-study of the nickel smelter in Norilsk (Siberia), the retrieval of trace gas fluxes using airborne remote sensing is discussed. A DOAS system onboard an Airbus 340 detected large amounts of SO2 and NO2 near Norilsk during a regular passenger flight within the CARIBIC project. The remote sensing data were combined with ECMWF wind data to estimate the SO2 output of the Norilsk industrial complex to be around 1 Mt per year, which is in agreement with independent estimates. This value is compared to results using data from satellite remote sensing (GOME, OMI). The validity of the assumptions underlying our estimate is discussed, including the adaptation of this method to other gases and sources like the NO2 emissions of large industries or cities.

  16. [Regime for treating the plague and the prescription of balm: some comments from the perspective of 'modern medicine'].

    PubMed

    de Carvalho, Diana Maul

    2005-01-01

    Regimento proueytoso contra ha pestenença and Modus curandi cum balsamo are probably the first texts addressing the prevention and treatment of diseases to be printed in Portugal. Their authorship and historical context are discussed elsewhere in this journal. Here we would like to raise some questions concerning the 'medical discourse' found in the texts and compare these with others from the eighteenth century. The authors chosen for the sake of comparison are two Portuguese--Luiz Gomes Ferreyra and João Curvo Semmedo--and one Englishman, John Huxham, author of An Essay on Fevers, which includes a lengthy discussion of smallpox, Europe's eighteenth-century 'plague'. It is our belief that these works, written in the early days of 'scientific medicine', represent a bridge between medieval/Renaissance texts and current medical compendia. They allow us to raise questions about the therapeutic indications and diagnostic criteria found in the documents.

  17. O2 A Band Studies for Cloud Detection and Algorithm Improvement

    NASA Technical Reports Server (NTRS)

    Chance, K. V.

    1996-01-01

    Detection of cloud parameters from space-based spectrometers can employ the vibrational bands of O2 in the (sup b1)Sigma(sub +)(sub g) yields X(sub 3) Sigma(sup -)(sub g) spin-forbidden electronic transition manifold, particularly the Delta nu = 0 A band. The GOME instrument uses the A band in the Initial Cloud Fitting Algorithm (ICFA). The work reported here consists of making substantial improvements in the line-by-line spectral database for the A band, testing whether an additional correction to the line shape function is necessary in order to correctly model the atmospheric transmission in this band, and calculating prototype cloud and ground template spectra for comparison with satellite measurements.

  18. Theoretical analysis of the effects of light intensity on the photocorrosion of semiconductor electrodes

    SciTech Connect

    Benito, R.M.; Nozik, A.J.

    1985-07-18

    A kinetic model was developed to describe the effects of light intensity on the photocorrosion of n-type semiconductor electrodes. The model is an extension of previous work by Gomes and co-workers that includes the possibility of multiple steps for the oxidation reaction of the reducing agent in the electrolyte. Six cases are considered where the semiconductor decomposition reaction is multistep (each step involves a hole); the oxidation reaction of the reducing agent is multistep (each step after the first involves a hole or a chemical intermediate), and the first steps of the competing oxidation reactions are reversible or irreversible. Itmore » was found, contrary to previous results, that the photostability of semiconductor electrodes could increase with increased light intensity if the desired oxidation reaction of the reducing agent in the electrolyte was multistep with the first step being reversible. 14 references, 5 figures, 1 table.« less

  19. Model-based monitoring and diagnosis of a satellite-based instrument

    NASA Technical Reports Server (NTRS)

    Bos, Andre; Callies, Jorg; Lefebvre, Alain

    1995-01-01

    For about a decade model-based reasoning has been propounded by a number of researchers. Maybe one of the most convincing arguments in favor of this kind of reasoning has been given by Davis in his paper on diagnosis from first principles (Davis 1984). Following their guidelines we have developed a system to verify the behavior of a satellite-based instrument GOME (which will be measuring Ozone concentrations in the near future (1995)). We start by giving a description of model-based monitoring. Besides recognizing that something is wrong, we also like to find the cause for misbehaving automatically. Therefore, we show how the monitoring technique can be extended to model-based diagnosis.

  20. Model-based monitoring and diagnosis of a satellite-based instrument

    NASA Astrophysics Data System (ADS)

    Bos, Andre; Callies, Jorg; Lefebvre, Alain

    1995-05-01

    For about a decade model-based reasoning has been propounded by a number of researchers. Maybe one of the most convincing arguments in favor of this kind of reasoning has been given by Davis in his paper on diagnosis from first principles (Davis 1984). Following their guidelines we have developed a system to verify the behavior of a satellite-based instrument GOME (which will be measuring Ozone concentrations in the near future (1995)). We start by giving a description of model-based monitoring. Besides recognizing that something is wrong, we also like to find the cause for misbehaving automatically. Therefore, we show how the monitoring technique can be extended to model-based diagnosis.

  1. Marine fluorescence from high spectrally resolved satellite measurements

    NASA Astrophysics Data System (ADS)

    Wolanin, Aleksandra; Dinter, Tilman; Rozanov, Vladimir; Noël, Stefan; Vountas, Marco; Burrows, John P.; Bracher, Astrid

    2014-05-01

    When chlorophyll molecules absorb light, most of this energy is transformed into chemical energy in a process of photosynthesis. However, a fraction of the energy absorbed is reemitted as fluorescence. As a result of its relationship to photosynthetic e?ciency, information about chlorophyll fluorescence can be used to assess the physiological state of phytoplankton (Falkowski and Kolber,1995). In-situ measurements of chlorophyll fluorescence are widespread in physiological and ecophysiological studies. When retrieved from space, chlorophyll fluorescence can improve our knowledge of global biogeochemical cycles and phytoplankton productivity (Behrenfeld et al., 2009; Huot et al., 2013) by providing high coverage and periodicity. So far, the only satellite retrieval of sun-induced marine fluorescence, Fluorescence Line Height (FLH), was designed for MODIS (Abbott and Letelier, 1999), and later also applied to the similar sensor MERIS (Gower et al., 2004). However, it could so far not be evaluated on global scale. Here, we present a different approach to observe marine chlorophyll fluorescence, based on the Differential Optical Absorption Spectroscopy (DOAS) technique (Perner and Platt, 1979) applied to the hyperspectral data from Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) and Global Ozone Monitoring Experiment-2 (GOME-2). Since fluorescence, as a trans-spectral process, leads to the shift of the wavelength of the radiation, it can be observed in the filling-in of Fraunhofer lines. In our retrieval, we evaluate the filling-in of the Zeeman triplet Fraunhofer line FeI at 684.3 nm, which is located very close to the emission peak of marine fluorescence (~685 nm). In order to conduct the chlorophyll fluorescence retrieval with the DOAS method, we calculated the reference spectra for chlorophyll fluorescence, based on simulations performed with the coupled ocean-atmosphere radiative transfer model SCIATRAN (Rozanov et al., 2014

  2. The evolution of a Pluto-like system during the migration of the ice giants

    NASA Astrophysics Data System (ADS)

    Pires, Pryscilla; Giuliatti Winter, Silvia M.; Gomes, Rodney S.

    2015-01-01

    The planetary migration of the Solar System giant planets in the framework of the Nice model (Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F. [2005]. Nature 435,459-461; Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R. [2005]. Nature 435, 462-465; Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A. [2005]. Nature 435, 466-469) creates a dynamical mechanism which can be used to explain the distribution of objects currently observed in the Kuiper belt (e.g., Levison, H.F., Morbidelli, A., Vanlaerhoven, C., Gomes, R., Tsiganis, K. [2008]. Icarus 196, 258-273). Through this mechanism the planetesimals within the disk, heliocentric distance ranging from beyond Neptune's orbit to approximately 34 AU, are delivered to the belt after a temporary eccentric phase of Uranus and Neptune's orbits. We reproduced the mechanism proposed by Levison et al. to implant bodies into the Kuiper belt. The capture of Pluto into the external 3:2 mean motion resonance with Neptune is associated with this gravitational scattering model. We verified the existence of several close encounters between the ice giants and the planetesimals during their outward radial migration, then we believe that the analysis of the dynamical history of the plutonian satellites during this kind of migration is important, and would provide some constrains about their place of formation - within the primordial planetesimal disk or in situ. We performed N-body simulations and recorded the trajectories of the planetesimals during close approaches with Uranus and Neptune. Close encounters with Neptune are the most common, reaching approximately 1200 in total. A Pluto similarly sized body assumed the hyperbolic trajectories of the former primordial planetesimal with respect to those giant planets. We assumed the current mutual orbital configuration and sizes for Pluto's satellites, then we found that the rate of destruction of systems similar to that of Pluto with closest approaches to Uranus or Neptune

  3. Development of Realistic Synthetic Data Products for the Tempo Geostationary Mission

    NASA Astrophysics Data System (ADS)

    Chan Miller, C.; Gonzalez Abad, G.; Zoogman, P.; Spurr, R. J. D.; Keller, C. A.; Liu, X.; Chance, K.

    2017-12-01

    TEMPO is a future geostationary satellite instrument designed to measure atmospheric pollution from solar backscatter over greater North America. Here we describe efforts to generate realistic synthetic level 1 (radiance) and level 2 (trace gas, aerosol and cloud) TEMPO observations, appropriate for retrieval algorithm validation and data assimilation observing system simulation experiments. The synthetic data are derived using a high resolution ( 12km x 12km) GEOS-5 GCM simulation with GEOS-Chem tropospheric chemistry combined with the VLIDORT radiative transfer model. The simulations include cloud and aerosol scattering, pressure- and temperature-dependent gas absorption, anisotropic surface reflectance derived from MODIS observations, solar-induced plant fluorescence derived from GOME-2 observations, and the Ring effect. We describe methods to speed up calculation of the synthetic level 2 products, and present a first validation of the TEMPO operational algorithms against the synthetic level 1 data.

  4. Product Quality of ESA's Atmospheric-Chemistry Missions

    NASA Astrophysics Data System (ADS)

    Dehn, Angelika; Bojkov, Bojan; Fehr, Thorsten

    2012-11-01

    ESA's Atmospheric Chemistry Mission is providing fundamental information for the understanding of atmospheric chemistry processes. The global datasets are supporting climate research, air quality assessments, stratospheric ozone monitoring and many other science areas and operational services.ENVISAT with GOMOS, MIPAS and SCIAMACHY has contributed to a unique data set over a period of 10 years, before its major anomaly in April 2012, leading to the end of the operational part of the mission. GOME, on board ERS-2 has been acquiring data for 16 years, before it's de-commissioning in July 2011.The quality of the corresponding data sets is continuously being improved, also beyond the termination of the satellite's operational phases. This is realised with the support of numerous teams of science experts, evolving the algorithm and calibration baseline and validation teams assessing the resulting upgraded data sets.

  5. Assessing potential changes of weather-related risk on chestnut productivity

    NASA Astrophysics Data System (ADS)

    Pereira, Mário; Calheiros, Tomas; Pinto, Joaquim; Caramelo, Liliana

    2013-04-01

    Weather conditions play an important role during different phases of the vegetative cycle of the chestnut trees and, consequently, several meteorological parameters seem to be associated chestnut productivity (Heiniger and Conedera, 1992, Cesaraccio et al., 2001, Wilczynski and Podalski, 2007, Gomes-Laranjo et al., 2008, Dinis et al., 2011, Pereira et al., 2011). Observed data from European Climate Assessment and simulated data by COSMO-CLM model for the actual (C20) and future (A1B and B1) climate scenarios were used in this study to: (i) assess the model ability to reproduce weather parameters distribution; and, (ii) to assess future changes in the distribution of meteorological parameters which play an important role in the productivity of chestnut for different future periods. Results points to statistical significant changes in the mean and in variance in the future, more prominent in temperature than in precipitation based parameters. Changes in precipitation will be more significant in Northwestern Iberian Peninsula and France in the end of the 21st century for A1B scenario conditions. As expected, more significant changes will be expected to occur during spring and summer, in the Mediterranean areas and in the later period. The number of days with Tmax<28°C will generally decrease in both scenarios, while the changes in the number of days with 24°C

  6. Global 3-D Modeling Studies Of Tropospheric Ozone And Related Gases

    NASA Technical Reports Server (NTRS)

    Jacob, Daniel J.; Logan, Jennifer A.

    2003-01-01

    Our research was targeted at three issues: (1) the factors controlling ozone in the tropical troposphere, (2) the Asian outflow of ozone and its precursors, and (3) the causes of decadal trends observed in ozone and CO. We have also used support from this ACMAP grant to (1) work with Kelly Chance on the retrieval and interpretation of HCHO and NO2 observations from GOME, and (2) develop GEOS-CHEM into a versatile model supporting the work of a large number of users including outside Harvard. ACMAP has provided the core support for GEOS-CHEM development. Applications of the GEOS-CHEM model with primary support from ACMAP are discussed below. A list of publications resulting from this grant is given at the end of the report.

  7. Estimating the volcanic emission rate and atmospheric lifetime of SO2 from space: a case study for Kīlauea volcano, Hawai'i

    USGS Publications Warehouse

    Beirle, Steffen; Hörmann, Christoph; Penning de Vries, Malouse; Dörner, Stefan; Kern, Christoph; Wagner, Thomas

    2014-01-01

    We present an analysis of SO2 column densities derived from GOME-2 satellite measurements for the Kīlauea volcano (Hawai`i) for 2007–2012. During a period of enhanced degassing activity in March–November 2008, monthly mean SO2 emission rates and effective SO2 lifetimes are determined simultaneously from the observed downwind plume evolution and meteorological wind fields, without further model input. Kīlauea is particularly suited for quantitative investigations from satellite observations owing to the absence of interfering sources, the clearly defined downwind plumes caused by steady trade winds, and generally low cloud fractions. For March–November 2008, the effective SO2 lifetime is 1–2 days, and Kīlauea SO2 emission rates are 9–21 kt day−1, which is about 3 times higher than initially reported from ground-based monitoring systems.

  8. Bioactive Compounds Found in Brazilian Cerrado Fruits

    PubMed Central

    Bailão, Elisa Flávia Luiz Cardoso; Devilla, Ivano Alessandro; da Conceição, Edemilson Cardoso; Borges, Leonardo Luiz

    2015-01-01

    Functional foods include any natural product that presents health-promoting effects, thereby reducing the risk of chronic diseases. Cerrado fruits are considered a source of bioactive substances, mainly phenolic compounds, making them important functional foods. Despite this, the losses of natural vegetation in the Cerrado are progressive. Hence, the knowledge propagation about the importance of the species found in Cerrado could contribute to the preservation of this biome. This review provides information about Cerrado fruits and highlights the structures and pharmacologic potential of functional compounds found in these fruits. Compounds detected in Caryocar brasiliense Camb. (pequi), Dipteryx alata Vog. (baru), Eugenia dysenterica DC. (cagaita), Eugenia uniflora L. (pitanga), Genipa americana L. (jenipapo), Hancornia speciosa Gomes (mangaba), Mauritia flexuosa L.f. (buriti), Myrciaria cauliflora (DC) Berg (jabuticaba), Psidium guajava L. (goiaba), Psidium spp. (araçá), Solanum lycocarpum St. Hill (lobeira), Spondias mombin L. (cajá), Annona crassiflora Mart. (araticum), among others are reported here. PMID:26473827

  9. Advances in Remote Sensing of Vegetation Merging NDVI, Soil Moisture, and Chlorophyll Fluorescence

    NASA Astrophysics Data System (ADS)

    Tucker, Compton

    2016-04-01

    I will describe an advance in remote sensing of vegetation in the time domain that combines simultaneous measurements of the normalized difference vegetation index, soil moisture, and chlorophyll fluorescence, all from different satellite sensors but acquired for the same areas at the same time step. The different sensor data are MODIS NDVI data from both Terra and Aqua platforms, soil moisture data from SMOS & SMP (aka SMAP but with only the passive radiometer), and chlorophyll fluorescence data from GOME-2. The complementary combination of these data provide important crop yield information for agricultural production estimates at critical phenological times in the growing season, provide a scientific basis to map land degradation, and enable quantitative determination of the end of the growing season in temperate zones.

  10. Patient-specific instrumentation for total shoulder arthroplasty

    PubMed Central

    Gomes, Nuno Sampaio

    2016-01-01

    Shoulder arthroplasty is a demanding procedure with a known complication rate. Most complications are associated with the glenoid component, a fact that has stimulated investigation into that specific component of the implant. Avoiding glenoid component malposition is very important and is a key reason for recent developments in pre-operative planning and instrumentation to minimise risk. Patient-specific instrumentation (PSI) was developed as an alternative to navigation systems, originally for total knee arthroplasty, and is a valid option for shoulder replacements today. It offers increased accuracy in the placement of the glenoid component, which improves the likelihood of an optimal outcome. A description of the method of pre-operative planning and surgical technique is presented, based on the author’s experience and a review of the current literature. Cite this article: Gomes N. Patient-specific instrumentation for total shoulder arthroplasty. EFORT Open Rev 2016;1:177-182. DOI: 10.1302/2058-5241.1.000033. PMID:28461945

  11. Global simulation of canopy scale sun-induced chlorophyll fluorescence with a 3 dimensional radiative transfer model

    NASA Astrophysics Data System (ADS)

    Kobayashi, H.; Yang, W.; Ichii, K.

    2015-12-01

    Global simulation of canopy scale sun-induced chlorophyll fluorescence with a 3 dimensional radiative transfer modelHideki Kobayashi, Wei Yang, and Kazuhito IchiiDepartment of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology3173-25, Showa-machi, Kanazawa-ku, Yokohama, Japan.Plant canopy scale sun-induced chlorophyll fluorescence (SIF) can be observed from satellites, such as Greenhouse gases Observation Satellite (GOSAT), Orbiting Carbon Observatory-2 (OCO-2), and Global Ozone Monitoring Experiment-2 (GOME-2), using Fraunhofer lines in the near infrared spectral domain [1]. SIF is used to infer photosynthetic capacity of plant canopy [2]. However, it is not well understoond how the leaf-level SIF emission contributes to the top of canopy directional SIF because SIFs observed by the satellites use the near infrared spectral domain where the multiple scatterings among leaves are not negligible. It is necessary to quantify the fraction of emission for each satellite observation angle. Absorbed photosynthetically active radiation of sunlit leaves are 100 times higher than that of shaded leaves. Thus, contribution of sunlit and shaded leaves to canopy scale directional SIF emission should also be quantified. Here, we show the results of global simulation of SIF using a 3 dimensional radiative transfer simulation with MODIS atmospheric (aerosol optical thickness) and land (land cover and leaf area index) products and a forest landscape data sets prepared for each land cover category. The results are compared with satellite-based SIF (e.g. GOME-2) and the gross primary production empirically estimated by FLUXNET and remote sensing data.

  12. Evaluating A Priori Ozone Profile Information Used in TEMPO Tropospheric Ozone Retrievals

    NASA Astrophysics Data System (ADS)

    Johnson, M. S.; Sullivan, J. T.; Liu, X.; Newchurch, M.; Kuang, S.; McGee, T. J.; Langford, A. O.; Senff, C. J.; Leblanc, T.; Berkoff, T.; Gronoff, G.; Chen, G.; Strawbridge, K. B.

    2016-12-01

    Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address these limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm uses a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB) O3 climatology). It has been shown that satellite O3 retrievals are sensitive to a priori O3 profiles and covariance matrices. During this work we investigate the climatological data to be used in TEMPO algorithms (TB O3) and simulated data from the NASA GMAO Goddard Earth Observing System (GEOS-5) Forward Processing (FP) near-real-time (NRT) model products. These two data products will be evaluated with ground-based lidar data from the Tropospheric Ozone Lidar Network (TOLNet) at various locations of the US. This study evaluates the TB climatology, GEOS-5 climatology, and 3-hourly GEOS-5 data compared to lower tropospheric observations to demonstrate the accuracy of a priori information to potentially be used in TEMPO O3 algorithms. Here we present our initial analysis and the theoretical impact on TEMPO retrievals in the lower troposphere.

  13. Drought onset mechanisms revealed by satellite solar-induced chlorophyll fluorescence: Insights from two contrasting extreme events

    DOE PAGES

    Sun, Ying; Fu, Rong; Dickinson, Robert; ...

    2015-11-02

    This study uses the droughts of 2011 in Texas and 2012 over the central Great Plains as case studies to explore the potential of satellite-observed solar-induced chlorophyll fluorescence (SIF) for monitoring drought dynamics. We find that the spatial patterns of negative SIF anomalies from the Global Ozone Monitoring Experiment 2 (GOME-2) closely resembled drought intensity maps from the U.S. Drought Monitor for both events. The drought-induced suppression of SIF occurred throughout 2011 but was exacerbated in summer in the Texas drought. This event was characterized by a persistent depletion of root zone soil moisture caused by yearlong below-normal precipitation. Inmore » contrast, for the central Great Plains drought, warmer temperatures and relatively normal precipitation boosted SIF in the spring of 2012; however, a sudden drop in precipitation coupled with unusually high temperatures rapidly depleted soil moisture through evapotranspiration, leading to a rapid onset of drought in early summer. Accordingly, SIF reversed from above to below normal. For both regions, the GOME-2 SIF anomalies were significantly correlated with those of root zone soil moisture, indicating that the former can potentially be used as proxy of the latter for monitoring agricultural droughts with different onset mechanisms. Further analyses indicate that the contrasting dynamics of SIF during these two extreme events were caused by changes in both fraction of absorbed photosynthetically active radiation fPAR and fluorescence yield, suggesting that satellite SIF is sensitive to both structural and physiological/biochemical variations of vegetation. Here, we conclude that the emerging satellite SIF has excellent potential for dynamic drought monitoring.« less

  14. Identification of tropospheric emissions sources from satellite observations: Synergistic use of HCHO, NO2, and SO2 trace gas measurements

    NASA Astrophysics Data System (ADS)

    Marbach, T.; Beirle, S.; Khokhar, F.; Platt, U.

    2005-12-01

    We present case studies for combined HCHO, NO2, and SO2 satellite observations, derived from GOME measurements. Launched on the ERS-2 satellite in April 1995, GOME has already performed continuous operations over 8 years providing global observations of the different trace gases. In this way, satellite observations provide unique opportunities for the identifications of trace gas sources. The satellite HCHO observations provide information concerning the localization of biomass burning (intense source of HCHO). The principal biomass burning areas can be observed in the Amazon basin region and in central Africa Weaker HCHO sources (south east of the United States, northern part of the Amazon basin, and over the African tropical forest), not correlated with biomass burning, could be due to biogenic isoprene emissions. The HCHO data can be compared with NO2 and SO2 results to identify more precisely the tropospheric sources (biomass burning events, human activities, additional sources like volcanic emissions). Biomass burning are important tropospheric sources for both HCHO and NO2. Nevertheless HCHO reflects more precisely the biomass burning as it appears in all biomass burning events. NO2 correlate with HCHO over Africa (grassland fires) but not over Indonesia (forest fires). In south America, an augmentation of the NO2 concentrations can be observed with the fire shift from the forest to grassland vegetation. So there seems to be a dependence between the NO2 emissions during biomass burning and the vegetation type. Other high HCHO, SO2, and NO2 emissions can be correlated with climatic events like the El Nino in 1997, which induced dry conditions in Indonesia causing many forest fires.

  15. Temporal and spatial distribution of metallic species in the upper atmosphere

    NASA Astrophysics Data System (ADS)

    Correira, John Thomas

    2009-06-01

    Every day the Earth is bombarded by approximately 100 tons of meteoric material. Much of this material is completely ablated on atmospheric entry, resulting in a layer of atomic metals in the upper atmosphere between 70 km - 150 km. These neutral atoms are ionized by solar radiation and charge exchange. Metal ions have a long lifetime against recombination loss, allowing them to be redistributed globally by electromagnetic forces, especially when lifted to altitudes >150 km. UV radiances from the Global Ozone Monitoring Experiment (GOME) spectrometer are used to determine long-term dayside variations of the total vertical column density below 795 km of the meteoric metal species Mg and Mg + in the upper atmosphere. A retrieval algorithm developed to determine magnesium column densities was applied to all available data from the years 1996-2001. Long term results show middle latitude dayside Mg + peaks in vertical content during the summer, while neutral Mg demonstrates a much more subtle maximum in summer. Atmospheric metal concentrations do not correlate strongly solar activity. An analysis of spatial variations shows geospatial distributions are patchy, with local regions of increased column density. To study short term variations and the role of meteor showers a time dependent mass flux rate is calculated using published estimates of meteor stream mass densities and activity profiles. An average daily mass flux rate is also calculated and used as a baseline against which shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal column densities. There appears to be little correlation between modeled meteor shower mass flux rates and changes in the observed neutral magnesium and Mg + metal column densities.

  16. Tropospheric NO2 and HCHO columns derived from ground-based MAX-DOAS system in Guangzhou, China and comparison with satellite observations: First results within the EU FP7 project MarcoPolo

    NASA Astrophysics Data System (ADS)

    Drosoglou, Theano; Kouremeti, Natalia; Bais, Alkis; Zyrichidou, Irene; Li, Shu; Balis, Dimitris; Huang, Zhonghui

    2016-04-01

    A miniature MAX-DOAS system, Phaethon, has been developed at the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki, Greece, for ground-based monitoring of column densities of atmospheric gases. Simultaneous measurements with two Phaethon systems at the city centre of Thessaloniki and at a rural location about 30 km away have shown that Phaethon provides NO2 and HCHO tropospheric column measurements of acceptable accuracy under both low and high air-pollution levels. Currently three systems have been deployed in areas with different pollution patterns to support air quality and satellite validation studies. In the framework of the EU FP7 Monitoring and Assessment of Regional air quality in China using space Observations, Project Of Long-term sino-european co-Operation, MarcoPolo project, one of the Phaethon systems has been installed since April 2015 in the Guangzhou region in China. Tropospheric NO2 and HCHO columns derived at Guangzhou during the first 10 months of operation are compared with corresponding retrievals from OMI/Aura and GOME-2/Metop-A and /Metop-B satellite sensors. The area is characterized by humid subtropical monsoon climate and cloud-free conditions are rather rare from early March to mid-October. Despite this limitation and the short period of operation of Phaethon in Guangzhou, the agreement between ground-based and satellite observations is generally good for both NO2 and HCHO. It appears that GOME-2 sensors seem to underestimate the tropospheric NO2, possibly due to their large pixel size, whereas the comparison with OMI data is better, especially when a small cloud fraction (< 0.2) is used for cloud screening.

  17. Analysis of Satellite-Derived Arctic Tropospheric BrO Columns in Conjunction with Aircraft Measurements During ARCTAS and ARCPAC

    NASA Technical Reports Server (NTRS)

    Choi, S.; Wang, Y.; Salawitch, R. J.; Canty, T.; Joiner, J.; Zeng, T.; Kurosu, T. P.; Chance, K.; Richter, A.; Huey, L. G.; hide

    2012-01-01

    We derive tropospheric column BrO during the ARCTAS and ARCPAC field campaigns in spring 2008 using retrievals of total column BrO from the satellite UV nadir sensors OMI and GOME-2 using a radiative transfer model and stratospheric column BrO from a photochemical simulation. We conduct a comprehensive comparison of satellite-derived tropospheric BrO column to aircraft in-situ observations ofBrO and related species. The aircraft profiles reveal that tropospheric BrO, when present during April 2008, was distributed over a broad range of altitudes rather than being confined to the planetary boundary layer (PBL). Perturbations to the total column resulting from tropospheric BrO are the same magnitude as perturbations due to longitudinal variations in the stratospheric component, so proper accounting of the stratospheric signal is essential for accurate determination of satellite-derived tropospheric BrO. We find reasonably good agreement between satellite-derived tropospheric BrO and columns found using aircraft in-situ BrO profiles, particularly when satellite radiances were obtained over bright surfaces (albedo> 0.7), for solar zenith angle < 80 and clear sky conditions. The rapid activation of BrO due to surface processes (the bromine explosion) is apparent in both the OMI and GOME-2 based tropospheric columns. The wide orbital swath of OMI allows examination of the evolution of tropospheric BrO on about hourly time intervals near the pole. Low surface pressure, strong wind, and high PBL height are associated with an observed BrO activation event, supporting the notion of bromine activation by high winds over snow.

  18. Drought onset mechanisms revealed by satellite solar-induced chlorophyll fluorescence: Insights from two contrasting extreme events

    SciTech Connect

    Sun, Ying; Fu, Rong; Dickinson, Robert

    This study uses the droughts of 2011 in Texas and 2012 over the central Great Plains as case studies to explore the potential of satellite-observed solar-induced chlorophyll fluorescence (SIF) for monitoring drought dynamics. We find that the spatial patterns of negative SIF anomalies from the Global Ozone Monitoring Experiment 2 (GOME-2) closely resembled drought intensity maps from the U.S. Drought Monitor for both events. The drought-induced suppression of SIF occurred throughout 2011 but was exacerbated in summer in the Texas drought. This event was characterized by a persistent depletion of root zone soil moisture caused by yearlong below-normal precipitation. Inmore » contrast, for the central Great Plains drought, warmer temperatures and relatively normal precipitation boosted SIF in the spring of 2012; however, a sudden drop in precipitation coupled with unusually high temperatures rapidly depleted soil moisture through evapotranspiration, leading to a rapid onset of drought in early summer. Accordingly, SIF reversed from above to below normal. For both regions, the GOME-2 SIF anomalies were significantly correlated with those of root zone soil moisture, indicating that the former can potentially be used as proxy of the latter for monitoring agricultural droughts with different onset mechanisms. Further analyses indicate that the contrasting dynamics of SIF during these two extreme events were caused by changes in both fraction of absorbed photosynthetically active radiation fPAR and fluorescence yield, suggesting that satellite SIF is sensitive to both structural and physiological/biochemical variations of vegetation. Here, we conclude that the emerging satellite SIF has excellent potential for dynamic drought monitoring.« less

  19. Observing the Anthropocene from Space: Selected Megacities

    NASA Astrophysics Data System (ADS)

    Burrows, John P.; Hilboll, Andreas; Richter, Andreas

    2014-05-01

    From the beginning of the Neolithic revolution around 10000 BC and 1800 A.D., the earth's human population is estimated to have risen from several million nomadic hunter gathers to 1 Billion rural settlement and city dwellers. This population increase and its related raising of the standard of living increase and life expectancy were fuelled by energy from the exploitation of biofuel and some use of coal. This rapid development is dwarfed by the impact of the industrial revolution over the past two centuries. There are no over 7 Billion people on earth with over half living in cities and urban areas, e.g. there are ~ 3 billion more citizens than when the author was born and 2 million more than when the project SCIAMACHY (SCanning Imaging and Absorption spectroMeter for Atmospheric ChartographY) was proposed! This industrialisation and urbanisation has been fuelled by the use of cheap energy from fossil fuel combustion. It has resulted in large scale changes in land use, air pollution, and the destruction of stratospheric ozone, the anthropogenic modification of biogeochemical cycling, the destruction of species, ecosystems and ecosystem services. In order to test our knowledge and understanding of the Earth system, accurate long term global measurements of atmospheric constituents and surface parameters are essential. The remote sounding of the atmosphere from instrumentation on satellite platforms provides a unique opportunity to retrieve regional and global observations of key trace atmospheric constituents (gases, aerosol and clouds) and surface parameters (ocean colour, ice extent, flora etc.). This talk describes results from the SCIAMACHY project and its spin offs, GOME (originally SCIA-mini - Global Ozone Monitoring Experiment), GOME-2, and their successors ESA Sentinel 4 (originally GeoSCIA), Sentinel 5, CarbonSat and SCIA-ISS. The interpretation of the data from these instruments has provided a paradigm shift in our understanding of global atmospheric

  20. Observing the Anthropocene from Space

    NASA Astrophysics Data System (ADS)

    Burrows, John

    The industrial revolution, which began in the UK in the late 18th century, has been fuelled by the use of cheap energy from fossil fuel combustion. It has facilitated a dramatic rise in both the human population, now above 7 Billion with 50% now living in urban agglomerations, and its standard of living. It is anticipated that by 2050 there will be of the order of 8.3 to 10 billion people, 75% living in cities. Anthropogenic activity has resulted in pollution from the local to the global scale changes in land use, the destruction of stratospheric ozone, the modification of biogeochemical cycling, acid deposition, impacted on ecosystems and ecosystem services, destruction of biodiversity and climate change. The impact of man has moved the earth from the Holocene to the new geological epoch of the Anthropocene. To improve our understanding of the earth atmosphere system and the accuracy of the prediction of its future changes, knowledge of the amounts and distributions of trace atmospheric constituents are essential -“One cannot manage what is not measured”. An integrated observing system, comprising ground and space based segments is required to improve our science and to provide an evidence base needed for environmental policymakers. Passive remote sensing measurements made of the up-welling radiation at the top of the atmosphere from instrumentation on space borne platforms provide a unique opportunity to retrieve globally atmospheric composition. This presentation describes results from the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY on ESA Envsiat 2002 to 2012) and its spin offs GOME (Global Ozone Monitoring Experiment ESA ERS-2 1995 to 2011) and GOME-2 (ESA/EUMETSAT Metop series). The potential of the SCIAMACHY successors Sentinel 5, CarbonSat, and SCIA-ISS will also be addressed.

  1. Angular Normalization of Ground and Satellite Observations of Sun-induced Chlorophyll Fluorescence for Assessing Vegetation Productivity

    NASA Astrophysics Data System (ADS)

    Chen, J. M.; He, L.; Chou, S.; Ju, W.; Zhang, Y.; Joiner, J.; Liu, J.; Mo, G.

    2017-12-01

    Sun-induced chlorophyll fluorescence (SIF) measured from plant canopies originates mostly from sunlit leaves. Observations of SIF by satellite sensors, such as GOME-2 and GOSAT, are often made over large view zenith angle ranges, causing large changes in the viewed sunlit leaf fraction across the scanning swath. Although observations made by OCO-2 are near nadir, the observed sunlit leaf fraction could still vary greatly due to changes in the solar zenith angle with latitude and time of overpass. To demonstrate the importance of considering the satellite-target-view geometry in using SIF for assessing vegetation productivity, we conducted multi-angle measurements of SIF using a hyperspectral sensor mounted on an automated rotating system over a rice field near Nanjing, China. A method is developed to separate SIF measurements at each angle into sunlit and shaded leaf components, and an angularly normalized canopy-level SIF is obtained as the weighted sum of sunlit and shaded SIF. This normalized SIF is shown to be a much better proxy of GPP of the rice field measured by an eddy covariance system than the unnormalized SIF observations. The same normalization scheme is also applied to the far-red GOME-2 SIF observations on sunny days, and we found that the normalized SIF is better correlated with model-simulated GPP than the original SIF observations. The coefficient of determination (R2) is improved by 0.07±0.04 on global average using the normalization scheme. The most significant improvement in R2 by 0.09±0.04 is found in deciduous broadleaf forests, where the observed sunlit leaf fraction is highly sensitive to solar zenith angle.

  2. Prospects for Chlorophyll Fluorescence Remote Sensing from the Orbiting Carbon Observatory-2

    NASA Technical Reports Server (NTRS)

    Frankenberg, Christian; Odell, Chris; Berry, Joseph; Guanter, Luis; Joiner, Joanna; Kohler, Philipp; Pollock, Randy; Taylor, Thomas E.

    2014-01-01

    The Orbiting Carbon Observatory-2 (OCO-2), scheduled to launch in July 2014, is a NASA mission designed to measure atmospheric CO2. Its main purpose is to allow inversions of net flux estimates of CO2 on regional to continental scales using the total column CO2 retrieved using high-resolution spectra in the 0.76, 1.6, and 2.0 nm ranges. Recently, it was shown that solar-induced chlorophyll fluorescence (SIF), a proxy for gross primary production (GPP, carbon uptake through photosynthesis), can be accurately retrieved from space using high spectral resolution radiances in the 750 nm range from the Japanese GOSAT and European GOME-2 instruments. Here, we use real OCO-2 thermal vacuum test data as well as a full repeat cycle (16 days) of simulated OCO-2 spectra under realistic conditions to evaluate the potential of OCO-2 for retrievals of chlorophyll fluorescence and also its dependence on clouds and aerosols. We find that the single-measurement precision is 0.3-0.5 Wm(exp -2)sr(exp -1) nm(exp -1) (15-25% of typical peak values), better than current measurements from space but still difficult to interpret on a single-sounding basis. The most significant advancement will come from smaller ground-pixel sizes and increased measurement frequency, with a 100-fold increase compared to GOSAT (and about 8 times higher than GOME-2). This will largely decrease the need for coarse spatial and temporal averaging in data analysis and pave the way to accurate local studies.We also find that the lack of full global mapping from the OCO-2 only incurs small representativeness errors on regional averages. Eventually, the combination of net ecosystem exchange (NEE) derived from CO2 source/sink inversions and SIF as proxy for GPP from the same satellite will provide a more process-based understanding of the global carbon cycle.

  3. Evaluating A Priori Ozone Profile Information Used in TEMPO Tropospheric Ozone Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew S.; Sullivan, John T.; Liu, Xiong; Newchurch, Mike; Kuang, Shi; McGee, Thomas J.; Langford, Andrew O'Neil; Senff, Christoph J.; Leblanc, Thierry; Berkoff, Timothy; hide

    2016-01-01

    Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address these limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm uses a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB) O3 climatology). It has been shown that satellite O3 retrievals are sensitive to a priori O3 profiles and covariance matrices. During this work we investigate the climatological data to be used in TEMPO algorithms (TB O3) and simulated data from the NASA GMAO Goddard Earth Observing System (GEOS-5) Forward Processing (FP) near-real-time (NRT) model products. These two data products will be evaluated with ground-based lidar data from the Tropospheric Ozone Lidar Network (TOLNet) at various locations of the US. This study evaluates the TB climatology, GEOS-5 climatology, and 3-hourly GEOS-5 data compared to lower tropospheric observations to demonstrate the accuracy of a priori information to potentially be used in TEMPO O3 algorithms. Here we present our initial analysis and the theoretical impact on TEMPO retrievals in the lower troposphere.

  4. Evaluating a Priori Ozone Profile Information Used in TEMPO Tropospheric Ozone Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew S.; Sullivan, John; Liu, Xiong; Newchurch, Mike; Kuang, Shi; McGee, Thomas; Langford, Andrew; Senff, Chris; Leblanc, Thierry; Berkoff, Timothy; hide

    2016-01-01

    Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address these limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product.TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm uses a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB) O3 climatology). It has been shown that satellite O3 retrievals are sensitive to a priori O3 profiles and covariance matrices. During this work we investigate the climatological data to be used in TEMPO algorithms (TB O3) and simulated data from the NASA GMAO Goddard Earth Observing System (GEOS-5) Forward Processing (FP) near-real-time (NRT) model products. These two data products will be evaluated with ground-based lidar data from the Tropospheric Ozone Lidar Network (TOLNet) at various locations of the US. This study evaluates the TB climatology, GEOS-5 climatology, and 3-hourly GEOS-5 data compared to lower tropospheric observations to demonstrate the accuracy of a priori information to potentially be used in TEMPO O3 algorithms. Here we present our initial analysis and the theoretical impact on TEMPO retrievals in the lower troposphere.

  5. Combined Ozone Retrieval From METOP Sensors Using META-Training Of Deep Neural Networks

    NASA Astrophysics Data System (ADS)

    Felder, Martin; Sehnke, Frank; Kaifel, Anton

    2013-12-01

    The newest installment of our well-proven Neural Net- work Ozone Retrieval System (NNORSY) combines the METOP sensors GOME-2 and IASI with cloud information from AVHRR. Through the use of advanced meta- learning techniques like automatic feature selection and automatic architecture search applied to a set of deep neural networks, having at least two or three hidden layers, we have been able to avoid many technical issues normally encountered during the construction of such a joint retrieval system. This has been made possible by harnessing the processing power of modern consumer graphics cards with high performance graphic processors (GPU), which decreases training times by about two orders of magnitude. The system was trained on data from 2009 and 2010, including target ozone profiles from ozone sondes, ACE- FTS and MLS-AURA. To make maximum use of tropospheric information in the spectra, the data were partitioned into several sets of different cloud fraction ranges with the GOME-2 FOV, on which specialized retrieval networks are being trained. For the final ozone retrieval processing the different specialized networks are combined. The resulting retrieval system is very stable and does not show any systematic dependence on solar zenith angle, scan angle or sensor degradation. We present several sensitivity studies with regard to cloud fraction and target sensor type, as well as the performance in several latitude bands and with respect to independent validation stations. A visual cross-comparison against high-resolution ozone profiles from the KNMI EUMETSAT Ozone SAF product has also been performed and shows some distinctive features which we will briefly discuss. Overall, we demonstrate that a complex retrieval system can now be constructed with a minimum of ma- chine learning knowledge, using automated algorithms for many design decisions previously requiring expert knowledge. Provided sufficient training data and computation power of GPUs is available, the

  6. Nursing workload for cancer patients under palliative care.

    PubMed

    Fuly, Patrícia Dos Santos Claro; Pires, Livia Márcia Vidal; Souza, Claudia Quinto Santos de; Oliveira, Beatriz Guitton Renaud Baptista de; Padilha, Katia Grillo

    2016-01-01

    To verify the nursing workload required by cancer patients undergoing palliative care and possible associations between the demographic and clinical characteristics of the patients and the nursing workload. This is a quantitative, cross-sectional, prospective study developed in the Connective Bone Tissue (TOC) clinics of Unit II of the Brazilian National Cancer Institute José Alencar Gomes da Silva with patients undergoing palliative care. Analysis of 197 measures of the Nursing Activities Score (NAS) revealed a mean score of 43.09% and an association between the performance status of patients undergoing palliative care and the mean NAS scores. The results of the study point to the need to resize the team of the unit. The NAS has proven to be a useful tool in oncologic clinical units for patients undergoing palliative care. Verificar a carga de trabalho de enfermagem requerida por pacientes com câncer sob cuidados paliativos e possíveis associações entre as características demográficas e clínicas dos pacientes e a carga de trabalho de enfermagem. Trata-se de um estudo de abordagem quantitativa, transversal, prospectivo, desenvolvido na clínica de Tecido Ósseo Conectivo (TOC) da Unidade II do Instituto Nacional de Câncer José Alencar Gomes da Silva, com pacientes em cuidados paliativos. A análise de 197 medidas do Nursing Activities Score (NAS) revelou um escore médio de 43,09% e uma associação entre a performance status de pacientes em cuidados paliativos com os valores médios do NAS. Os resultados do estudo apontam para a necessidade de redimensionamento da equipe da Unidade. O NAS mostrou-se um instrumento passível de utilização em unidades clínicas oncológicas, com pacientes em cuidados paliativos.

  7. Total ozone column, aerosol optical depth and precipitable water effects on solar erythemal ultraviolet radiation recorded in Malta.

    NASA Astrophysics Data System (ADS)

    Bilbao, Julia; Román, Roberto; Yousif, Charles; Mateos, David; Miguel, Argimiro

    2013-04-01

    The Universities of Malta and Valladolid (Spain) developed a measurement campaign, which took place in the Institute for Energy Technology in Marsaxlokk (Southern Malta) between May and October 2012, and it was supported by the Spanish government through the Project titled "Measurement campaign about Solar Radiation, Ozone, and Aerosol in the Mediterranean area" (with reference CGL2010-12140-E). This campaign provided the first ground-based measurements in Malta of erythemal radiation and UV index, which indicate the effectiveness of the sun exposure to produce sunburn on human skin. A wide variety of instruments was involved in the campaign, providing a complete atmospheric characterization. Data of erythemal radiation and UV index (from UVB-1 pyranometer), total shortwave radiaton (global and diffuse components from CM-6B pyranometers), and total ozone column, aerosol optical thickness, and precitable water column (from a Microtops-II sunphotometer) were available in the campaign. Ground-based and satellite instruments were used in the analysis, and several intercomparisons were carried out to validate remote sensing data. OMI, GOME, GOME-2, and MODIS instruments, which provide data of ozone, aerosol load and optical properties, were used to this end. The effects on solar radiation, ultraviolet and total shortwave ranges, of total ozone column, aerosol optical thickness and precipitable water column were obtained using radiation measurements at different fixed solar zenith angles. The empirical results shown a determinant role of the solar position, a negligible effect of ozone on total shortwave radiation, and a stronger attenuation provided by aerosol particles in the erythemal radiation. A variety of aerosol types from different sources (desert dust, biomass burning, continental, and maritime) reach Malta, in this campaign several dust events from the Sahara desert occurred and were analyzed establishing the air mass back-trajectories ending at Malta at

  8. Intercomparison among tropospheric ozone and nitrogen dioxide data obtained by satellite- and ground-based measurements

    NASA Astrophysics Data System (ADS)

    Noguchi, K.; Urita, N.; Ohta, E.; Hayashida, S.; Richter, A.; Burrows, J. P.; Liu, X.; Chance, K.; Ziemke, J. R.

    2005-12-01

    Rapid economical growth and industrial development in East Asian regions are causing serious air pollution. The influence of such air pollution is not limited to a local scale but reaches an intercontinental or hemispheric scale. Satellite-borne observations can monitor the behaviors of air pollutants in a global scale for long periods with a single instrument. In particular, ozone and nitrogen dioxide in the troposphere have a crucial role in air pollution, and many studies have tried to derive those species. Recently, instrumentations and retrieval techniques have made a lot of progress in measurements of tropospheric constituents. However, tropospheric observations from space need careful validation because of difficulties in detecting signals from the lower atmosphere through the middle atmosphere. In the present study, we intercompare the tropospheric ozone and nitrogen dioxide data obtained by satellite- and ground-based measurements in order to validate the satellite measurements. For the validation of tropospheric ozone, we utilize ozonesonde data provided by WOUDC, and three satellite-borne data (Tropospheric Ozone Residual (TOR), Cloud Slicing, and GOME) are intercompared. For nitrogen dioxide, we compare GOME observations with ground-based air monitoring measurements in Japan which are operationally conducted by the Ministry of the Environment Japan. This study demonstrates the validity and potential of those satellite datasets to apply for quantitative analysis of dispersion of air pollutants and their chemical lifetime. Acknowledgments. TOR data is provided by J. Fishman via http://asd-www.larc.nasa.gov/TOR/data.html. The ground observation data of nitrogen dioxide over Japan is provided by National Institute for Environmental Studies (NIES) under the collaboration study with NIES and Nara Women's University.

  9. Seasonal controls of aragonite saturation states in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Wang, Zhaohui Aleck; Lawson, Gareth L.; Pilskaln, Cynthia H.; Maas, Amy E.

    2017-01-01

    The Gulf of Maine (GoME) is a shelf region especially vulnerable to ocean acidification (OA) due to natural conditions of low pH and aragonite saturation states (Ω-Ar). This study is the first to assess the major oceanic processes controlling seasonal variability of the carbonate system and its linkages with pteropod abundance in Wilkinson Basin in the GoME. Two years of seasonal sampling cruises suggest that water-column carbonate chemistry in the region undergoes a seasonal cycle, wherein the annual cycle of stratification-overturn, primary production, respiration-remineralization and mixing all play important roles, at distinct spatiotemporal scales. Surface production was tightly coupled with remineralization in the benthic nepheloid layer during high production seasons, which results in occasional aragonite undersaturation. From spring to summer, carbonate chemistry in the surface across Wilkinson Basin reflects a transition from a production-respiration balanced system to a net autotropic system. Mean water-column Ω-Ar and abundance of large thecosomatous pteropods show some correlation, although patchiness and discrete cohort reproductive success likely also influence their abundance. Overall, photosynthesis-respiration is the primary driving force controlling Ω-Ar variability during the spring-to-summer transition as well as over the seasonal cycle. However, calcium carbonate (CaCO3) dissolution appears to occur near bottom in fall and winter when bottom water Ω-Ar is generally low but slightly above 1. This is accompanied by a decrease in pteropod abundance that is consistent with previous CaCO3 flux trap measurements. The region might experience persistent subsurface aragonite undersaturation in 30-40 years under continued ocean acidification.

  10. Calibration of TOMS Radiances From Ground Observations

    NASA Technical Reports Server (NTRS)

    Bojkov, B. R.; Kowalewski, M.; Wellemeyer, C.; Labow, G.; Hilsenrath, E.; Bhartia, P. K.; Ahmad, Z.

    2003-01-01

    Verification of a stratospheric ozone recovery remains a high priority for environmental research and policy definition. Models predict an ozone recovery at a much lower rate than the measured depletion rate observed to date. Therefore improved precision of the satellite and ground ozone observing systems are required over the long term to verify its recovery. We show that validation of radiances from the ground can be a very effective means for correcting long term drifts of backscatter type satellite measurements and can be used to cross calibrate all BUV instruments in orbit (TOMS, SBUV/2, GOME, SCIAMACHY, OMI, GOME-2, OMPS). This method bypasses the retrieval algorithms used to derive ozone products from both satellite and ground based measurements that are normally used to validate the satellite data. Radiance comparisons employ forward models, but they are inherently more accurate than the retrieval This method employs very accurate comparisons between ground based zenith sicy radiances and satellite nadir radiances and employs two well established capabilities at the Goddard Space Flight Center, 1) the SSBUV calibration facilities and 2) the radiative transfer codes used for the TOMS and SBUV/2 algorithms and their subsequent refinements. The zenith sky observations are made by the SSBUV where its calibration is maintained to a high degree of accuracy and precision. Radiative transfer calculations show that ground based zenith sky and satellite nadir backscatter ultraviolet comparisons can be made very accurately under certain viewing conditions. Initial ground observations taken from Goddard Space Flight Center compared with radiative transfer calculations has indicated the feasibility of this method. The effect of aerosols and varying ozone amounts are considered in the model simulations and the theoretical comparisons. The radiative transfer simulations show that the ground and satellite radiance comparisons can be made with an uncertainty of less than l

  11. New Developments in the SCIAMACHY L2 Ground Processor

    NASA Astrophysics Data System (ADS)

    Gretschany, Sergei; Lichtenberg, Günter; Meringer, Markus; Theys, Nicolas; Lerot, Christophe; Liebing, Patricia; Noel, Stefan; Dehn, Angelika; Fehr, Thorsten

    2016-04-01

    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002. SCIAMACHY doubled its originally planned in-orbit lifetime of five years before the communication to ENVISAT was severed in April 2012, and the mission entered its post-operational phase. In order to preserve the best quality of the outstanding data recorded by SCIAMACHY, data processors are still being updated. This presentation will highlight three new developments that are currently being incorporated into the forthcoming Version 7 of ESA's operational Level 2 processor: 1. Tropospheric BrO, a new retrieval based on the scientific algorithm of (Theys et al., 2011). This algorithm had been originally developed for the GOME-2 sensor and later adapted for SCIAMACHY. The main principle of the new algorithm is to utilize BrO total columns (already an operational product) and split them into stratospheric VCDstrat and tropospheric VCDtrop fractions. BrO VCDstrat is determined from a climatological approach, driven by SCIAMACHY O3 and NO2 observations. VCDtrop is then determined simply as a difference: VCDtrop = VCDtotal - VCDstrat. 2. Improved cloud flagging using limb measurements (Liebing, 2015). Limb cloud flags are already part of the SCIAMACHY L2 product. They are currently calculated employing the scientific algorithm developed by (Eichmann et al., 2015). Clouds are categorized into four types: water, ice, polar stratospheric and noctilucent clouds. High atmospheric aerosol loadings, however, often lead to spurious cloud flags, when aerosols had been misidentified as clouds. The new algorithm will better discriminate between aerosol and clouds. It will also have a higher sensitivity w.r.t. thin clouds. 3. A new

  12. One decade of space-based isoprene emission estimates: Interannual variations and emission trends between 2005 and 2014

    NASA Astrophysics Data System (ADS)

    Bauwens, Maite; Stavrakou, Trissevgeni; Müller, Jean-François; De Smedt, Isabelle; Van Roozendael, Michel

    2016-04-01

    Isoprene is one of the most largely emitted hydrocarbons in the atmosphere, with global annual emissions estimated at about 500 Tg, but with large uncertainties (Arneth et al., 2011). Here we use the source inversion approach to derive top-down biogenic isoprene emission estimates for the period between 2005 and 2014 constrained by formaldehyde observations, a high-yield intermediate in the oxidation of isoprene in the atmosphere. Formaldehyde columns retrieved from the Ozone Monitoring Instrument (OMI) are used to constrain the IMAGESv2 global chemistry-transport model and its adjoint code (Stavrakou et al., 2009). The MEGAN-MOHYCAN isoprene emissions (Stavrakou et al., 2014) are used as bottom-up inventory in the model. The inversions are performed separately for each year of the study period, and monthly emissions are derived for every model grid cell. The inversion results are compared to independent isoprene emissions from GUESS-ES (Arneth et al., 2007) and MEGAN-MACC (Sinderalova et al., 2014) and to top-down fluxes based on GOME-2 formaldehyde columns (Bauwens et al., 2014; Stavrakou et al., 2015). The mean global annual OMI-based isoprene flux for the period 2005-2014 is estimated to be 270 Tg, with small interannual variation. This estimate is by 20% lower with regard to the a priori inventory on average, but on the regional scale strong emission updates are inferred. The OMI-based emissions are substantially lower than the MEGAN-MACC and the GUESS-ES inventory, but agree well with the isoprene fluxes constrained by GOME-2 formaldehyde columns. Strong emission reductions are derived over tropical regions. The seasonal pattern of isoprene emissions is generally well preserved after inversion and relatively consistent with other inventories, lending confidence to the MEGAN parameterization of the a priori inventory. In boreal regions the isoprene emission trend is positive and reinforced after inversion, whereas the inversion suggests negative trends in the

  13. Assessment of the chestnut production weather dependence

    NASA Astrophysics Data System (ADS)

    Pereira, Mário; Caramelo, Liliana; Gouveia, Célia; Gomes-Laranjo, José

    2010-05-01

    The vegetative cycle of chestnut trees is highly dependent on weather. Photosynthesis and pollen germination are mainly conditioned by the air temperature while heavy precipitation and strong wind have significant impacts during the flushing phase period (Gomes-Laranjo et al., 2005, 2006). In Portugal, chestnut tree orchads are located in mountainous areas of the Northeast region of Trás-os-Montes, between 600 and 1000 m of altitude. Topography controls the atmospheric environment and assures adequate conditions for the chestnut production. In the above mentioned context, remote sensing plays an important role because of its ability to monitor and characterise vegetation dynamics. A number of studies, based on remote sensing, have been conducted in Europe to analyse the year-to-year variations in European vegetation greenness as a function of precipitation and temperature (Gouveia et al., 2008). A previous study focusing on the relationship between meteorological variables and chestnut productivity provides indication that simulation models may benefit from the incorporation of such kind of relationships. The aim of the present work is to provide a detailed description of recent developments, in particular of the added value that may be brought by using satellite data. We have relied on regional fields of the Normalized Difference Vegetation Index (NDVI) dataset, at 8-km resolution, provided by the Global Inventory Monitoring and Modelling System (GIMMS) group. The data are derived from the Advanced Very High Resolution Radiometers (AVHRR), and cover the period from 1982 to 2006. Additionally we have used the chestnut productivity dataset, which includes the annual values of chestnut production and area of production provided by INE, the National Institute of Statistics of Portugal and the meteorological dataset which includes values of several variables from different providers (Meteorod, NCEP/NCAR, ECA&D and national Meteorological Institute). Results show that

  14. Iceless Icy Moons: Is the Nice Model In Trouble?

    NASA Astrophysics Data System (ADS)

    Dones, Henry C. Luke; Levison, H. F.

    2012-05-01

    Nimmo and Korycansky (2012; henceforth NK12) stated that if the outer Solar System underwent a Late Heavy Bombardment (LHB) in the Nice model, the mass striking the icy satellites at speeds up to tens of km/s would have vaporized so much ice that moons such as Mimas, Enceladus, and Miranda would have been devolatilized. NK12's possible explanations of this apparent discrepancy with observations include (1) the mass influx was a factor of 10 less than that in the Nice model; (2) the mass distribution of the impactors was top-heavy, so that luck might have saved some of the moons from suffering large, vapor-removing impacts; or (3) the inner moons formed after the LHB. NK12 calculated the mass influx onto the satellites from the lunar impact rate estimated by Gomes et al. (2005) and scaling factors calculated by Zahnle et al. (1998, 2003; also see Barr and Canup 2010). Production of vapor in hypervelocity impacts is calculated from Kraus et al. (2011). Our preliminary results show that there is about an order-of-magnitude uncertainty in the mass striking the satellites during the LHB, with NK12's estimate at the upper end of the range. We will discuss how the mass influx depends on the velocity and mass distributions of the impactors. The Nice model lives. We thank the NASA Lunar Science Institute (http://lunarscience.nasa.gov/) for support. Barr, A.C., Canup, R.M., Nature Geoscience 3, 164-167 (2010). Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A., Nature 435, 466-469 (2005). Kraus, R.G., Senft, L.E., Stewart, S.T., Icarus 214, 724-738 (2011). Nimmo, F., Korycansky, D.G., Icarus, in press, http://www.sciencedirect.com/science/article/pii/S0019103512000310 (2012). Zahnle, K., Dones, L., Levison, H.F., Icarus 136, 202-222 (1998). Zahnle, K., Schenk, P., Levison, H.F., Dones, L., Icarus 163, 263-289 (2003).

  15. Extended and refined multi sensor reanalysis of total ozone for the period 1970-2012

    NASA Astrophysics Data System (ADS)

    van der A, R. J.; Allaart, M. A. F.; Eskes, H. J.

    2015-07-01

    The ozone multi-sensor reanalysis (MSR) is a multi-decadal ozone column data record constructed using all available ozone column satellite data sets, surface Brewer and Dobson observations and a data assimilation technique with detailed error modelling. The result is a high-resolution time series of 6-hourly global ozone column fields and forecast error fields that may be used for ozone trend analyses as well as detailed case studies. The ozone MSR is produced in two steps. First, the latest reprocessed versions of all available ozone column satellite data sets are collected and then are corrected for biases as a function of solar zenith angle (SZA), viewing zenith angle (VZA), time (trend), and stratospheric temperature using surface observations of the ozone column from Brewer and Dobson spectrophotometers from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). Subsequently the de-biased satellite observations are assimilated within the ozone chemistry and data assimilation model TMDAM. The MSR2 (MSR version 2) reanalysis upgrade described in this paper consists of an ozone record for the 43-year period 1970-2012. The chemistry transport model and data assimilation system have been adapted to improve the resolution, error modelling and processing speed. Backscatter ultraviolet (BUV) satellite observations have been included for the period 1970-1977. The total record is extended by 13 years compared to the first version of the ozone multi sensor reanalysis, the MSR1. The latest total ozone retrievals of 15 satellite instruments are used: BUV-Nimbus4, TOMS-Nimbus7, TOMS-EP, SBUV-7, -9, -11, -14, -16, -17, -18, -19, GOME, SCIAMACHY, OMI and GOME-2. The resolution of the model runs, assimilation and output is increased from 2° × 3° to 1° × 1°. The analysis is driven by 3-hourly meteorology from the ERA-Interim reanalysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) starting from 1979, and ERA-40 before that date. The chemistry

  16. Characterisation of Central-African emissions based on MAX-DOAS measurements, satellite observations and model simulations over Bujumbura, Burundi.

    NASA Astrophysics Data System (ADS)

    Gielen, Clio; Hendrick, Francois; Pinardi, Gaia; De Smedt, Isabelle; Stavrakou, Trissevgeni; Yu, Huan; Fayt, Caroline; Hermans, Christian; Bauwens, Maité; Ndenzako, Eugene; Nzohabonayo, Pierre; Akimana, Rachel; Niyonzima, Sébastien; Müller, Jean-Francois; Van Roozendael, Michel

    2016-04-01

    Central Africa is known for its strong biogenic, pyrogenic, and to a lesser extent anthropogenic emissions. Satellite observations of species like nitrogen dioxide (NO2) and formaldehyde (HCHO), as well as inverse modelling results have shown that there are large uncertainties associated with the emissions in this region. There is thus a need for additional measurements, especially from the ground, in order to better characterise the biomass-burning and biogenic products emitted in this area. We present MAX-DOAS measurements of NO2, HCHO, and aerosols performed in Central Africa, in the city of Bujumbura, Burundi (3°S, 29°E, 850m). A MAX-DOAS instrument has been operating at this location by BIRA-IASB since late 2013. Aerosol-extinction and trace-gases vertical profiles are retrieved by applying the optimal-estimation-based profiling tool bePRO to the measured O4, NO2 and HCHO slant-column densities. The MAX-DOAS vertical columns and profiles are used for investigating the diurnal and seasonal cycles of NO2, HCHO, and aerosols. Regarding the aerosols, the retrieved AODs are compared to co-located AERONET sun photometer measurements for verification purpose, while in the case of NO2 and HCHO, the MAX-DOAS vertical columns and profiles are used for validating GOME-2 and OMI satellite observations. To characterise the biomass-burning and biogenic emissions in the Bujumbura region, the trace gases and aerosol MAX-DOAS retrievals are used in combination to MODIS fire counts/radiative-power and GOME-2/OMI NO2 and HCHO satellite data, as well as simulations from the NOAA backward trajectory model HYSPLIT. First results show that HCHO seasonal variation around local noon is driven by the alternation of rain and dry periods, the latter being associated with intense biomass-burning agricultural activities and forest fires in the south/south-east and transport from this region to Bujumbura. In contrast, NO2 is seen to depend mainly on local emissions close to the city, due

  17. The Use of Meteosat Second Generation Satellite Data Within A New Type of Solar Irradiance Calculation Scheme

    NASA Astrophysics Data System (ADS)

    Mueller, R. W.; Beyer, H. G.; Cros, S.; Dagestad, K. F.; Dumortier, D.; Ineichen, P.; Hammer, A.; Heinemann, D.; Kuhlemann, R.; Olseth, J. A.; Piernavieja, G.; Reise, C.; Schroedter, M.; Skartveit, A.; Wald, L.

    1-University of Oldenburg, 2-University of Appl. Sciences Magdeburg, 3-Ecole des Mines de Paris, 4-University of Bergen, 5-Ecole Nationale des Travaux Publics de l'Etat, 6-University of Geneva, 7-Instituto Tecnologico de Canarias, 8-Fraunhofer Institute for Solar Energy Systems, 9-German Aerospace Center Geostationary satellites such as Meteosat provide cloud information with a high spatial and temporal resolution. Such satellites are therefore not only useful for weather fore- casting, but also for the estimation of solar irradiance since the knowledge of the light reflected by clouds is the basis for the calculation of the transmitted light. Additionally an the knowledge of atmospheric parameters involved in scattering and absorption of the sunlight is necessary for an accurate calculation of the solar irradiance. An accurate estimation of the downward solar irradiance is not only of particular im- portance for the assessment of the radiative forcing of the climate system, but also necessary for an efficient planning and operation of solar energy systems. Currently, most of the operational calculation schemes for solar irradiance are semi- empirical. They use cloud information from the current Meteosat satellite and clima- tologies of atmospheric parameters e.g. turbidity (aerosols and water vapor). The Me- teosat Second Generation satellites (MSG, to be launched in 2002) will provide not only a higher spatial and temporal resolution, but also the potential for the retrieval of atmospheric parameters such as ozone, water vapor and with restrictions aerosols. With this more detailed knowledge about atmospheric parameters it is evident to set up a new calculation scheme based on radiative transfer models using the retrieved atmospheric parameters as input. Unfortunately the possibility of deriving aerosol in- formation from MSG data is limited. As a cosequence the use of data from additional satellite instruments ( e.g. GOME/ATSR-2) is neeeded. Within this

  18. Importance of A Priori Vertical Ozone Profiles for TEMPO Air Quality Retrievals

    NASA Astrophysics Data System (ADS)

    Johnson, M. S.; Sullivan, J. T.; Liu, X.; Zoogman, P.; Newchurch, M.; Kuang, S.; McGee, T. J.; Leblanc, T.

    2017-12-01

    Ozone (O3) is a toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address the limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm is suggested to use a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB-Clim) O3 climatology). This study evaluates the TB-Clim dataset and model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time data assimilation model products (NASA GMAO's operational GEOS-5 FP model and reanalysis data from MERRA2) and a full chemical transport model (CTM), GEOS-Chem. In this study, vertical profile products are evaluated with surface (0-2 km) and tropospheric (0-10 km) TOLNet observations and the theoretical impact of individual a priori profile sources on the accuracy of TEMPO O3 retrievals in the troposphere and at the surface are presented. Results indicate that while the TB-Clim climatological dataset can replicate seasonally-averaged tropospheric O3 profiles, model-simulated profiles from a full CTM resulted in more accurate tropospheric and surface-level O3 retrievals from

  19. Destruction and Re-Accretion of Mid-Size Moons During an Outer Solar System Late Heavy Bombardment

    NASA Astrophysics Data System (ADS)

    Movshovitz, N.; Nimmo, F.; Korycansky, D. G.; Asphaug, E. I.; Owen, M.

    2014-12-01

    To explain the lunar Late Heavy Bombardment the Nice Model (Tsiganis, K., Gomes, R., Morbidelli, A., & Levison, H. 2005, Nature, 435, 459; Tsiganis, K., Gomes, R., Morbidelli, A., & Levison, H. 2005, Nature, 435, 459) invokes a period of dynamical instability, occurring long after planet formation, that destabilizes both the main asteroid belt and a remnant exterior planetesimal disk. As a side effect of explaining the lunar LHB, this model also predicts an LHB-like period in the outer Solar System. With higher collision probabilities and impact energies due to gravitational focusing by the giant planets the inner satellites of Jupiter, Saturn, and Uranus would have experienced a bombardment much more severe than the one supposedly responsible for the lunar basins. The concern is that such bombardment should have resulted in significant, even catastrophic modification of the mid-size satellites. Here we look at the problem of satellite survival during a hypothetical outer Solar System LHB. Using a Monte-Carlo approach we calculate, for 10 satellites of Saturn and Uranus, the probability of having experienced at least one catastrophic collision during an LHB. We use a scaling law for the energy required to disrupt a target in a gravity-dominated collision derived from new SPH simulations. These simulations extend the scaling law previously obtained by Benz & Asphaug (1999, Icarus, 142, 5) to larger targets. We then simulate randomized LHB impacts by drawing from appropriate size and velocity distributions, with the total delivered mass as a controlled parameter. We find that Mimas, Enceladus, Tethys, Hyperion, and Miranda experience at least one catastrophic impact in every simulation. In most simulations, Mimas, Enceladus, and Tethys experience multiple catastrophic impacts, including impacts with energies several times that required to completely disrupt the target. The implication is that these close-in, mid-size satellites could not have survived a Late Heavy

  20. Validation of OMPS Ozone Profile Data with Expanded Dataset from Brewer and Automated Dobson Network.

    NASA Astrophysics Data System (ADS)

    Petropavlovskikh, I.; Weatherhead, E.; Cede, A.; Oltmans, S. J.; Kireev, S.; Maillard, E.; Bhartia, P. K.; Flynn, L. E.

    2005-12-01

    The first NPOESS satellite is scheduled to be launched in 2010 and will carry the Ozone Mapping and Profiler Suite (OMPS) instruments for ozone monitoring. Prior this, the OMPS instruments and algorithms will be tested by flight on the NPOESS/NPP satellite, scheduled for launch in 2008. Pre-launch planning for validation, post launch data validation and verification of the nadir and limb profile algorithm are key components for insuring that the NPOESS will produce a high quality, reliable ozone profile data set. The heritage of satellite instrument validation (TOMS, SBUV, GOME, SCIAMACHY, SAGE, HALOE, ATMOS, etc) has always relied upon surface-based observations. While the global coverage of satellite observations is appealing for validating another satellite, there is no substitute for the hard reference point of a ground-based system such as the Dobson or Brewer network, whose instruments are routinely calibrated and intercompared to standard references. The standard solar occultation instruments, SAGE II and HALOE are well beyond their planned lifetimes and might be inoperative during the OMPS period. The Umkehr network has been one of the key data sets for stratospheric ozone trend calculations and has earned its place as a benchmark network for stratospheric ozone profile observations. The normalization of measurements at different solar zenith angle (SZAs) to the measurement at the smallest SZA cancels out many calibration parameters, including the extra-terrestrial solar flux and instrumental constant, thus providing a "self-calibrating" technique in the same manner relied upon by the occultation sensors on satellites. Moreover, the ground-based Umkehr measurement is the only technique that provides data with the same altitude resolution and in the same units (DU) as do the UV-nadir instruments (SBUV-2, GOME-2, OMPS-nadir), i.e., as ozone amount in pressure layers, whereas, occultation instruments measure ozone density with height. A new Umkehr algorithm

  1. How much do different global GPP products agree in distribution and magnitude of GPP extremes?

    NASA Astrophysics Data System (ADS)

    Kim, S.; Ryu, Y.; Jiang, C.

    2016-12-01

    To evaluate uncertainty of global Gross Primary Productivity (GPP) extremes, we compare three global GPP datasets derived from different data processing methods (e.g. MPI-BGC: machine-learning, MODIS GPP (MOD17): semi-empirical, Breathing Earth System Simulator (BESS): process based). We preprocess the datasets following the method from Zscheischler et al., (2012) to detect GPP extremes which occur in less than 1% of the number of whole pixels, and to identify 3D-connected spatiotemporal GPP extremes. We firstly analyze global patterns and the magnitude of GPP extremes with MPI-BGC, MOD17, and BESS over 2001-2011. For consistent analysis in the three products, spatial and temporal resolution were set at 50 km and a monthly scale, respectively. Our results indicated that the global patterns of GPP extremes derived from MPI-BGC and BESS agreed with each other by showing hotspots in Northeastern Brazil and Eastern Texas. However, the extreme events detected from MOD17 were concentrated in tropical forests (e.g. Southeast Asia and South America). The amount of GPP reduction caused by climate extremes considerably differed across the products. For example, Russian heatwave in 2010 led to 100 Tg C uncertainty (198.7 Tg C in MPI-BGC, 305.6 Tg C in MOD17, and 237.8 Tg C in BESS). Moreover, the duration of extreme events differ among the three GPP datasets for the Russian heatwave (MPI-BGC: May-Sep, MOD17: Jun-Aug, and BESS: May-Aug). To test whether Sun induced Fluorescence (SiF), a proxy of GPP, can capture GPP extremes, we investigate global distribution of GPP extreme events in BESS, MOD17 and GOME-2 SiF between 2008 and 2014 when SiF data is available. We found that extreme GPP events in GOME-2 SiF and MOD17 appear in tropical forests whereas those in BESS emerged in Northeastern Brazil and Eastern Texas. The GPP extremes by severe 2011 US drought were detected by BESS and MODIS, but not by SiF. Our findings highlight that different GPP datasets could result in varying

  2. Test-retest reliability of Brazilian version of Memorial Symptom Assessment Scale for assessing symptoms in cancer patients.

    PubMed

    Menezes, Josiane Roberta de; Luvisaro, Bianca Maria Oliveira; Rodrigues, Claudia Fernandes; Muzi, Camila Drumond; Guimarães, Raphael Mendonça

    2017-01-01

    To assess the test-retest reliability of the Memorial Symptom Assessment Scale translated and culturally adapted into Brazilian Portuguese. The scale was applied in an interview format for 190 patients with various cancers type hospitalized in clinical and surgical sectors of the Instituto Nacional de Câncer José de Alencar Gomes da Silva and reapplied in 58 patients. Data from the test-retest were double typed into a Microsoft Excel spreadsheet and analyzed by the weighted Kappa. The reliability of the scale was satisfactory in test-retest. The weighted Kappa values obtained for each scale item had to be adequate, the largest item was 0.96 and the lowest was 0.69. The Kappa subscale was also evaluated and values were 0.84 for high frequency physic symptoms, 0.81 for low frequency physical symptoms, 0.81 for psychological symptoms, and 0.78 for Global Distress Index. High level of reliability estimated suggests that the process of measurement of Memorial Symptom Assessment Scale aspects was adequate. Avaliar a confiabilidade teste-reteste da versão traduzida e adaptada culturalmente para o português do Brasil do Memorial Symptom Assessment Scale. A escala foi aplicada em forma de entrevista em 190 pacientes com diversos tipos de câncer internados nos setores clínicos e cirúrgicos do Instituto Nacional de Câncer José de Alencar Gomes da Silva e reaplicada em 58 pacientes. Os dados dos testes-retestes foram inseridos num banco de dados por dupla digitação independente em Excel e analisados pelo Kappa ponderado. A confiabilidade da escala mostrou-se satisfatória nos testes-retestes. Os valores do Kappa ponderado obtidos para cada item da escala apresentaram-se adequados, sendo o maior item de 0,96 e o menor de 0,69. Também se avaliou o Kappa das subescalas, sendo de 0,84 para sintomas físicos de alta frequência, de 0,81 para sintomas físicos de baixa frequência, de 0,81 também para sintomas psicológicos, e de 0,78 para Índice Geral de Sofrimento

  3. Satellite-Derived NO2 as an Indicator of Urban Air Quality and Emissions

    NASA Astrophysics Data System (ADS)

    Holloway, T.; Penn, E.; Harkey, M.

    2016-12-01

    Nitrogen dioxide (NO2) is the satellite-derived constituent with the most direct connection to fossil fuel emissions. At present the Ozone Monitoring Instrument aboard the NASA Aura satellite offers the highest resolution NO2retrievals, and new missions under development (TropOMI, TEMPO, GEMS, Sentinel-4) offer the potential for improved data in coming years. We present results applying satellite-derived NO2data to characterize air quality and emissions in U.S. cities. We highlight research findings geared toward increasing the relevance of satellite data to evaluate urban-scale air quality issues. This work reflects activities under the NASA Air Quality Applied Sciences Team (AQAST), and emerging work under the NASA Health and Air Quality Applied Sciences Team (H-AQAST). Among our results is a characterization of the diurnal cycle of nitrogen oxides using ground-based observations and satellite data. In situ monitoring from the U.S. EPA Air Quality System (AQS) shows that most locations have two daily peaks in NO2 (morning and evening) and a single daily peak in NO (morning). Spaced-based observations from the ESA Global Ozone Monitoring Experiment-2 (GOME-2), with a mid-morning overpass, and the NASA OMI, with an early afternoon overpass, support a complementary analysis for characterizing diurnal variability in NO2. Both ground-based monitors and satellite data show a reduction in the amplitude of the diurnal NO2 cycle. In the Western U.S., satellite data showed evidence of higher NO2 in urban centers in the afternoon (OMI) and higher NO2 in suburban areas in the morning (GOME-2), consistent with diurnal traffic patterns associated with commuting. Some power plants in the Western U.S. showed an increase in NO2in the afternoon, consistent with peak power demand associated with building air conditioning use. We extend this city-focused analysis satellite-derived HCHO:NO2 ratios as an indicator of ozone production regime, comparing modeled and measured ratios

  4. Cross Calibration of TOMS, SBUV/2 and Sciamachy Radiances from Ground Observations

    NASA Technical Reports Server (NTRS)

    Hillsenrath, Ernest; Ahmad, Ziauddin; Bhartia, Pawan K. (Technical Monitor)

    2001-01-01

    Verification of a stratospheric ozone recovery remains a high priority for environmental research and policy definition. Models predict an ozone recovery at a much lower rate than the measured depletion rate observed to date. Therefore improved precision of the satellite and ground ozone observing systems are required over the long term to verify recovery. We have shown that validation of radiances is the most effective means for correcting absolute accuracy and long term drifts of backscatter type satellite measurements. This method by-passes the algorithms used for both satellite and ground based measurements which are normally used to validate and correct the satellite data. Validation of radiances will also improve all higher level data products derived from the satellite observations. Backscatter algorithms suffer from several errors such as unrepresentative a-priori data and air mass factor corrections. Radiance comparisons employ forward models but are inherently more accurate and than inverse (retrieval) algorithms. A new method for satellite validation is planned which will compliment measurements from the existing ground-based networks. This method will employ very accurate comparisons between ground based zenith sky radiances and satellite nadir radiances. These comparisons will rely heavily on the experience derived from the Shuttle SBUV (SSBUV) program which provided a reference standard of radiance measurements for SBUV/2, TOMS, and GOME. This new measurement program, called "Skyrad", employs two well established capabilities at the Goddard Space Flight Center, 1) the SSBUV calibration facilities and 2) the radiative transfer codes used for the TOMS and SBUV/2 algorithms and their subsequent refinements. Radiative transfer calculations show that ground based zenith sky and satellite nadir backscatter ultraviolet comparisons can be made very accurately under certain viewing conditions. The Skyrad instruments (SSBUV, Brewer spectrophotometers, and

  5. Importance of a Priori Vertical Ozone Profiles for TEMPO Air Quality Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew S.; Sullivan, John; Liu, Xiong; Zoogman, Peter; Newchurch, Mike; Kuang, Shi; McGee, Thomas; Leblanc, Thierry

    2017-01-01

    Ozone (O3) is a toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address the limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME (Global Ozone Monitoring Experiment), GOME-2, and OMI (Ozone Monitoring Instrument). This algorithm is suggested to use a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB-Clim) O3 climatology). This study evaluates the TB-Clim dataset and model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time data assimilation model products (NASA GMAO's (Global Modeling and Assimilation Office) operational GEOS-5 (Goddard Earth Observing System, Version 5) FP (Forecast Products) model and reanalysis data from MERRA2 (Modern-Era Retrospective analysis for Research and Applications, Version 2)) and a full chemical transport model (CTM), GEOS-Chem. In this study, vertical profile products are evaluated with surface (0-2 kilometers) and tropospheric (0-10 kilometers) TOLNet (Tropospheric Ozone Lidar Network) observations and the theoretical impact of individual a priori profile sources on the accuracy of TEMPO O3

  6. A global 2007-2015 spaceborne sun-induced vegetation fluorescence time series evaluated with Australian flux tower observations

    NASA Astrophysics Data System (ADS)

    Verstraeten, Willem W.; Sanders, Abram F. J.; Kooreman, Maurits L.; van Leth, Thomas C.; Beringer, Jason; Joiner, Joanna; Delcloo, Andy

    2017-04-01

    The Gross Primary Production (GPP) of the terrestrial biosphere is a key quantity in the understanding of the global carbon cycle. GPP is the amount of atmospheric carbon fixed through the process of plant photosynthesis and it represents the largest ecosystem gross flux of CO2 between the atmosphere and the Earth surface. To date, monitoring of GPP has not been possible at scales beyond that of a single agricultural field or natural ecosystem. At those scales, networks of eddy-covariance towers provide a platform to measure Net Ecosystem Exchange (NEE) of carbon at high temporal resolution, although with only sparse spatial coverage. Satellite observations can bridge that gap by providing the spatial distributions and changes over time of vegetation-related spectral indices. These "greenness indicators", however, tend to return the potential carbon uptake by plants rather than the actual uptake since short term environmental changes affecting plant productivity (e.g., water availability, temperature, nutrient deficiency, diseases) are not well captured. Sun-induced plant fluorescence (SiF), however, is tightly related to photosynthetic activity in the red and near-infrared wavelength range, and SiF can be retrieved from spaceborne measurements from sensors with good signal-to-noise ratios and fine spectral resolutions. We use optical data from the Global Ozone Monitoring Instrument 2 (GOME-2A) satellite sensor to infer terrestrial fluorescence from space. The spectral signatures of atmospheric absorption, surface reflectance, and fluorescence radiance are disentangled using reference hyperspectral data of non-fluorescence surfaces (desserts) to solve for the atmospheric absorption. An empirically based principal component analysis (PCA) approach was applied. Here we show a global 2007-2015 times series of sun-induced vegetation fluorescence derived from GOME-2A observations which we have compared with GPP data derived from twelve Net Ecosystem Exchange flux tower

  7. MAX-DOAS measurements of nitrogen dioxide at the high altitude sites Zugspitze (2964 m) and Pico Espejo (4765 m)

    NASA Astrophysics Data System (ADS)

    Schreier, Stefan F.; Richter, Andreas; Wittrock, Folkard; Burrows, John P.

    2015-04-01

    Spectral measurements at two mountain sites were performed with a MAX-DOAS (Multi AXis Differential Optical Absorption Spectroscopy) instrument from February to July 2003 (Zugspitze, Germany) and from March 2004 to November 2008 (Pico Espejo, Venezuela). Here, these measurements are used for the retrieval of slant column densities (SCDs) of nitrogen dioxide (NO2). While at the altitude of observations the NO2 levels are usually small, uplifting of anthropogenic emissions from the valley and in Venezuela also transport of emissions from biomass burning can lead to significant enhancements. Daily, weekly, and seasonal cycles of NO2 SCDs are shown for the two stations, linked to different meteorological conditions and compared between the two sites. In a next step, a preliminary approach to derive vertical column densities (VCDs) is presented. VCDs of NO2 from ground-based MAX-DOAS instruments provide useful information for the validation of satellite instruments such as SCIAMACHY, OMI, and GOME-2. Comparisons between ground-based and satellite-based NO2 VCDs are shown for selected periods.

  8. Solvatochromic shifts from coupled-cluster theory embedded in density functional theory

    NASA Astrophysics Data System (ADS)

    Höfener, Sebastian; Gomes, André Severo Pereira; Visscher, Lucas

    2013-09-01

    Building on the framework recently reported for determining general response properties for frozen-density embedding [S. Höfener, A. S. P. Gomes, and L. Visscher, J. Chem. Phys. 136, 044104 (2012)], 10.1063/1.3675845, in this work we report a first implementation of an embedded coupled-cluster in density-functional theory (CC-in-DFT) scheme for electronic excitations, where only the response of the active subsystem is taken into account. The formalism is applied to the calculation of coupled-cluster excitation energies of water and uracil in aqueous solution. We find that the CC-in-DFT results are in good agreement with reference calculations and experimental results. The accuracy of calculations is mainly sensitive to factors influencing the correlation treatment (basis set quality, truncation of the cluster operator) and to the embedding treatment of the ground-state (choice of density functionals). This allows for efficient approximations at the excited state calculation step without compromising the accuracy. This approximate scheme makes it possible to use a first principles approach to investigate environment effects with specific interactions at coupled-cluster level of theory at a cost comparable to that of calculations of the individual subsystems in vacuum.

  9. MAX-DOAS measurements of African continental pollution outflow over the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Behrens, Lisa K.; Hilboll, Andreas; Peters, Enno; Richter, Andreas; Alvarado, Leonardo; Wittrock, Folkard; Burrows, John P.; Vrekoussis, Mihalis

    2017-04-01

    Enhanced levels of atmospheric key pollutants can regularly be identified over the Atlantic Ocean in global trace gas maps retrieved from satellite measurements. The aim of the DFG project COPMAR (Continental outflow of pollutants towards the marine troposphere) was to validate these enhanced values using ship-based measurements and to identify the spatial gradients of the pollutants NO2, CHOCHO, and HCHO over the Atlantic Ocean. Therefore, a multi-axis differential optical absorption spectrometer (MAX-DOAS) was installed on board the research vessel Maria S. Merian for the cruise MSM58/2. This cruise was conducted in October 2016 and went from Ponta Delgada (Azores) to Cape Town (South Africa), crossing between Cape Verde and the African continent. The instrument was continuously scanning the horizon looking towards the African continent, and the ship sailed at nearly constant speed during the whole cruise. In this study, we present the results from the MAX-DOAS measurements for the three species. We discuss the influence of different fit settings and a-priori assumptions on the results and present the observed spatial gradients along the cruise track. Finally, we compare our results with satellite measurements by the GOME-2 and OMI instruments and discuss possible sources of the discrepancies.

  10. VizieR Online Data Catalog: Solar spectral irradiance (Marchenko+, 2014)

    NASA Astrophysics Data System (ADS)

    Marchenko, S. V.; Deland, M. T.

    2017-03-01

    Combining the contemporaneous Ozone Monitoring Instrument (OMI) and GOME-2 observations with the records from previous solar cycles, we construct the normalized (to the Mg II doublet at 280 nm) solar variability spectrum in the 170-795 nm spectral range, which could be used in combination with a reference spectrum (e.g., Thuillier et al. 2004, Solar Variability and its Effects on Climate (Geophysical Monograph 141), ed. J. M. Pup et al. (Washington, DC: AGU Geophysical Monograph Series), 171) to reproduce a dynamical solar spectrum at any epoch.The remote-sensing OMI (part of the Aura instrumental suite; Levelt et al., 2006ITGRS..44.1093L) has collected information about trace gases in the Earth's atmosphere since 2004 July. OMI comprises three different spectral channels, UV1 (264-311 nm spectral domain, resolution δλ = 0.63 nm), UV2 (307-383 nm, δλ = 0.42 nm), and VIS (349-504 nm, δλ = 0.63 nm), each acquiring data through partially shared optical pathways (Dobber et al., 2006ITGRS..44.1209D). The UV1 and UV2 light falls on the same CCD detector while VIS spectra are recorded by a different CCD. (1 data file).

  11. Strong constraint on modelled global carbon uptake using solar-induced chlorophyll fluorescence data.

    PubMed

    MacBean, Natasha; Maignan, Fabienne; Bacour, Cédric; Lewis, Philip; Peylin, Philippe; Guanter, Luis; Köhler, Philipp; Gómez-Dans, Jose; Disney, Mathias

    2018-01-31

    Accurate terrestrial biosphere model (TBM) simulations of gross carbon uptake (gross primary productivity - GPP) are essential for reliable future terrestrial carbon sink projections. However, uncertainties in TBM GPP estimates remain. Newly-available satellite-derived sun-induced chlorophyll fluorescence (SIF) data offer a promising direction for addressing this issue by constraining regional-to-global scale modelled GPP. Here, we use monthly 0.5° GOME-2 SIF data from 2007 to 2011 to optimise GPP parameters of the ORCHIDEE TBM. The optimisation reduces GPP magnitude across all vegetation types except C4 plants. Global mean annual GPP therefore decreases from 194 ± 57 PgCyr -1 to 166 ± 10 PgCyr -1 , bringing the model more in line with an up-scaled flux tower estimate of 133 PgCyr -1 . Strongest reductions in GPP are seen in boreal forests: the result is a shift in global GPP distribution, with a ~50% increase in the tropical to boreal productivity ratio. The optimisation resulted in a greater reduction in GPP than similar ORCHIDEE parameter optimisation studies using satellite-derived NDVI from MODIS and eddy covariance measurements of net CO 2 fluxes from the FLUXNET network. Our study shows that SIF data will be instrumental in constraining TBM GPP estimates, with a consequent improvement in global carbon cycle projections.

  12. Isoprene emissions over Asia 1979-2012 : impact of climate and land use changes

    NASA Astrophysics Data System (ADS)

    Stavrakou, Trissevgeni; Müller, Jean-Francois; Bauwens, Maite; Guenther, Alex; De Smedt, Isabelle; Van Roozendael, Michel

    2014-05-01

    Due to the scarcity of observational contraints and the rapidly changing environment in East and Southeast Asia, isoprene emissions predicted by models are expected to bear substantial uncertainties. This study aims at improving upon current bottom-up estimates, and investigate the temporal evolution of isoprene fluxes in Asia over 1979-2012. For that, we use the MEGAN model and incorporate (i) changes in land use, including the rapid expansion of oil palms, (ii) meteorological variability, (iii) long-term changes in solar radiation constrained by surface network measurements, and (iv) recent experimental evidence that South Asian forests are much weaker isoprene emitters than previously assumed. These effects lead to a significant reduction of the total isoprene fluxes over the studied domain compared to the standard simulation. The bottom-up emissions are evaluated using satellite-based emission estimates derived from inverse modelling constrained by GOME-2/MetOp-A formaldehyde columns through 2007-2012. The top-down estimates support our assumptions and confirm the lower isoprene emission rate in tropical forests of Indonesia and Malaysia.

  13. Dynamic Monte Carlo Simulations of Phase Ordering in Br Electrosorption on Ag(100)

    NASA Astrophysics Data System (ADS)

    Mitchell, S. J.; Brown, G.; Rikvold, P. A.

    2000-03-01

    We study the dynamics of Br electrosorption on single-crystal Ag(100) by Monte Carlo simulation. The system has a second-order phase transition from a low-coverage disordered phase at more negative potentials to a doubly degenerate c(2× 2) ordered phase at more positive potentials.(B.M. Ocko, et al.), Phys. Rev. Lett. 79, 1511 (1997). Effective lateral interactions were estimated by fitting equilibrium Monte Carlo isotherms to experiments. These are well described by nearest-neighbor exclusion and repulsive 1/r^3 interactions.(M.T.M. Koper, J. Electroanal. Chem. 450), 189 (1997). Considering adsorption/desorption and diffusion with barriers estimated from ab-initio calculations,(A. Ignaczak and J.A.N.F. Gomes, J. Electroanal. Chem. 420), 71 (1997). we simulate the time dependent Br coverage, order parameter, and x-ray scattering intensity following sudden potential steps across the phase boundary. For steps far into the ordered phase, dynamical scaling is observed. For smaller steps, the dynamics are more complicated. We also analyze hysteresis in a simulated cyclic-voltammetry experiment. Movies at http://www.scri.fsu.edu/ ~mitchell/.

  14. The total ozone and UV solar radiation over Stara Zagora, Bulgaria

    NASA Astrophysics Data System (ADS)

    Mendeva, B. D.; Gogosheva, Ts. N.; Petkov, B. H.; Krastev, D. G.

    The results from direct ground-based solar UV irradiance measurements and the total ozone content (TOC) over Stara Zagora (42° 25'N, 25° 37'E), Bulgaria are presented. During the period 1999-2003 the TOC data show seasonal variations, typical for the middle latitudes - maximum in the spring and minimum in the autumn. The comparison between TOC ground-based data and Global Ozone Monitoring Experiment (GOME) satellite-borne ones shows a seasonal dependence of the differences between them. A strong negative relationship between the total ozone and the 305 nm wavelength irradiance was found. The dependence between the two variables is significant ( r = -0.62 ± 0.18) at 98% confidence level. The direct sun UV doses for some specific biological effects (erythema and eyes) are obtained. The estimation of the radiation amplification factor RAF shows that the ozone reduction by 1% increases the erythemal dose by 2.3%. The eye-damaging doses are more influenced by the TOC changes and in this case RAF = -2.7%. The amount of these biological doses depended on the solar altitude over the horizon. This dependence was not so strong when the total ozone content in the atmosphere was lower.

  15. Total ozone trends and variability during 1979-2012 from merged data sets of various satellites

    NASA Astrophysics Data System (ADS)

    Chehade, W.; Weber, M.; Burrows, J. P.

    2014-07-01

    The study presents a long-term statistical trend analysis of total ozone data sets obtained from various satellites. A multi-variate linear regression was applied to annual mean zonal mean data using various natural and anthropogenic explanatory variables that represent dynamical and chemical processes which modify global ozone distributions in a changing climate. The study investigated the magnitude and zonal distribution of the different atmospheric chemical and dynamical factors contributing to long-term total ozone changes. The regression model included the equivalent effective stratospheric chlorine (EESC), the 11-year solar cycle, the quasi-biennial oscillation (QBO), stratospheric aerosol loading describing the effects from major volcanic eruptions, the El Niño-Southern Oscillation (ENSO), the Arctic and Antarctic oscillation (AO/AAO), and accumulated eddy heat flux (EHF), the latter representing changes due to the Brewer-Dobson circulation. The total ozone column data set used here comprises the Solar Backscater Ultraviolet SBUV/SBUV-2 merged ozone data set (MOD) V8.6, the merged data set of the Solar Backscaterr Ultraviolet, the Total Ozone Mapping Spectrometer and the Ozone Monitoring Instrument SBUV/TOMS/OMI (1979-2012) MOD V8.0 and the merged data set of the Global Ozone Monitoring Experiment, the Scanning Imaging Absorption spectroMeter for Atmospheric ChartograpHY and the Global Ozone Monitoring Experiment 2 GOME/SCIAMACHY/GOME-2 (GSG) (1995-2012). The trend analysis was performed for twenty-six 5° wide latitude bands from 65° S to 65° N, and the analysis explained most of the ozone variability to within 70 to 90%. The results show that QBO dominates the ozone variability in the tropics (±7 DU) while at higher latitudes, the dynamical indices, AO/AAO and eddy heat flux, have substantial influence on total ozone variations by up to ±10 DU. The contribution from volcanic aerosols is only prominent during the major eruption periods (El Chichón and

  16. Smooth Muscle Cell Genome Browser: Enabling the Identification of Novel Serum Response Factor Target Genes

    PubMed Central

    Lee, Moon Young; Park, Chanjae; Berent, Robyn M.; Park, Paul J.; Fuchs, Robert; Syn, Hannah; Chin, Albert; Townsend, Jared; Benson, Craig C.; Redelman, Doug; Shen, Tsai-wei; Park, Jong Kun; Miano, Joseph M.; Sanders, Kenton M.; Ro, Seungil

    2015-01-01

    Genome-scale expression data on the absolute numbers of gene isoforms offers essential clues in cellular functions and biological processes. Smooth muscle cells (SMCs) perform a unique contractile function through expression of specific genes controlled by serum response factor (SRF), a transcription factor that binds to DNA sites known as the CArG boxes. To identify SRF-regulated genes specifically expressed in SMCs, we isolated SMC populations from mouse small intestine and colon, obtained their transcriptomes, and constructed an interactive SMC genome and CArGome browser. To our knowledge, this is the first online resource that provides a comprehensive library of all genetic transcripts expressed in primary SMCs. The browser also serves as the first genome-wide map of SRF binding sites. The browser analysis revealed novel SMC-specific transcriptional variants and SRF target genes, which provided new and unique insights into the cellular and biological functions of the cells in gastrointestinal (GI) physiology. The SRF target genes in SMCs, which were discovered in silico, were confirmed by proteomic analysis of SMC-specific Srf knockout mice. Our genome browser offers a new perspective into the alternative expression of genes in the context of SRF binding sites in SMCs and provides a valuable reference for future functional studies. PMID:26241044

  17. Fermion localization and resonances on a de Sitter thick brane

    SciTech Connect

    Liu Yuxiao; Yang Jie; Zhao Zhenhua

    2009-09-15

    In C. A. S. Almeida, R. Casana, M. M. Ferreira, Jr., and A. R. Gomes, Phys. Rev. D 79, 125022 (2009), the simplest Yukawa coupling {eta}{psi}{phi}{chi}{psi} was considered for a two-scalar-generated Bloch brane model. Fermionic resonances for both chiralities were obtained, and their appearance is related to branes with internal structure. Inspired on this result, we investigate the localization and resonance spectrum of fermions on a one-scalar-generated de Sitter thick brane with a class of scalar-fermion couplings {eta}{psi}{phi}{sup k}{psi} with positive odd integer k. A set of massive fermionic resonances for both chiralities is obtained when provided large coupling constantmore » {eta}. We find that the masses and lifetimes of left and right chiral resonances are almost the same, which demonstrates that it is possible to compose massive Dirac fermions from the left and right chiral resonances. The resonance with lower mass has longer lifetime. For a same set of parameters, the number of resonances increases with k and the lifetime of the lower level resonance for larger k is much longer than the one for smaller k.« less

  18. PREFACE: XXXVI Symposium on Nuclear Physics (Cocoyoc 2013)

    NASA Astrophysics Data System (ADS)

    Barrón-Palos, Libertad; Morales-Agiss, Irving; Martínez-Quiroz, Enrique

    2014-03-01

    logo The XXXVI Symposium on Nuclear Physics, organized by the Division of Nuclear Physics of the Mexican Physical Society, took place from 7-10 January, 2013. As it is customary, the Symposium was held at the Hotel Hacienda Cocoyoc, in the state of Morelos, Mexico. Conference photograph This international venue with many years of tradition was attended by outstanding physicists, some of them already regulars to this meeting and others who joined us for the first time; a total of 45 attendees from different countries (Argentina, Brazil, Canada, China, Germany, Italy, Japan, Mexico and the United States). A variety of topics related to nuclear physics (nuclear reactions, radioactive beams, nuclear structure, fundamental neutron physics, sub-nuclear physics and nuclear astrophysics, among others) were presented in 26 invited talks and 10 contributed posters. Local Organizing Committee Libertad Barrón-Palos (IF-UNAM)) Enrique Martínez-Quíroz (ININ)) Irving Morales-Agiss (ICN-UNAM)) International Advisory Committee Osvaldo Civitarese (UNLP, Argentina) Jerry P Draayer (LSU, USA)) Alfredo Galindo-Uribarri (ORNL, USA)) Paulo Gomes (UFF, Brazil)) Piet Van Isacker (GANIL, France)) James J Kolata (UND, USA)) Reiner Krücken (TRIUMF, Canada)) Jorge López (UTEP, USA)) Stuart Pittel (UD, USA)) W Michael Snow (IU, USA)) Adam Szczepaniak (IU, USA)) Michael Wiescher (UND, USA)) A list of participants is available in the PDF

  19. Off-axis Doas Measurements At Observatoire De Haute Provence During 2001

    NASA Astrophysics Data System (ADS)

    Roozendael, M. Van; de Mazière, M.; Fayt, C.; Hendrick, F.; Hermans, C.

    Since December 2000, a ground-based off-axis DOAS spectrometer has been operated by BIRA-IASB in the South of France at the Observatoire de Haute Provence (OHP, 44°N). The design of the instrument allows automated observations of the scattered light alternatively in the zenith direction and at 10° above the horizon (off-axis geometry). The spectrometer is polarised and follows the azimuth of the sun. Its temperature is regulated and it is equipped with a Princeton Instruments/ Hammamatsu cooled diode array detector. Observations are made every 5 minutes in the 320-390 nm range. The analysis of the spectra recorded between January and December 2001 demonstrates the sensitivity of the measurements to tropospheric contents of NO2, HCHO, O3 and BrO. Results show a large seasonality in the HCHO content with maximum values in summer. The tropospheric BrO column is found to be stable over the year in the range of approximately 1.5-2 x1013 molec/cm2, roughly consistent with GOME observations at Northern mid-latitudes. Large increases of the BrO concentration are observed in summer likely due to local pollution in the vicinity of the station.

  20. The Arizona Wallow Wildfire: Monitoring It's Progress, Extreme Behavior and Long Range Smoke Transport from Multiple Satellite Platforms

    NASA Astrophysics Data System (ADS)

    Ruminski, M. G.; Fromm, M. D.; Ramirez, E.

    2011-12-01

    The Wallow fire in southeast Arizona was the largest wildfire in Arizona history, consuming over 500,000 acres. The fire began on May 29, 2011 and quickly grew to nearly 70,000 acres in size by June 4. This event exhibited anomalous behavioral characteristics as deep pyroconvection was observed for an unprecedented six consecutive days. The rapid spread and extreme pyroconvection occurred in response to a unique confluence of high biomass fuel availability in arid conditions. Strong winds in combination with low relative humidity and atmospheric instability acted to create an environment conducive to explosive fire growth. The resultant smoke from the blaze reached an altitude of nearly 15 km into the upper troposphere/lower stratosphere and eventually crossed the Atlantic reaching Europe. This presentation focuses on the detection and characterization of the Wallow fire from a satellite perspective. Geostationary and polar orbiting satellite platforms have captured various aspects of the fire and resulting smoke plumes. An animation of nearly 100 NOAA polar orbiting 4 micron channel images during the first 2 weeks of the fire illustrate its explosive growth while GOES visible channel animations display the density and coverage of the pall of smoke and the development of pyroconvection. True color MODIS imagery provides higher resolution views of the pyrocumulonimbus clouds at different stages in their evolution. CALIPSO, GOME2, and OMI data detail the vertical structure and composition of the plume as it drifts eastward and expands in coverage, eventually reaching Europe.

  1. Prevalence of communication, swallowing and orofacial myofunctional disorders in children and adolescents at the time of admission at a cancer hospital.

    PubMed

    Coça, Kaliani Lima; Bergmann, Anke; Ferman, Sima; Angelis, Elisabete Carrara de; Ribeiro, Márcia Gonçalves

    2018-03-01

    Describe the prevalence of communication, swallowing and orofacial myofunctional disorders in a group of children and adolescents at the time of registration at a cancer hospital. A cross-sectional study conducted with children aged ≥2 and adolescents, of both genders, admitted to the Pediatric Oncology Section of the Instituto Nacional de Câncer José de Alencar Gomes da Silva (INCA) from March 2014 to April 2015 for investigation and/or treatment of solid tumors. A protocol was used to record the sociodemographic and clinical information and findings of the speech-language pathology clinical evaluation, which included aspects of the oral sensorimotor system, swallowing, speech, language, voice, and hearing. Eighty-eight children/adolescents (41.3%) presented some type of speech-language disorder. The most frequent speech-language disorders were orofacial myofunctional disorder, dysphonia, and language impairments, whereas the less frequent ones were dysacusis, tongue paralysis, and trismus. Site of the lesion was the clinical variable that presented statistically significant correlation with presence of speech-language disorders. High prevalence of speech-language disorders was observed in children and adolescents at the time of admission at a cancer hospital. Occurrence of speech-language disorders was higher in participants with lesions in the central nervous system and in the head and neck region.

  2. Astronomy in Brazilian music and poetry

    NASA Astrophysics Data System (ADS)

    de Freitas Mourão, Ronaldo Rogério

    2011-06-01

    The rôle of astronomy in the Brazilian cultural diversity -though little known world- has been enormous. Thus, the different forms of popular music and erudite, find musical compositions and lyrics inspired by the stars, the eclipses in rare phenomena such as the transit of Venus in front of the sun in 1882, the appearance of Halley's Comet in 1910, in the Big Bang theory. Even in the carnival parades of the blocks at the beginning of the century astronomy was present. More recently, the parade of 1997, the samba school Unidos do Viradouro, under the direction of Joãozinho Trinta, offered a new picture of the first moments of the creation of the universe to join in the white and dark in the components of their school, the idea of matter and anti-matter that reigned in the early moments of the creation of the universe in an explosion of joy. Examples in classical music include Dawn of Carlos Gomes and Carta Celeste by Almeida Prado. Unlike The Planets by Gustav Holst -who between 1914 and 1916 composed a symphonical tribute to the solar system based on astrology- Almeida Prado composed a symphony that is not limited to the world of planets, penetrating the deep cosmos of galaxies. Using various resources of the technique for the piano on the clusters and static movements, violent conflicts between the records of super acute and serious instrument, harpejos cross, etc . . .

  3. Retrieval of CHOCHO from MAX-DOAS measurements in the Beijing area

    NASA Astrophysics Data System (ADS)

    Hendrick, Francois; Lerot, Christophe; Stavrakou, Trissevgeni; De Smedt, Isabelle; Fayt, Caroline; Gielen, Clio; Hermans, Christian; Müller, Jean-Francois; Pinardi, Gaia; Van Roozendael, Michel

    2015-04-01

    Glyoxal (CHOCHO) is one of the most important carbonyl compounds in the atmosphere. It is produced mainly by the oxidation of biogenic and anthropogenic non-methane volatile organic compounds (NMVOCs) which participate to the formation of tropospheric ozone and secondary organic aerosols. CHOCHO is also directly released by biomass burning and fossil fuel combustion. Measuring this species is therefore of major importance for air quality monitoring, especially given the scarcity of available CHOCHO observational data sets. In this presentation, CHOCHO vertical profiles and corresponding column densities are retrieved from MAX-DOAS measurements in the Beijing city center and at the suburban site of Xianghe located at 60km East of Beijing. The periods covered by the observations are June 2008-April 2009 in Beijing and March 2010-December 2014 in Xianghe. We first investigate the capability of the MAX-DOAS technique to measure this species in such highly-polluted environment. Then the diurnal and seasonal cycles of CHOCHO near-surface concentrations and vertical column densities as well as the corresponding CHOCHO/HCHO ratios are examined on a long-term basis at both locations. The CHOCHO/HCHO ratios are derived from MAX-DOAS HCHO vertical profiles retrieved in parallel to the CHOCHO profiles. These diurnal and seasonal cycles are further assessed using simulations from the 3D-CTM IMAGES and observations from the OMI and GOME-2 satellite nadir instruments. The impact of these results on our knowledge about the CHOCHO budget is discussed.

  4. Simultaneous assimilation of satellite NO2, O3, CO, and HNO3 data for the analysis of the tropospheric chemical composition

    NASA Astrophysics Data System (ADS)

    Miyazaki, K.; Eskes, H.; Sudo, K.

    2012-04-01

    Carbon monoxide (CO) and nitrogen oxides (NOx) play an important role in tropospheric chemistry through their influences on the ozone and hydroxyl radical (OH). The simultaneous optimization of various chemical components is expected to improve the emission inversion through the better description of the chemical feedbacks in the NOx- and CO-chemistry. This study aims to reproduce chemical composition distributions in the troposphere by combining information obtained from multiple satellite data sets. The emissions of CO and NOx, together with the 3D concentration fields of all forecasted chemical species in the global CTM CHASER have been simultaneously optimized using the ensemble Kalman filter (EnKF) data assimilation technique, and NO2, O3, CO, and HNO3 data obtained from OMI, TES, MOPITT, and MLS satellite measurements. The performance is evaluated against independent data from ozone sondes, aircraft measurements, GOME-2, and SCIAMACHY satellite data. Observing System Experiments (OSEs) have been carried out. These OSEs quantify the relative importance of each data set on constraining the emissions and concentrations. We confirmed that the simultaneous data assimilation improved the agreement with these independent data sets. The combined analysis of multiple data sets by means of advanced data assimilation system can provide a useful framework for the air quality research.

  5. Assessment of the Impact of The East Asian Summer Monsoon on the Air Quality Over China

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Ding, Aijun; Safieddine, Sarah; Valks, Pieter; Clerbaux, Cathy; Trautmann, Thomas

    2016-04-01

    Air pollution is one of the most important environmental problems in developing Asian countries like China. In this region, studies showed that the East Asian monsoon plays a significant role in characterizing the temporal variation and spatial patterns of air pollution, since monsoon is a major atmospheric system affecting air mass transport, convection, and precipitation. Knowledge gaps still exist in the understanding of Asian monsoon impact on the air quality in China under the background of global climate change. For the first time satellite observations of tropospheric ozone and its precursors will be integrated with the ground-based, aircraft measurements of air pollutants and model simulations to study the impact of the East Asian monsoon on air quality in China. We apply multi-platform satellite observations by the GOME-2, IASI, and MOPITT instruments to analyze tropospheric ozone and CO, precursors of ozone (NO2, HCHO and CHOCHO) and other related trace gases over China. Two years measurements of air pollutants including NO2, HONO, SO2, HCHO and CHOCHO at a regional back-ground site in the western part of the Yangtze River Delta (YRD) in eastern China will be presented. The potential of using the current generation of satellite instruments, ground-based instruments and aircraft to monitor air quality changes caused by the East Asian monsoon circulation will be presented. Preliminary comparison results between satellite measurement and limited but valuable ground-based and aircraft measurements will also be showed.

  6. Temporal Consistency Between Gross Primary Production and Solar-Induced Chlorophyll Fluorescence in the Ten Most Populous Megacity Areas over Years

    NASA Technical Reports Server (NTRS)

    Cui, Yaoping; Xiao, Xiangmin; Zhang, Yao; Dong, Jinwei; Qin, Yuanwei; Doughty, Russell B.; Zhang, Geli; Wang, Jie; Wu, Xiaocui; Qin, Yaochen; hide

    2017-01-01

    The gross primary production (GPP) of vegetation in urban areas plays an important role in the study of urban ecology. It is difficult however, to accurately estimate GPP in urban areas, mostly due to the complexity of impervious land surfaces, buildings, vegetation, and management. Recently, we used the Vegetation Photosynthesis Model (VPM), climate data, and satellite images to estimate the GPP of terrestrial ecosystems including urban areas. Here, we report VPM-based GPP (GPPvpm) estimates for the world's ten most populous megacities during 2000-2014. The seasonal dynamics of GPPvpm during 2007-2014 in the ten megacities track well that of the solar-induced chlorophyll fluorescence (SIF) data from GOME-2 at 0.5deg x 0.5deg resolution. Annual GPPvpm during 2000-2014 also shows substantial variation among the ten megacities, and year-to-year trends show increases, no change, and decreases. Urban expansion and vegetation collectively impact GPP variations in these megacities. The results of this study demonstrate the potential of a satellite-based vegetation photosynthesis model for diagnostic studies of GPP and the terrestrial carbon cycle in urban areas.

  7. Trends of total water vapor column above the Arctic from satellites observations

    NASA Astrophysics Data System (ADS)

    Alraddawi, Dunya; Sarkissian, Alain; Keckhut, Philippe; Bock, Olivier; Claud, Chantal; Irbah, Abdenour

    2016-04-01

    Atmospheric water vapor (H2O) is the most important natural (as opposed to man-made) greenhouse gas, accounting for about two-thirds of the natural greenhouse effect. Despite this importance, its role in climate and its reaction to climate change are still difficult to assess. Many details of the hydrological cycle are poorly understood, such as the process of cloud formation and the transport and release of latent heat contained in the water vapor. In contrast to other important greenhouse gases like carbon dioxide (CO2) and methane, water vapor has a much higher temporal and spatial variability. Total precipitable water (TPW) or the total column of water vapor (TCWV) is the amount of liquid water that would result if all the water vapor in the atmospheric column of unit area were condensed. TCWV distribution contains valuable information on the vigor of the hydrological processes and moisture transport in the atmosphere. Measurement of TPW can be obtained based on atmospheric water vapor absorption or emission of radiation in the spectral range from UV to MW. TRENDS were found over the terrestrial Arctic by means of TCWV retrievals (using Moderate Resolution Imaging Spectro-radiometer (MODIS) near-infrared (2001-2015) records). More detailed approach was made for comparisons with ground based instruments over Sodankyla - Finland (TCWV from: SCIAMACHY 2003-2011, GOME-2A 2007-2011, SAOZ 2003-2011, GPS 2003-2011, MODIS 2003-2011)

  8. Estimating daily surface NO2 concentrations from satellite data - a case study over Hong Kong using land use regression models

    NASA Astrophysics Data System (ADS)

    Anand, Jasdeep S.; Monks, Paul S.

    2017-07-01

    Land use regression (LUR) models have been used in epidemiology to determine the fine-scale spatial variation in air pollutants such as nitrogen dioxide (NO2) in cities and larger regions. However, they are often limited in their temporal resolution, which may potentially be rectified by employing the synoptic coverage provided by satellite measurements. In this work a mixed-effects LUR model is developed to model daily surface NO2 concentrations over the Hong Kong SAR during the period 2005-2015. In situ measurements from the Hong Kong Air Quality Monitoring Network, along with tropospheric vertical column density (VCD) data from the OMI, GOME-2A, and SCIAMACHY satellite instruments were combined with fine-scale land use parameters to provide the spatiotemporal information necessary to predict daily surface concentrations. Cross-validation with the in situ data shows that the mixed-effects LUR model using OMI data has a high predictive power (adj. R2 = 0. 84), especially when compared with surface concentrations derived using the MACC-II reanalysis model dataset (adj. R2 = 0. 11). Time series analysis shows no statistically significant trend in NO2 concentrations during 2005-2015, despite a reported decline in NOx emissions. This study demonstrates the utility in combining satellite data with LUR models to derive daily maps of ambient surface NO2 for use in exposure studies.

  9. Common Calibration Source for Monitoring Long-term Ozone Trends

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew

    2004-01-01

    Accurate long-term satellite measurements are crucial for monitoring the recovery of the ozone layer. The slow pace of the recovery and limited lifetimes of satellite monitoring instruments demands that datasets from multiple observation systems be combined to provide the long-term accuracy needed. A fundamental component of accurately monitoring long-term trends is the calibration of these various instruments. NASA s Radiometric Calibration and Development Facility at the Goddard Space Flight Center has provided resources to minimize calibration biases between multiple instruments through the use of a common calibration source and standardized procedures traceable to national standards. The Facility s 50 cm barium sulfate integrating sphere has been used as a common calibration source for both US and international satellite instruments, including the Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet 2 (SBUV/2) instruments, Shuttle SBUV (SSBUV), Ozone Mapping Instrument (OMI), Global Ozone Monitoring Experiment (GOME) (ESA), Scanning Imaging SpectroMeter for Atmospheric ChartographY (SCIAMACHY) (ESA), and others. We will discuss the advantages of using a common calibration source and its effects on long-term ozone data sets. In addition, sphere calibration results from various instruments will be presented to demonstrate the accuracy of the long-term characterization of the source itself.

  10. Distribution of stress on TMJ disc induced by use of chincup therapy: assessment by the finite element method.

    PubMed

    Calçada, Flávio Siqueira; Guimarães, Antônio Sérgio; Teixeira, Marcelo Lucchesi; Takamatsu, Flávio Atsushi

    2017-01-01

    To assess the distribution of stress produced on TMJ disc by chincup therapy, by means of the finite element method. a simplified three-dimensional TMJ disc model was developed by using Rhinoceros 3D software, and exported to ANSYS software. A 4.9N load was applied on the inferior surface of the model at inclinations of 30, 40, and 50 degrees to the mandibular plane (GoMe). ANSYS was used to analyze stress distribution on the TMJ disc for the different angulations, by means of finite element method. The results showed that the tensile and compressive stresses concentrations were higher on the inferior surface of the model. More presence of tensile stress was found in the middle-anterior region of the model and its location was not altered in the three directions of load application. There was more presence of compressive stress in the middle and mid-posterior regions, but when a 50o inclined load was applied, concentration in the middle region was prevalent. Tensile and compressive stresses intensities progressively diminished as the load was more vertically applied. stress induced by the chincup therapy is mainly located on the inferior surface of the model. Loads at greater angles to the mandibular plane produced distribution of stresses with lower intensity and a concentration of compressive stresses in the middle region. The simplified three-dimensional model proved useful for assessing the distribution of stresses on the TMJ disc induced by the chincup therapy.

  11. The use of microsatellites for germplasm management in a Portuguese grapevine collection.

    PubMed

    Lopes, M S; Sefc, K M; Eiras Dias, E; Steinkellner, H; Laimer Câmara Machado, M; Câmara Machado, A

    1999-08-01

    To initiate the characterization of the Portuguese grapevine genepool, we have genotyped 49 Portuguese grapevine cultivars at 11 microsatellite loci. The markers proved to be informative in the Portuguese cultivars, with expected heterozygosity ranging from 0.67 to 0.84. At most loci, an excess of heterozygous individuals was observed, while the deficiency of heterozygotes at 1 locus (VVMD6) indicated the presence of null alleles. On the basis of the microsatellite allele data several previously assumed synonyms were verified: (1) 'Fernão Pires'='Maria Gomes', (2) 'Moscatel de Setúbal'='Muscat of Alexandria', (3) 'Boal Cachudo'='Boal da Madeira'='Malvasia Fina', (4) 'Síria'='Crato Branco'= 'Roupeiro' and (5) 'Periquita'='Castelão Francês'='João de Santarém'='Trincadeira'. Although the three varieties 'Verdelho da Madeira', 'Verdelho dos Açores', and 'Verdelho roxo' are regarded by the Lista Nacional de Sinónimos as distinct cultivars, they displayed identical SSR profiles at 17 loci and appear to represent types of 1 single cultivar. The genetic profiles of all 49 cultivars were searched for possible parent-offspring groups. The data obtained revealed the descendence of 'Boal Ratinho' from 'Malvasia Fina' and 'Síria'.

  12. Phytochemical Analysis and Antimicrobial, Antinociceptive, and Anti-Inflammatory Activities of Two Chemotypes of Pimenta pseudocaryophyllus (Myrtaceae)

    PubMed Central

    de Paula, Joelma Abadia Marciano; Silva, Maria do Rosário Rodrigues; Costa, Maysa P.; Diniz, Danielle Guimarães Almeida; Sá, Fabyola A. S.; Alves, Suzana Ferreira; Costa, Élson Alves; Lino, Roberta Campos; de Paula, José Realino

    2012-01-01

    Preparations from Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae) have been widely used in Brazilian folk medicine. This study aims to evaluate the antimicrobial activity of the crude ethanol extracts, fractions, semipurified substances, and essential oils obtained from leaves of two chemotypes of P. pseudocaryophyllus and to perform the antinociceptive and anti-inflammatory screening. The ethanol extracts were purified by column chromatography and main compounds were spectrally characterised (1D and 2D 1H and 13C NMR). The essential oils constituents were identified by GC/MS. The broth microdilution method was used for testing the antimicrobial activity. The abdominal contortions induced by acetic acid and the ear oedema induced by croton oil were used for screening of antinociceptive and anti-inflammatory activities, respectively. The phytochemical analysis resulted in the isolation of pentacyclic triterpenes, flavonoids, and phenol acids. The oleanolic acid showed the best profile of antibacterial activity for Gram-positive bacteria (31.2–125 μg mL−1), followed by the essential oil of the citral chemotype (62.5–250 μg mL−1). Among the semipurified substances, Ppm5, which contained gallic acid, was the most active for Candida spp. (31.2 μg mL−1) and Cryptococcus spp. (3.9–15.6 μg mL−1). The crude ethanol extract and fractions from citral chemotype showed antinociceptive and anti-inflammatory effects. PMID:23082081

  13. Exploitation of the UV Aerosol Index scattering angle dependence: Properties of Siberian smoke plumes

    NASA Astrophysics Data System (ADS)

    Penning de Vries, Marloes; Beirle, Steffen; Sihler, Holger; Wagner, Thomas

    2017-04-01

    The UV Aerosol Index (UVAI) is a simple measure of aerosols from satellite that is particularly sensitive to elevated layers of absorbing particles. It has been determined from a range of instruments including TOMS, GOME-2, and OMI, for almost four decades and will be continued in the upcoming Sentinel missions S5-precursor, S4, and S5. Despite its apparent simplicity, the interpretation of UVAI is not straightforward, as it depends on aerosol abundance, absorption, and altitude in a non-linear way. In addition, UVAI depends on the geometry of the measurement (viewing angle, solar zenith and relative azimuth angles), particularly if viewing angles exceed 45 degrees, as is the case for OMI and TROPOMI (on S5-precursor). The dependence on scattering angle complicates the interpretation and further processing (e.g., averaging) of UVAI. In certain favorable cases, however, independent information on aerosol altitude and absorption may become available. We present a detailed study of the scatter angle dependence using SCIATRAN radiative transfer calculations. The model results were compared to observations of an extensive Siberian smoke plume, of which parts reached 10-12 km altitude. Due to its large extent and the high latitude, OMI observed the complete plume in five consecutive orbits under a wide range of scattering angles. This allowed us to deduce aerosol characteristics (absorption and layer height) that were compared with collocated CALIOP lidar measurements.

  14. Towards a Solid Foundation of Using Remotely Sensed Solar-Induced Chlorophyll Fluorescence for Crop Monitoring and Yield Forecast

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Sun, Y.; You, L.; Liu, Y.

    2017-12-01

    The growing demand for food production due to population increase coupled with high vulnerability to volatile environmental changes poses a paramount challenge for mankind in the coming century. Real-time crop monitoring and yield forecasting must be a key part of any solution to this challenge as these activities provide vital information needed for effective and efficient crop management and for decision making. However, traditional methods of crop growth monitoring (e.g., remotely sensed vegetation indices) do not directly relate to the most important function of plants - photosynthesis and therefore crop yield. The recent advance in the satellite remote sensing of Solar-Induced chlorophyll Fluorescence (SIF), an integrative photosynthetic signal from molecular origin and a direct measure of plant functions holds great promise for real-time monitoring of crop growth conditions and forecasting yields. In this study, we use satellite measurements of SIF from both the Global Ozone Monitoring Experiment-2 (GOME-2) onboard MetOp-A and the Orbiting Carbon Observatory-2 (OCO-2) satellites to estimate crop yield using both process-based and statistical models. We find that SIF-based crop yield well correlates with the global yield product Spatial Production Allocation Model (SPAM) derived from ground surveys for all major crops including maize, soybean, wheat, sorghum, and rice. The potential and challenges of using upcoming SIF satellite missions for crop monitoring and prediction will also be discussed.

  15. Spatial-temporal consistency between gross primary productivity and solar-induced chlorophyll fluorescence of vegetation in China during 2007-2014

    NASA Astrophysics Data System (ADS)

    Ma, J.; Xiao, X.; Zhang, Y.; Chen, B.; Zhao, B.

    2017-12-01

    Great significance exists in accurately estimating spatial-temporal patterns of gross primary production (GPP) because of its important role in global carbon cycle. Satellite-based light use efficiency (LUE) models are regarded as an efficient tool in simulating spatially time-sires GPP. However, the estimation of the accuracy of GPP simulations from LUE at both spatial and temporal scales is still a challenging work. In this study, we simulated GPP of vegetation in China during 2007-2014 using a LUE model (Vegetation Photosynthesis Model, VPM) based on MODIS (moderate-resolution imaging spectroradiometer) images of 8-day temporal and 500-m spatial resolutions and NCEP (National Center for Environmental Prediction) climate data. Global Ozone Monitoring Instrument 2 (GOME-2) solar-induced chlorophyll fluorescence (SIF) data were used to compare with VPM simulated GPP (GPPVPM) temporally and spatially using linear correlation analysis. Significant positive linear correlations exist between monthly GPPVPM and SIF data over both single year (2010) and multiple years (2007-2014) in China. Annual GPPVPM is significantly positive correlated with SIF (R2>0.43) spatially for all years during 2007-2014 and all seasons in 2010 (R2>0.37). GPP dynamic trends is high spatial-temporal heterogeneous in China during 2007-2014. The results of this study indicate that GPPVPM is temporally and spatially in line with SIF data, and space-borne SIF data have great potential in validating and parameterizing GPP estimation of LUE-based models.

  16. A detailed study of the 2010 fires in Russia by multiple satellite instruments: what can we learn from the UV Aerosol Indices?

    NASA Astrophysics Data System (ADS)

    Penning de Vries, M. J.; Wagner, T.; Fromm, M. D.

    2010-12-01

    For almost a month in July and August 2010, an exceptionally high number of fires occurred across western Russia. Varying fire characteristics and intensity due to differences in fuel composition and meteorological conditions caused smoke plumes to vary in color, altitude and optical density. Peat bog fires around Moscow tended to produce low-lying, whitish smoke layers, whereas some severe forest fires were found to have caused so-called pyro-Cbs: thick, mostly dark smoke plumes on top of large convective clouds that reached as high as the stratosphere. In situations where an aerosol layer overlays a cloud, many remote sensing aerosol retrievals break down due to the brightness of the “surface”. The UV Aerosol Indices (UVAI) do not suffer from this drawback, and in fact are more sensitive to absorbing aerosols if the underlying surface is bright, therefore making them very suitable for our type of investigation. However, aerosol plumes are very complex and the UVAI are only semi-quantitative measures that are determined by aerosol extinction and absorption, but also by the altitude of the aerosol plume. We therefore chose to combine our UVAI measurements from the instruments SCIAMACHY, OMI, and GOME-2 with observations by other satellite instruments, such as MODIS, MISR, MERIS, and CALIOP. We also compared the measurements to radiative transfer model calculations of many different aerosol scenarios to draw conclusions about what specific aerosol characteristics cause the variation in pyro-Cb appearances.

  17. Polar boundary layer bromine explosion and ozone depletion events in the chemistry-climate model EMAC v2.52: implementation and evaluation of AirSnow algorithm

    NASA Astrophysics Data System (ADS)

    Falk, Stefanie; Sinnhuber, Björn-Martin

    2018-03-01

    Ozone depletion events (ODEs) in the polar boundary layer have been observed frequently during springtime. They are related to events of boundary layer enhancement of bromine. Consequently, increased amounts of boundary layer volume mixing ratio (VMR) and vertical column densities (VCDs) of BrO have been observed by in situ observation, ground-based as well as airborne remote sensing, and from satellites. These so-called bromine explosion (BE) events have been discussed serving as a source of tropospheric BrO at high latitudes, which has been underestimated in global models so far. We have implemented a treatment of bromine release and recycling on sea-ice- and snow-covered surfaces in the global chemistry-climate model EMAC (ECHAM/MESSy Atmospheric Chemistry) based on the scheme of Toyota et al. (2011). In this scheme, dry deposition fluxes of HBr, HOBr, and BrNO3 over ice- and snow-covered surfaces are recycled into Br2 fluxes. In addition, dry deposition of O3, dependent on temperature and sunlight, triggers a Br2 release from surfaces associated with first-year sea ice. Many aspects of observed bromine enhancements and associated episodes of near-complete depletion of boundary layer ozone, both in the Arctic and in the Antarctic, are reproduced by this relatively simple approach. We present first results from our global model studies extending over a full annual cycle, including comparisons with Global Ozone Monitoring Experiment (GOME) satellite BrO VCDs and surface ozone observations.

  18. Global multi-sensor satellite monitoring of volcanic SO2 and ash emissions in support to aviation control

    NASA Astrophysics Data System (ADS)

    Brenot, H.; Theys, N.; van Gent, J.; Van Roozendael, M.; van der A, R.; Clarisse, L.; Hurtmans, D.; Ngadi, Y.; Coheur, P.-F.; Clerbaux, C.

    2012-04-01

    The "Support to Aviation Control Service" (SACS; http://sacs.aeronomie.be) is an ESA-funded project hosted by the Belgian Institute for Space Aeronomy. The service provides near real-time (NRT) global SO2 and volcanic ash data, as well as alerts in case of volcanic eruptions. The SACS service is primarily designed to support the Volcanic Ash Advisory Centers (VAACs) in their mandate to gather information on volcanic clouds and give advice to airline and air traffic control organisations. SACS also serves other users that subscribe to the service, in particular local volcano observatories and research scientists. SACS is based on the combined use of UV-visible (SCIAMACHY, OMI, GOME-2) and infrared (AIRS, IASI) satellite instruments. When a volcanic eruption is detected, SACS issues an alert that takes the form of a notification sent by e-mail to users. This notification points to a dedicated web page where all relevant information is available and can be visualized with user-friendly tools. The strength of a multi-sensor approach relies in the use of satellite data with different overpasses times, minimizing the time-lag for detection and enhancing the reliability of such alerts. This paper will give a general presentation of the SACS service, different techniques used to detect volcanic plumes. It will also highlight the strengths and limitations of the service and measurements.

  19. Viper and cobra venom neutralization by beta-sitosterol and stigmasterol isolated from the root extract of Pluchea indica Less. (Asteraceae).

    PubMed

    Gomes, A; Saha, Archita; Chatterjee, Ipshita; Chakravarty, A K

    2007-09-01

    We reported previously that the methanolic root extract of the Indian medicinal plant Pluchea indica Less. (Asteraceae) could neutralize viper venom-induced action [Alam, M.I., Auddy, B., Gomes, A., 1996. Viper venom neutralization by Indian medicinal plant (Hemidesmus indicus and P. indica) root extracts. Phytother. Res. 10, 58-61]. The present study reports the neutralization of viper and cobra venom by beta-sitosterol and stigmasterol isolated from the root extract of P. indica Less. (Asteraceae). The active fraction (containing the major compound beta-sitosterol and the minor compound stigmasterol) was isolated and purified by silica gel column chromatography and the structure was determined using spectroscopic analysis (EIMS, (1)H NMR, (13)C NMR). Anti-snake venom activity was studied in experimental animals. The active fraction was found to significantly neutralize viper venom-induced lethal, hemorrhagic, defibrinogenation, edema and PLA(2) activity. Cobra venom-induced lethality, cardiotoxicity, neurotoxicity, respiratory changes and PLA(2) activity were also antagonized by the active component. It potentiated commercial snake venom antiserum action against venom-induced lethality in male albino mice. The active fraction could antagonize venom-induced changes in lipid peroxidation and superoxide dismutase activity. This study suggests that beta-sitosterol and stigmasterol may play an important role, along with antiserum, in neutralizing snake venom-induced actions.

  20. Origin of B chromosomes in Characidium alipioi (Characiformes, Crenuchidae) and its relationship with supernumerary chromosomes in other Characidium species.

    PubMed

    Serrano, Érica Alves; Utsunomia, Ricardo; Scudeller, Patrícia Sobrinho; Oliveira, Claudio; Foresti, Fausto

    2017-01-01

    B chromosomes are apparently dispensable components found in the genomes of many species that are mainly composed of repetitive DNA sequences. Among the numerous questions concerning B chromosomes, the origin of these elements has been widely studied. To date, supernumerary chromosomes have been identified in approximately 60 species of fish, including species of the genus Characidium Reinhardt, 1867 in which these elements appear to have independently originated. In this study, we used molecular cytogenetic techniques to investigate the origin of B chromosomes in a population of Characidium alipioi Travassos, 1955 and determine their relationship with the extra chromosomes of other species of the genus. The results showed that the B chromosomes of Characidium alipioi had an intraspecific origin, apparently originated independently in relation to the B chromosomes of Characidium gomesi Travassos, 1956 Characidium pterostictum Gomes, 1947 and Characidium oiticicai Travassos, 1967, since they do not share specific DNA sequences, as well as their possible ancestral chromosomes and belong to different phylogenetic clades. The shared sequences between the supernumerary chromosomes and the autosommal sm pair indicate the origin of these chromosomes.

  1. Toward Rotational State-Selective Photoionization of ThF+ Ions

    NASA Astrophysics Data System (ADS)

    Zhou, Yan; Ng, Kia Boon; Gresh, Dan; Cairncross, William; Grau, Matt; Ni, Yiqi; Cornell, Eric; Ye, Jun

    2016-06-01

    ThF+ has been chosen to replace HfF+ for a second-generation measurement of the electric dipole moment of the electron (eEDM). Compared to the currently running HfF+ eEDM experiment, ThF+ has several advantages: (i) the eEDM-sensitive state (3Δ1) is the ground state, which facilitates a long coherence time [1]; (ii) its effective electric field (35 GV/cm) is 50% larger than that of HfF+, which promises a direct increase of the eEDM sensitivity [2]; and (iii) the ionization energy of neutral ThF is lower than its dissociation energy, which introduces greater flexibility in rotational state-selective photoionization via core-nonpenetrating Rydberg states [3]. In this talk, we first present our strategy of preparing and utilizing core-nonpenetrating Rydberg states for rotational state-selective ionization. Then, we report spectroscopic data of laser-induced fluorescence of neutral ThF, which provides critical information for multi-photon ionization spectroscopy. [1] D. N. Gresh, K. C. Cossel, Y. Zhou, J. Ye, E. A. Cornell, Journal of Molecular Spectroscopy, 319 (2016), 1-9 [2] M. Denis, M. S. Nørby, H. J. A. Jensen, A. S. P. Gomes, M. K. Nayak, S. Knecht, T. Fleig, New Journal of Physics, 17 (2015) 043005. [3] Z. J. Jakubek, R. W. Field, Journal of Molecular Spectroscopy 205 (2001) 197-220.

  2. Value Assessment Study for Air quality in Regulation Services of Ecosystems Services target on NO2 using Remote sensing data

    NASA Astrophysics Data System (ADS)

    Jeon, S. W.; Ryu, J.; Choi, Y.; Jung, H. I.; Jang, R.; Lee, J.

    2017-12-01

    The purpose of this study is to evaluate the value of green space that regulates the air quality in the regulatory service classification of ecosystem services. In this study, statistical data and satellite images (GOME) were used to construct data and evaluate the control functions of the whole country. In order to evaluate the value, national economic activities are evaluated and typified based on national GDP. This is because the amount of No2 emissions and the damage caused by them are different depending on the speed and characteristics of national development. After that, regression models were made using land cover, change in urban green area ratio, NDVI (Normalised Difference Vegetation Index), increase or decrease in population, increase in urban area, altitude and slope, cardiovascular due to NO2 and respiratory population. After that, the value of green space was evaluated by applying the scenario of NO2 increase or decrease for each type. The value of green space was converted into economic value by increasing or decreasing the number of affected people and the damage amount when NO2 increased. The results of this study are expected to provide a basis for conservation of forests by assessing the value of greenery to control air quality globally.

  3. Extreme ultraviolet index due to broken clouds at a midlatitude site, Granada (southeastern Spain)

    NASA Astrophysics Data System (ADS)

    Antón, M.; Piedehierro, A. A.; Alados-Arboledas, L.; Wolfran, E.; Olmo, F. J.

    2012-11-01

    Cloud cover usually attenuates the ultraviolet (UV) solar radiation but, under certain sky conditions, the clouds may produce an enhancement effect increasing the UV levels at surface. The main objective of this paper is to analyze an extreme UV enhancement episode recorded on 16 June 2009 at Granada (southeastern Spain). This phenomenon was characterized by a quick and intense increase in surface UV radiation under broken cloud fields (5-7 oktas) in which the Sun was surrounded by cumulus clouds (confirmed with sky images). Thus, the UV index (UVI) showed an enhancement of a factor 4 in the course of only 30 min around midday, varying from 2.6 to 10.4 (higher than the corresponding clear-sky UVI value). Additionally, the UVI presented values higher than 10 (extreme erythemal risk) for about 20 min running, with a maximum value around 11.5. The use of an empirical model and the total ozone column (TOC) derived from the Global Ozone Monitoring Experiment (GOME) for the period 1995-2011 showed that the value of UVI ~ 11.5 is substantially larger than the highest index that could origin the natural TOC variations over Granada. Finally, the UV erythemal dose accumulated during the period of 20 min with the extreme UVI values under broken cloud fields was 350 J/m2 which surpass the energy required to produce sunburn of the most human skin types.

  4. TEMPO Early Adopters in Air-Quality Forecasting, Planning and Assessment, Pollution Emissions, Health, Agriculture, and Environmental Impacts: Applications and Decision Support

    NASA Astrophysics Data System (ADS)

    Newchurch, M.; Zavodsky, B.; Chance, K.; Haynes, J.; Lefer, B. L.; Naeger, A.

    2016-12-01

    The AQ research community has a long legacy of using space-based observations (e.g., Solar Backscatter Ultraviolet Instrument [SBUV], Global Ozone Monitoring Experiment [GOME], Ozone Monitoring Instrument [OMI], and the Ozone Mapping & Profiler Suite [OMPS]) to study atmospheric chemistry. These measurements have been used to observe day-to-day and year-to-year changes in atmospheric constituents. However, they have not been able to capture the diurnal variability of pollution with enough temporal or spatial fidelity and a low enough latency for regular use by operational decision makers. As a result, the operational AQ community has traditionally relied on ground-based (e.g., collection stations, LIDAR) and airborne observing systems to study tropospheric chemistry. In order to maximize its utility for applications and decision support, there is a need to educate the community about the game-changing potential for the geostationary TEMPO mission well ahead of its expected launch date early in the third decade of this millinium. This NASA mission will engage user communities and enable science across the NASA Applied Science Focus Areas of Health and Air Quality, Disasters, Water Resources, and Ecological Forecasting, In addition, topics discussed will provide opportunities for collaborations extending TEMPO applications to future program areas in Agriculture, Weather and Climate (including Numerical Weather Prediction), Energy, and Oceans.

  5. Real-Time Estimation of Volcanic ASH/SO2 Cloud Height from Combined Uv/ir Satellite Observations and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Vicente, Gilberto A.

    An efficient iterative method has been developed to estimate the vertical profile of SO2 and ash clouds from volcanic eruptions by comparing near real-time satellite observations with numerical modeling outputs. The approach uses UV based SO2 concentration and IR based ash cloud images, the volcanic ash transport model PUFF and wind speed, height and directional information to find the best match between the simulated and the observed displays. The method is computationally fast and is being implemented for operational use at the NOAA Volcanic Ash Advisory Centers (VAACs) in Washington, DC, USA, to support the Federal Aviation Administration (FAA) effort to detect, track and measure volcanic ash cloud heights for air traffic safety and management. The presentation will show the methodology, results, statistical analysis and SO2 and Aerosol Index input products derived from the Ozone Monitoring Instrument (OMI) onboard the NASA EOS/Aura research satellite and from the Global Ozone Monitoring Experiment-2 (GOME-2) instrument in the MetOp-A. The volcanic ash products are derived from AVHRR instruments in the NOAA POES-16, 17, 18, 19 as well as MetOp-A. The presentation will also show how a VAAC volcanic ash analyst interacts with the system providing initial condition inputs such as location and time of the volcanic eruption, followed by the automatic real-time tracking of all the satellite data available, subsequent activation of the iterative approach and the data/product delivery process in numerical and graphical format for operational applications.

  6. TOMS UV Algorithm: Problems and Enhancements. 2

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Herman, Jay; Bhartia, P. K.; Seftor, Colin; Arola, Antti; Kaurola, Jussi; Kroskinen, Lasse; Kalliskota, S.; Taalas, Petteri; Geogdzhaev, I.

    2002-01-01

    Satellite instruments provide global maps of surface ultraviolet (UV) irradiance by combining backscattered radiance measurements with radiative transfer models. The models are limited by uncertainties in input parameters of the atmosphere and the surface. We evaluate the effects of possible enhancements of the current Total Ozone Mapping Spectrometer (TOMS) surface UV irradiance algorithm focusing on effects of diurnal variation of cloudiness and improved treatment of snow/ice. The emphasis is on comparison between the results of the current (version 1) TOMS UV algorithm and each of the changes proposed. We evaluate different approaches for improved treatment of pixel average cloud attenuation, with and without snow/ice on the ground. In addition to treating clouds based only on the measurements at the local time of the TOMS observations, the results from other satellites and weather assimilation models can be used to estimate attenuation of the incident UV irradiance throughout the day. A new method is proposed to obtain a more realistic treatment of snow covered terrain. The method is based on a statistical relation between UV reflectivity and snow depth. The new method reduced the bias between the TOMS UV estimations and ground-based UV measurements for snow periods. The improved (version 2) algorithm will be applied to re-process the existing TOMS UV data record (since 1978) and to the future satellite sensors (e.g., Quik/TOMS, GOME, OMI on EOS/Aura and Triana/EPIC).

  7. Current Applications of OMI Tropospheric NO2 Data for Air Quality and a Look to the Future

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Bucsela, E.; Allen, D.; Prados, A.; Gleason, J.; Kondragunta, S.

    2010-01-01

    Ozone Monitoring Instrument (OMI) Tropospheric NO2 products are being used to enhance the ability to monitor changes in NO2 air quality, update emission inventories, and evaluate regional air quality models. Trends in tropospheric column NO2 have been examined over the eastern United States in relation to emissions changes mandated by regulatory actions. Decreases of 20 to 40 percent over the period 2005 to 2008 were noted, largely in response to major emission reductions at power plants. The OMI data have been used to identify regions in which the opposite trend has been found. We have also used OMI NO2 in efforts to improve emission inventories for NOx emissions from soil. Lightning NOx emissions have been added to CMAQ, the US Environmental Protection Agency's regional air quality model. Evaluation of the resulting NO2 columns in the model is being conducted using the OMI NO2 observations. Community Multiscale Air Quality (CMAQ) together with the OMI NO2 data comprise a valuable tool for monitoring and predicting air quality. Looking to the future, we expect that the combination of Global Ozone Monitoring Experiment-2 (GOME-2) (morning) and OMI (afternoon) data sets obtained through use of the same retrieval algorithms will substantially increase the possibility of successful integration of satellite information into regional air quality forecast models. Farther down the road, we anticipate the Geostationary Coastal and Air Pollution Events (GEO-CAPE) platform to supply data possibly on an hourly basis, allowing much more comprehensive analysis of air quality from space.

  8. Overview on grating developments at ESA

    NASA Astrophysics Data System (ADS)

    Guldimann, B.; Deep, A.; Vink, R.; Harnisch, B.; Kraft, S.; Sierk, B.; Bazalgette, G.; Bézy, J.-L.

    2017-11-01

    In the frame of recent studies and missions, ESA has been performing various pre-developments of optical gratings for instruments operating at wavelengths from the UV up to the SWIR. The instrument requirements of Sentinel-4, Sentinel-5, CarbonSat and FLEX are driving the need for advanced designs and technologies leading to gratings with high efficiency, high spectral resolution, low stray light and low polarization sensitivities. Typical ESA instruments (e.g. Sciamachy, GOME, MERIS, OLCI, NIRSpec) were and are based on ruled gratings or gratings manufactured with one holographic photoresist mask layer which is transferred to an optical substrate (e.g. glass, glass ceramic) with dry etching methods and subsequently either coated with a reflective coating or used as a mold for replication. These manufacturing methods lead to blazed grating profiles with a metallic reflective surface. The vast majority of spectrometers on ground are still based on such gratings. In general, gratings based on grooved metallic surfaces tend for instance to polarize the incoming light significantly and are therefore not always suitable for ESA's needs of today. Gratings made for space therefore evolved to many other designs and concepts which will be reported in this paper.

  9. Simulations of planet migration driven by planetesimal scattering

    NASA Astrophysics Data System (ADS)

    Kirsh, David R.; Duncan, Martin; Brasser, Ramon; Levison, Harold F.

    2009-01-01

    Evidence has mounted for some time that planet migration is an important part of the formation of planetary systems, both in the Solar System [Malhotra, R., 1993. Nature 365, 819-821] and in extrasolar systems [Mayor, M., Queloz, D., 1995. Nature 378, 355-359; Lin, D.N.C., Bodenheimer, P., Richardson, D.C., 1996. Nature 380, 606-607]. One mechanism that produces migration (the change in a planet's semi-major axis a over time) is the scattering of comet- and asteroid-size bodies called planetesimals [Fernandez, J.A., Ip, W.-H., 1984. Icarus 58, 109-120]. Significant angular momentum exchange can occur between the planets and the planetesimals during local scattering, enough to cause a rapid, self-sustained migration of the planet [Ida, S., Bryden, G., Lin, D.N.C., Tanaka, H., 2000. Astrophys. J. 534, 428-445]. This migration has been studied for the particular case of the four outer planets of the Solar System (as in Gomes et al. [Gomes, R.S., Morbidelli, A., Levison, H.F., 2004. Icarus 170, 492-507]), but is not well understood in general. We have used the Miranda [McNeil, D., Duncan, M., Levison, H.F., 2005. Astron. J. 130, 2884-2899] computer simulation code to perform a broad parameter-space survey of the physical variables that determine the migration of a single planet in a planetesimal disk. Migration is found to be predominantly inwards, and the migration rate is found to be independent of planet mass for low-mass planets in relatively high-mass disks. Indeed, a simple scaling relation from Ida et al. [Ida, S., Bryden, G., Lin, D.N.C., Tanaka, H., 2000. Astrophys. J. 534, 428-445] matches well with the dependencies of the migration rate: |{da}/{dt}|=aT{4πΣa/M; with T the orbital period of the planet and Σ the surface density of the planetesimal disk. When the planet's mass exceeds that of the planetesimals within a few Hill radii (the unit of the planet's gravitational reach), the migration rate decreases strongly with planet mass. Other trends are

  10. Factors associated with disease-specific survival of patients with non-small cell lung cancer.

    PubMed

    Souza, Mirian Carvalho de; Cruz, Oswaldo Gonçalves; Vasconcelos, Ana Glória Godoi

    2016-01-01

    Lung cancer is a global public health problem and is associated with high mortality. Lung cancer could be largely avoided by reducing the prevalence of smoking. The objective of this study was to analyze the effects of social, behavioral, and clinical factors on the survival time of patients with non-small cell lung cancer treated at Cancer Hospital I of the José Alencar Gomes da Silva National Cancer Institute, located in the city of Rio de Janeiro, Brazil, between 2000 and 2003. This was a retrospective hospital cohort study involving 1,194 patients. The 60-month disease-specific survival probabilities were calculated with the Kaplan-Meier method for three stage groups. The importance of the studied factors was assessed with a hierarchical theoretical model after adjustment by Cox multiple regression. The estimated 60-month specific-disease lethality rate was 86.0%. The 60-month disease-specific survival probability ranged from 25.0% (stages I/II) to 2.5% (stage IV). The performance status, the intention to treat, and the initial treatment modality were the major prognostic factors identified in the study population. In this cohort of patients, the disease-specific survival probabilities were extremely low. We identified no factors that could be modified after the diagnosis in order to improve survival. Primary prevention, such as reducing the prevalence of smoking, is still the best method to reduce the number of people who will suffer the consequences of lung cancer. O câncer de pulmão é um problema de saúde pública global e é associado a elevada mortalidade. Ele poderia ser evitado em grande parte com a redução da prevalência do tabagismo. O objetivo deste estudo foi analisar os efeitos de fatores sociais, comportamentais e clínicos sobre o tempo de sobrevida de pacientes com câncer de pulmão de células não pequenas atendidos, entre 2000 e 2003, no Hospital do Câncer I do Instituto Nacional de Câncer José Alencar Gomes da Silva, localizado na

  11. The ESA DUE GlobVapour Project

    NASA Astrophysics Data System (ADS)

    Schröder, M.; ESA Due Globvapour Project Team

    2010-12-01

    DUE GlobVapour project is the preparation of recognised data sets and successful concepts that can be used to ensure a sustainable provision of such data from operational entities such as the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Satellite Application Facility (SAF) network. Key scientific questions which GlobVapour data can contribute to are climate monitoring and attribution, assimilation of different water vapour datasets to form a consistent analysis, model process studies, evaluation of in-situ water vapour measurements, validation of climate models and reanalyses, assessing the relationship between water vapour and dynamics, research and development for operational applications and input to atmospheric reanalyses. This presentation will introduce the GlobVapour project and concept as well as the products which are the global total column water vapour (TCWV) time series from a combination of MERIS and SSM/I as well as TCWV data sets derived from the GOME/SCIAMACHY/GOME-2 and the (A)ATSR instruments. A shorter time series of water vapour profiles will be derived from a combination of IASI and SEVIRI. The retrieval and combination methods as well as first validation results will also be discussed.

  12. Standardizing Interfaces for External Access to Data and Processing for the NASA Ozone Product Evaluation and Test Element (PEATE)

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt A.; Fleig, Albert J.

    2008-01-01

    NASA's traditional science data processing systems have focused on specific missions, and providing data access, processing and services to the funded science teams of those specific missions. Recently NASA has been modifying this stance, changing the focus from Missions to Measurements. Where a specific Mission has a discrete beginning and end, the Measurement considers long term data continuity across multiple missions. Total Column Ozone, a critical measurement of atmospheric composition, has been monitored for'decades on a series of Total Ozone Mapping Spectrometer (TOMS) instruments. Some important European missions also monitor ozone, including the Global Ozone Monitoring Experiment (GOME) and SCIAMACHY. With the U.S.IEuropean cooperative launch of the Dutch Ozone Monitoring Instrument (OMI) on NASA Aura satellite, and the GOME-2 instrumental on MetOp, the ozone monitoring record has been further extended. In conjunction with the U.S. Department of Defense (DoD) and the National Oceanic and Atmospheric Administration (NOAA), NASA is now preparing to evaluate data and algorithms for the next generation Ozone Mapping and Profiler Suite (OMPS) which will launch on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) in 2010. NASA is constructing the Science Data Segment (SDS) which is comprised of several elements to evaluate the various NPP data products and algorithms. The NPP SDS Ozone Product Evaluation and Test Element (PEATE) will build on the heritage of the TOMS and OM1 mission based processing systems. The overall measurement based system that will encompass these efforts is the Atmospheric Composition Processing System (ACPS). We have extended the system to include access to publically available data sets from other instruments where feasible, including non-NASA missions as appropriate. The heritage system was largely monolithic providing a very controlled processing flow from data.ingest of

  13. Multiannual tropical tropospheric ozone columns and the case of the 2015 el Niño event

    NASA Astrophysics Data System (ADS)

    Leventidou, Elpida; Eichmann, Kai-Uwe; Weber, Mark; Burrows, John P.

    2016-04-01

    Stratospheric ozone is well known for protecting the surface from harmful ultraviolet solar radiation whereas ozone in the troposphere plays a more complex role. In the lower troposphere ozone can be extremely harmful for human health as it can oxidize biological tissues and causes respiratory problems. Several studies have shown that the tropospheric ozone burden (300±30Tg (IPCC, 2007)) increases by 1-7% per decade in the tropics (Beig and Singh, 2007; Cooper et al., 2014) which makes the need to monitor it on a global scale crucial. Remote sensing from satellites has been proven to be very useful in providing consistent information of tropospheric ozone concentrations over large areas. Tropical tropospheric ozone columns can be retrieved with the Convective Cloud Differential (CCD) technique (Ziemke et al. 1998) using retrieved total ozone columns and cloud parameters from space-borne observations. We have developed a CCD-IUP algorithm which was applied to GOME/ ERS-2 (1995-2003), SCIAMACHY/ Envisat (2002-2012), and GOME-2/ MetOpA (2007-2012) weighting function DOAS (Coldewey-Egbers et al., 2005, Weber et al., 2005) total ozone data. A unique long-term record of monthly averaged tropical tropospheric ozone columns (20°S - 20°N) was created starting in 1996. This dataset has been extensively validated by comparisons with SHADOZ (Thompson et al., 2003) ozonesonde data and limb-nadir Matching (Ebojie et al. 2014) tropospheric ozone data. The comparison shows good agreement with respect to range, inter-annual variation, and variance. Biases where found to be within 5DU and the RMS errors less than 10 DU. This 17-years dataset has been harmonized into one consistent time series, taking into account the three instruments' difference in ground pixel size. The harmonised dataset is used to determine tropical tropospheric ozone trends and climatological values. The 2015 el Niño event has been characterised as one of the top three strongest el Niños since 1950. El Ni

  14. Anthropogenic sulphur dioxide load over China as observed from different satellite sensors

    NASA Astrophysics Data System (ADS)

    Koukouli, M. E.; Balis, D. S.; van der A, Ronald Johannes; Theys, N.; Hedelt, P.; Richter, A.; Krotkov, N.; Li, C.; Taylor, M.

    2016-11-01

    China, with its rapid economic growth and immense exporting power, has been the focus of many studies during this previous decade quantifying its increasing emissions contribution to the Earth's atmosphere. With a population slowly shifting towards enlarged power and purchasing needs, the ceaseless inauguration of new power plants, smelters, refineries and industrial parks leads infallibly to increases in sulphur dioxide, SO2, emissions. The recent capability of next generation algorithms as well as new space-borne instruments to detect anthropogenic SO2 loads has enabled a fast advancement in this field. In the following work, algorithms providing total SO2 columns over China based on SCIAMACHY/Envisat, OMI/Aura and GOME2/MetopA observations are presented. The need for post-processing and gridding of the SO2 fields is further revealed in this work, following the path of previous publications. Further, it is demonstrated that the usage of appropriate statistical tools permits studying parts of the datasets typically excluded, such as the winter months loads. Focusing on actual point sources, such as megacities and known power plant locations, instead of entire provinces, monthly mean time series have been examined in detail. The sharp decline in SO2 emissions in more than 90%-95% of the locations studied confirms the recent implementation of government desulphurisation legislation; however, locations with increases, even for the previous five years, are also identified. These belong to provinces with emerging economies which are in haste to install power plants and are possibly viewed leniently by the authorities, in favour of growth. The SO2 load seasonality has also been examined in detail with a novel mathematical tool, with 70% of the point sources having a statistically significant annual cycle with highs in winter and lows in summer, following the heating requirements of the Chinese population.

  15. Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

    NASA Technical Reports Server (NTRS)

    Jaegle, Lyatt; Steinberger, Linda; Martin, Randall V.; Chance, Kelly

    2005-01-01

    This document contains the following abstract for the paper "Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions." Satellite observations have been used to provide important new information about emissions of nitrogen oxides. Nitrogen oxides (NOx) are significant in atmospheric chemistry, having a role in ozone air pollution, acid deposition and climate change. We know that human activities have led to a three- to six-fold increase in NOx emissions since pre-industrial times, and that there are three main surface sources of NOx: fuel combustion, large-scale fires, and microbial soil processes. How each of these sources contributes to the total NOx emissions is subject to some doubt, however. The problem is that current NOx emission inventories rely on bottom-up approaches, compiling large quantities of statistical information from diverse sources such as fuel and land use, agricultural data, and estimates of burned areas. This results in inherently large uncertainties. To overcome this, Lyatt Jaegle and colleagues from the University of Washington, USA, used new satellite observations from the Global Ozone Monitoring Experiment (GOME) instrument. As the spatial and seasonal distribution of each of the sources of NOx can be clearly mapped from space, the team could provide independent topdown constraints on the individual strengths of NOx sources, and thus help resolve discrepancies in existing inventories. Jaegle's analysis of the satellite observations, presented at the recent Faraday Discussion on "Atmospheric Chemistry", shows that fuel combustion dominates emissions at northern mid-latitudes, while fires are a significant source in the Tropics. Additionally, she discovered a larger than expected role for soil emissions, especially over agricultural regions with heavy fertilizer use. Additional information is included in the original extended abstract.

  16. Global relation between microwave satellite vegetation products and vegetation productivity

    NASA Astrophysics Data System (ADS)

    Teubner, Irene E.; Forkel, Matthias; Jung, Martin; Miralles, Diego G.; Dorigo, Wouter A.

    2017-04-01

    The occurrence of unfavourable environmental conditions like droughts commonly reduces the photosynthetic activity of ecosystems and, hence, their potential to take up carbon from the atmosphere. Ecosystem photosynthetic activity is commonly determined using remote sensing observations in the optical domain, which however have limitations particularly in regions of frequent cloud cover, e.g. the tropics. In this study, we explore the potential of vegetation optical depth (VOD) from microwave satellite observations as an alternative source for assessing vegetation productivity. VOD serves as an estimate for vegetation density and water content, which has an impact on plant physiological processes and hence should potentially provide a link to gross primary production (GPP). However, to date, it is unclear how microwave-retrieved VOD data and GPP data are related. We compare seasonal dynamics and anomalies of VOD retrievals from different satellite sensors and microwave frequencies with site level and global GPP estimates. We use VOD observations from active (ASCAT) and passive microwave sensors (AMSR-E, SMOS). We include eddy covariance measurements from the FLUXNET2015 dataset to assess the VOD products at site level. For a global scale analysis, we use the solar-induced chlorophyll fluorescence (SIF) observations from GOME-2 as a proxy for GPP and the FLUXCOM GPP product, which presents an upscaling of site measurements based on remote sensing data. Our results demonstrate that in general a good agreement between VOD and GPP or SIF exists. However, the strength of these relations depends on the microwave frequency, land cover type, and the time within the growing season. Correlations between anomalies of VOD and GPP or SIF support the assumption that microwave-derived VOD can be used to monitor vegetation productivity dynamics. The study is performed as part of the EOWAVE project funded by the Vienna University of Technology (http://eowave.geo.tuwien.ac.at/) and

  17. Planetary migration in protoplanetary discs and outer Solar System architecture.

    NASA Astrophysics Data System (ADS)

    Crida, A.; Morbidelli, A.; Tsiganis, K.

    2007-08-01

    Planets form around stars in gaseous protoplanetary discs. Due to tidal effects, they perturb the gas distribution, which in turn affects their motion. If the planet is massive enough (see for instance Crida et al. 2006 for a criterion), it repels the gas efficiently and opens a gap around its orbit ; then, locked into its gap, the planet follows the disc viscous evolution, which generally consists in accretion onto the central star. This process is called type II migration and leads to the orbital decay of the planet on a timescale shorter than the disc lifetime. After a review of these processes, we will focus on the Solar System giant planets. Strong constraints suggest that they did not migrate significantly. Masset and Snellgrove (2001) have shown that the evolution of 2 giants planets in mean motion resonance in a common gap differs from the evolution of a single planet. For what concerns Jupiter and Saturn, we found that in some conditions on the disc parameter, they can avoid significant migration (Morbidelli and Crida 2007). Adding Uranus and Neptune to the system, six stable fully resonant configurations for the four giants in the gas disc appear. Of course, none of them correspond to the present configuration. However, after the gas disc phase, the system was surrounded by a planetesimal disk. Interactions with this debris disk make the planets slowly evolve, until an instability in reached. This destabilises the planetesimal disc and triggers the Late Heavy Bombardment, while the planets reach their actual position, like in the model by Tsiganis et al (2005) and Gomes et al (2005). Our simulations show a very satisfying case, opening the possibility for a dynamically consistent scenario of the outer Solar System evolution, starting from the gas phase.

  18. Does Swimming at a Moderate Altitude Favor a Lower Oxidative Stress in an Intensity-Dependent Manner? Role of Nonenzymatic Antioxidants.

    PubMed

    Casuso, Rafael A; Aragón-Vela, Jerónimo; López-Contreras, Gracia; Gomes, Silvana N; Casals, Cristina; Barranco-Ruiz, Yaira; Mercadé, Jordi J; Huertas, Jesus R

    2017-03-01

    Casuso, Rafael A., Jerónimo Aragón-Vela, Gracia López-Contreras, Silvana N. Gomes, Cristina Casals, Yaira Barranco-Ruiz, Jordi J. Mercadé, and Jesus R. Huertas. Does swimming at a moderate altitude favor a lower oxidative stress in an intensity-dependent manner? Role of nonenzymatic antioxidants. High-Alt Med Biol. 18:46-55, 2017.-we aimed to describe oxidative damage and enzymatic and nonenzymatic antioxidant responses to swimming at different intensities in hypoxia. We recruited 12 highly experienced swimmers who have been involved in competitive swimming for at least 9 years. They performed a total of six swimming sessions carried out at low (LOW), moderate (MOD), or high (HIGH) intensity at low altitude (630 m) and at 2320 m above sea level. Blood samples were collected before the session (Pre), after the cool down (Post), and after 15 minutes of recovery (Rec). Blood lactate (BL) and heart rate were recorded throughout the main part of the session. Average velocities did not change between hypoxia and normoxia. We found a higher BL in response to MOD intensity in hypoxia. Plasmatic hydroperoxide level decreased at all intensities when swimming in hypoxia. This effect coincided with a lower glutation peroxidase activity and a marked mobilization of the circulating levels of α-tocopherol and coenzyme Q10 in an intensity-dependent manner. Our results suggest that, regardless of the intensity, no oxidative damage is found in response to hypoxic swimming in well-trained swimmers. Indeed, swimmers show a highly efficient antioxidant system by stimulating the mobilization of nonenzymatic antioxidants.

  19. Economical crisis detected from space: Trends in air quality of Athens in Greece

    NASA Astrophysics Data System (ADS)

    Vrekoussis, Mihalis; Richter, Andreas; Hilboll, Andreas; Burrows, John P.; Zerefos, Christos; Gerasopoulos, Evangelos; Lelieveld, Jos; Barrie, Leonard; Mihalopoulos, Nikos

    2013-04-01

    Data from three satellite spectrometers (SCIAMACHY, GOME2 and OMI) have been analyzed together with a number of economic metrics to investigate the impact of the economic crisis (from 2008 onward) on air quality over Greece, and Athens in particular. Athens is a heavily polluted city due to the extensive number of registered vehicles, the presence of industrial regions close to the city, the complex topography of the area favouring pollutant accumulation, the intense photochemical processes favoured by high temperature and insolation and the reception of transboundary pollution. The multiannual analysis shows a significant 30-40% reduction of primary gaseous pollutants in the form of NO2 tropospheric columnar densities observed over Athens, during the economic recession period, indicating large reductions in pollutant emissions. This decline is further supported by surface measurements of atmospheric NO2 mixing ratios. Additionally, the declining local concentrations of NO, CO, SO2 are associated with an increase in ozone due to reduced titration by NO. In particular, regression analysis revealed that the reduction of NO2 (0.3±0.2 ppbv y-1) and SO2 (0.2±0.1ppbv y-1) during the period 2000-2007, significantly accelerated during the economic crisis period (from 2008 onward), reaching 2.3±0.2 ppbv y-1 and 0.7±0.1 ppbv y-1, respectively. The strong correlations between pollutant concentrations and economic indicators show that economic recession has resulted in proportionally lower levels of pollutants not only in Athens but also in large parts of Greece.

  20. Satellite Detection of Smoke Aerosols Over a Snow/Ice Surface by TOMS

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina; Herman, Jay R.; Gleason, J. F.; Torres, O.; Seftor, C. J.

    1998-01-01

    The use of TOMS (Total Ozone Mapping Spectrometer) satellite data demonstrates the recently developed technique of using satellite UV radiance measurements to detect absorbing tropospheric aerosols is effective over snow/ice surfaces. Instead of the traditional single wavelength (visible or infrared) method of measuring tropospheric aerosols, this method takes advantage of the wavelength dependent reduction in the backscattered radiance due to the presence of absorbing aerosols over snow/ice surfaces. An example of the resulting aerosol distribution derived from TOMS data is shown for an August 1998 event in which smoke generated by Canadian forest fires drifts over and across Greenland. As the smoke plume moved over Greenland, the TOMS observed 380 nm reflectivity over the snow/ice surface dropped drastically from 90-100% down to 30-40%. To study the effects of this smoke plume in both the UV and visible regions of the spectrum, we compared a smoke-laden spectrum taken over Greenland by the high spectral resolution (300 to 800 nm) GOME instrument with one that is aerosol-free. We also discuss the results of modeling the darkening effects of various types of absorbing aerosols over snow/ice surfaces using a radiative transfer code. Finally, we investigated the history of such events by looking at the nearly twenty year record of TOMS aerosol index measurements and found that there is a large interannual variability in the amount of smoke aerosols observed over Greenland. This information will be available for studies of radiation and transport properties in the Arctic.

  1. Variability of trace gas concentrations over Asian region: satellite observations vs model

    NASA Astrophysics Data System (ADS)

    Sheel, Varun; Richter, Andreas; Srivastava, Shuchita; Lal, Shyam

    2012-07-01

    Nitrogen dioxide (NO_2) and Carbon Monoxide (CO) play a key role in the chemistry of the tropospheric ozone and are emitted mainly by anthropogenic processes. These emissions have been increasing over Asia over the past few years due to rapid economic growth and yet there are very few systematic ground based observations of these species over this region. We have analysed ten years of data from space borne instruments: Global Ozone Monitoring Experiment (GOME), SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) and Measurements of Pollution in the Troposphere (MOPITT), which have been measuring the tropospheric abundance of these trace gases. We have examined trends over the period 1996-2008 in NO_2 and CO over a few Indian regions where high economic growth in the present decade is likely to see increased emissions for these species. However, even the highest growth rate of these species seen in the present study, is less when compared with similar polluted regions of China, where a much more rapid increase has been observed. In order to understand the trends and variability in atmospheric trace gas concentrations, one must take into account changes in emissions and transport. Only by assessing the relevance of each of these factors will it be possible to predict future changes with reasonable confidence. To this effect we have used a global chemical transport model, MOZART, to simulate concentrations of NO_2 and CO using the POET (European) and REAS (Asian) emission inventories. These are compared with satellite measurements to study seasonal variations and the discrepancies are discussed. The combined uncertainties of the emission inventory and retrieval of the satellite data could be contributing factors to the discrepancies. It may be thus worthwhile to develop emission inventories for India at a higher resolution to include local level activity data.

  2. Fast emission estimates in China and South Africa constrained by satellite observations

    NASA Astrophysics Data System (ADS)

    Mijling, Bas; van der A, Ronald

    2013-04-01

    Emission inventories of air pollutants are crucial information for policy makers and form important input data for air quality models. Unfortunately, bottom-up emission inventories, compiled from large quantities of statistical data, are easily outdated for emerging economies such as China and South Africa, where rapid economic growth change emissions accordingly. Alternatively, top-down emission estimates from satellite observations of air constituents have important advantages of being spatial consistent, having high temporal resolution, and enabling emission updates shortly after the satellite data become available. However, constraining emissions from observations of concentrations is computationally challenging. Within the GlobEmission project (part of the Data User Element programme of ESA) a new algorithm has been developed, specifically designed for fast daily emission estimates of short-lived atmospheric species on a mesoscopic scale (0.25 × 0.25 degree) from satellite observations of column concentrations. The algorithm needs only one forward model run from a chemical transport model to calculate the sensitivity of concentration to emission, using trajectory analysis to account for transport away from the source. By using a Kalman filter in the inverse step, optimal use of the a priori knowledge and the newly observed data is made. We apply the algorithm for NOx emission estimates in East China and South Africa, using the CHIMERE chemical transport model together with tropospheric NO2 column retrievals of the OMI and GOME-2 satellite instruments. The observations are used to construct a monthly emission time series, which reveal important emission trends such as the emission reduction measures during the Beijing Olympic Games, and the impact and recovery from the global economic crisis. The algorithm is also able to detect emerging sources (e.g. new power plants) and improve emission information for areas where proxy data are not or badly known (e

  3. Error sources in the retrieval of aerosol information over bright surfaces from satellite measurements in the oxygen A band

    NASA Astrophysics Data System (ADS)

    Nanda, Swadhin; de Graaf, Martin; Sneep, Maarten; de Haan, Johan F.; Stammes, Piet; Sanders, Abram F. J.; Tuinder, Olaf; Pepijn Veefkind, J.; Levelt, Pieternel F.

    2018-01-01

    Retrieving aerosol optical thickness and aerosol layer height over a bright surface from measured top-of-atmosphere reflectance spectrum in the oxygen A band is known to be challenging, often resulting in large errors. In certain atmospheric conditions and viewing geometries, a loss of sensitivity to aerosol optical thickness has been reported in the literature. This loss of sensitivity has been attributed to a phenomenon known as critical surface albedo regime, which is a range of surface albedos for which the top-of-atmosphere reflectance has minimal sensitivity to aerosol optical thickness. This paper extends the concept of critical surface albedo for aerosol layer height retrievals in the oxygen A band, and discusses its implications. The underlying physics are introduced by analysing the top-of-atmosphere reflectance spectrum as a sum of atmospheric path contribution and surface contribution, obtained using a radiative transfer model. Furthermore, error analysis of an aerosol layer height retrieval algorithm is conducted over dark and bright surfaces to show the dependence on surface reflectance. The analysis shows that the derivative with respect to aerosol layer height of the atmospheric path contribution to the top-of-atmosphere reflectance is opposite in sign to that of the surface contribution - an increase in surface brightness results in a decrease in information content. In the case of aerosol optical thickness, these derivatives are anti-correlated, leading to large retrieval errors in high surface albedo regimes. The consequence of this anti-correlation is demonstrated with measured spectra in the oxygen A band from the GOME-2 instrument on board the Metop-A satellite over the 2010 Russian wildfires incident.

  4. Satellite chlorophyll fluorescence measurements reveal large-scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests.

    PubMed

    Walther, Sophia; Voigt, Maximilian; Thum, Tea; Gonsamo, Alemu; Zhang, Yongguang; Köhler, Philipp; Jung, Martin; Varlagin, Andrej; Guanter, Luis

    2016-09-01

    Mid-to-high latitude forests play an important role in the terrestrial carbon cycle, but the representation of photosynthesis in boreal forests by current modelling and observational methods is still challenging. In particular, the applicability of existing satellite-based proxies of greenness to indicate photosynthetic activity is hindered by small annual changes in green biomass of the often evergreen tree population and by the confounding effects of background materials such as snow. As an alternative, satellite measurements of sun-induced chlorophyll fluorescence (SIF) can be used as a direct proxy of photosynthetic activity. In this study, the start and end of the photosynthetically active season of the main boreal forests are analysed using spaceborne SIF measurements retrieved from the GOME-2 instrument and compared to that of green biomass, proxied by vegetation indices including the Enhanced Vegetation Index (EVI) derived from MODIS data. We find that photosynthesis and greenness show a similar seasonality in deciduous forests. In high-latitude evergreen needleleaf forests, however, the length of the photosynthetically active period indicated by SIF is up to 6 weeks longer than the green biomass changing period proxied by EVI, with SIF showing a start-of-season of approximately 1 month earlier than EVI. On average, the photosynthetic spring recovery as signalled by SIF occurs as soon as air temperatures exceed the freezing point (2-3 °C) and when the snow on the ground has not yet completely melted. These findings are supported by model data of gross primary production and a number of other studies which evaluated in situ observations of CO2 fluxes, meteorology and the physiological state of the needles. Our results demonstrate the sensitivity of space-based SIF measurements to light-use efficiency of boreal forests and their potential for an unbiased detection of photosynthetic activity even under the challenging conditions interposed by evergreen

  5. The total ozone and UV solar radiation over Stara Zagora, Bulgaria

    NASA Astrophysics Data System (ADS)

    Mendeva, B.; Gogosheva, Ts.; Petkov, B.; Krastev, D.

    Direct ground-based UV measurements and the total ozone content (TOC) over Stara Zagora, Bulgaria are presented. The observations are conducted by a scanning spectrophotometer, which measures the direct solar radiation in the range 290 - 360 nm with 1 nm resolution. For the time period 1998 -- 2003 the TOC data show seasonal variations, typical for the middle latitudes -- maximum in the spring and minimum in the autumn. The comparison of these TOC ground-based data to TOC satellite-borne data from the Global Ozone Monitoring Experiment (GOME) shows a seasonal dependence of the differences between the ground-based and satellite data. The relation between the UV radiation and TOC is investigated. Clear negative relationship is recognized between the total ozone and the irradiance of the wavelength 305 nm. The opposition of the two variables is significant ( r = - 0,62 ± 0,18) at 98 % confidence level. Yet, for 325 nm it is almost independent with the total ozone. The dependence of the UV-B radiation on the solar zenith angle at given TOC is also analyzed. A decrease of all wavelengths intensities with increase of the solar zenith angle is obtained but with different rate for each of them. The direct sun UV doses for some specific biological effects (erythema and eyes) are obtained as the integral in the wavelength interval 290-330 nm of the measured UV solar spectrum, weighted with an action spectrum, typical for each effect. The estimation of the radiation amplification factor RAF shows that the ozone reduction by 1% increases the erythemal dose by 2,3 %.The eye-damaging doses are more influenced by the TOC changes and in this case RAF=-2,7%. The amount of these biological doses is in a direct ratio with the solar altitude over the horizon. This dependence is more markedly expressed at lower total ozone content in the atmosphere.

  6. Commentary on the special issue on the adolescent brain: Adolescence, trajectories, and the importance of prevention.

    PubMed

    Andersen, Susan L

    2016-11-01

    Adolescence as highlighted in this special issue is a period of tremendous growth, synaptic exuberance, and plasticity, but also a period for the emergence of mental illness and addiction. This commentary aims to stimulate research on prevention science to reduce the impact of early life events that often manifest during adolescence. By promoting a better understanding of what creates a normal and abnormal trajectory, the reviews by van Duijvenvoorde et al., Kilford et al., Lichenstein et al., and Tottenham and Galvan in this special issue comprehensively describe how the adolescent brain develops under typical conditions and how this process can go awry in humans. Preclinical reviews also within this issue describe how adolescents have prolonged extinction periods to maximize learning about their environment (Baker et al.), whereas Schulz and Sisk focus on the importance of puberty and how it interacts with stress (Romeo). Caballero and Tseng then set the stage of describing the neural circuitry that is often central to these changes and psychopathology. Factors that affect the mis-wiring of the brain for illness, including prenatal exposure to anti-mitotic agents (Gomes et al.) and early life stress and inflammation (Schwarz and Brenhouse), are included as examples of how exposure to early adversity manifests. These reviews are synthesized and show how information from the maturational stages that precede or occur during adolescence is likely to hold the key towards optimizing development to produce an adolescent and adult that is resilient and well adapted to their environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards: Part II. Validation of satellite-derived Volcanic Sulphur Dioxide Levels.

    NASA Astrophysics Data System (ADS)

    Koukouli, MariLiza; Balis, Dimitris; Dimopoulos, Spiros; Clarisse, Lieven; Carboni, Elisa; Hedelt, Pascal; Spinetti, Claudia; Theys, Nicolas; Tampellini, Lucia; Zehner, Claus

    2014-05-01

    The eruption of the Icelandic volcano Eyjafjallajökull in the spring of 2010 turned the attention of both the public and the scientific community to the susceptibility of the European airspace to the outflows of large volcanic eruptions. The ash-rich plume from Eyjafjallajökull drifted towards Europe and caused major disruptions of European air traffic for several weeks affecting the everyday life of millions of people and with a strong economic impact. This unparalleled situation revealed limitations in the decision making process due to the lack of information on the tolerance to ash of commercial aircraft engines as well as limitations in the ash monitoring and prediction capabilities. The European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards, was introduced to facilitate the development of an optimal End-to-End System for Volcanic Ash Plume Monitoring and Prediction. This system is based on comprehensive satellite-derived ash plume and sulphur dioxide [SO2] level estimates, as well as a widespread validation using supplementary satellite, aircraft and ground-based measurements. The validation of volcanic SO2 levels extracted from the sensors GOME-2/MetopA and IASI/MetopA are shown here with emphasis on the total column observed right before, during and after the Eyjafjallajökull 2010 eruptions. Co-located ground-based Brewer Spectrophotometer data extracted from the World Ozone and Ultraviolet Radiation Data Centre, WOUDC, were compared to the different satellite estimates. The findings are presented at length, alongside a comprehensive discussion of future scenarios.

  8. Prediction of Gross Primary Production during the Drought and Normal Years over the US Using Solar-Induced Chlorophyll Fluorescence

    NASA Astrophysics Data System (ADS)

    Halubok, M.; Yang, Z. L.

    2016-12-01

    This study investigates how gross primary production (GPP) estimates can be improved with the use of solar-induced chlorophyll fluorescence (SIF) and presents an effort to produce GPP predictions based on the interdependence between SIF, precipitation, soil moisture and GPP using Global Ozone Monitoring Experiment-2 (GOME-2), Tropical Rainfall Measuring Mission (TRMM), European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM) datasets and FLUXNET observations. We found that considering the relationships between SIF, precipitation and soil moisture, isolating SIF-GPP relationships for different plant functional types (PFTs), and using precipitation and soil moisture conditions pertinent to the continental US provides the most accurate GPP estimates over the Great Plains and Texas. We found that there exists a lag between a precipitation event and corresponding fluorescence levels, ranging from about 2 weeks for grasses to a month for crops. Using these lead-lag relationships, we estimate GPP using SIF, precipitation and soil moisture data for two different PFTs (C3 non-arctic grass and crop) over the US applying the multiple linear regression technique. GPP values estimated from our lead-lag based SIF show the closest possible match with the observational data from the FLUXNET stations. During the drought 2011 year over Texas, our GPP values show a decrease by 100 gC/m2/month as compared to the reference year of 2007. In 2012 (drought year over the Great Plains), we observe significant decrease in GPP, especially in the area of high production (>500 gC/m2/month) that is reduced in July and August 2012. Hence, estimating GPP using specific SIF-GPP relationships, considering the differences in biomes and their interactions with precipitation and soil moisture pertinent to a certain region can detect the drought trends and produce reasonable GPP estimates. Thus, this simple and computationally efficient method based on derived linear equations can be

  9. Intercomparison of spectral irradiance measurements and provision of alternative radiation scheme for CCMs of middle atmosphere

    NASA Astrophysics Data System (ADS)

    Pagaran, Joseph; Weber, Mark; Burrows, John P.

    The Sun's radiative output (total solar irradiance or TSI) determines the thermal structure of the Earth's atmosphere. Its variability is a strong function of wavelength, which drives the photochemistry and general circulation. Contributions to TSI variability from UV wavelengths below 400 nm, i.e. 0.227-day solar rotation or 0.1to be in the 40-60three decades of UV and about a decade of vis-IR observations. Significant progress in UV/vis-IR regions has been achieved with daily monitoring from SCIAMACHY aboard Envisat (ESA) in 2002 and by SIM aboard SORCE (NASA) about a year after. In this contribution, we intercompare SSI measurements from SCIAMACHY and SIM and RGB filters of SPM/VIRGO SoHO: same (a) day and (b) few 27-day time series of spectral measurements in both irradiance and integrated irradiance over selected wavelength intervals. Finally, we show how SSI measurements from GOME, SOLSTICE, in addition to SCIAMACHY and SIM, can be modeled together with solar proxies F10.7 cm, Mg II and sunspot index (PSI) to derive daily SSI variability in the period 1947-2008. The derived variabilities are currently being used as solar input to Bremen's 3D-CTM and are to be recommended as extended alternative to Berlin's FUBRaD radiation scheme. This proxy-based radiation scheme are compared with SATIRE, NRLSSI (or Lean et al.), SUSIM, SSAI (or DeLand et al), and SIP (or Solar2000) models. The use of realistic spectrally resolved solar input to CCMs is to better understand the effects of solar variability on chemistry and temperature in the middle atmosphere over several decades.

  10. Ozone and Aerosol Retrieval from Backscattered Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2012-01-01

    In this presentation we will discuss the techniques to estimate total column ozone and aerosol absorption optical depth from the measurements of back scattered ultraviolet (buv) radiation. The total ozone algorithm has been used to create a unique record of the ozone layer, spanning more than 3 decades, from a series of instruments (BUV, SBUV, TOMS, SBUV/2) flown on NASA, NOAA, Japanese and Russian satellites. We will discuss how this algorithm can be considered a generalization of the well-known Dobson/Brewer technique that has been used to process data from ground-based instruments for many decades, and how it differs from the DOAS techniques that have been used to estimate vertical column densities of a host of trace gases from data collected by GOME and SCIAMACHY instruments. The buv aerosol algorithm is most suitable for the detection of UV absorbing aerosols (smoke, desert dust, volcanic ash) and is the only technique that can detect aerosols embedded in clouds. This algorithm has been used to create a quarter century record of aerosol absorption optical depth using the buv data collected by a series of TOMS instruments. We will also discuss how the data from the OMI instrument launched on July 15, 2004 will be combined with data from MODIS and CALIPSO lidar data to enhance the accuracy and information content of satellite-derived aerosol measurements. The OMI and MODIS instruments are currently flying on EOS Aura and EOS Aqua satellites respectively, part of a constellation of satellites called the "A-train".

  11. Ozone and Aerosol Retrieval from Backscattered Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2004-01-01

    In this presentation we will discuss the techniques to estimate total column ozone and aerosol absorption optical depth from the measurements of backscattered ultraviolet (buv) radiation. The total ozone algorithm has been used to create a unique record of the ozone layer, spanning more than 3 decades, from a series of instruments (BUV, SBUV, TOMS, SBUV/2) flown on NASA, NOAA, Japanese and Russian satellites. We will discuss how this algorithm can be considered a generalization of the well-known Dobson/Brewer technique that has been used to process data from ground-based instruments for many decades, and how it differs from the DOAS techniques that have been used to estimate vertical column densities of a host of trace gases from data collected by GOME and SCIAMACHY instruments. The BUV aerosol algorithm is most suitable for the detection of UV absorbing aerosols (smoke, desert dust, volcanic ash) and is the only technique that can detect aerosols embedded in clouds. This algorithm has been used to create a quarter century record of aerosol absorption optical depth using the BUV data collected by a series of TOMS instruments. We will also discuss how the data from the OM1 instrument launched on July 15,2004 will be combined with data from MODIS and CALIPSO lidar data to enhance the accuracy and information content of satellite-derived aerosol measurements. The OM1 and MODIS instruments are currently flying on EOS Aura and EOS Aqua satellites respectively, part of a constellation of satellites called the "A-train". The CALIPSO satellite is expected to join this constellation in mid 2005.

  12. On the Nature and Timing of Giant Planet Migration in the Solar System

    NASA Astrophysics Data System (ADS)

    Agnor, Craig B.

    2016-05-01

    Giant planet migration is a natural outcome of gravitational scattering and planet formation processes (Fernandez & Ip 1984). There is compelling evidence that the solar system's giant planets experienced large-scale migration involving close approaches between planets as well as smooth radial migration via planetesimal scattering. Aspects of giant planet migration have been invoked to explain many features of the outer solar system including the resonant structure of the Kuiper Belt (e.g., Malhotra 1993, Levison et al. 2008), the eccentricities of Jupiter and Saturn (Tsiganis et al. 2005, Morbidelli et al. 2009), the capture of Jupiter's Trojan companions (Morbidelli et al. 2005) and the capture of irregular planetary satellites (e.g., Nesvorny et al. 2007) to name a few. If this migration epoch occurred after the formation of the inner planets, then it may also explain the so-called lunar Late Heavy Bombardment (Gomes et al. 2005). This scenario necessarily requires coeval terrestrial and migrating giant planets. Recent N-body integrations exploring this issue have shown that giant planet migration may excite the terrestrial system via nodal and apsidal secular resonances (e.g., Brasser et al. 2013), may drive the terrestrial planets to crossing orbits (Kaib & Chambers 2016) or alternatively leave the inner solar system in a state closely resembling the observed one (Roig et al. 2016). The factors accounting for the large range of outcomes remain unclear. Using linear secular models and N-body simulations I am identifying and characterising the principal aspects of giant planet migration that excite the terrestrial planets' orbits. I will present these results and discuss how they inform the nature and timing of giant planet migration in the solar system.

  13. Modeling regional cropland GPP by empirically incorporating sun-induced chlorophyll fluorescence into a coupled photosynthesis-fluorescence model

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Guanter, L.; Van der Tol, C.; Joiner, J.; Berry, J. A.

    2015-12-01

    Global sun-induced chlorophyll fluorescence (SIF) retrievals are currently available from several satellites. SIF is intrinsically linked to photosynthesis, so the new data sets allow to link remotely-sensed vegetation parameters and the actual photosynthetic activity of plants. In this study, we used space measurements of SIF together with the Soil-Canopy Observation of Photosynthesis and Energy (SCOPE) balance model in order to simulate regional photosynthetic uptake of croplands in the US corn belt. SCOPE couples fluorescence and photosynthesis at leaf and canopy levels. To do this, we first retrieved a key parameter of photosynthesis model, the maximum rate of carboxylation (Vcmax), from field measurements of CO2 and water flux during 2007-2012 at some crop eddy covariance flux sites in the Midwestern US. Then we empirically calibrated Vcmax with apparent fluorescence yield which is SIF divided by PAR. SIF retrievals are from the European GOME-2 instrument onboard the MetOp-A platform. The resulting apparent fluorescence yield shows a stronger relationship with Vcmax during the growing season than widely-used vegetation index, EVI and NDVI. New seasonal and regional Vcmax maps were derived based on the calibration model for the cropland of the corn belt. The uncertainties of Vcmax were also estimated through Gaussian error propagation. With the newly derived Vcmax maps, we modeled regional cropland GPP during the growing season for the Midwestern USA, with meteorological data from MERRA reanalysis data and LAI from MODIS product (MCD15A2). The results show the improvement in the seasonal and spatial patterns of cropland productivity in comparisons with both flux tower and agricultural inventory data.

  14. Solar-induced Fluorescence as a Proxy for Canopy Photosynthesis in a Temperate Deciduous Forest: Comparisons between Observations and Model Results

    NASA Astrophysics Data System (ADS)

    Yang, X.; Lee, J. E.; Berry, J. A.; Tang, J.; Mustard, J. F.; Van der Tol, C.; Kellner, J. R.; Silva, C. E.

    2015-12-01

    Photosynthesis in the terrestrial ecosystems contributes to the largest carbon flux in the global carbon cycle. The use of solar-induced fluorescence (SIF) as a proxy of photosynthesis at the ecosystem scale (Gross Primary Production, GPP) is a critical emerging technology. Satellite measurements of SIF were found to be significantly correlated with GPP, and several ground campaigns suggested that SIF could improve the GPP estimation. However, it remains unclear to what extent this relationship is due to absorbed photosynthetically active radiation (APAR) and/or light use efficiency (LUE). In addition, models that simulate SIF have not been rigorously validated. Here we present the first time-series of near-surface measurement of canopy-scale SIF at 760nm in temperate deciduous forests during year 2013-2014. SIF correlated with GPP estimated with eddy covariance at diurnal and seasonal scales (r2=0.82 and 0.73, respectively), as well as with APAR diurnally and seasonally (r2=0.90 and 0.80, respectively). SIF/APAR is significantly positively correlated with LUE and is higher during cloudy days than sunny days. Weekly tower-based SIF agreed with SIF from GOME-2 (The Global Ozone Monitoring Experiment-2, r2 = 0.82). We further compared SIF observations with those simulated by Soil Canopy Observation Photochemistry and Energy fluxes (SCOPE) model. We found that key parameters in SCOPE including Vcmax, LAI, chlorophyll content, and viewing angles determine the agreement between observations and model. Our results provide support to the use of SIF to estimate canopy photosynthetic activities, and present a framework of validating fluorescence simulated by canopy radiative transfer models.

  15. Simulating Canopy-Level Solar Induced Fluorescence with CLM-SIF 4.5 at a Sub-Alpine Conifer Forest in the Colorado Rockies

    NASA Astrophysics Data System (ADS)

    Raczka, B. M.; Bowling, D. R.; Lin, J. C.; Lee, J. E.; Yang, X.; Duarte, H.; Zuromski, L.

    2017-12-01

    Forests of the Western United States are prone to drought, temperature extremes, forest fires and insect infestation. These disturbance render carbon stocks and land-atmosphere carbon exchanges highly variable and vulnerable to change. Regional estimates of carbon exchange from terrestrial ecosystem models are challenged, in part, by a lack of net ecosystem exchange observations (e.g. flux towers) due to the complex mountainous terrain. Alternatively, carbon estimates based on light use efficiency models that depend upon remotely-sensed greenness indices are challenged due to a weak relationship with GPP during the winter season. Recent advances in the retrieval of remotely sensed solar induced fluorescence (SIF) have demonstrated a strong seasonal relationship between GPP and SIF for deciduous, grass and, to a lesser extent, conifer species. This provides an important opportunity to use remotely-sensed SIF to calibrate terrestrial ecosystem models providing a more accurate regional representation of biomass and carbon exchange across mountainous terrain. Here we incorporate both leaf-level fluorescence and leaf-to-canopy radiative transfer represented by the SCOPE model into CLM 4.5 (CLM-SIF). We simulate canopy level fluorescence at a sub-alpine forest site (Niwot Ridge, Colorado) and test whether these simulations reproduce remotely-sensed SIF from a satellite (GOME2). We found that the average peak SIF during the growing season (yrs 2007-2013) was similar between the model and satellite observations (within 15%); however, simulated SIF during the winter season was significantly greater than the satellite observations (5x higher). This implies that the fluorescence yield is overestimated by the model during the winter season. It is important that the modeled representation of seasonal fluorescence yield is improved to provide an accurate seasonal representation of SIF across the Western United States.

  16. Science verification of operational aerosol and cloud products for TROPOMI on Sentinel-5 precursor

    NASA Astrophysics Data System (ADS)

    Lelli, Luca; Gimeno-Garcia, Sebastian; Sanders, Abram; Sneep, Maarten; Rozanov, Vladimir V.; Kokhanvosky, Alexander A.; Loyola, Diego; Burrows, John P.

    2016-04-01

    With the approaching launch of the Sentinel-5 precursor (S-5P) satellite, scheduled by mid 2016, one preparatory task of the L2 working group (composed by the Institute of Environmental Physics IUP Bremen, the Royal Netherlands Meteorological Institute KNMI De Bilt, and the German Aerospace Center DLR Oberpfaffenhofen) has been the assessment of biases among aerosol and cloud products, that are going to be inferred by the respective algorithms from measurements of the platform's payload TROPOspheric Monitoring Instrument (TROPOMI). The instrument will measure terrestrial radiance with varying moderate spectral resolutions from the ultraviolet throughout the shortwave infrared. Specifically, all the operational and verification algorithms involved in this comparison exploit the sensitivity of molecular oxygen absorption (the A-band, 755-775 nm, with a resolution of 0.54 nm) to changes in optical and geometrical parameters of tropospheric scattering layers. Therefore, aerosol layer height (ALH) and thickness (AOT), cloud top height (CTH), thickness (COT) and albedo (CA) are the targeted properties. First, the verification of these properties has been accomplished upon synchronisation of the respective forward radiative transfer models for a variety of atmospheric scenarios. Then, biases against independent techniques have been evaluated with real measurements of selected GOME-2 orbits. Global seasonal bias assessment has been carried out for CTH, CA and COT, whereas the verification of ALH and AOT is based on the analysis of the ash plume emitted by the icelandic volcanic eruption Eyjafjallajökull in May 2010 and selected dust scenes off the Saharan west coast sensed by SCIAMACHY in year 2009.

  17. Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn

    NASA Astrophysics Data System (ADS)

    Lin, J.-T.; McElroy, M. B.

    2011-08-01

    Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27-33 % in 12-month mean VCD of NO2 prior to the downturn, consistent with an increase of 49 % in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005-2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20 % from January 2008 to January 2009, close to the reduction of 18 % in TPG that occurred over the same interval. A combination of three independent approaches indicates that the economic downturn was responsible for a reduction in emissions by 9-11 % in January 2009 with an additional decrease of 10 % attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year; errors in the estimate are most likely less than 3.4 %.

  18. Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn

    NASA Astrophysics Data System (ADS)

    Lin, J.-T.; McElroy, M. B.

    2011-01-01

    Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27-33% in annual mean VCD of NO2 prior to the downturn, consistent with an increase of 49% in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005-2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20% from January 2008 to January 2009, close to the reduction of 18% in TPG that occurred over the same interval. A combination of three relatively independent approaches indicates that the economic downturn was responsible for a~reduction in emissions by 9-11% in January 2009 with an additional decrease of 10% attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year.

  19. Anthropogenic Sulphur Dioxide Load over China as Observed from Different Satellite Sensors

    NASA Technical Reports Server (NTRS)

    Koukouli, M. E.; Balis, D. S.; Johannes Van Der A, Ronald; Theys, N.; Hedelt, P.; Richter, A.; Krotkov, N.; Li, Can; Taylor, M.

    2016-01-01

    China, with its rapid economic growth and immense exporting power, has been the focus of many studies during this previous decade quantifying its increasing emissions contribution to the Earth's atmosphere. With a population slowly shifting towards enlarged power and purchasing needs, the ceaseless inauguration of new power plants, smelters, refineries and industrial parks leads infallibly to increases in sulphur dioxide, SO2, emissions. The recent capability of next generation algorithms as well as new space-borne instruments to detect anthropogenic SO2 loads has enabled a fast advancement in this field. In the following work, algorithms providing total SO2 columns over China based on SCIAMACHY/Envisat, OMI/Aura and GOME2/MetopA observations are presented. The need for post-processing and gridding of the SO2 fields is further revealed in this work, following the path of previous publications. Further, it is demonstrated that the usage of appropriate statistical tools permits studying parts of the datasets typically excluded, such as the winter months loads. Focusing on actual point sources, such as megacities and known power plant locations, instead of entire provinces, monthly mean time series have been examined in detail. The sharp decline in SO2 emissions in more than 90% - 95% of the locations studied confirms the recent implementation of government desulphurisation legislation; however, locations with increases, even for the previous five years, are also identified. These belong to provinces with emerging economies which are in haste to install power plants and are possibly viewed leniently by the authorities, in favour of growth. The SO2 load seasonality has also been examined in detail with a novel mathematical tool, with 70% of the point sources having a statistically significant annual cycle with highs in winter and lows in summer, following the heating requirements of the Chinese population.

  20. Solar Spectral Irradiance Changes During Cycle 24

    NASA Technical Reports Server (NTRS)

    Marchenko, Sergey; Deland, Matthew

    2014-01-01

    We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the solar spectral irradiance (SSI) in the 265-500 nm spectral range. During solar Cycle 24, in the relatively line-free regions the SSI changed by approximately 0.6% +/- 0.2% around 265 nm. These changes gradually diminish to 0.15% +/- 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the solar "continuum." Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the solar "continuum," the variability of spectral lines also decreases toward longer wavelengths. The long-term solar cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at lambda approximately or greater than 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the solar data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.

  1. Applications of OMI Tropospheric NO(Sub 2) Data: Air Quality Trends in the US and Lightning NO(x) Source Strength

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth; Prados, Ana; Bucsela, Eric

    2010-01-01

    This talk will be presented in two parts: 1) an analysis of tropospheric column NO2 trends in the eastern half of the United States over the period 2005 to 2009 and 2) estimation of lightning NO(x) production rates based on OMI observations and lightning flash rate data. The air quality trends in the eastern US will be determined for specific subregions using tropospheric column NO2 data from OMI for 2005 through 2008 and from GOME-2 for 2007 through 2009. This period is characterized by significant NO(x) emission reductions at power plants within most of this region. The air quality trends will be compared with those estimated from continuous emission monitoring data from the power plants compiled by the US Environmental Protection Agency. OMI NO2 data have also been used to estimate lightning NOx production per flash in selected storms near Costa Rica and Panama during the 2007 NASA TC4 field campaign and over the continental US, Gulf of Mexico, and western Atlantic during the summers of 2005 and 2006. The lightning signal is extracted from the OMI data through a custom retrieval in which an NO2 profile representative of convective outflow is used in the airmass factor calculation and the background NO2 column is subtracted from the tropospheric column. When combined with NO(x)/NO2 ratios from the NASA GMT model and observed flash rates, the resulting estimates of NO(x) production per flash are comparable to those estimated obtained from analyses of aircraft data and cloud-resolving modeling.

  2. Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

    NASA Technical Reports Server (NTRS)

    Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.; hide

    2012-01-01

    We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by <1-8 nmol/mol (6.5% globally), with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4 %. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT) to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  3. Solar-Induced Plant Fluorescence as seen from space-borne instruments

    NASA Astrophysics Data System (ADS)

    Khosravi, Narges; Vountas, Marco; Rozanov, Vladimir V.; Bracher, Astrid; Burrows, John P.

    2015-04-01

    Solar induced chlorophyll fluorescence (SIF) retrieval can be linked to vegetation correspondence to global carbon cycle, and could be useful for terrestrial carbon budget assessment as well as agricultural and environmental purposes. There have been several investigations using space-borne SIF retrieval due to its good spatial coverage and time efficiency. These methods are mainly based on the fact that plant leaves absorb sunlight mainly within the visible spectral range and use it either for photosynthesis and/or release it as heat or fluorescence (in red and Near Infra Red, NIR, spectral region) back to the atmosphere. As a result, SIF can be considered an additive signal on top of the ground reflectance reaching TOA (Top Of the Atmosphere). Chlorophyll fluorescence is mainly emitted in the spectral range of red to the near-infrared with a pronounced peak at 690 and another at 740 nm. Although it is a very weak signal and two orders of magnitude smaller than the received radiance at TOA, it is feasible to retrieve it within spectral wavelength windows in the NIR. We developed a novel SIF retrieval method based on a modeled assumption of the emitted fluorescence spectrum at canopy level as it would be seen at TOA. The application of it to 10 years of SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY) data showed promising results. Comparing our SIF retrieval with results from other studies showed that SIF values of our retrieval are in a general agreement with them. With some variations. As there is no validated SIF retrieval, it is difficult to judge the retrieval quality. Our approach is of generic nature and therefore, could be applied to other data sets as well. Hence, the method is being applied on GOME-2 level 1 data, as the instrument has a better spatial resolution (in the wavelength range needed) and a better global coverage.

  4. Recent developments and future directions in the monitoring of terrestrial sun-induced chlorophyll fluorescence from space

    NASA Astrophysics Data System (ADS)

    Guanter, L.

    2017-12-01

    Sun-induced chlorophyll fluorescence (SIF) is an electromagnetic signal emitted by the chlorophyll-a of assimilating plants in the 650-850 nm spectral range. The SIF emission has a mechanistic link to photosynthesis and responds instantaneously to perturbations in environmental conditions such as light and water stress, which makes it a powerful proxy for plants' photosynthetic activity. Global measurements of SIF from space have been available since late 2011 from four different atmospheric satellite missions (chronologically, GOSAT, SCIAMACHY, GOME-2 and OCO-2). The potential of the derived SIF data sets to represent the photosynthetic activity of different ecosystems, including large crop belts worldwide, the Amazon rainforest and boreal evergreen forests has been demonstrated in the relatively short life-time of global SIF data. Despite the demonstrated potential of SIF data as a proxy for global terrestrial gross primary production, current observations are partly hampered by a coarse spatial resolution or the lack of spatial coverage. For this reason, great expectations are put on the upcoming TROPOMI instrument onboard the Copernicus' Sentinel 5-Precursor mission to be launched by mid-end of 2017. TROPOMI will provide daily global coverage with a spatial resolution between 3 and 7 km and continuous spectral coverage of the visible and near-infrared part of the spectrum. The recent selection of FLEX as the ESA Earth Explorer 8 to be launched around 2022 and several upcoming geostationary missions (TEMPO, Sentinel-4 and GeoCARB, covering Europe and the Americas) with potential for SIF retrievals complete an exciting near-future scenario for the monitoring of SIF from space. In this contribution, we will provide an overview of recent developments in the global monitoring of SIF and will introduce the near-future observational scenario with especial emphasis on TROPOMI and the geostationary missions to be launched in the coming years.

  5. Cross-cultural variation in the association between family's socioeconomic status and adolescent alcohol use.

    PubMed

    Gomes de Matos, Elena; Kraus, Ludwig; Hannemann, Tessa-Virginia; Soellner, Renate; Piontek, Daniela

    2017-11-01

    This study estimates cross-country variation in socioeconomic disparities in adolescent alcohol use and identifies country-level characteristics associated with these disparities. The association between socioeconomic status (family wealth and parental education) and alcohol use (lifetime use and episodic heavy drinking) of 15- to 16-year-olds from 32 European countries was investigated. Country-level characteristics were national income, income inequality and per capita alcohol consumption. Multilevel modelling was applied. Across countries, lifetime use was lower in wealthy than in less wealthy families (odds ratio [OR] (girls)  = 0.95, OR (boys)  = 0.94). The risk of episodic heavy drinking, in contrast, was higher for children from wealthier families (OR (girls)  = 1.04, OR (boys)  = 1.08) and lower when parents were highly educated (ORs = 0.95-0.98). Socioeconomic disparities varied substantially between countries. National wealth and income inequality were associated with cross-country variation of disparities in lifetime use in few comparisons, such that among girls, the (negative) effect of family wealth was greatest in countries with unequally distributed income (OR = 0.86). Among boys, the (negative) effect of family wealth was greatest in low-income countries (OR = 1.00), and the (positive) effect of mothers' education was greatest in countries with high income inequality (OR = 1.11). Socioeconomic disparities in adolescent alcohol use vary across European countries. Broad country-level indicators can explain this variation only to a limited extent, but results point towards slightly greater socioeconomic disparities in drinking in countries of low national income and countries with a high income inequality. [Gomes de Matos E, Kraus L, Hannemann T-V, Soellner R, Piontek D. Cross-cultural variation in the association between family's socioeconomic status and adolescent alcohol use. © 2017 Australasian Professional Society on Alcohol and

  6. Mapping the Distribution of Wildfire Fuels Using AVIRIS in the Santa Monica Mountains

    NASA Technical Reports Server (NTRS)

    Roberts, Dar; Gardner, M.; Regelbrugge, J.; Pedreros, D.; Ustin, S.

    1998-01-01

    Catastrophic wildfires, such as the 1990 Painted Cave Fire in Santa Barbara or Oakland fire of 1991, attest to the destructive potential of fire in the wildland/urban interface. For example, during the Painted Cave Fire, 673 structures were consumed over a period of only six hours at an estimated cost of 250 million dollars (Gomes et al., 1993). One of the primary sources of fuels is chaparral, which consists of plant species that are adapted to frequent fires and may actually promote its ignition and spread of through volatile organic compounds in foliage. As one of the most widely distributed plant communities in Southern California, and one of the most common vegetation types along the wildland urban interface, chaparral represents one of the greatest sources of wildfire hazard in the region. An ongoing NASA funded research project was initiated in 1994 to study the potential of AVIRIS for mapping wildfire fuel properties in Southern California chaparral. The project was initiated in the Santa Monica Mountains, an east-west trending range in western Los Angeles County that has experienced extremely high fire frequencies over the past 70 years. The Santa Monica Mountains were selected because they exemplify many of the problems facing the southwest, forming a complex mosaic of land ownership intermixed with a diversity of chaparral age classes and fuel loads. Furthermore, the area has a wide diversity of chaparral community types and a rich background in supporting geographic information including fire history, soils and topography. Recent fires in the Santa Monica Mountains, including several in 1993 and the Calabasas fire of 1996 attest to the active fire regime present in the area. The long term objectives of this project are to improve existing maps of wildland fuel properties in the area, link AVIRIS derived products to fuel models under development for the region, then predict fire hazard through models that simulate fire spread. In this paper, we describe

  7. SCIAMACHY: The new Level 0-1 Processor

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Günter; Slijkhuis, Sander; Aberle, Bernd; Sherbakov, Denis; Meringer, Markus; Noel, Stefan; Bramstedt, Klaus; Liebing, Patricia; Bovensmann, Heinrich; Snel, Ralph; Krijger, Mathijs; van Hees, Richard; van der Meer, Pieter; Lerot, Christophe; Dehn, Angelika; Fehr, Thorsten

    2016-04-01

    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) is a scanning nadir and limb spectrometer covering the wavelength range from 212 nm to 2386 nm in 8 channels. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002 on the ENVISAT platform. After the platform failure in April 2012, SCIAMACHY is now in the postprocessing phase F. SCIAMACHYs originally specified in-orbit lifetime was double the planned lifetime. SCIAMACHY was designed to measure column densities and vertical profiles of trace gas species in the mesosphere, in the stratosphere and in the troposphere (Bovensmann et al., 1999). It can detect O3 , H2CO, SO2 , BrO, OClO, NO2 , H2 O, CO, CO2 , CH4 , N2 O , O2 , (O2)2 and can provide information about aerosols and clouds. The operational processing of SCIAMACHY is split into Level 0-1 processing (essentially providing calibrated radiances) and Level 1-2 processing providing geophysical products. The operational Level 0-1 processor has been completely re-coded and embedded in a newly developed framework that speeds up processing considerably. Currently Version 9 of the Level 0-1 processor is implemented. It will include - An updated degradation correction - Several improvements in the SWIR spectral range like a better dark correction, an improved dead & bad pixel characterisation and an improved spectral calibration - Improvements to the polarisation correction algorithm - Improvements to the geolocation by a better pointing characterisation Additionally a new format for the Level 1b and Level 1c will be implemented. The version 9 products will be available in netCDF version 4 that is aligned with the formats of the GOME-1 and Sentinel missions. We will present the first results of the new Level 0-1 processing in this paper.

  8. Comparison of linear measurements between CBCT orthogonally synthesized cephalograms and conventional cephalograms

    PubMed Central

    Yang, S; Liu, D G

    2014-01-01

    Objectives: The purposes of the study are to investigate the consistency of linear measurements between CBCT orthogonally synthesized cephalograms and conventional cephalograms and to evaluate the influence of different magnifications on these comparisons based on a simulation algorithm. Methods: Conventional cephalograms and CBCT scans were taken on 12 dry skulls with spherical metal markers. Orthogonally synthesized cephalograms were created from CBCT data. Linear parameters on both cephalograms were measured via Photoshop CS v. 5.0 (Adobe® Systems, San Jose, CA), named measurement group (MG). Bland–Altman analysis was utilized to assess the agreement of two imaging modalities. Reproducibility was investigated using paired t-test. By a specific mathematical programme “cepha”, corresponding linear parameters [mandibular corpus length (Go-Me), mandibular ramus length (Co-Go), posterior facial height (Go-S)] on these two types of cephalograms were calculated, named simulation group (SG). Bland–Altman analysis was used to assess the agreement between MG and SG. Simulated linear measurements with varying magnifications were generated based on “cepha” as well. Bland–Altman analysis was used to assess the agreement of simulated measurements between two modalities. Results: Bland–Altman analysis suggested the agreement between measurements on conventional cephalograms and orthogonally synthesized cephalograms, with a mean bias of 0.47 mm. Comparison between MG and SG showed that the difference did not reach clinical significance. The consistency between simulated measurements of both modalities with four different magnifications was demonstrated. Conclusions: Normative data of conventional cephalograms could be used for CBCT orthogonally synthesized cephalograms during this transitional period. PMID:25029593

  9. Ozone column density determination from direct irradiance measurements in the ultraviolet performed by a four-channel precision filter radiometer.

    PubMed

    Ingold, T; Mätzler, C; Wehrli, C; Heimo, A; Kämpfer, N; Philipona, R

    2001-04-20

    Ultraviolet light was measured at four channels (305, 311, 318, and 332 nm) with a precision filter radiometer (UV-PFR) at Arosa, Switzerland (46.78 degrees , 9.68 degrees , 1850 m above sea level), within the instrument trial phase of a cooperative venture of the Swiss Meteorological Institute (MeteoSwiss) and the Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center. We retrieved ozone-column density data from these direct relative irradiance measurements by adapting the Dobson standard method for all possible single-difference wavelength pairs and one double-difference pair (305/311 and 305/318) under conditions of cloud-free sky and of thin clouds (cloud optical depth <2.5 at 500 nm). All UV-PFR retrievals exhibited excellent agreement with those of collocated Dobson and Brewer spectrophotometers for data obtained during two months in 1999. Combining the results of the error analysis and the findings of the validation, we propose to retrieve ozone-column density by using the 305/311 single difference pair and the double-difference pair. Furthermore, combining both retrievals by building the ratio of ozone-column density yields information that is relevant to data quality control. Estimates of the 305/311 pair agree with measurements by the Dobson and Brewer instruments within 1% for both the mean and the standard deviation of the differences. For the double pair these values are in a range up to 1.6%. However, this pair is less sensitive to model errors. The retrieval performance is also consistent with satellite-based data from the Earth Probe Total Ozone Mapping Spectrometer (EP-TOMS) and the Global Ozone Monitoring Experiment instrument (GOME).

  10. Ozone Column Density Determination From Direct Irradiance Measurements in the Ultraviolet Performed by a Four-Channel Precision Filter Radiometer

    NASA Astrophysics Data System (ADS)

    Ingold, Thomas; Mätzler, Christian; Wehrli, Christoph; Heimo, Alain; Kämpfer, Niklaus; Philipona, Rolf

    2001-04-01

    Ultraviolet light was measured at four channels (305, 311, 318, and 332 nm) with a precision filter radiometer (UV-PFR) at Arosa, Switzerland (46.78 , 9.68 , 1850 m above sea level), within the instrument trial phase of a cooperative venture of the Swiss Meteorological Institute (MeteoSwiss) and the Physikalisch-Meteorologisches Observatorium Davos /World Radiation Center. We retrieved ozone-column density data from these direct relative irradiance measurements by adapting the Dobson standard method for all possible single-difference wavelength pairs and one double-difference pair (305 /311 and 305 /318) under conditions of cloud-free sky and of thin clouds (cloud optical depth <2.5 at 500 nm). All UV-PFR retrievals exhibited excellent agreement with those of collocated Dobson and Brewer spectrophotometers for data obtained during two months in 1999. Combining the results of the error analysis and the findings of the validation, we propose to retrieve ozone-column density by using the 305 /311 single difference pair and the double-difference pair. Furthermore, combining both retrievals by building the ratio of ozone-column density yields information that is relevant to data quality control. Estimates of the 305 /311 pair agree with measurements by the Dobson and Brewer instruments within 1% for both the mean and the standard deviation of the differences. For the double pair these values are in a range up to 1.6%. However, this pair is less sensitive to model errors. The retrieval performance is also consistent with satellite-based data from the Earth Probe Total Ozone Mapping Spectrometer (EP-TOMS) and the Global Ozone Monitoring Experiment instrument (GOME).

  11. Temperature And Bandwidth Effect in Brewer and Dobson Direct Sun Observations

    NASA Astrophysics Data System (ADS)

    Scarnato, B.; Staehelin, J.; Stuebi, R.

    2007-12-01

    Dobson and Brewer spectrophotometer are the main instruments to monitor the ozone shield by ground based observations, and they have an important role for validation of ozone satellite data. Ground based total ozone observations from Brewer and Dobson spectrophotometers, operated at mid-latitudes stations, typically show a seasonal bias in the residual with a amplitude of a few percent. Mid-latitude total ozone trends caused by ozone depleting substances are on the order of few percents per decade. Therefore, only a maximum instrumental shift of 1% over the measured period can be tolerated for measurements to derive reliable trends. At Arosa two Dobson and three Brewers instruments have been co-located since 1992, producing a unique data set of quasi-simultaneous observations that is valuable for the study of systematic differences within the measurements. The differences can be at least partially attributed to the different sensitivities of the wavelengths used in the retrieval algorithms. This might explain different column ozone as a consequence of seasonal variability, mainly, in temperature in the lower stratosphere and in ozone slant path. The temperature dependence has been calculated using three different absorption spectra (Bass and Paur, Daumont and those used in the GOME satellite), weighing of the slit functions for each operational Brewer and for the primary standard Dobson spectrophotometers. The seasonal bias between Dobson and Brewer total ozone measurements is reduced from 3% to 1%, if one takes into account the temperature dependence of the Bass and Paur absorptions spectra and the ozone slant path effect. The accuracy and the resolution step of the experimental data of ozone cross sections have an important role. The ozone cross section must be convoluted for the slits functions that can vary from one instrument to an other, therefore the different spectra yield different results.

  12. Signatures Of A Putative Planetary Mass Solar Companion On The Orbital Distribution Of Tno's And Centaurs

    NASA Astrophysics Data System (ADS)

    Gomes, Rodney S.; Soares, J. S.

    2012-05-01

    Gomes et al. 2006 (Icarus 184, 589) show that a planetary mass solar companion (PMSC) can produce orbits in an inner Oort cloud that can account for Sedna's orbit. On the other hand, one should expect that this faraway planet would also produce some peculiar orbital distribution for distant TNO's and Centaurs. A pair of interesting orbits in this respect are those of 2006 SQ372 and 2000 OO67. These objects have very large semimajor axes and perihelion between Uranus and Neptune orbits. It has been claimed that a likely source for 2006 SQ372 is the Oort cloud. Yet a PMSC has an important effect on objects at inner Oort cloud distances, say between 300 AU and 2000 AU, to make their perihelion distances to continually oscillate with a large enough amplitude to account for objects both inside and outside Neptune's orbit. This naturally produces an extra amount of TNO's with semimajor axes between 300 and 2000 AU and perihelion inside Neptune's orbit, like 2006 SQ372 and 2000 OO67. This signature should be found in present observations. To deal with this problem we construct a numerical simulator and apply it to populations of distant TNO's produced by numerical integration of planetesimals and planets according to the Nice model, either including or not a PMSC. With the results from the numerical simulator we compare the model with and without the PMSC with observations. We conclude that a PMSC is compatible with the existence of 2006 SQ372 and 2000 OO67 and, in fact, although not conclusively, we can also claim that the observations of 2006 SQ372 and 2000 OO67, compared to all other scattered objects, would be lucky events if no PMSC exists.

  13. Evaluation Metrics for Simulations of Tropical South America

    NASA Astrophysics Data System (ADS)

    Gallup, S.; Baker, I. T.; Denning, A. S.; Cheeseman, M.; Haynes, K. D.; Phillips, M.

    2017-12-01

    The evergreen broadleaf forest of the Amazon Basin is the largest rainforest on earth, and has teleconnections to global climate and carbon cycle characteristics. This region defies simple characterization, spanning large gradients in total rainfall and seasonal variability. Broadly, the region can be thought of as trending from light-limited in its wettest areas to water-limited near the ecotone, with individual landscapes possibly exhibiting the characteristics of either (or both) limitations during an annual cycle. A basin-scale classification of mean behavior has been elusive, and ecosystem response to seasonal cycles and anomalous drought events has resulted in some disagreement in the literature, to say the least. However, new observational platforms and instruments make characterization of the heterogeneity and variability more feasible.To evaluate simulations of ecophysiological function, we develop metrics that correlate various observational products with meteorological variables such as precipitation and radiation. Observations include eddy covariance fluxes, Solar Induced Fluorescence (SIF, from GOME2 and OCO2), biomass and vegetation indices. We find that the modest correlation between SIF and precipitation decreases with increasing annual precipitation, although the relationship is not consistent between products. Biomass increases with increasing precipitation. Although vegetation indices are generally correlated with biomass and precipitation, they can saturate or experience retrieval issues during cloudy periods.Using these observational products and relationships, we develop a set of model evaluation metrics. These metrics are designed to call attention to models that get "the right answer only if it's for the right reason," and provide an opportunity for more critical evaluation of model physics. These metrics represent a testbed that can be applied to multiple models as a means to evaluate their performance in tropical South America.

  14. Satellite-derived SIF and CO2 Observations Show Coherent Responses to Interannual Climate Variations

    NASA Astrophysics Data System (ADS)

    Butterfield, Z.; Hogikyan, A.; Kulawik, S. S.; Keppel-Aleks, G.

    2017-12-01

    Gross primary production (GPP) is the single largest carbon flux in the Earth system, but its sensitivity to changes in climate is subject to significant uncertainty. Satellite measurements of solar-induced chlorophyll fluorescence (SIF) offer insight into spatial and temporal patterns in GPP at a global scale and, combined with other satellite-derived datasets, provide unprecedented opportunity to explore interactions between atmospheric CO2, GPP, and climate variability. To explore potential drivers of GPP in the Northern Hemisphere (NH), we compare monthly-averaged SIF data from the Global Ozone Monitoring Experiment 2 (GOME-2) with observed anomalies in temperature (T; CRU-TS), liquid water equivalent (LWE) from the Gravity Recovery and Climate Experiment (GRACE), and photosynthetically active radiation (PAR; CERES SYN1deg). Using observations from 2007 through 2015 for several NH regions, we calculate month-specific sensitivities of SIF to variability in T, LWE, and PAR. These sensitivities provide insight into the seasonal progression of how productivity is affected by climate variability and can be used to effectively model the observed SIF signal. In general, we find that high temperatures are beneficial to productivity in the spring, but detrimental in the summer. The influences of PAR and LWE are more heterogeneous between regions; for example, higher LWE in North American temperate forest leads to decreased springtime productivity, while exhibiting a contrasting effect in water-limited regions. Lastly, we assess the influence of variations in terrestrial productivity on atmospheric carbon using a new lower tropospheric CO2 product derived from the Greenhouse Gases Observing Satellite (GOSAT). Together, these data shed light on the drivers of interannual variability in the annual cycle of NH atmospheric CO2, and may provide improved constraints on projections of long-term carbon cycle responses to climate change.

  15. Estimated global nitrogen deposition using NO2 column density

    USGS Publications Warehouse

    Lu, Xuehe; Jiang, Hong; Zhang, Xiuying; Liu, Jinxun; Zhang, Zhen; Jin, Jiaxin; Wang, Ying; Xu, Jianhui; Cheng, Miaomiao

    2013-01-01

    Global nitrogen deposition has increased over the past 100 years. Monitoring and simulation studies of nitrogen deposition have evaluated nitrogen deposition at both the global and regional scale. With the development of remote-sensing instruments, tropospheric NO2 column density retrieved from Global Ozone Monitoring Experiment (GOME) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) sensors now provides us with a new opportunity to understand changes in reactive nitrogen in the atmosphere. The concentration of NO2 in the atmosphere has a significant effect on atmospheric nitrogen deposition. According to the general nitrogen deposition calculation method, we use the principal component regression method to evaluate global nitrogen deposition based on global NO2 column density and meteorological data. From the accuracy of the simulation, about 70% of the land area of the Earth passed a significance test of regression. In addition, NO2 column density has a significant influence on regression results over 44% of global land. The simulated results show that global average nitrogen deposition was 0.34 g m−2 yr−1 from 1996 to 2009 and is increasing at about 1% per year. Our simulated results show that China, Europe, and the USA are the three hotspots of nitrogen deposition according to previous research findings. In this study, Southern Asia was found to be another hotspot of nitrogen deposition (about 1.58 g m−2 yr−1 and maintaining a high growth rate). As nitrogen deposition increases, the number of regions threatened by high nitrogen deposits is also increasing. With N emissions continuing to increase in the future, areas whose ecosystem is affected by high level nitrogen deposition will increase.

  16. Global high-resolution simulations of tropospheric nitrogen dioxide using CHASER V4.0

    NASA Astrophysics Data System (ADS)

    Sekiya, Takashi; Miyazaki, Kazuyuki; Ogochi, Koji; Sudo, Kengo; Takigawa, Masayuki

    2018-03-01

    We evaluate global tropospheric nitrogen dioxide (NO2) simulations using the CHASER V4.0 global chemical transport model (CTM) at horizontal resolutions of 0.56, 1.1, and 2.8°. Model evaluation was conducted using satellite tropospheric NO2 retrievals from the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment-2 (GOME-2) and aircraft observations from the 2014 Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ). Agreement against satellite retrievals improved greatly at 1.1 and 0.56° resolutions (compared to 2.8° resolution) over polluted and biomass burning regions. The 1.1° simulation generally captured the regional distribution of the tropospheric NO2 column well, whereas 0.56° resolution was necessary to improve the model performance over areas with strong local sources, with mean bias reductions of 67 % over Beijing and 73 % over San Francisco in summer. Validation using aircraft observations indicated that high-resolution simulations reduced negative NO2 biases below 700 hPa over the Denver metropolitan area. These improvements in high-resolution simulations were attributable to (1) closer spatial representativeness between simulations and observations and (2) better representation of large-scale concentration fields (i.e., at 2.8°) through the consideration of small-scale processes. Model evaluations conducted at 0.5 and 2.8° bin grids indicated that the contributions of both these processes were comparable over most polluted regions, whereas the latter effect (2) made a larger contribution over eastern China and biomass burning areas. The evaluations presented in this paper demonstrate the potential of using a high-resolution global CTM for studying megacity-scale air pollutants across the entire globe, potentially also contributing to global satellite retrievals and chemical data assimilation.

  17. A systematic review of medicinal plants used for weight loss in Brazil: Is there potential for obesity treatment?

    PubMed

    Cercato, Luana M; White, Pollyanna A S; Nampo, Fernando K; Santos, Márcio R V; Camargo, Enilton A

    2015-12-24

    Obesity is a pandemic disease and its prevalence is still increasing. Moreover, it has important costs to public health. In Brazil, many plants are used for weight loss by overweight or obese people, but there is a lack of scientific basis for this practice. Many ethnobotanical studies aiming to characterize this usage have been published, but they are still limited by the region considered and the diversity of the popular knowledge. The present study was undertaken to systematically review the ethnobotanical surveys regarding the species utilized to reduce body weight in overweight or obese people in Brazil. Ethnobotanical surveys related to this usage and performed in Brazilian regions were systematically found in MEDLINE, LILACS and Scopus. Thirty-three studies were included in this review. Fifty species were popularly utilized to lose weight. The most cited species were Baccharis trimera (Less.) DC, Annona muricata L. and Hancornia speciosa Gomes. Camellia sinensis (L.) Kuntze and Hibiscus sabdariffa L. were also cited and are supported by either animal or human investigations that indicate some beneficial activity against obesity. However, for the majority of species cited in the included studies, there is no scientific basis that assures the biological effects of this usage. Many studies have demonstrated important effects of these plants on glycemia, serum lipid levels or body weight control in non-obese conditions, which is not sufficient to recommend the use of these plants to reduce body weight in overweight or obese people. Although many plants are popularly used to reduce weight in overweight or obese people in Brazil, there is little scientific evidence corroborating its usage. Based on the ethnobotanical data presented, this review indicates the plants that should be considered for scientifically controlled studies devoted to investigating their effects on obesity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Mercury distribution in organs of fish species and the associated risk in traditional subsistence villagers of the Pantanal wetland.

    PubMed

    Ceccatto, Ana P S; Testoni, Magalei C; Ignácio, Aurea R A; Santos-Filho, Manoel; Malm, Olaf; Díez, Sergi

    2016-06-01

    This study evaluated the risk to human health from mercury (Hg) exposure through fish consumption in the Pantanal, Brazil. In order to address these risks, Hg concentrations and accumulation patterns were determined in target organs of predatory fish (Crenicichla lepidota and Pygocentrus nattereri). Levels of Hg were analysed during the two phases of the flood pulse (flood and drought) in fish from different local ecosystems, such as the Bento Gomes and Paraguay rivers. Although the former study area is directly affected by gold mining, a higher, but not significantly different, Hg concentration in fish was found compared with fish at the Paraguay River, which is regarded as pristine area. Moreover, no seasonal variability was found in either river. Although total mercury levels in fish did not exceed the maximum FAO/WHO threshold (0.5 μg g(-1)), according to dietary habits in riverine communities of the Pantanal (up to 6 oz of fish per day), there is reason for concern over the potential for deleterious health effects that could be caused by high Hg intake. In fact, the estimated daily intake in the present study ranged from 0.49 to 1.08 μg Hg kg(-1) day(-1), for adults (including women of childbearing age) and children, respectively. Because of high Hg intakes in riverine groups, which exceed the recommended reference dose value, these communities could be considered at risk. Therefore, it is necessary to consider regulatory measures and public education regarding fish consumption, particularly in vulnerable groups (i.e. children, pregnant women and women of childbearing age).

  19. Science Requirements Document for OMI-EOS. 2

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K.; Chance, K.; Isaksen, I.; Levelt, P. F.; Boersma, F.; Brinksma, E.; Carpay, J.; vanderA, R.; deHaan, J.; Hilsenrath, E.

    2000-01-01

    A Dutch-Finnish scientific and industrial consortium is supplying the Ozone Monitoring Instrument (OMI) for Earth Observing System-Aura (EOS-Aura). EOS-Aura is the next NASA mission to study the Earth's atmosphere extensively, and successor to the highly successful UARS (Upper Atmospheric Research Satellite) mission. The 'Science Requirements Document for OMI-EOS' presents an overview of the Aura and OMI mission objectives. It describes how OMI fits into the Aura mission and it reviews the synergy with the other instruments onboard Aura to fulfill the mission. This evolves in the Scientific Requirements for OMI (Chapter 3), stating which trace gases have to be measured with what necessary accuracy, in order for OMI to meet Aura's objectives. The most important data product of OMI, the ozone vertical column, densities shall have a better accuracy and an improved global coverage than the predecessor instruments TOMS (Total Ozone Monitoring Spectrometer) and GOME (Global Ozone Monitoring Experiment), which is a.o. achieved by a better signal to noise ratio, improved calibration and a wide field-of-view. Moreover, in order to meet its role on Aura, OMI shall measure trace gases, such as NO2, OClO, BrO, HCHO and SO2, aerosols, cloud top height and cloud coverage. Improved accuracy, better coverage, and finer ground grid than has been done in the past are goals for OMI. After the scientific requirements are defined, three sets of subordinate requirements are derived. These are: the algorithm requirements, i.e. what do the algorithms need in order to meet the scientific requirements; the instrument and calibration requirements, i.e. what has to be measured and how accurately in order to provide the quality of data necessary for deriving the data products; and the validation requirements, i.e. a strategy of how the OMI program will assure that its data products are valid in the atmosphere, at least to the required accuracy.

  20. Year-round records of sea salt, gaseous, and particulate inorganic bromine in the atmospheric boundary layer at coastal (Dumont d'Urville) and central (Concordia) East Antarctic sites

    NASA Astrophysics Data System (ADS)

    Legrand, Michel; Yang, Xin; Preunkert, Susanne; Theys, Nicolas

    2016-01-01

    Multiple year-round records of bulk and size-segregated compositions of aerosol were obtained at the coastal Dumont d'Urville (DDU) and inland Concordia sites located in East Antarctica. They document the sea-salt aerosol load and composition including, for the first time in Antarctica, the bromide depletion of sea-salt aerosol relative to sodium with respect to seawater. In parallel, measurements of bromide trapped in mist chambers and denuder tubes were done to investigate the concentrations of gaseous inorganic bromine species. These data are compared to simulations done with an off-line chemistry transport model, coupled with a full tropospheric bromine chemistry scheme and a process-based sea-salt production module that includes both sea-ice-sourced and open-ocean-sourced aerosol emissions. Observed and simulated sea-salt concentrations sometime differ by up to a factor of 2 to 3, particularly at DDU possibly due to local wind pattern. In spite of these discrepancies, both at coastal and inland Antarctica, the dominance of sea-ice-related processes with respect to open ocean emissions for the sea-salt aerosol load in winter is confirmed. For summer, observations and simulations point out sea salt as the main source of gaseous inorganic bromine species. Investigations of bromide in snow pit samples do not support the importance of snowpack bromine emissions over the Antarctic Plateau. To evaluate the overall importance of the bromine chemistry over East Antarctica, BrO simulations were also discussed with respect data derived from GOME-2 satellite observations over Antarctica.

  1. The Effect of Aerosol on Gravity Wave Characteristics above the Boundary Layer over a Tropical Location

    NASA Astrophysics Data System (ADS)

    Rakshit, G.; Jana, S.; Maitra, A.

    2017-12-01

    The perturbations of temperature profile over a location give an estimate of the potential energy of gravity waves propagating through the atmosphere. Disturbances in the lower atmosphere due to tropical deep convection, orographic effects and various atmospheric disturbances generates of gravity waves. The present study investigates the gravity wave energy estimated from fluctuations in temperature profiles over the tropical location Kolkata (22°34' N, 88°22' E). Gravity waves are most intense during the pre-monsoon period (March-June) at the present location, the potential energy having high values above the boundary layer (2-4 km) as observed from radiosonde profiles. An increase in temperature perturbation, due to high ambient temperature in the presence of heat absorbing aerosols, causes an enhancement in potential energy. As the present study location is an urban metropolitan city experiencing high level of pollution, pollutant aerosols can go much above the normal boundary layer during daytime due to convection causing an extended boundary layer. The Aerosol Index (AAI) obtained from Global Ozone Monitoring Experiment-2 (GOME-2) on MetOp-A platform at 340 nm and 380 nm confirms the presence of absorbing aerosol particles over the present location. The Hysplit back trajectory analysis shows that the aerosol particles at those heights are of local origin and are responsible for depleting liquid water content due to cloud burning. The aerosol extinction coefficient obtained from CALIPSO data exhibits an increasing trend during 2006-2016 accompanied by a similar pattern of gravity wave energy. Thus the absorbing aerosols have a significant role in increasing the potential energy of gravity wave at an urban location in the tropical region.

  2. Spaceborne Sun-Induced Vegetation Fluorescence Time Series from 2007 to 2015 Evaluated with Australian Flux Tower Measurements

    NASA Technical Reports Server (NTRS)

    Sanders, Abram F. J.; Verstraeten, Willem W.; Kooreman, Maurits L.; van Leth, Thomas C.; Beringer, Jason; Joiner, Joanna

    2016-01-01

    A global, monthly averaged time series of Sun-induced Fluorescence (SiF), spanning January 2007 to June 2015, was derived from Metop-A Global Ozone Monitoring Experiment 2 (GOME-2) spectral measurements. Far-red SiF was retrieved using the filling-in of deep solar Fraunhofer lines and atmospheric absorption bands based on the general methodology described by Joiner et al, AMT, 2013. A Principal Component (PC) analysis of spectra over non-vegetated areas was performed to describe the effects of atmospheric absorption. Our implementation (SiF KNMI) is an independent algorithm and differs from the latest implementation of Joiner et al, AMT, 2013 (SiF NASA, v26), because we used desert reference areas for determining PCs (as opposed to cloudy ocean and some desert) and a wider fit window that covers water vapour and oxygen absorption bands (as opposed to only Fraunhofer lines). As a consequence, more PCs were needed (35 as opposed to 12). The two time series (SiF KNMI and SiF NASA, v26) correlate well (overall R of 0.78) except for tropical rain forests. Sensitivity experiments suggest the strong impact of the water vapour absorption band on retrieved SiF values. Furthermore, we evaluated the SiF time series with Gross Primary Productivity (GPP) derived from twelve flux towers in Australia. Correlations for individual towers range from 0.37 to 0.84. They are particularly high for managed biome types. In the de-seasonalized Australian SiF time series, the break of the Millennium Drought during local summer of 2010/2011 is clearly observed.

  3. BrO, OClO and HCHO Observations from the EOS-Aura Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    Kurosu, T. P.; Chance, K.; Sioris, C. E.

    2004-12-01

    The Ozone Monitoring Instrument (OMI) was launched on 15 July 2004 on the EOS-Aura platform into a sun-synchronous, polar orbit with an equator crossing time of 13:45h (ascending node). OMI is a nadir-viewing near-UV/Visible spectrometer, covering the spectral region of 270 nm to 500 nm with a resolution between 0.45 nm and 1.0 nm and a nominal ground footprint of 13 km×24 km. Global coverage is achieved in one day. The very high spatial resolution of OMI measurements sets a new standard for trace gas and air quality monitoring from space. Combined with daily global coverage, this significantly advances our ability to answer outstanding questions on air pollution, including the determination of BrO sources in mid and low latitudes, BrO--O3 anti-correlations as a function of latitude, and the production of formaldehyde in cities of the developing world. We introduce the design of the OMI operational retrieval algorithm for BrO, OClO and HCHO. Based on a direct (non-DOAS) non-linear fitting approach, it includes wavelength calibration for radiances and irradiances, an undersampling correction, and the characterization of the instrument slit function. We will present results of BrO (global distribution, and tropospheric contributions from the break-up ice shelves and volcanic emissions), formaldehyde (over regions of isoprene emissions, forest fires, and heavy urban pollution), and, contingent upon the availability of suitable OMI observations, OClO (under ozone hole conditions). Where available, trace gas retrievals from OMI will be compared to results from the SCIAMACHY and GOME instruments.

  4. Some Comments on Topological Approaches to the π-Electron Currents in Conjugated Systems.

    PubMed

    Dickens, Timothy K; Gomes, José A N F; Mallion, Roger B

    2011-11-08

    Within the past two years, three sets of independent authors (Mandado, Ciesielski et al., and Randić) have proposed methods in which π-electron currents in conjugated systems are estimated by invoking the concept of circuits of conjugation. These methods are here compared with ostensibly similar approaches published more than 30 years ago by two of the present authors (Gomes and Mallion) and (likewise independently) by Gayoso. Patterns of bond currents and ring currents computed by these methods for the nonalternant isomer of coronene that was studied by Randić are also systematically compared with those calculated by the Hückel-London-Pople-McWeeny (HLPM) "topological" approach and with the ab initio, "ipso-centric" current-density maps of Balaban et al. These all agree that a substantial diamagnetic π-electron current flows around the periphery of the selected structure (which could be thought of as a "perturbed" [18]-annulene), and consideration is given to the differing trends predicted by these several methods for the π-electron currents around its central six-membered ring and in its internal bonds. It is observed that, for any method in which calculated π-electron currents respect Kirchhoff's Laws of current conservation at a junction, consideration of bond currents-as an alternative to the more-traditional ring currents-can give a different insight into the magnetic properties of conjugated systems. However, provided that charge/current conservation is guaranteed-or Kirchhoff's First Law holds for bond currents instead of the more-general current-densities-then ring currents represent a more efficient way of describing the molecular reaction to the external magnetic field: ring currents are independent quantities, while bond currents are not.

  5. Cross Calibration of TOMS, SBUV/2 and SCIAMACHY Radiances from Ground Observations

    NASA Technical Reports Server (NTRS)

    Hilsenrath, Ernest; Bhartia, P. K.; Bojkov, B.; Kowaleski, M.; Labow, G.; Ahmad, Z.

    2002-01-01

    We have shown that validation of radiances is a very effective means for correcting absolute accuracy and long term drifts of backscatter type satellite measurements. This method by-passes the algorithms used for both satellite and ground based measurements which are normally used to validate and correct the satellite data. A new method for satellite validation is planned which will compliment measurements from the existing ground-based networks. This method will employ very accurate comparisons between ground based zenith sky radiances and satellite nadir radiances. These comparisons will rely heavily on the experience derived from the Shuttle SBUV (SSBUV) program which provided a reference standard of radiance measurements for SBUV/2, TOMS, and GOME. This new measurement program, called 'Skyrad', employs two well established capabilities at the Goddard Space Flight Center, 1) the SSBUV calibration facilities and 2) the radiative transfer codes used for the TOMS and SBUV/2 algorithms and their subsequent refinements. Radiative transfer calculations show that ground based zenith sky and satellite nadir backscatter ultraviolet comparisons can be made very accurately under certain viewing conditions. The Skyrad instruments (SSBUV, Brewer spectrophotometers, and possibly others) will be calibrated and maintained to a precision of a few tenths of a percent. Skyrad data will then enable long term calibration of upcoming satellite instruments such as QuickTOMS, SBUV/2s and SCIAMACHY with a high degree of precision. This technique can be further employed to monitor the performance of future instruments such as GOMEZ, OMI, and OMPS. Additional information is included in the original extended abstract.

  6. A New Method to Cross Calibrate and Validate TOMS, SBUV/2, and SCIAMACHY Measurements

    NASA Technical Reports Server (NTRS)

    Ahmad, Ziauddin; Hilsenrath, Ernest; Einaudi, Franco (Technical Monitor)

    2001-01-01

    A unique method to validate back scattered ultraviolet (buv) type satellite data that complements the measurements from existing ground networks is proposed. The method involves comparing the zenith sky radiance measurements from the ground to the nadir radiance measurements taken from space. Since the measurements are compared directly, the proposed method is superior to any other method that involves comparing derived products (for example, ozone), because comparison of derived products involve inversion algorithms which are susceptible to several type of errors. Forward radiative transfer (RT) calculations show that for an aerosol free atmosphere, the ground-based zenith sky radiance measurement and the satellite nadir radiance measurements can be predicted with an accuracy of better than 1 percent. The RT computations also show that for certain values of the solar zenith angles, the radiance comparisons could be better than half a percent. This accuracy is practically independent of ozone amount and aerosols in the atmosphere. Experiences with the Shuttle Solar Backscatter Ultraviolet (SSBUV) program show that the accuracy of the ground-based zenith sky radiance measuring instrument can be maintained at a level of a few tenth of a percent. This implies that the zenith sky radiance measurements can be used to validate Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV/2), and The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) radiance data. Also, this method will help improve the long term precision of the measurements for better trend detection and the accuracy of other BUV products such as tropospheric ozone and aerosols. Finally, in the long term, this method is a good candidate to inter-calibrate and validate long term observations of upcoming operational instruments such as Global Ozone Monitoring Experiment (GOME-2), Ozone Mapping Instrument (OMI), Ozone Dynamics Ultraviolet Spectrometer (ODUS

  7. The TROPOMI surface UV algorithm

    NASA Astrophysics Data System (ADS)

    Lindfors, Anders V.; Kujanpää, Jukka; Kalakoski, Niilo; Heikkilä, Anu; Lakkala, Kaisa; Mielonen, Tero; Sneep, Maarten; Krotkov, Nickolay A.; Arola, Antti; Tamminen, Johanna

    2018-02-01

    The TROPOspheric Monitoring Instrument (TROPOMI) is the only payload of the Sentinel-5 Precursor (S5P), which is a polar-orbiting satellite mission of the European Space Agency (ESA). TROPOMI is a nadir-viewing spectrometer measuring in the ultraviolet, visible, near-infrared, and the shortwave infrared that provides near-global daily coverage. Among other things, TROPOMI measurements will be used for calculating the UV radiation reaching the Earth's surface. Thus, the TROPOMI surface UV product will contribute to the monitoring of UV radiation by providing daily information on the prevailing UV conditions over the globe. The TROPOMI UV algorithm builds on the heritage of the Ozone Monitoring Instrument (OMI) and the Satellite Application Facility for Atmospheric Composition and UV Radiation (AC SAF) algorithms. This paper provides a description of the algorithm that will be used for estimating surface UV radiation from TROPOMI observations. The TROPOMI surface UV product includes the following UV quantities: the UV irradiance at 305, 310, 324, and 380 nm; the erythemally weighted UV; and the vitamin-D weighted UV. Each of these are available as (i) daily dose or daily accumulated irradiance, (ii) overpass dose rate or irradiance, and (iii) local noon dose rate or irradiance. In addition, all quantities are available corresponding to actual cloud conditions and as clear-sky values, which otherwise correspond to the same conditions but assume a cloud-free atmosphere. This yields 36 UV parameters altogether. The TROPOMI UV algorithm has been tested using input based on OMI and the Global Ozone Monitoring Experiment-2 (GOME-2) satellite measurements. These preliminary results indicate that the algorithm is functioning according to expectations.

  8. Oxygen consumption and heart rate during repeated squatting exercises with or without whole-body vibration in the elderly.

    PubMed

    Avelar, Núbia Cp; Simão, Adriano P; Tossige-Gomes, Rosalina; Neves, Camila Dc; Mezencio, Bruno; Szmuchrowski, Leszek; Coimbra, Cândido C; Lacerda, Ana Cr

    2011-12-01

    Avelar, NCP, Simão, AP, Tossige-Gomes, R, Neves, CDC, Mezencio, B, Szmuchrowski, L, Coimbra, CC, and Lacerda, ACR. Oxygen consumption and heart rate during repeated squatting exercises with or without whole-body vibration in the elderly. J Strength Cond Res 25(12): 3495-3500, 2011-The aim of this study was to investigate whether vibration plus squatting would increase cardiovascular demand to the optimal exercise limits needed for the prescription of cardiovascular training. Oxygen consumption, measured breath by breath by a portable gas analysis system, and heart rate (HR), measured using an HR monitor, were evaluated in 18 elderly individuals, 15 women and 3 men with a mean age of 72 ± 6 years. These variables were measured simultaneously and at the same time points in each subject during rest and randomly during the performance of squatting exercises (8 series of 40 seconds, with 40 seconds of rest between series of performing squats in 3-second cycles with 10-60° of flexion, a total of 5 repetitions for 40 seconds) with or without vibration at a frequency of 40 Hz and amplitude of 4 mm, separated by at least 1 day. Associating whole-body vibration with squatting exercise resulted in an additional increase of around 20% in oxygen consumption and 7.5% in the HR recorded during exercise. However, during squatting exercise with vibration, the increase achieved in oxygen consumption was limited to around 2 metabolic equivalents, and mean HR represented around 56% of the predicted maximum HR for age. The results of this study show that, despite the fact that vibration increased oxygen consumption and HR during the performance of squatting exercise, the minimum standards of intensity for the prescription of physical exercise with the specific objective of improving cardiorespiratory fitness were not achieved. Therefore, a protocol such as that used in the study does not meet the threshold for cardiovascular training prescription.

  9. Satellite Soil Moisture and Water Storage Observations Identify Early and Late Season Water Supply Influencing Plant Growth in the Missouri Watershed

    NASA Astrophysics Data System (ADS)

    A, G.; Velicogna, I.; Kimball, J. S.; Du, J.; Kim, Y.; Colliander, A.; Njoku, E. G.

    2017-12-01

    We employ an array of continuously overlapping global satellite sensor observations including combined surface soil moisture (SM) estimates from SMAP, AMSR-E and AMSR-2, GRACE terrestrial water storage (TWS), and satellite precipitation measurements, to characterize seasonal timing and inter-annual variations of the regional water supply pattern and its associated influence on vegetation growth estimates from MODIS enhanced vegetation index (EVI), AMSR-E/2 vegetation optical depth (VOD) and GOME-2 solar-induced florescence (SIF). Satellite SM is used as a proxy of plant-available water supply sensitive to relatively rapid changes in surface condition, GRACE TWS measures seasonal and inter-annual variations in regional water storage, while precipitation measurements represent the direct water input to the analyzed ecosystem. In the Missouri watershed, we find surface SM variations are the dominant factor controlling vegetation growth following the peak of the growing season. Water supply to growth responds to both direct precipitation inputs and groundwater storage carry-over from prior seasons (winter and spring), depending on land cover distribution and regional climatic condition. For the natural grassland in the more arid central and northwest watershed areas, an early season anomaly in precipitation or surface temperature can have a lagged impact on summer vegetation growth by affecting the surface SM and the underlying TWS supplies. For the croplands in the more humid eastern portions of the watershed, the correspondence between surface SM and plant growth weakens. The combination of these complementary remote-sensing observations provides an effective means for evaluating regional variations in the timing and availability of water supply influencing vegetation growth.

  10. Satellite-observed changes in vegetation sensitivities to surface soil moisture and total water storage variations since the 2011 Texas drought

    NASA Astrophysics Data System (ADS)

    A, Geruo; Velicogna, Isabella; Kimball, John S.; Du, Jinyang; Kim, Youngwook; Colliander, Andreas; Njoku, Eni

    2017-05-01

    We combine soil moisture (SM) data from AMSR-E and AMSR-2, and changes in terrestrial water storage (TWS) from time-variable gravity data from GRACE to delineate and characterize the evolution of drought and its impact on vegetation growth. GRACE-derived TWS provides spatially continuous observations of changes in overall water supply and regional drought extent, persistence and severity, while satellite-derived SM provides enhanced delineation of shallow-depth soil water supply. Together these data provide complementary metrics quantifying available plant water supply. We use these data to investigate the supply changes from water components at different depths in relation to satellite-based enhanced vegetation index (EVI) and gross primary productivity (GPP) from MODIS and solar-induced fluorescence (SIF) from GOME-2, during and following major drought events observed in the state of Texas, USA and its surrounding semiarid area for the past decade. We find that in normal years the spatial pattern of the vegetation-moisture relationship follows the gradient in mean annual precipitation. However since the 2011 hydrological drought, vegetation growth shows enhanced sensitivity to surface SM variations in the grassland area located in central Texas, implying that the grassland, although susceptible to drought, has the capacity for a speedy recovery. Vegetation dependency on TWS weakens in the shrub-dominated west and strengthens in the grassland and forest area spanning from central to eastern Texas, consistent with changes in water supply pattern. We find that in normal years GRACE TWS shows strong coupling and similar characteristic time scale to surface SM, while in drier years GRACE TWS manifests stronger persistence, implying longer recovery time and prolonged water supply constraint on vegetation growth. The synergistic combination of GRACE TWS and surface SM, along with remote-sensing vegetation observations provides new insights into drought impact on

  11. Science Objectives of EOS-Aura's Ozone Monitoring Instrument (OMI)

    NASA Technical Reports Server (NTRS)

    Levelt, P. F.; Veefkind, J. P.; Stammes, P.; Hilsenrath, E.; Bhartia, P. K.; Chance, K. V.; Leppelmeier, G. W.; Maelkki, A.; Bhartia, Pawan (Technical Monitor)

    2002-01-01

    OMI is a UV/VIS nadir solar backscatter spectrograph, which provides near global coverage in one day with a spatial resolution of 13 x 24 sq km. OMI is a new instrument, with a heritage from the European satellite instruments GOME, GOMOS and SCIAMACHY. OMI's unique capabilities for measuring important trace gases with a small footprint and daily global coverage, in conjunction with the other Aura instruments, will make a major contribution to our understanding of stratospheric and tropospheric chemistry and climate change. OMI will measure solar irradiance and Earth radiances in the wavelength range of 270 to 500 nm with spectral resolution of about 0.5 nm and a spectral sampling of about 2-3 per FWHM. From these observations, total columns of O3, NO2, BrO and SO2 will be derived from the back-scattered solar radiance using differential absorption spectroscopy (DOAS). The TOMS total ozone record will also be continued by employing the well established TOMS algorithm. Because of the high accuracy and spatial resolution of the measurements, a good estimate of tropospheric amounts of ozone and NO2 are expected. Ozone profiles will be derived using the optimal estimation method. The spectral aerosol optical depth will be determined from measurements between 340 and 500 nm. This will provide information on aerosol concentration, aerosol size distribution and aerosol type. This wavelength range makes it possible to retrieve aerosol information over both land and sea. OMI observations will also allow retrievals of cloud coverage and cloud heights. From these products, the UV-B flux at the surface can then be derived with high spatial resolution.

  12. Neural Network-Based Retrieval of Surface and Root Zone Soil Moisture using Multi-Frequency Remotely-Sensed Observations

    NASA Astrophysics Data System (ADS)

    Hamed Alemohammad, Seyed; Kolassa, Jana; Prigent, Catherine; Aires, Filipe; Gentine, Pierre

    2017-04-01

    Knowledge of root zone soil moisture is essential in studying plant's response to different stress conditions since plant photosynthetic activity and transpiration rate are constrained by the water available through their roots. Current global root zone soil moisture estimates are based on either outputs from physical models constrained by observations, or assimilation of remotely-sensed microwave-based surface soil moisture estimates with physical model outputs. However, quality of these estimates are limited by the accuracy of the model representations of physical processes (such as radiative transfer, infiltration, percolation, and evapotranspiration) as well as errors in the estimates of the surface parameters. Additionally, statistical approaches provide an alternative efficient platform to develop root zone soil moisture retrieval algorithms from remotely-sensed observations. In this study, we present a new neural network based retrieval algorithm to estimate surface and root zone soil moisture from passive microwave observations of SMAP satellite (L-band) and AMSR2 instrument (X-band). SMAP early morning observations are ideal for surface soil moisture retrieval. AMSR2 mid-night observations are used here as an indicator of plant hydraulic properties that are related to root zone soil moisture. The combined observations from SMAP and AMSR2 together with other ancillary observations including the Solar-Induced Fluorescence (SIF) estimates from GOME-2 instrument provide necessary information to estimate surface and root zone soil moisture. The algorithm is applied to observations from the first 18 months of SMAP mission and retrievals are validated against in-situ observations and other global datasets.

  13. Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards: Part I. Validation of satellite-derived Volcanic Ash Levels.

    NASA Astrophysics Data System (ADS)

    Koukouli, MariLiza; Balis, Dimitris; Simopoulos, Spiros; Siomos, Nikos; Clarisse, Lieven; Carboni, Elisa; Wang, Ping; Siddans, Richard; Marenco, Franco; Mona, Lucia; Pappalardo, Gelsomina; Spinetti, Claudia; Theys, Nicolas; Tampellini, Lucia; Zehner, Claus

    2014-05-01

    The 2010 eruption of the Icelandic volcano Eyjafjallajökull attracted the attention of the public and the scientific community to the vulnerability of the European airspace to volcanic eruptions. Major disruptions in European air traffic were observed for several weeks surrounding the two eruptive episodes, which had a strong impact on the everyday life of many Europeans as well as a noticable economic loss of around 2-3 billion Euros in total. The eruptions made obvious that the decision-making bodies were not informed properly and timely about the commercial aircraft capabilities to ash-leaden air, and that the ash monitoring and prediction potential is rather limited. After the Eyjafjallajökull eruptions new guidelines for aviation, changing from zero tolerance to newly established ash threshold values, were introduced. Within this spirit, the European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards, called for the creation of an optimal End-to-End System for Volcanic Ash Plume Monitoring and Prediction . This system is based on improved and dedicated satellite-derived ash plume and sulphur dioxide level assessments, as well as an extensive validation using auxiliary satellite, aircraft and ground-based measurements. The validation of volcanic ash levels extracted from the sensors GOME-2/MetopA, IASI/MetopA and MODIS/Terra and MODIS/Aqua is presented in this work with emphasis on the ash plume height and ash optical depth levels. Co-located aircraft flights, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation [CALIPSO] soundings and well as European Aerosol Research Lidar Network [EARLINET] measurements were compared to the different satellite estimates for the those two eruptive episodes. The validation results are extremely promising with most satellite sensors performing quite well and within the estimated uncertainties compared to the comparative datasets. The findings are

  14. DISCOVER-AQ: An Overview and Initial Comparisons of NO2 with OMI Observations

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth; Crawford, James; Krotkov, Nickolay; Bucsela, Eric; Lamsal, Lok; Celarier, Edward; Herman, Jay; Janz, Scott; Cohen, Ron; Weinheimer, Andrew

    2011-01-01

    The first deployment of the Earth Venture -1 DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) project was conducted during July 2011 in the Baltimore-Washington region. Two aircraft (a P-3B for in-situ sampling and a King Air for remote sensing) were used along with an extensive array of surface-based in-situ and remote sensing instrumentation. Fourteen flight days were accomplished by both aircraft and over 250 profiles of trace gases and aerosols were performed by the P-3B over surface air quality monitoring stations, which were specially outfitted with sunphotometers and Pandora UV/Vis spectrometers. The King Air flew with the High Spectral Resolution Lidar for aerosols and the ACAM UV/Vis spectrometer for trace gases. This suite of observations allows linkage of surface air quality with the vertical distributions of gases and aerosols, with remotely-sensed column amounts observed from the surface and from the King Air, and with satellite observations from Aura (OMI and TES), GOME-2, MODIS and GOES. The DISCOVER-AQ data will allow determination of under what conditions satellite retrievals are indicative of surface air quality, and they will be useful in planning new satellites. In addition to an overview of the project, a preliminary comparison of tropospheric column NO2 densities from the integration of in-situ P-3B observations, from the Pandoras and ACAM, and from the new Goddard OMI NO2 algorithm will be presented.

  15. Chlorophyll Fluorescence Is a Better Proxy for Sunlit Leaf Than Total Canopy Photosynthesis

    NASA Astrophysics Data System (ADS)

    Chen, J. M.; Wang, Z.; Zhang, F.; Mo, G.

    2015-12-01

    Chlorophyll fluorescence (CF) results from non-photochemical quenching during plant photosynthesis under excessive radiation. We explore the relationship between gross primary productivity (GPP) and CF using a process ecosystem model, which separates a vegetation canopy into sunlit and shaded leaf groups and simulates the total canopy GPP as the sum of sunlit and shaded leaf GPP. Using GOME-2 and GOSAT data acquired in 2010 over the global land surface, we found that measured CF signals gridded in 1 degree resolution are well correlated with simulated total GPP and its sunlit and shaded components, but the correlation coefficients (R) are largest for the sunlit GPP and smallest for shaded GPP. The seasonal R2 values vary from 0.57 to 0.74, 0.58 to 0.71, and 0.48 to 0.56 for sunlit, total and shaded GPP, respectively. The significance levels for these correlations are all greater than p<0.01. Averaged over the globe, the total simulated shaded GPP is 39% of the total GPP. Theoretically, CF from vegetation comes mostly from sunlit leaves. The significant correlation between measured canopy-level CF and the shaded GPP is likely due to the correlation between shaded and sunlit GPP as both increase with leaf area index. Our simulation confirms the validity of using canopy-level CF measurements to assess the total GPP as the first approximation, although these measurements are a consistently better indicator of sunlit GPP than total GPP. In previous studies, the R2 values for the correlation between CF and total GPP were found to range from 0.76 to 0.88, 0.56 to 0.78, and 0.57 to 0.77 for MPI-BGC, MODIS and CASA model results, respectively. These values are similar or larger than those for sunlit GPP simulated in our study, but are considerably larger than those for total GPP in our study because the correlation for total GPP is contaminated by the inclusion of shaded GPP. All these three models use canopy total light use efficiency without considering the differences

  16. Application of multi-constituent satellite data assimilation for KORUS-AQ

    NASA Astrophysics Data System (ADS)

    Miyazaki, K.; Sekiya, T.; Fu, D.; Bowman, K. W.; Kulawik, S. S.; Walker, T.; Takigawa, M.; Ogochi, K.; Gaubert, B.; Barré, J.; Emmons, L. K.

    2017-12-01

    Comprehensive tropospheric maps of multi-constituent fields at 1.1 degree resolution, provided by an assimilation of multiple satellite measurements of O3, CO, NO2, and HNO3 from multiple satellite (OMI, GOME-2, MOPITT, MLS, and AIRS) using an ensemble Kalman filter, are used to study variations in tropospheric composition over east Asia during KORUS-AQ. Assimilated model results for both direct ozone assimilations and assimilations of ozone precursors (NOx and CO) were compared to DC-8 aircraft observations, with significant improvements in model/aircraft comparisons for ozone (the negative model bias was reduced by up to 80 %), CO (by up to 90 %), OH (by up to 40 %), and NOx seen in both approaches. Corrections made to the precursor emissions (i.e., surface NOx and CO emissions), especially over eastern and central China and over South Korea, were important in reducing the negative bias of O3 and CO over South Korea. We obtained additional bias reductions from assimilation of multispectral retrievals of tropospheric ozone profiles from AIRS and OMI, especially for the middle troposphere ozone. Improved agreements with the ground-based measurements at remote sites over South Korea and western Japan suggest that the representation of long-range transport of polluted air is improved by data assimilation, as a result of the optimization of precursor emissions, mainly over China. The higher estimated NOx, by 60-90 % over South Korea and by 20-40 % over eastern China compared to bottom-up inventories, suggests an important underestimation of anthropogenic sources in the emission inventories in these areas. Additional bias reductions were obtained by assimilating the multispectral retrievals, especially for the middle troposphere O3. In the future, assimilating datasets from a new constellation of low Earth orbiting sounders (e.g., IASI, AIRS, CrIS, Sentinel-5p (TROPOMI), and Sentinel-5) and geostationary satellites (Sentinel-4, GEMS, and TEMPO) will provide more

  17. Evaluation of the osteogenic potential of Hancornia speciosa latex in rat calvaria and its phytochemical profile.

    PubMed

    Dos Santos Neves, Juliana; Franchin, Marcelo; Rosalen, Pedro Luiz; Omar, Nadia Fayez; Dos Santos, Mariana Albuquerque; Paschoal, Jonas Augusto Rizzato; Novaes, Pedro Duarte

    2016-05-13

    Hancornia speciosa Gomes, commonly known as Mangabeira, is a Brazilian native fruit tree belonging to the Apocynaceae family. In folk medicine, the latex obtained from Mangabeira's trunk has been used as an adjunct therapy for bone fractures. Few pharmacological studies on the Hancornia speciosa latex have been developed and despite its popular use for bone healing there is no data about its biological effect on bone. The present study aimed to investigate the osteogenic potential of Hancornia speciosa latex in rat calvaria, as well as its phytochemical profile. A neutral gel composition containing 5% latex was topical applied to a critical size bone defect and over intact calvaria of rats. Areas of newly formed bone on the borders of the defect and of calvaria periosteum were quantified, as well as the percentage of BrdU-positive cells and total cells in the periosteum at different periods of time after latex application. The cytotoxicity of the latex aqueous phase was evaluated in rat calvarial cells in vitro by MTT assay and its phytochemical profile was investigated by ESI-MS/MS. The area of newly formed bone on the borders of the calvaria defect was larger in rats that received latex at 15 and 30 days of healing. After 3 days of latex application over the intact calvaria, the periosteum area was increased and newly formed bone was observed after 5 and 11 days. There was also an increase in periosteum cell proliferation and population followed latex application on calvaria (p<0.05). The latex aqueous phase limited rat calvarial cell viability in vitro in concentrations larger than 0.6mg/mL. Chlorogenic acid and naringenin-7-O-glucoside were identified in the latex aqueous phase, along with catechin and procyanidin compounds. There was a stimulus for periosteum cell proliferation and bone formation when Hancornia speciosa latex was topically applied on rat calvaria. In addition, chlorogenic acid and naringenin-7-O-glucoside present in Hancornia speciosa latex

  18. Advanced Outage and Control Center: Strategies for Nuclear Plant Outage Work Status Capabilities

    SciTech Connect

    Gregory Weatherby

    The research effort is a part of the Light Water Reactor Sustainability (LWRS) Program. LWRS is a research and development program sponsored by the Department of Energy, performed in close collaboration with industry to provide the technical foundations for licensing and managing the long-term, safe and economical operation of current nuclear power plants. The LWRS Program serves to help the US nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The Outage Control Center (OCC) Pilot Project was directed at carrying out the applied researchmore » for development and pilot of technology designed to enhance safe outage and maintenance operations, improve human performance and reliability, increase overall operational efficiency, and improve plant status control. Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Unfortunately, many of the underlying technologies supporting outage control are the same as those used in the 1980’s. They depend heavily upon large teams of staff, multiple work and coordination locations, and manual administrative actions that require large amounts of paper. Previous work in human reliability analysis suggests that many repetitive tasks, including paper work tasks, may have a failure rate of 1.0E-3 or higher (Gertman, 1996). With between 10,000 and 45,000 subtasks being performed during an outage (Gomes, 1996), the opportunity for human error of some consequence is a realistic concern. Although a number of factors exist that can make these errors recoverable, reducing and effectively coordinating the sheer number of tasks to be performed, particularly those that are error prone, has the potential to enhance outage efficiency and safety. Additionally, outage management requires precise coordination of work groups that do not always share similar objectives

  19. Evaluation of the MACC operational forecast system - potential and challenges of global near-real-time modelling with respect to reactive gases in the troposphere

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Blechschmidt, A.-M.; Bouarar, I.; Brunke, E.-G.; Clerbaux, C.; Cupeiro, M.; Cristofanelli, P.; Eskes, H.; Flemming, J.; Flentje, H.; George, M.; Gilge, S.; Hilboll, A.; Inness, A.; Kapsomenakis, J.; Richter, A.; Ries, L.; Spangl, W.; Stein, O.; Weller, R.; Zerefos, C.

    2015-03-01

    Monitoring Atmospheric Composition and Climate (MACC/MACCII) currently represents the European Union's Copernicus Atmosphere Monitoring Service (CAMS) (http://www.copernicus.eu), which will become fully operational in the course of 2015. The global near-real-time MACC model production run for aerosol and reactive gases provides daily analyses and 5 day forecasts of atmospheric composition fields. It is the only assimilation system world-wide that is operational to produce global analyses and forecasts of reactive gases and aerosol fields. We have investigated the ability of the MACC analysis system to simulate tropospheric concentrations of reactive gases (CO, O3, and NO2) covering the period between 2009 and 2012. A validation was performed based on CO and O3 surface observations from the Global Atmosphere Watch (GAW) network, O3 surface observations from the European Monitoring and Evaluation Programme (EMEP) and furthermore, NO2 tropospheric columns derived from the satellite sensors SCIAMACHY and GOME-2, and CO total columns derived from the satellite sensor MOPITT. The MACC system proved capable of reproducing reactive gas concentrations in consistent quality, however, with a seasonally dependent bias compared to surface and satellite observations: for northern hemispheric surface O3 mixing ratios, positive biases appear during the warm seasons and negative biases during the cold parts of the years, with monthly Modified Normalised Mean Biases (MNMBs) ranging between -30 and 30% at the surface. Model biases are likely to result from difficulties in the simulation of vertical mixing at night and deficiencies in the model's dry deposition parameterization. Observed tropospheric columns of NO2 and CO could be reproduced correctly during the warm seasons, but are mostly underestimated by the model during the cold seasons, when anthropogenic emissions are at a highest, especially over the US, Europe and Asia

  20. Observations of land-atmosphere interactions using satellite data

    NASA Astrophysics Data System (ADS)

    Green, Julia; Gentine, Pierre; Konings, Alexandra; Alemohammad, Hamed; Kolassa, Jana

    2016-04-01

    Observations of land-atmosphere interactions using satellite data Julia Green (1), Pierre Gentine (1), Alexandra Konings (1,2), Seyed Hamed Alemohammad (3), Jana Kolassa (4) (1) Columbia University, Earth and Environmental Engineering, NY, NY, USA, (2) Stanford University, Environmental Earth System Science, Stanford, CA, USA, (3) Massachusetts Institute of Technology, Civil and Environmental Engineering, Cambridge, MA, USA, (4) National Aeronautics and Space Administration/Goddard Space Flight Center, Greenbelt, MD, USA. Previous studies of global land-atmosphere hotspots have often relied solely on data from global models with the consequence that they are sensitive to model error. On the other hand, by only analyzing observations, it can be difficult to distinguish causality from mere correlation. In this study, we present a general framework for investigating land-atmosphere interactions using Granger Causality analysis applied to remote sensing data. Based on the near linear relationship between chlorophyll sun induced fluorescence (SIF) and photosynthesis (and thus its relationship with transpiration), we use the GOME-2 fluorescence direct measurements to quantify the surface fluxes between the land and atmosphere. By using SIF data to represent the flux, we bypass the need to use soil moisture data from FLUXNET (limited spatially and temporally) or remote sensing (limited by spatial resolution, canopy interference, measurement depth, and radio frequency interference) thus eliminating additional uncertainty. The Granger Causality analysis allows for the determination of the strength of the two-way causal relationship between SIF and several climatic variables: precipitation, radiation and temperature. We determine that warm regions transitioning from water to energy limitation exhibit strong feedbacks between the land surface and atmosphere due to their high sensitivity to climate and weather variability. Tropical rainforest regions show low magnitudes of

  1. Fast Emission Estimates in China Constrained by Satellite Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R.

    2013-12-01

    Emission inventories of air pollutants are crucial information for policy makers and form important input data for air quality models. Unfortunately, bottom-up emission inventories, compiled from large quantities of statistical data, are easily outdated for an emerging economy such as China, where rapid economic growth changes emissions accordingly. Alternatively, top-down emission estimates from satellite observations of air constituents have important advantages of being spatial consistent, having high temporal resolution, and enabling emission updates shortly after the satellite data become available. Constraining emissions from concentration measurements is, however, computationally challenging. Within the GlobEmission project of the European Space Agency (ESA) a new algorithm has been developed, specifically designed for fast daily emission estimates of short-lived atmospheric species on a mesoscopic scale (0.25 × 0.25 degree) from satellite observations of column concentrations. The algorithm needs only one forward model run from a chemical transport model to calculate the sensitivity of concentration to emission, using trajectory analysis to account for transport away from the source. By using a Kalman filter in the inverse step, optimal use of the a priori knowledge and the newly observed data is made. We apply the algorithm for NOx emission estimates in East China, using the CHIMERE model together with tropospheric NO2 column retrievals of the OMI and GOME-2 satellite instruments. The observations are used to construct a monthly emission time series, which reveal important emission trends such as the emission reduction measures during the Beijing Olympic Games, and the impact and recovery from the global economic crisis. The algorithm is also able to detect emerging sources (e.g. new power plants) and improve emission information for areas where proxy data are not or badly known (e.g. shipping emissions). The new emission estimates result in a better

  2. Dust emission parameterization scheme over the MENA region: Sensitivity analysis to soil moisture and soil texture

    NASA Astrophysics Data System (ADS)

    Gherboudj, Imen; Beegum, S. Naseema; Marticorena, Beatrice; Ghedira, Hosni

    2015-10-01

    The mineral dust emissions from arid/semiarid soils were simulated over the MENA (Middle East and North Africa) region using the dust parameterization scheme proposed by Alfaro and Gomes (2001), to quantify the effect of the soil moisture and clay fraction in the emissions. For this purpose, an extensive data set of Soil Moisture and Ocean Salinity soil moisture, European Centre for Medium-Range Weather Forecasting wind speed at 10 m height, Food Agricultural Organization soil texture maps, MODIS (Moderate Resolution Imaging Spectroradiometer) Normalized Difference Vegetation Index, and erodibility of the soil surface were collected for the a period of 3 years, from 2010 to 2013. Though the considered data sets have different temporal and spatial resolution, efforts have been made to make them consistent in time and space. At first, the simulated sandblasting flux over the region were validated qualitatively using MODIS Deep Blue aerosol optical depth and EUMETSAT MSG (Meteosat Seciond Generation) dust product from SEVIRI (Meteosat Spinning Enhanced Visible and Infrared Imager) and quantitatively based on the available ground-based measurements of near-surface particulate mass concentrations (PM10) collected over four stations in the MENA region. Sensitivity analyses were performed to investigate the effect of soil moisture and clay fraction on the emissions flux. The results showed that soil moisture and soil texture have significant roles in the dust emissions over the MENA region, particularly over the Arabian Peninsula. An inversely proportional dependency is observed between the soil moisture and the sandblasting flux, where a steep reduction in flux is observed at low friction velocity and a gradual reduction is observed at high friction velocity. Conversely, a directly proportional dependency is observed between the soil clay fraction and the sandblasting flux where a steep increase in flux is observed at low friction velocity and a gradual increase is

  3. Molecular simulations and experimental studies of solubility and diffusivity for pure and mixed gases of H2, CO2, and Ar absorbed in the ionic liquid 1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]).

    PubMed

    Shi, Wei; Sorescu, Dan C; Luebke, David R; Keller, Murphy J; Wickramanayake, Shan

    2010-05-20

    Classical molecular dynamics and Monte Carlo simulations are used to calculate the self-diffusivity and solubility of pure and mixed CO(2), H(2), and Ar gases absorbed in the ionic liquid 1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf(2)N]). Overall, the computed absorption isotherms, Henry's law constants, and partial molar enthalpies for pure H(2) agree well with the experimental data obtained by Maurer et al. [J. Chem. Eng. Data 2006, 51, 1364] and the experimental values determined in this work. However, the agreement is poor between the simulations and the experimental data by Noble et al. [Ind. Eng. Chem. Res. 2008, 47, 3453] and Costa Gomes [J. Chem. Eng. Data 2007, 52, 472] at high temperatures. The computed H(2) permeability values are in good agreement with the experimental data at 313 K obtained by Luebke et al. [J. Membr. Sci. 2007, 298, 41; ibid, 2008, 322, 28], but about three times larger than the experimental value at 573 K from the same group. Our computed H(2) solubilities using different H(2) potential models have similar values and solute polarizations were found to have a negligible effect on the predicted gas solubilities for both the H(2) and Ar. The interaction between H(2) and the ionic liquid is weak, about three times smaller than between the ionic liquid and Ar and six times smaller than that of CO(2) with the ionic liquid, results that are consistent with a decreasing solubility from CO(2) to Ar and to H(2). The molar volume of the ionic liquid was found to be the determining factor for the H(2) solubility. For mixed H(2) and Ar gases, the solubilities for both solutes decrease compared to the respective pure gas solubilities. For mixed gases of CO(2) and H(2), the solubility selectivity of CO(2) over H(2) decreases from about 30 at 313 K to about 3 at 573 K. For the permeability, the simulated values for CO(2) in [hmim][Tf(2)N] are about 20-60% different than the experimental data by Luebke et al. [J. Membr

  4. Impact of drought on the North America carbon balance: implications for global carbon mitigation.

    NASA Astrophysics Data System (ADS)

    Bowman, K. W.; Liu, J.; Parazoo, N.; Bloom, A. A.; Wunch, D.; Jiang, Z.; Gurney, K. R.; Schimel, D.

    2017-12-01

    Drought and heat events are significant contributors to the interanual variability of terrestrial biosphere carbon flux in temperate North America. In order to be understand the drivers of this variability, we quantified the impact of two drought events in Texas and Mexico in 2011 as wells as the United States Midwest in 2012 on Net Biome Exchange, Gross Primary Productivity, Biomass Burning, and total ecosystem respiration using the NASA Carbon Monitoring System Flux (CMS-Flux) carbon cycle data assimilation system constrained with a suite of satellite observations. The global spatial distribution of NBE was constrained by column CO2 (XCO2) observations from the Greenhouse Gases Observing Satellite (GOSAT) accounting for fossil fuel contributions, while GPP was estimated with Solar Induced Fluorescence (SIF) from the Global Ozone Monitoring Experiment-2 (GOME-2), and biomass burning was computed from CO emissions constrained by MOPITT. Total ecosystem respiration (TER) was calculated as a residual term. We found that both drought events greatly reduced NBE and GPP during the seasonal peak, but had quite different effects on the annual NBE. Due to the year-long duration of the 2011 Texas-Northern Mexico (Tex-Mex) drought, the annual net uptake was reduced by 0.28 ± 0.10 GtC, which was dominated by the reduction of GPP (-0.34 ± 0.14 GtC). The regional contribution to the atmospheric CO2 growth, which is the sum of fossil fuel emissions and the biosphere net uptake, increased by more than a factor of 3 from an average of 0.09 GtC to 0.30 GtC in 2011. In contrast, a seasonally enhanced NBE in the Midwest partially offset the drought leading to an annual NBE reduction of only 0.16 ± 0.16 GtC. The reduction of net carbon uptake from the 2011 and 2012 drought impact was 50% and 25% respectively of the regional annual fossil fuel emissions. The results show that climate variability needs to be considered in order to relate carbon mitigation strategies to regional and

  5. Three-Dimensional Analysis of Mandibular Angle Classification and Aesthetic Evaluation of the Lower Face in Chinese Female Adults.

    PubMed

    Mao, Xiaoyan; Fu, Xi; Niu, Feng; Chen, Ying; Jin, Qi; Qiao, Jia; Gui, Lai

    2018-05-14

    Reduction gonioplasty is very popular in East Asia. However, there has been little quantitative criteria for mandibular angle classification or aesthetics. The aim of this study was to investigate the quantitative differences of mandibular angle types and determine the morphologic features of mandibular angle in attractive women. We created a database of skull computed tomography and standardized frontal and lateral photographs of 96 Chinese female adults. Mandibular angle was classified into 3 groups, namely, extraversion, introversion, and healthy group, based on the position of gonion. We used a 5-point Likert scale to quantify attractiveness based on photographs. Those who scored 4 or higher were defined as attractive women. Three types of computed tomography measurements of the mandible were taken, including 4 distances, 4 angles, and 3 proportions. Discriminant analysis was applied to establish a mathematic model for mandibular angle aesthetics evaluation. Significant differences were observed between the different types of mandibular angle in lower facial width (Gol-Gor), mandibular angle (Co-Go-Me), and gonion divergence angle (Gol-Me-Gor) (P < 0.01). Chinese attractive women had a mandibular angle of 123.913 ± 2.989 degrees, a FH-MP of 27.033 ± 2.695 degrees, and a Go-Me/Co-Go index of 2.0. The "healthy" women had a mandibular angle of 116.402 ± 5.373 degrees, a FH-MP of 19.556 ± 5.999 degrees, and a Go-Me/Co-Go index of 1.6. The estimated Fisher linear discriminant function for the identification of attractive women was as follows: Y = -0.1516X1(Co-Go) + 0.128X2(Go-Me) + 0.04936X3(Co-Go-Me) +0.0218X4(FH-MP). Our study quantified the differences of mandibular angle types and identified the morphological features of mandibular angle in attractive Chinese female adults. Our results could assist plastic surgeons in presurgical designing of new aesthetic gonion and help to evaluate lower face aesthetics.

  6. Assessing the relationship between microwave vegetation optical depth and gross primary production

    NASA Astrophysics Data System (ADS)

    Teubner, Irene E.; Forkel, Matthias; Jung, Martin; Liu, Yi Y.; Miralles, Diego G.; Parinussa, Robert; van der Schalie, Robin; Vreugdenhil, Mariette; Schwalm, Christopher R.; Tramontana, Gianluca; Camps-Valls, Gustau; Dorigo, Wouter A.

    2018-03-01

    At the global scale, the uptake of atmospheric carbon dioxide by terrestrial ecosystems through photosynthesis is commonly estimated through vegetation indices or biophysical properties derived from optical remote sensing data. Microwave observations of vegetated areas are sensitive to different components of the vegetation layer than observations in the optical domain and may therefore provide complementary information on the vegetation state, which may be used in the estimation of Gross Primary Production (GPP). However, the relation between GPP and Vegetation Optical Depth (VOD), a biophysical quantity derived from microwave observations, is not yet known. This study aims to explore the relationship between VOD and GPP. VOD data were taken from different frequencies (L-, C-, and X-band) and from both active and passive microwave sensors, including the Advanced Scatterometer (ASCAT), the Soil Moisture Ocean Salinity (SMOS) mission, the Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) and a merged VOD data set from various passive microwave sensors. VOD data were compared against FLUXCOM GPP and Solar-Induced chlorophyll Fluorescence (SIF) from the Global Ozone Monitoring Experiment-2 (GOME-2). FLUXCOM GPP estimates are based on the upscaling of flux tower GPP observations using optical satellite data, while SIF observations present a measure of photosynthetic activity and are often used as a proxy for GPP. For relating VOD to GPP, three variables were analyzed: original VOD time series, temporal changes in VOD (ΔVOD), and positive changes in VOD (ΔVOD≥0). Results show widespread positive correlations between VOD and GPP with some negative correlations mainly occurring in dry and wet regions for active and passive VOD, respectively. Correlations between VOD and GPP were similar or higher than between VOD and SIF. When comparing the three variables for relating VOD to GPP, correlations with GPP were higher for the original VOD time

  7. Pre-referral rectal artesunate in severe malaria: flawed trial.

    PubMed

    Hirji, Karim F; Premji, Zulfiqarali G

    2011-08-08

    Immediate injectable treatment is essential for severe malaria. Otherwise, the afflicted risk lifelong impairment or death. In rural areas of Africa and Asia, appropriate care is often miles away. In 2009, Melba Gomes and her colleagues published the findings of a randomized, placebo-controlled trial of rectal artesunate for suspected severe malaria in such remote areas. Enrolling nearly 18,000 cases, the aim was to evaluate whether, as patients were in transit to a health facility, a pre-referral artesunate suppository blocked disease progression sufficiently to reduce these risks. The affirmative findings of this, the only trial on the issue thus far, have led the WHO to endorse rectal artesunate as a pre-referral treatment for severe malaria. In the light of its public health importance and because its scientific quality has not been assessed for a systematic review, our paper provides a detailed evaluation of the design, conduct, analysis, reporting, and practical features of this trial. We performed a checklist-based and an in-depth evaluation of the trial. The evaluation criteria were based on the CONSORT statement for reporting clinical trials, the clinical trial methodology literature, and practice in malaria research. Our main findings are: The inclusion and exclusion criteria and the sample size justification are not stated. Many clearly ineligible subjects were enrolled. The training of the recruiters does not appear to have been satisfactory. There was excessive between center heterogeneity in design and conduct. Outcome evaluation schedule was not defined, and in practice, became too wide. Large gaps in the collection of key data were evident. Primary endpoints were inconsistently utilized and reported; an overall analysis of the outcomes was not done; analyses of time to event data had major flaws; the stated intent-to-treat analysis excluded a third of the randomized subjects; the design-indicated stratified or multi-variate analysis was not done

  8. Visible spectral slope survey of Jupiter Trojans

    NASA Astrophysics Data System (ADS)

    Erasmus, Nicolas; Rivkin, Andrew S.; Sickafoose, Amanda A.

    2016-10-01

    Jupiter's Trojans are predicted by the Nice Model [1,2] to be Trans-Neptunian Objects (TNOs) that moved from 30+ AU to 5.2 AU during the early evolution period of the Solar System. This model, predicting giant planet migration and widespread transport of material throughout the Solar System, is however still lacking important constraints. Correlations between the composition, size, and orbital geometry of Jupiter's Trojans can provide additional information to test predicted migration and evolution models.Two main colour groups have been observed, roughly equivalent to the C (plus low-albedo X) and D classes with distinguishable spectral slopes, and one interpretation is that the two groups have different compositions [3]. Independent compositions together with hints of differing orbital inclination distributions could imply separate formation locations; therefore, determining the relative fractions of C and D asteroids at different sizes would provide a key test for Solar System dynamical models. However, there is a caveat: the distinct colour groups could also arise by other means. Regolith processes or "space weathering" such as micrometeorite impacts and UV irradiation of ice are also plausible explanations for a range of spectrographic slopes from C-like to D-like [4].Here we report on our latest survey observations at Sutherland, South Africa of approximately 50 Trojan targets using the Sutherland High Speed Optical Camera (SHOC) [5] on the 74" telescope. These observations are part of a larger multi-telescope survey to determine the spectral slopes (C-like or D-like) for multiple Trojans, focusing on those of small size. These slopes can be used to determine the relative fraction of C+X and D asteroids at different sizes to determine whether what is seen is more consistent with regolith processes or different compositions.References:[1] A. Morbidelli, et al. Nature, 435, 462-465, (2005)[2] R. Gomes, et al. Nature 435, 466-469 (2005)[3] J.P. Emery, et al. The

  9. Observational evidence of planetary wave influences on ozone enhancements over upper troposphere North Africa

    NASA Astrophysics Data System (ADS)

    Mengistu Tsidu, Gizaw; Ture, Kassahun; Sivakumar, V.

    2013-07-01

    MOZAIC instrument measured enhanced ozone on two occasions in February, 1996 and 1997 at cruise altitude over North Africa. The cause and source of ozone enhancements over the region are investigated using additional reanalysis data from ERA-Interim. The ERA-Interim reprocessed GOME ozone indicated existence of enhancement as well. Both observational data revealed that the increase in ozone has wider latitudinal coverage extending from North Europe upto North Africa. The geopotential heights and zonal wind from ERA-Interim have indicated existence of planetary-scale flow that allowed meridional airmass exchanges between subtropics and higher latitudes. The presence of troughs-ridge pattern are attributable to large amplitude waves of zonal wavenumber 1-5 propagating eastward in the winter hemisphere westerly current as determined from Hayashi spectra as well as local fractional variance spectra determined from Multitaper Method-Singular Value Decomposition (MTM-SVD) spectral method. MTM-SVD is also used to understand the role of these waves on ozone enhancement and variability during the observation period in a mechanistic approach. A joint analysis of driving field, such as wind and potential vorticity (PV) for which only signals of the dominant zonal wavenumbers of prevailing planetary waves are retained, has revealed strong linkage between wave activity and ozone enhancement over the region at a temporal cycle of 5.8 days. One of these features is the displacement of the polar vortex southward during the enhancements, allowing strong airmass, energy and momentum exchanges. Evidence of cutoff laws that are formed within the deep trough, characteristics of Rossby wave breaking, is also seen in the ozone horizontal distribution at different pressure levels during the events. The reconstruction of signals with the cycle of 5.8 days has shown that the time and strength of enhancement depend on the circulation patterns dictated by planetary-scale flow relative to the

  10. Four dimensional variational assimilation of in-situ and remote-sensing aerosol data

    NASA Astrophysics Data System (ADS)

    Nieradzik, L. P.; Elbern, H.

    2012-04-01

    Aerosols play an increasingly important role in atmospheric modelling. They have a strong influence on the radiative transfer balance and a significant impact on human health. Their origin is various and so are its effects. Most of the measurement sites in Europe account for an integrated aerosol load PMx (Particulate Matter of less than x μm in diameter) which does not give any qualitative information on the composition of the aerosol. Since very different constituents contribute to PMx, like e.g. mineral dust derived from desert storms or sea salt, it is necessary to make aerosol forecasts not only of load, but also type resolved. The method of four dimensional variational data assimilation (4Dvar) is a widely known technique to enhance forecast skills of CTMs (Chemistry-Transport-Models) by ingesting in-situ and, especially, remote-sensing measurements. The EURAD-IM (EURopean Air pollution Dispersion - Inverse Model), containing a full adjoint gas-phase model, has been expanded with an adjoint of the MADE (Modal Aerosol Dynamics model for Europe) to optimise initial and boundary values for aerosols using 4Dvar. A forward and an adjoint radiative transfer model is driven by the EURAD-IM as mapping between BLAOT (Boundary Layer Aerosol Optical Thickness) and internal aerosol species. Furthermore, its condensation scheme has been bypassed by an HDMR (High-Dimensional-Model-Representation) to ensure differentiability. In this study both in-situ measured PMx as well as satellite retrieved aerosol optical thicknesses have been assimilated and the effect on forecast performance has been investigated. The source of BLAOT is the aerosol retrieval system SYNAER (SYNergetic AErosol Retrieval) from DLR-DFD that retrieves AOT by making use of both AATSR/SCIAMACHY and AVHRR/GOME-2 data respectively. Its strengths are a large spatial coverage, near real-time availability, and the classification of five intrinsic aerosol species, namely water-solubles, water-insolubles, soot

  11. Evaluating the relationships between solar-induced chlorophyll fluorescence from Orbiting Carbon Observatory-2 and gross primary productivity from eddy covariance flux towers

    NASA Astrophysics Data System (ADS)

    Li, X.; Xiao, J.; He, B.

    2017-12-01

    Solar-induced chlorophyll fluorescence (SIF) opens a new perspective on the monitoring of vegetation photosynthesis from space, and has been recently used to estimate gross primary productivity (GPP). However, previous studies on SIF were mainly based on satellite observations from the Greenhouse Gases Observing Satellite (GOSAT) and Global Ozone Monitoring Experiment-2 (GOME-2), and the evaluation of these coarse-resolution SIF measurements using GPP derived from eddy covariance (EC) flux towers has been hindered by the scale mismatch between satellite and tower footprints. We use new far-red SIF observations from the Orbiting Carbon Observatory-2 (OCO-2) satellite with much finer spatial resolution and GPP data from EC flux towers from 2014 to 2016 to examine the relationship between GPP and SIF for temperate forests. The OCO-2 SIF tracked tower GPP fairly well, and had strong correlation with tower GPP at both retrieval bands (757nm and 771nm) and both instantaneous (mid-day) and daily timescales. Daily SIF at 757nm (SIF757) exhibited much stronger correlation with tower GPP compared to MODIS enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) derived from either Terra or Aqua and had a similarly strong relationship as EVI based on the bidirectional reflectance distribution function (BRDF) corrected reflectance product (Terra+Aqua). Absorbed photosynthetically active radiation (APAR) explained 85% of the variance in SIF757, while the product of APAR and two environmental scalars - fTmin and fVPD (representing minimum temperature stress and water stress) explained slightly higher variance (92%) in SIF757. This suggests that SIF mainly depends on APAR and also contains information on light use efficiency (LUE) reflecting environmental stresses and physiological or biochemical variations of vegetation. The hyperbolic model based on SIF757 estimated GPP well (R2=0.81, p<0.0001; RMSE=1.11 gC m-2 d-1), and its performance was comparable

  12. Vegetation Function and Physiology: Photosynthesis, Fluorescence and Non-photochemical Quenching (NPQ)

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Yao, T.

    2017-12-01

    Photosynthesis is a basic physiological function of vegetation that relies on PAR provided through photosynthetic pigments (mainly chlorophyll) for plant growth and biomass accumulation. Vegetation chlorophyll (chl) content and non-chlorophyll (non-chl) components vary with plant functional types (PFTs) and growing stages. The PAR absorbed by canopy chlorophyll (APARchl) is associated with photosynthesis (i.e., gross primary production, GPP) while the PAR absorbed by canopy non-chl components (APARnon-chl) is not associated with photosynthesis. Under non-optimal environmental conditions, vegetation is "stressed" and both photosynthesis (GPP) and light use efficiency are reduced, therefore, excess portions of APARchl are discarded as fluorescence or non-photochemical quenching (NPQ). The photochemical reflectance index (PRI) is a measurement related to NPQ. Both PRI and yield of solar induced chlorophyll fluorescence (SIFyield = SIF/APARchl) have been proposed as possible bio-indicators of LUEchl. We have successfully developed an algorithm to distinguish between chlorophyll and non-chl components of vegetation, and to retrieve fractional absorptions of PAR by chlorophyll (fAPARchl) and by non-chl components (fAPARnon-chl) with surface reflectance of MODIS bands 1 - 7. A method originally pioneered by Hanan et al. (2002) has been used to retrieve fAPAR for vegetation photosynthesis (fAPARPSN) at flux tower sites based on the light response curve of tower net ecosystem exchange (NEE) and incident PAR at low light intensity. We have also retrieved the PRI from MODIS data (bands 11 and 1) and have derived SIFyield with the Global Ozone Monitoring Experiment - 2 (GOME-2) SIF data. We find that fAPARPSN at flux tower sites matches well with site fAPARchl, and ratio fAPARnon-chl/fAPARchl varies largely. APARchl can explain >=78% variation in seasonal GPP . We disentangle the possible impact of fAPARchl on PRI from physiological stress response, disentangle the possible

  13. Large scale variability, long-term trends and extreme events in total ozone over the northern mid-latitudes based on satellite time series

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Staehelin, J.; Maeder, J. A.; Ribatet, M.; Davison, A. C.

    2009-04-01

    Various generations of satellites (e.g. TOMS, GOME, OMI) made spatial datasets of column ozone available to the scientific community. This study has a special focus on column ozone over the northern mid-latitudes. Tools from geostatistics and extreme value theory are applied to analyze variability, long-term trends and frequency distributions of extreme events in total ozone. In a recent case study (Rieder et al., 2009) new tools from extreme value theory (Coles, 2001; Ribatet, 2007) have been applied to the world's longest total ozone record from Arosa, Switzerland (e.g. Staehelin 1998a,b), in order to describe extreme events in low and high total ozone. Within the current study this analysis is extended to satellite datasets for the northern mid-latitudes. Further special emphasis is given on patterns and spatial correlations and the influence of changes in atmospheric dynamics (e.g. tropospheric and lower stratospheric pressure systems) on column ozone. References: Coles, S.: An Introduction to Statistical Modeling of Extreme Values, Springer Series in Statistics, ISBN:1852334592, Springer, Berlin, 2001. Ribatet, M.: POT: Modelling peaks over a threshold, R News, 7, 34-36, 2007. Rieder, H.E., Staehelin, J., Maeder, J.A., Ribatet, M., Stübi, R., Weihs, P., Holawe, F., Peter, T., and Davison, A.C.: From ozone mini holes and mini highs towards extreme value theory: New insights from extreme events and non stationarity, submitted to J. Geophys. Res., 2009. Staehelin, J., Kegel, R., and Harris, N. R.: Trend analysis of the homogenized total ozone series of Arosa (Switzerland), 1929-1996, J. Geophys. Res., 103(D7), 8389-8400, doi:10.1029/97JD03650, 1998a. Staehelin, J., Renaud, A., Bader, J., McPeters, R., Viatte, P., Hoegger, B., Bugnion, V., Giroud, M., and Schill, H.: Total ozone series at Arosa (Switzerland): Homogenization and data comparison, J. Geophys. Res., 103(D5), 5827-5842, doi:10.1029/97JD02402, 1998b.

  14. Information operator approach applied to the retrieval of vertical distributions of atmospheric constituents from ground-based FTIR measurements

    NASA Astrophysics Data System (ADS)

    Senten, Cindy; de Mazière, Martine; Vanhaelewyn, Gauthier; Vigouroux, Corinne; Delmas, Robert

    2010-05-01

    . Hoogen, R., Rozanov, V.V., and Burrows, J.P.: Ozone profiles from GOME satellite data: description and first validation, J. Geophys. Res., 104(D7), 8263-8280, 1999.

  15. Detecting volcanic sulfur dioxide plumes in the Northern Hemisphere using the Brewer spectrophotometers, other networks, and satellite observations

    NASA Astrophysics Data System (ADS)

    Zerefos, Christos S.; Eleftheratos, Kostas; Kapsomenakis, John; Solomos, Stavros; Inness, Antje; Balis, Dimitris; Redondas, Alberto; Eskes, Henk; Allaart, Marc; Amiridis, Vassilis; Dahlback, Arne; De Bock, Veerle; Diémoz, Henri; Engelmann, Ronny; Eriksen, Paul; Fioletov, Vitali; Gröbner, Julian; Heikkilä, Anu; Petropavlovskikh, Irina; Jarosławski, Janusz; Josefsson, Weine; Karppinen, Tomi; Köhler, Ulf; Meleti, Charoula; Repapis, Christos; Rimmer, John; Savinykh, Vladimir; Shirotov, Vadim; Siani, Anna Maria; Smedley, Andrew R. D.; Stanek, Martin; Stübi, René

    2017-01-01

    This study examines the adequacy of the existing Brewer network to supplement other networks from the ground and space to detect SO2 plumes of volcanic origin. It was found that large volcanic eruptions of the last decade in the Northern Hemisphere have a positive columnar SO2 signal seen by the Brewer instruments located under the plume. It is shown that a few days after the eruption the Brewer instrument is capable of detecting significant columnar SO2 increases, exceeding on average 2 DU relative to an unperturbed pre-volcanic 10-day baseline, with a mean close to 0 and σ = 0.46, as calculated from the 32 Brewer stations under study. Intercomparisons with independent measurements from the ground and space as well as theoretical calculations corroborate the capability of the Brewer network to detect volcanic plumes. For instance, the comparison with OMI (Ozone Monitoring Instrument) and GOME-2 (Global Ozone Monitoring Experiment-2) SO2 space-borne retrievals shows statistically significant agreement between the Brewer network data and the collocated satellite overpasses in the case of the Kasatochi eruption. Unfortunately, due to sparsity of satellite data, the significant positive departures seen in the Brewer and other ground networks following the Eyjafjallajökull, Bárðarbunga and Nabro eruptions could not be statistically confirmed by the data from satellite overpasses. A model exercise from the MACC (Monitoring Atmospheric Composition and Climate) project shows that the large increases in SO2 over Europe following the Bárðarbunga eruption in Iceland were not caused by local pollution sources or ship emissions but were clearly linked to the volcanic eruption. Sulfur dioxide positive departures in Europe following Bárðarbunga could be traced by other networks from the free troposphere down to the surface (AirBase (European air quality database) and EARLINET (European Aerosol Research Lidar Network)). We propose that by combining Brewer data with that

  16. Mapping cropland GPP in the north temperate region with space measurements of chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Guanter, L.; Zhang, Y.; Jung, M.; Joiner, J.; Voigt, M.; Huete, A. R.; Zarco-Tejada, P.; Frankenberg, C.; Lee, J.; Berry, J. A.; Moran, S. M.; Ponce-Campos, G.; Beer, C.; Camps-Valls, G.; Buchmann, N. C.; Gianelle, D.; Klumpp, K.; Cescatti, A.; Baker, J. M.; Griffis, T.

    2013-12-01

    Monitoring agricultural productivity is important for optimizing management practices in a world under a continuous increase of food and biofuel demand. We used new space measurements of sun-induced chlorophyll fluorescence (SIF), a vegetation parameter intrinsically linked to photosynthesis, to capture photosynthetic uptake of the crop belts in the north temperate region. The following data streams and procedures have been used in this analysis: (1) SIF retrievals have been derived from measurements of the MetOp-A / GOME-2 instrument in the 2007-2011 time period; (2) ensembles of process-based and data-driven biogeochemistry models have been analyzed in order to assess the capability of global models to represent crop gross primary production (GPP); (3) flux tower-based GPP estimates covering the 2007-2011 time period have been extracted over 18 cropland and grassland sites in the Midwest US and Western Europe from the Ameriflux and the European Fluxes Database networks; (4) large-scale NPP estimates have been derived by the agricultural inventory data sets developed by USDA-NASS and Monfreda et al. The strong linear correlation between the SIF space retrievals and the flux tower-based GPP, found to be significantly higher than that between reflectance-based vegetation indices (EVI, NDVI and MTCI) and GPP, has enabled the direct upscaling of SIF to cropland GPP maps at the synoptic scale. The new crop GPP estimates we derive from the scaling of SIF space retrievals are consistent with both flux tower GPP estimates and agricultural inventory data. These new GPP estimates show that crop productivity in the US Western Corn Belt, and most likely also in the rice production areas in the Indo-Gangetic plain and China, is up to 50-75% higher than estimates by state-of-the-art data-driven and process-oriented biogeochemistry models. From our analysis we conclude that current carbon models have difficulties in reproducing the special conditions of those highly productive

  17. Assessing the Suitability and Limitations of Satellite-based Measurements for Estimating CO, CO2, NO2 and O3 Concentrations over the Niger Delta

    NASA Astrophysics Data System (ADS)

    Fagbeja, M. A.; Hill, J. L.; Chatterton, T. J.; Longhurst, J. W.; Akinyede, J. O.

    2011-12-01

    Space-based satellite sensor technology may provide important tools in the study and assessment of national, regional and local air pollution. However, the application of optical satellite sensor observation of atmospheric trace gases, including those considered to be 'air pollutants', within the lower latitudes is limited due to prevailing climatic conditions. The lack of appropriate air pollution ground monitoring stations within the tropical belt reduces the ability to verify and calibrate space-based measurements. This paper considers the suitability of satellite remotely sensed data in estimating concentrations of atmospheric trace gases in view of the prevailing climate over the Niger Delta region. The methodological approach involved identifying suitable satellite data products and using the ArcGIS Geostatistical Analyst kriging interpolation technique to generate surface concentrations from satellite column measurements. The observed results are considered in the context of the climate of the study area. Using data from January 2001 to December 2005, an assessment of the suitability of satellite sensor data to interpolate column concentrations of trace gases over the Niger Delta has been undertaken and indicates varying degrees of reliability. The level of reliability of the interpolated surfaces is predicated on the number and spatial distributions of column measurements. Accounting for the two climatic seasons in the region, the interpolation of total column concentrations of CO and CO2 from SCIAMACHY produced both reliable and unreliable results over inland parts of the region during the dry season, while mainly unreliable results are observed over the coastal parts especially during the rainy season due to inadequate column measurements. The interpolation of tropospheric measurements of NO2 and O3 from GOME and OMI respectively produced reliable results all year. This is thought to be due to the spatial distribution of available column measurements

  18. A new SO2 emissions budget for Anatahan volcano (Mariana Islands) based on ten years of satellite observations

    NASA Astrophysics Data System (ADS)

    McCormick, Brendan; Popp, Christoph; Andrews, Benjamin; Cottrell, Elizabeth

    2015-04-01

    Satellite remote sensing offers great potential for the study of sulphur dioxide (SO2) gas emissions from volcanoes worldwide. Anatahan is a remote volcano in the Mariana Islands, SW Pacific. Existing SO2 emissions data from Anatahan, from ground-based UV spectrometer measurements, place the volcano among the largest natural SO2 sources worldwide. However, these measurements are limited in number and only available from intervals of eruptive activity. Activity varies widely at Anatahan: over the past decade, records held in the Smithsonian Institution Global Volcanism Program Volcanoes of the World database describe the alternation of intense eruptions with long intervals of quiescence, where much lower intensity activity took place. We present ten years of satellite-based measurements of SO2 in the atmosphere over Anatahan, using data from the UV spectrometers OMI, GOME-2, and SCIAMACHY, and the IR spectrometer AIRS. We find Anatahan's emissions to be highly variable both within and between intervals of eruption and quiescence. We demonstrate a close agreement between trends in SO2 emission evident from our remote sensing data and records of activity compiled from a range of other sources and instruments, across daily to annual temporal scales. Mean eruptive SO2 emissions at Anatahan are ~6400 t/d, and range from <1000 to >18000 t/d. Quiescent emissions are below our instrument detection limits and are therefore unlikely to exceed 150-300 t/d. Overall, accounting for both eruptive and quiescent emissions, we calculate a revised decadal mean SO2 emission rate of 1060-1200 t/d. We further calculate a total decadal SO2 yield from Anatahan of 4-5 Mt, significantly lower than the 17-34 Mt calculated if ground-based campaign data are used in isolation. The use of isolated measurements to extrapolate longer term emissions budgets is subject to clear uncertainty, and we argue that our satellite observations, covering a longer interval of Anatahan's history, are better

  19. Injection of Lightning-Produced NOx, Water Vapor, Wildfire Emissions, and Stratospheric Air to the UT/LS as Observed from DC3 Measurements

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Lichtenstern, M.; Scheibe, M.; Aufmhoff, H.; Schlager, H.; Minikin, A.; Weinzierl, B.; Pollack, I. B.; Peischl, J.; Ryerson, T. B.; Weinheimer, A. J.; Honomichl, S.; Ridley, B. A.; Hair, J. W.; Schwartz, M. J.; Rappenglück, B.; Pickering, K. E.; Cummings, K.; Biggerstaff, M. I.; Heimerl, K.; Pucik, T.; Fütterer, D.; Ackermann, L.; Betten, D.; Butler, C. F.; Barth, M. C.

    2015-12-01

    In summer 2012 the Deep Convective Clouds and Chemistry Project (DC3) field campaign investigated a number of severe thunderstorms over the Central U.S. and their impact on the upper tropospheric (UT) - lower stratospheric (LS) composition and chemistry. In addition, during DC3 some of the largest and most destructive wildfires in New Mexico and Colorado state history were burning, influencing the air quality in the DC3 thunderstorm inflow and outflow region. Besides three instrumented aircraft platforms measuring a variety of trace species in-situ and remotely (e.g. CO, O3, SO2, NOx, VOC, CN, and black carbon), dense networks of ground-based instruments (e.g. radar and lightning) complemented the airborne measurements. Satellite measurements (e.g. GOES, MODIS, and GOME-2) and model forecasts (e.g. WRF-Chem and FLEXPART) were used to monitor the rapid development of the thunderstorms (which frequently developed huge anvils with overshooting tops) and the spread of smoke plumes in the vicinity of the storms. In-situ probing of fresh and aged (12-24 h) anvil outflows showed injection of lightning-produced NOx and wildfire emissions into the UTLS. Vertical cross sections of lidar and Doppler radar measurements supported these observations and gave detailed information on dynamical processes within and in the vicinity of the storms. Besides very strong updrafts in the storm core, surrounding downdrafts caused a direct in-mixing of O3-rich LS air masses into the boundaries of the anvil outflow. The wrapping of O3-rich LS air masses around and below the anvil outflow was also a prominent feature in several storms. The in-situ probing of the aged anvil outflow showed a pronounced influence on the UT composition and chemistry with average O3 enhancements in the range of 20-50 nmol mol-1 and evidence of new particle formation. A 10-year global climatology of H2O data from Aura-MLS confirms that the Central U.S. is a preferred region for convective injection into the LS.

  20. Injection of Lightning-Produced NOx, Water Vapor, Wildfire Emissions, and Stratospheric Air to the UT/LS as Observed from DC3 Measurements

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Lichtenstern, M.; Scheibe, M.; Aufmhoff, H.; Schlager, H.; Minikin, A.; Weinzierl, B.; Pollack, I. B.; Peischl, J.; Ryerson, T. B.; Weinheimer, A. J.; Honomichl, S.; Ridley, B. A.; Hair, J. W.; Schwartz, M. J.; Rappenglück, B.; Pickering, K. E.; Cummings, K.; Biggerstaff, M. I.; Heimerl, K.; Pucik, T.; Fütterer, D.; Ackermann, L.; Betten, D.; Butler, C. F.; Barth, M. C.

    2014-12-01

    In summer 2012 the Deep Convective Clouds and Chemistry Project (DC3) field campaign investigated a number of severe thunderstorms over the Central U.S. and their impact on the upper tropospheric (UT) - lower stratospheric (LS) composition and chemistry. In addition, during DC3 some of the largest and most destructive wildfires in New Mexico and Colorado state history were burning, influencing the air quality in the DC3 thunderstorm inflow and outflow region. Besides three instrumented aircraft platforms measuring a variety of trace species in-situ and remotely (e.g. CO, O3, SO2, NOx, VOC, CN, and black carbon), dense networks of ground-based instruments (e.g. radar and lightning) complemented the airborne measurements. Satellite measurements (e.g. GOES, MODIS, and GOME-2) and model forecasts (e.g. WRF-Chem and FLEXPART) were used to monitor the rapid development of the thunderstorms (which frequently developed huge anvils with overshooting tops) and the spread of smoke plumes in the vicinity of the storms. In-situ probing of fresh and aged (12-24 h) anvil outflows showed injection of lightning-produced NOx and wildfire emissions into the UTLS. Vertical cross sections of lidar and Doppler radar measurements supported these observations and gave detailed information on dynamical processes within and in the vicinity of the storms. Besides very strong updrafts in the storm core, surrounding downdrafts caused a direct in-mixing of O3-rich LS air masses into the boundaries of the anvil outflow. The wrapping of O3-rich LS air masses around and below the anvil outflow was also a prominent feature in several storms. The in-situ probing of the aged anvil outflow showed a pronounced influence on the UT composition and chemistry with average O3 enhancements in the range of 20-50 nmol mol-1 and evidence of new particle formation. A 10-year global climatology of H2O data from Aura-MLS confirms that the Central U.S. is a preferred region for convective injection into the LS.

  1. Experiences of a Motivational Interview Delivered by a Robot: Qualitative Study.

    PubMed

    Galvão Gomes da Silva, Joana; Kavanagh, David J; Belpaeme, Tony; Taylor, Lloyd; Beeson, Konna; Andrade, Jackie

    2018-05-03

    intervention increased their physical activity levels. Social robots can achieve a fundamental objective of motivational interviewing, encouraging participants to articulate their goals and dilemmas aloud. Because they are perceived as nonjudgmental, robots may have advantages over more humanoid avatars for delivering virtual support for behavioral change. ©Joana Galvão Gomes da Silva, David J Kavanagh, Tony Belpaeme, Lloyd Taylor, Konna Beeson, Jackie Andrade. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 03.05.2018.

  2. Antarctic ozone loss in 1989-2010: evidence for ozone recovery?

    NASA Astrophysics Data System (ADS)

    Kuttippurath, J.; Lefèvre, F.; Pommereau, J.-P.; Roscoe, H. K.; Goutail, F.; Pazmiño, A.; Shanklin, J. D.

    2012-04-01

    We present a detailed estimation of chemical ozone loss in the Antarctic polar vortex from 1989 to 2010. The analyses include ozone loss estimates for 12 Antarctic ground-based (GB) stations. All GB observations show minimum ozone in the late September-early October period. Among the stations, the lowest minimum ozone values are observed at South Pole and the highest at Dumont d'Urville. The ozone loss starts by mid-June at the vortex edge and then progresses towards the vortex core with time. The loss intensifies in August-September, peaks by the end of September-early October, and recovers thereafter. The average ozone loss in the Antarctic is revealed to be about 33-50% in 1989-1992 in agreement with the increase in halogens during this period, and then stayed at around 48% due to saturation of the loss. The ozone loss in the warmer winters (e.g. 2002, and 2004) is lower (37-46%) and in the colder winters (e.g. 2003, and 2006) is higher (52-55%). Because of small inter-annual variability, the correlation between ozone loss and the volume of polar stratospheric clouds yields ~0.51. The GB ozone and ozone loss values are in good agreement with those found from the space-based observations of the Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), the Global Ozone Monitoring Experiment (GOME), the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and the Aura Microwave Limb Sounder (MLS), where the differences are within ±5% and are mostly within the error bars of the measurements. The piece-wise linear trends computed from the September-November vortex average GB and TOMS/OMI ozone show about -4 to -5.6 DU (Dobson Unit) yr-1 in 1989-1996 and about +1 DU yr-1 in 1997-2010. The trend during the former period is significant at 95% confidence intervals, but the trend in 1997-2010 is significant only at 85% confidence intervals. Our analyses suggest a period of about 9-10 yr to get the first detectable ozone

  3. Sensitivity of spectral climate signals to the emissions of atmospheric dust

    NASA Astrophysics Data System (ADS)

    Xu, X.; Wang, J.; Wang, Y.; Henze, D. K.; Zhang, L.

    2015-12-01

    Mineral dust particles profoundly influence the Earth climate due to their varied affects on the radiation and cloud physics. The knowledge of dust emissions from daily to seasonal scales is thus important for interpreting the past and predicting the future climate changes. Satellite measured radiances in the shortwave and thermal infrared are sensitive to the amount and properties of mineral dust present in the atmosphere. Therefore, the climate (i.e., monthly averages) of these reflectance spectra could contain valuable information on the change of dust emissions. In this work, we investigate the feasibility of using the climate of spectral radiances for recovering dust emissions. An observation simulation system (OSS) that incorporates the Unified Linearized Vector Radiative Transfer Model (UNL-VRTM) with forward and adjoint global chemistry transport models (GEOS-Chem and FIM-Chem) has been applied to generate synthetic hyperspectral climate data in the shortwave and thermal infrared (TIR) for summer 2008. Along with the calculation of radiances at the top of the atmosphere (TOA), the OSS also computes their Jacobians of these synthetic data to dust optical depth, plume height, and effective radius, as well as the adjoint gradients of spectral radiances to dust emissions. We found that the brightness temperature (BT) in the TIR spectra at TOA is sensitive to both of the dust plume height and particle size. For the same relative changes of these parameters, BT shows largest change with respect to particle size at the wavenumber of 890-1200 cm-1. This demonstrates the potential for retrieving three-dimensional dust information along with the particle size from hyperspectral TIR measurements. We also assess the information content of monthly versus instantaneous radiances for constraining dust emissionsthe from the calculated adjoint gradients. Our analysis may guide new applications of long-term spectral radiance measurements (such as those from GOME, AIRS, IASI

  4. Multi-satellite sensor study on precipitation-induced emission pulses of NOx from soils in semi-arid ecosystems

    NASA Astrophysics Data System (ADS)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Sihler, Holger; Veres, Patrick R.; Williams, Jonathan; Wagner, Thomas

    2016-07-01

    We present a top-down approach to infer and quantify rain-induced emission pulses of NOx ( ≡ NO + NO2), stemming from biotic emissions of NO from soils, from satellite-borne measurements of NO2. This is achieved by synchronizing time series at single grid pixels according to the first day of rain after a dry spell of prescribed duration. The full track of the temporal evolution several weeks before and after a rain pulse is retained with daily resolution. These are needed for a sophisticated background correction, which accounts for seasonal variations in the time series and allows for improved quantification of rain-induced soil emissions. The method is applied globally and provides constraints on pulsed soil emissions of NOx in regions where the NOx budget is seasonally dominated by soil emissions. We find strong peaks of enhanced NO2 vertical column densities (VCDs) induced by the first intense precipitation after prolonged droughts in many semi-arid regions of the world, in particular in the Sahel. Detailed investigations show that the rain-induced NO2 pulse detected by the OMI (Ozone Monitoring Instrument), GOME-2 and SCIAMACHY satellite instruments could not be explained by other sources, such as biomass burning or lightning, or by retrieval artefacts (e.g. due to clouds). For the Sahel region, absolute enhancements of the NO2 VCDs on the first day of rain based on OMI measurements 2007-2010 are on average 4 × 1014  molec cm-2 and exceed 1 × 1015  molec cm-2 for individual grid cells. Assuming a NOx lifetime of 4 h, this corresponds to soil NOx emissions in the range of 6 up to 65 ng N m-2 s-1, which is in good agreement with literature values. Apart from the clear first-day peak, NO2 VCDs are moderately enhanced (2 × 1014  molec cm-2) compared to the background over the following 2 weeks, suggesting potential further emissions during that period of about 3.3 ng N m-2 s-1

  5. Modeling dynamic exchange of gaseous elemental mercury at polar sunrise.

    PubMed

    Dastoor, Ashu P; Davignon, Didier; Theys, Nicolas; Van Roozendael, Michel; Steffen, Alexandra; Ariya, Parisa A

    2008-07-15

    At polar sunrise, gaseous elemental mercury (GEM) undergoes an exceptional dynamic exchange in the air and at the snow surface during which GEM can be rapidly removed from the atmosphere (the so-called atmospheric mercury depletion events (AMDEs)) as well as re-emitted from the snow within a few hours to days in the Polar Regions. Although high concentrations of total mercury in snow following AMDEs is well documented, there is very little data available on the redox transformation processes of mercury in the snow and the fluxes of mercury at the air/snow interface. Therefore, the net gain of mercury in the Polar Regions as a result of AMDEs is still an open question. We developed a new version of the global mercury model, GRAHM, which includes for the first time bidirectional surface exchange of GEM in Polar Regions in spring and summer by developing schemes for mercury halogen oxidation, deposition, and re-emission. Also for the first time, GOME satellite data-derived boundary layer concentrations of BrO have been used in a global mercury model for representation of halogen mercury chemistry. Comparison of model simulated and measured atmospheric concentrations of GEM at Alert, Canada, for 3 years (2002-2004) shows the model's capability in simulating the rapid cycling of mercury during and after AMDEs. Brooks et al. (1) measured mercury deposition, reemission, and net surface gain fluxes of mercury at Barrow, AK, during an intensive measurement campaign for a 2 week period in spring (March 25 to April 7, 2003). They reported 1.7, 1.0 +/- 0.2, and 0.7 +/- 0.2 microg m(-2) deposition, re-emission, and net surface gain, respectively. Using the optimal configuration of the model, we estimated 1.8 microg m(-2) deposition, 1.0 microg m(-2) re-emission, and 0.8 microg m(-2) net surface gain of mercury for the same time period at Barrow. The estimated net annual accumulation of mercury within the Arctic Circle north of 66.5 degrees is approximately 174 t with +/-7 t of

  6. Effects of Sabbagh Universal Spring 2 fixed functional appliance on class II/1 patients at their postpubertal-peak growth period compared with the extraction method : A randomized clinical trial.

    PubMed

    Hemmatpour, Siamak; Mokhtar, Ali; Rakhshan, Vahid

    2017-01-01

    The aim of this study was to evaluate the therapeutic effects of the Sabbagh Universal Spring 2 (SUS 2) fixed functional appliance compared to the premolar extraction method in correcting class II/1 malocclusion in patients who had passed their peak of postpubertal growth (stages 4-6 of Cervical Vertebral Maturation Index). In all, 40 class II/1 patients were randomized to receive SUS 2 application (7 males, 13 females, age 15.75 ± 1.02 years) or maxillary premolar extraction (8 males, 12 females, age 15.40 ± 0.99 years). Pre- and posttreatment digital cephalographs were traced at least twice. A paired t test was used to compare the pre- and posttreatment measurements. Treatment changes were compared using an independent samples t test (P ≤ 0.05). The extent of change was significant in the following variables: ANB, nasolabial angle, Mand1-ML, 1L-NB, anterior and posterior facial heights, N-A-Pog, 1U-NF, 6L-MP, Ar-Go, OP-HP, A-B, A-Sn, B-Sm, APDI, NAPog, AB-NPog, POr-DOP, SN-OcP, POr-OcP, Wits, 1 l-APog, 1LMeLm, S-Go:N-Me, N-ANS-Pog, Ap1LAp1u-DOP, ANS-Cond, Pog-Cond, SS-Ls, A-N-Pog, Pog-Pog', MeGoOcP, 1L-Npog, Go-Me, Go-Me:N-S, S-Me, Ls-(Sn-Pog'), Stms-Stmi, N'-Gn', N'NsPog', 6u-PTV, 1u-NA, FMIA, and IMPA. SUS 2 corrected class II/1 malocclusion of patients in the postpubertal growth period by inhibiting the maxilla's forward growth, advancing the mandible, decreasing the nasolabial and interincisal angles, proclining the incisors, increasing the facial height, and clockwise rotation of the occlusal plane. Extraction reduced the interincisal angle and protruded the lower incisors. However, it did not change the soft tissue thickness and did not cause a clockwise rotation in the occlusal plane.

  7. Impact of Ozone Radiative Feedbacks on Global Weather Forecasting

    NASA Astrophysics Data System (ADS)

    Ivanova, I.; de Grandpré, J.; Rochon, Y. J.; Sitwell, M.

    2017-12-01

    A coupled Chemical Data Assimilation system for ozone is being developed at Environment and Climate Change Canada (ECCC) with the goals to improve the forecasting of UV index and the forecasting of air quality with the Global Environmental Multi-scale (GEM) Model for Air quality and Chemistry (MACH). Furthermore, this system provides an opportunity to evaluate the benefit of ozone assimilation for improving weather forecasting with the ECCC Global Deterministic Prediction System (GDPS) for Numerical Weather Prediction (NWP). The present UV index forecasting system uses a statistical approach for evaluating the impact of ozone in clear-sky and cloudy conditions, and the use of real-time ozone analysis and ozone forecasts is highly desirable. Improving air quality forecasting with GEM-MACH further necessitates the development of integrated dynamical-chemical assimilation system. Upon its completion, real-time ozone analysis and ozone forecasts will also be available for piloting the regional air quality system, and for the computation of ozone heating rates, in replacement of the monthly mean ozone distribution currently used in the GDPS. Experiments with ozone radiative feedbacks were run with the GDPS at 25km resolution and 84 levels with a lid at 0.1 hPa and were initialized with ozone analysis that has assimilated total ozone column from OMI, OMPS, and GOME satellite instruments. The results show that the use of prognostic ozone for the computation of the heating/cooling rates has a significant impact on the temperature distribution throughout the stratosphere and upper troposphere regions. The impact of ozone assimilation is especially significant in the tropopause region, where ozone heating in the infrared wavelengths is important and ozone lifetime is relatively long. The implementation of the ozone radiative feedback in the GDPS requires addressing various issues related to model biases (temperature and humidity) and biases in equilibrium state (ozone mixing

  8. A space-borne, multi-parameter, Virtual Volcano Observatory for the real-time, anywhere-anytime support to decision-making during eruptive crises

    NASA Astrophysics Data System (ADS)

    Ferrucci, F.; Tampellini, M.; Loughlin, S. C.; Tait, S.; Theys, N.; Valks, P.; Hirn, B.

    2013-12-01

    The EVOSS consortium of academic, industrial and institutional partners in Europe and Africa, has created a satellite-based volcano observatory, designed to support crisis management within the Global Monitoring for Environment and Security (GMES) framework of the European Commission. Data from 8 different payloads orbiting on 14 satellite platforms (SEVIRI on-board MSG-1, -2 and -3, MODIS on-board Terra and Aqua, GOME-2 and IASI onboard MetOp-A, OMI on-board Aura, Cosmo-SkyMED/1, /2, /3 and /4, JAMI on-board MTSAT-1 and -2, and, until April 8th2012, SCHIAMACHY on-board ENVISAT) acquired at 5 different down-link stations, are disseminated to and automatically processed at 6 locations in 4 countries. The results are sent, in four separate geographic data streams (high-temperature thermal anomalies, volcanic Sulfur dioxide daily fluxes, volcanic ash and ground deformation), to a central facility called VVO, the 'Virtual Volcano Observatory'. This system operates 24H/24-7D/7 since September 2011 on all volcanoes in Europe, Africa, the Lesser Antilles, and the oceans around them, and during this interval has detected, measured and monitored all subaerial eruptions occurred in this region (44 over 45 certified, with overall detection and processing efficiency of ~97%). EVOSS borne realtime information is delivered to a group of 14 qualified end users, bearing the direct or indirect responsibility of monitoring and managing volcano emergencies, and of advising governments in Comoros, DR Congo, Djibouti, Ethiopia, Montserrat, Uganda, Tanzania, France and Iceland. We present the full set of eruptions detected and monitored - from 2004 to present - by multispectral payloads SEVIRI onboard the geostationary platforms of the MSG constellation, for developing and fine tuning-up the EVOSS system along with its real-time, pre- and post-processing automated algorithms. The set includes 91% of subaerial eruptions occurred at 15 volcanoes (Piton de la Fournaise, Karthala, Jebel al

  9. PREFACE: XXXV Symposium on Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Padilla-Rodal, E.; Bijker, R.

    2012-09-01

    for Mexican students to present their current research and interact with the visiting scientists. The present volume contains 21 research articles based on invited talks presented at the symposium. We cannot thank enough to all the authors for their enthusiastic contribution, to the anonymous referees for the time they devoted to the review process, which helped us to maintain the high standard of the Conference Proceedings. Finally we would like to thank the International Advisory Committee and the Sponsoring Organizations that made this event possible. E Padilla-Rodal and R Bijker Editors Conference photograph International Advisory Committee Osvaldo Civitarese, Universidad Nacional de La Plata, Argentina Jerry P Draayer, Louisiana State University, USA Alfredo Galindo-Uribarri, Oak Ridge National Laboratory, USA Paulo Gomes, Universidade Federal Fluminense, Brazil Piet Van Isacker, GANIL, France James J Kolata, University of Notre Dame, USA Reiner Krücken, TRIUMF, Canada Jorge López, The University of Texas at El Paso, USA Stuart Pittel, University of Delaware, USA W Michael Snow, Indiana University, USA Adam Szczepaniak, Indiana University, USA Michael Wiescher, University of Notre Dame, USA Organizing Committee Elizabeth Padilla-Rodal (Chair), Instituto de Ciencias Nucleares, UNAM, Mexico Roelof Bijker, Instituto de Ciencias Nucleares, UNAM, Mexico Sponsoring Organizations División de Física Nuclear, SMF Dirección General de Asuntos de Personal Académico, UNAM Centro Latino-Americano de Física Instituto de Ciencias Nucleares, UNAM Instituto de Física, UNAM Instituto Nacional de Investigaciones Nucleares

  10. Isoprene emissions over Asia 1979-2012: impact of climate and land use changes

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; Guenther, A.; Wild, M.; Xia, X.

    2013-11-01

    using top-down isoprene emission estimates derived from inverse modelling constrained by GOME-2/MetOp-A formaldehyde columns through 2007-2012. The satellite-based estimates appear to support our assumptions, and confirm the lower emission rate in tropical forests of Indonesia and Malaysia. Additional flux measurements are clearly needed to better characterize the spatial variability of emission factors. Finally, a decreasing trend in the top-down Chinese emissions inferred after 2007, is in line with the cooling episode recorded in China after that year, thus suggesting that the satellite HCHO columns are able to capture climate-induced changes in emissions.

  11. Isoprene emissions over Asia 1979-2012: impact of climate and land-use changes

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; Guenther, A.; Wild, M.; Xia, X.

    2014-05-01

    positive flux trends of 0.2% and 0.52% throughout the entire period are found in Asia and China, respectively, related to a positive trend in temperature and solar radiation. The impact of oil palm expansion in Indonesia and Malaysia is to enhance the trends over that region, e.g., from 1.17% to 1.5% in 1979-2005 in Malaysia. A negative emission trend is derived in India (-0.4%), owing to the negative trend in solar radiation data associated with the strong dimming effect likely due to increasing aerosol loadings. The bottom-up emissions are compared to field campaign measurements in Borneo and South China and further evaluated against top-down isoprene emission estimates constrained by GOME-2/MetOp-A formaldehyde columns through 2007-2012. The satellite-based estimates appear to support our assumptions, and confirm the lower emission rate in tropical forests of Indonesia and Malaysia. Additional flux measurements are clearly needed to characterize the spatial variability of emission factors better. Finally, a decreasing trend in the inferred top-down Chinese emissions since 2007 is in line with recorded cooling in China after that year, thus suggesting that the satellite HCHO columns are able to capture climate-induced changes in emissions.

  12. Isoprene emissions over Asia 1979–2012: impact of climate and land-use changes

    SciTech Connect

    Stavrakou, T.; Müller, J. -F.; Bauwens, M.

    2014-01-01

    simulation, annual positive flux trends of 0.2% and 0.52% throughout the entire period are found in Asia and China, respectively, related to a positive trend in temperature and solar radiation. The impact of oil palm expansion in Indonesia and Malaysia is to enhance the trends over that region, e.g., from 1.17% to 1.5% in 1979–2005 in Malaysia. A negative emission trend is derived in India (-0.4%), owing to the negative trend in solar radiation data associated with the strong dimming effect likely due to increasing aerosol loadings. The bottom-up emissions are compared to field campaign measurements in Borneo and South China and further evaluated against top-down isoprene emission estimates constrained by GOME-2/MetOp-A formaldehyde columns through 2007–2012. The satellite-based estimates appear to support our assumptions, and confirm the lower emission rate in tropical forests of Indonesia and Malaysia. Additional flux measurements are clearly needed to characterize the spatial variability of emission factors better. To conclude, a decreasing trend in the inferred top-down Chinese emissions since 2007 is in line with recorded cooling in China after that year, thus suggesting that the satellite HCHO columns are able to capture climate-induced changes in emissions.« less

  13. Aerosol indirect effects on lightning in the generation of induced NOx and tropospheric ozone over an Indian urban metropolis

    NASA Astrophysics Data System (ADS)

    Saha, Upal; Maitra, Animesh; Talukdar, Shamitaksha; Jana, Soumyajyoti

    Lightning flashes, associated with vigorous convective activity, is one of the most prominent weather phenomena in the tropical atmosphere. High aerosol loading is indirectly associated with the increase in lightning flash rates via the formation of tropospheric ozone during the pre-monsoon and monsoon over the tropics. Tropospheric ozone, an important greenhouse pollutant gas have impact on Earth’s radiation budget and play a key role in changing the atmospheric circulation patterns. Lightning-induced NOx is a primary pollutant found in photochemical smog and an important precursor for the formation of tropospheric ozone. A critical analysis is done to study the indirect effects of high aerosol loading on the formation of tropospheric ozone via lightning flashes and induced NOx formation over an urban metropolitan location Kolkata (22°32'N, 88°20'E), India during the period 2001-2012. The seasonal variation of lightning flash rates (LFR), taken from TRMM-LIS 2.5o x 2.5o gridded dataset, show that the LFR was observed to be intensified in the pre-monsoon (March-May) and high in monsoon (June-September) months over the region. Aerosol Optical Depth (AOD) at 555nm, taken from MISR 0.5o x 0.5o gridded level-3 dataset, plays an indirect effect on the increase in LFR during the pre-monsoon and monsoon months and has positive correlations between them during these periods. This is also justified from the seasonal variation of the increase in LFR due to the increase in AOD over the region during 2001-2012. The calibrated GOME and OMI/AURA satellite data analysis shows that the tropospheric ozone, formed as a result of lightning-induced NOx and due to the increased AOD at 555 nm, also increases during the pre-monsoon and monsoon months. The seasonal variation of lightning-induced tropospheric NOx, taken from SCIAMACHY observations also justified the fact that the pre-monsoon and monsoon LFR solely responsible for the generation of induced NOx over the region. The

  14. Chronology of the 2014 volcanic eruption on the island of Fogo, Cape Verde

    NASA Astrophysics Data System (ADS)

    Silva, Sónia; Cardoso, Nadir; Alfama, Vera; Cabral, Jeremias; Semedo, Helio; Pérez, Nemesio M.; Dionis, Samara; Hernández, Pedro A.; Barrancos, José; Melián, Gladys V.; Pereira, José Manuel; Rodríguez, Fátima

    2015-04-01

    . Day, S. J., Heleno da Silva, S. I. N., and Fonseca, J. F. B. D.: A past giant lateral collapse and present-day flank instability of Fogo, Cape Verde Islands, J. Volcanol. Geotherm. Res., 94, 191-218, 1999. Foeken, J., Day, S., and Stuart, F.: Cosmogenic 3He exposure dating of the Quaternary basalts from Fogo, Cape Verdes: Implications for rift zone and magmatic reorganisation, Quaternary Geochron., 4, 37-49, doi:10.1016/j.quageo.2008.07.002, 2009. Ribeiro, O.: A ilha do Fogo e as suas erupções, 12a edição, Memórias, Série Geográfica, J. Inv. Ultramar, 1960. Torres, P.C., Madeira, J., Silva, L.C., Silveira, A.B., Serralheiro, A. & Mota Gomes, A. (1997) - Carta geológica das erupções históricas da ilha do Fogo: revisão e actualização, in "A erupção vulcânica de 1995 na ilha do Fogo, Cabo Verde", Lisboa, 119-132.

  15. GENESI-DR: Discovery, Access and on-Demand Processing in Federated Repositories

    NASA Astrophysics Data System (ADS)

    Cossu, Roberto; Pacini, Fabrizio; Parrini, Andrea; Santi, Eliana Li; Fusco, Luigi

    2010-05-01

    -DR operational platform is currently being validated against several applications from different domains, such as: automatic orthorectification of SPOT data; SAR Interferometry; GlobModel results visualization and verification by comparison with satellite observations; ozone estimation from ERS-GOME products and comparison with in-situ LIDAR measures; access to ocean-related heterogeneous data and on-the-fly generated products. The project is adopting, ISO 19115, ISO 19139 and OGC standards for geospatial metadata discovery and processing, is compliant with the basis of INSPIRE Implementing Rules for Metadata and Discovery, and uses the OpenSearch protocol with Geo extensions for data and services discovery. OpenSearch is now considered by OGC a mass-market standard to provide machine accessible search interface to data repositories. GENESI-DR is gaining momentum in the Earth Science community thanks to the active participation to the GEO task force "Data Integration and Analysis Systems" and to the several collaborations with EC projects. It is now extending international cooperation agreements specifically with the NASA (Goddard Earth Sciences Data Information Services), with CEODE (the Center of Earth Observation for Digital Earth of Beijing), with the APN (Asia-Pacific Network), with University of Tokyo (Japanese GeoGrid and Data Integration and Analysis System).

  16. TEMIS UV product validation using NILU-UV ground-based measurements in Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Zempila, Melina-Maria; van Geffen, Jos H. G. M.; Taylor, Michael; Fountoulakis, Ilias; Koukouli, Maria-Elissavet; van Weele, Michiel; van der A, Ronald J.; Bais, Alkiviadis; Meleti, Charikleia; Balis, Dimitrios

    2017-06-01

    This study aims to cross-validate ground-based and satellite-based models of three photobiological UV effective dose products: the Commission Internationale de l'Éclairage (CIE) erythemal UV, the production of vitamin D in the skin, and DNA damage, using high-temporal-resolution surface-based measurements of solar UV spectral irradiances from a synergy of instruments and models. The satellite-based Tropospheric Emission Monitoring Internet Service (TEMIS; version 1.4) UV daily dose data products were evaluated over the period 2009 to 2014 with ground-based data from a Norsk Institutt for Luftforskning (NILU)-UV multifilter radiometer located at the northern midlatitude super-site of the Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki (LAP/AUTh), in Greece. For the NILU-UV effective dose rates retrieval algorithm, a neural network (NN) was trained to learn the nonlinear functional relation between NILU-UV irradiances and collocated Brewer-based photobiological effective dose products. Then the algorithm was subjected to sensitivity analysis and validation. The correlation of the NN estimates with target outputs was high (r = 0. 988 to 0.990) and with a very low bias (0.000 to 0.011 in absolute units) proving the robustness of the NN algorithm. For further evaluation of the NILU NN-derived products, retrievals of the vitamin D and DNA-damage effective doses from a collocated Yankee Environmental Systems (YES) UVB-1 pyranometer were used. For cloud-free days, differences in the derived UV doses are better than 2 % for all UV dose products, revealing the reference quality of the ground-based UV doses at Thessaloniki from the NILU-UV NN retrievals. The TEMIS UV doses used in this study are derived from ozone measurements by the SCIAMACHY/Envisat and GOME2/MetOp-A satellite instruments, over the European domain in combination with SEVIRI/Meteosat-based diurnal cycle of the cloud cover fraction per 0. 5° × 0. 5° (lat × long) grid cells. TEMIS

  17. An Oceanographic Decision Support System for Scientific Field Experiments

    NASA Astrophysics Data System (ADS)

    Maughan, T.; Das, J.; McCann, M. P.; Rajan, K.

    2011-12-01

    Thom Maughan, Jnaneshwar Das, Mike McCann, Danelle Cline, Mike Godin, Fred Bahr, Kevin Gomes, Tom O'Reilly, Frederic Py, Monique Messie, John Ryan, Francisco Chavez, Jim Bellingham, Maria Fox, Kanna Rajan Monterey Bay Aquarium Research Institute Moss Lading, California, United States Many of the coastal ocean processes we wish to observe in order to characterize marine ecosystems have large spatial extant (tens of square km) and are dynamic moving kilometers in a day with biological processes spanning anywhere from minutes to days. Some like harmful algal blooms generate toxins which can significantly impact human health and coastal economies. In order to obtain a viable understanding of the biogeochemical processes which define their dynamics and ecology, it is necessary to persistently observe, track and sample within and near the dynamic fields using augmented methods of observation such as autonomous platforms like AUVs, gliders and surface craft. Field experiments to plan, execute and manage such multitude of assets are challenging. To alleviate this problem the autonomous systems group with its collaborators at MBARI and USC designed, built and fielded a prototype Oceanographic Decision Support System (ODSS) that provides situational awareness and a single portal to visualize and plan deployments for the large scale October 2010 CANON field program as well as a series of 2 week field programs in 2011. The field programs were conducted in Monterey Bay, a known 'red tide' incubator, and varied from as many as twenty autonomous platforms, four ships and 2 manned airplanes to coordinated AUV operations, drifters and a single ship. The ODSS web-based portal was used to assimilate information from a collection of sources at sea, including AUVs, moorings, radar data as well as remote sensing products generated by partner organizations to provide a synthesis of views useful to predict the movement of a chlorophyll patch in the confines of the northern Monterey Bay

  18. Meteorite and meteoroid: New comprehensive definitions

    USGS Publications Warehouse

    Rubin, A.E.; Grossman, J.N.

    2010-01-01

    International Astronomical Union (IAU) definition, quoted by Millman 1961); "a solid body which has arrived on the Earth from outer space" (Mason 1962); "[a] solid bod[y] which reach[es] the Earth (or the Moon, Mars, etc.) from interplanetary space and [is] large enough to survive passage through the Earth's (or Mars', etc.) atmosphere" (Gomes and Keil 1980); "[a meteoroid] that survive[s] passage through the atmosphere and fall[s] to earth" (Burke 1986); "a recovered fragment of a meteoroid that has survived transit through the earth's atmosphere" (McSween 1987); "[a] solid bod[y] of extraterrestrial material that penetrate[s] the atmosphere and reach[es] the Earth's surface" (Krot et al. 2003). ?? The Meteoritical Society, 2010.

  19. Quantitative comparisons of analogue models of brittle wedge dynamics

    NASA Astrophysics Data System (ADS)

    Schreurs, Guido

    2010-05-01

    , models accommodated initial shortening by a forward- and a backward-verging thrust. Further shortening was taken up by in-sequence formation of forward-verging thrusts. In all experiments, boundary stresses created significant drag of structures along the sidewalls. We therefore compared the surface slope and the location, dip angle and spacing of thrusts in sections through the central part of the model. All models show very similar cross-sectional evolutions demonstrating reproducibility of first-order experimental observations. Nevertheless, there are significant along-strike variations of structures in map view highlighting the limits of interpretations of analogue model results. These variations may be related to the human factor, differences in model width and/or differences in laboratory temperature and especially humidity affecting the mechanical properties of the granular materials. GeoMod2008 Analogue Team: Susanne Buiter, Caroline Burberry, Jean-Paul Callot, Cristian Cavozzi, Mariano Cerca, Ernesto Cristallini, Alexander Cruden, Jian-Hong Chen, Leonardo Cruz, Jean-Marc Daniel, Victor H. Garcia, Caroline Gomes, Céline Grall, Cecilia Guzmán, Triyani Nur Hidayah, George Hilley, Chia-Yu Lu, Matthias Klinkmüller, Hemin Koyi, Jenny Macauley, Bertrand Maillot, Catherine Meriaux, Faramarz Nilfouroushan, Chang-Chih Pan, Daniel Pillot, Rodrigo Portillo, Matthias Rosenau, Wouter P. Schellart, Roy Schlische, Andy Take, Bruno Vendeville, Matteo Vettori, M. Vergnaud, Shih-Hsien Wang, Martha Withjack, Daniel Yagupsky, Yasuhiro Yamada

  20. Assessing boreal forest photosynthetic dynamics through space-borne measurements of greenness, chlorophyll fluorescence and model GPP

    NASA Astrophysics Data System (ADS)

    Walther, Sophia; Guanter, Luis; Voigt, Maximilian; Köhler, Philipp; Jung, Martin; Joiner, Joanna

    2015-04-01

    sophia.walther@gfz-potsdam.de The seasonality of photosynthesis of boreal forests is an essential driver of the terrestrial carbon, water and energy cycles. However, current carbon cycle model results only poorly represent interannual variability and predict very different magnitudes and timings of carbon fluxes between the atmosphere and the land surface (e.g. Jung et al. 2011, Richardson et al. 2012). Reflectance-based satellite measurements, which give an indication of the amount of green biomass on the Earth's surface, have so far been used as input to global carbon cycle simulations, but they have limitations as they are not directly linked to instantaneous photosynthesis. As an alternative, space-borne retrievals of sun-induced chlorophyll fluorescence (SIF) boast the potential to provide a direct indication of the seasonality of boreal forest photosynthetic activity and thus to improve carbon model performances. SIF is a small electromagnetic signal that is re-emitted from the photosystems in the chloroplasts, which results in a direct relationship to photosynthetic efficiency. In this contribution we examine the seasonality of the boreal forests with three different vegetation parameters, namely greenness, SIF and model simulations of gross primary production (gross carbon flux into the plants by photosynthesis, GPP). We use the enhanced vegetation index (EVI) to represent green biomass. EVI is calculated from NBAR MODIS reflectance measurements (0.05deg, 16 days temporal resolution) for the time from January 2007-May 2013. SIF data originate from GOME-2 measurements on board the MetOp-A satellite in a spatial resolution of 0.5deg for the time from 2007-2011 (Joiner et al. (2013), Köhler et al. (2014)). As a third data source, data-driven GPP model results are used for the time from 2006-2012 with 0.5deg spatial resolution. The method to quantify phenology developed by Gonsamo et al. (2013) is applied to infer the main phenological phases (greenup/onset of

  1. Introduction and Committees

    NASA Astrophysics Data System (ADS)

    Angelova, Maia; Zakrzewski, Wojciech; Hussin, Véronique; Piette, Bernard

    2011-03-01

    This volume contains contributions to the XXVIIIth International Colloquium on Group-Theoretical Methods in Physics, the GROUP 28 conference, which took place in Newcastle upon Tyne from 26-30 July 2010. All plenary and contributed papers have undergone an independent review; as a result of this review and the decisions of the Editorial Board most but not all of the contributions were accepted. The volume is organised as follows: it starts with notes in memory of Marcos Moshinsky, followed by contributions related to the Wigner Medal and Hermann Weyl prize. Then the invited talks at the plenary sessions and the public lecture are published followed by contributions in the parallel and poster sessions in alphabetical order. The Editors:Maia Angelova, Wojciech Zakrzewski, Véronique Hussin and Bernard Piette International Advisory Committee Michael BaakeUniversity of Bielefeld, Germany Gerald DunneUniversity of Connecticut, USA J F (Frank) GomesUNESP, Sao Paolo, Brazil Peter HanggiUniversity of Augsburg, Germany Jeffrey C LagariasUniversity of Michigan, USA Michael MackeyMcGill University, Canada Nicholas MantonCambridge University, UK Alexei MorozovITEP, Moscow, Russia Valery RubakovINR, Moscow, Russia Barry SandersUniversity of Calgary, Canada Allan SolomonOpen University, Milton Keynes, UK Christoph SchweigertUniversity of Hamburg, Germany Standing Committee Twareque AliConcordia University, Canada Luis BoyaSalamanca University, Spain Enrico CeleghiniFirenze University, Italy Vladimir DobrevBulgarian Academy of Sciences, Bulgaria Heinz-Dietrich DoebnerHonorary Member, Clausthal University, Germany Jean-Pierre GazeauChairman, Paris Diderot University, France Mo-Lin GeNankai University. China Gerald GoldinRutgers University, USA Francesco IachelloYale University, USA Joris Van der JeugtGhent University, Belgium Richard KernerPierre et Marie Curie University, France Piotr KielanowskiCINVESTAV, Mexico Alan KosteleckyIndiana University, USA Mariano del Olmo

  2. The July 17, 2006 Java Tsunami: Tsunami Modeling and the Probable Causes of the Extreme Run-up

    NASA Astrophysics Data System (ADS)

    Kongko, W.; Schlurmann, T.

    2009-04-01

    .M., Kongko, W., Moore, A., McAdoo, B., Goff, J., Harbitz, C., Uslu, B., Kalligeris, N., Suteja, D., Kalsum, K., Titov, V., Gusman, A., Latief, H., Santoso, E., Sujoko, S., Djulkarnaen, D., Sunendar, H., and Synolakis, C., 2007. Extreme Run-up from the 17 July 2006 Java Tsunami. Geophysical Research Letters, 34(L12602). Fujii, Y., and Satake, K., 2006. Source of the July 2006 Java Tsunami Estimated from Tide Gauge Records. Geophysical Research Letters, 33(L23417). Intermap Federal Services Inc., 2007. Digital Terrain Model Cilacap, version 1. Project of GITEWS, DLR Germany. Kongko, W., and Leschka, S., 2008. Nearshore Bathymetry Measurements in Indonesia: Part 1. Cilacap, Technical Report, DHI-WASY GmbH Syke Germany. Kongko, W., Suranto, Chaeroni, Aprijanto, Zikra, and SUjantoko, 2006, Rapid Survey on Tsunami Jawa 17 July 2006, http://nctr.pmel.noaa.gov/java20060717/tsunami-java170706_e.pdf Lavigne, F., Gomes, C., Giffo, M., Wassmer, P., Hoebreck, C., Mardiatno, D., Prioyono, J., and Paris R., 2007. Field Observation of the 17 July 2006 Tsunami in Java. Natural Hazards and Earth Systems Sciences, 7: 177-183.

  3. Total ozone patterns over the northern mid-latitudes: spatial correlations, extreme events and dynamical contributions

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Staehelin, J.; Maeder, J. A.; Ribatet, M.; Bodeker, G. E.; Davison, A. C.

    2009-04-01

    Tools from geostatistics and extreme value theory are applied to analyze spatial correlations in total ozone for the northern mid-latitudes. The dataset used in this study is the NIWA combined total ozone dataset (Bodeker et al., 2001; Müller et al., 2008). New tools from extreme value theory (Coles, 2001; Ribatet, 2007) have recently been applied to the world's longest total ozone record from Arosa, Switzerland (e.g. Staehelin 1998a,b), in order to describe extreme events in low and high total ozone (Rieder et al., 200x). Within the current study, patterns in spatial correlation and frequency distributions of extreme events (e.g. ELOs and EHOs) are studied for the northern mid-latitudes. New insights in spatial patterns of total ozone for the northern mid-latitudes are presented. Koch et al. (2005) found that the increase in fast isentropic transport of tropical air to northern mid-latitudes contributed significantly to ozone changes between 1980 and 1989. Within this study the influence of changes in atmospheric dynamics (e.g. tropospheric and lower stratospheric pressure systems) on column ozone over the northern mid-latitudes is analyzed for the time period 1979-2007. References: Bodeker, G.E., J.C. Scott, K. Kreher, and R.L. McKenzie, Global ozone trends in potential vorticity coordinates using TOMS and GOME intercompared against the Dobson network: 1978-1998, J. Geophys. Res., 106 (D19), 23029-23042, 2001. Coles, S.: An Introduction to Statistical Modeling of Extreme Values, Springer Series in Statistics, ISBN:1852334592, Springer, Berlin, 2001. Koch, G., H. Wernli, C. Schwierz, J. Staehelin, and T. Peter (2005), A composite study on the structure and formation of ozone miniholes and minihighs over central Europe, Geophys. Res. Lett., 32, L12810, doi:10.1029/2004GL022062. Müller, R., Grooß, J.-U., Lemmen, C., Heinze, D., Dameris, M., and Bodeker, G.: Simple measures of ozone depletion in the polar stratosphere, Atmos. Chem. Phys., 8, 251-264, 2008. Ribatet

  4. CONFERENCE NOTE: CETO—Centro de Ciências e Tecnologias Opticas, Trends in Optical Fibre Metrology and Standards

    NASA Astrophysics Data System (ADS)

    1994-01-01

    requirements of the new generation of analogue and digital fibre optical systems, which require sophisticated measurement techniques employing complex instruments unique to optical measurements. The school will foster and enhance the interaction between material, devices, systems, and standards-oriented R&D communities, as well as between engineers concerned with design and manufacturers of systems and instrumentation. Topics Review of optical fibre communication technology and systems Measurement techniques for fibre characterization: Reliability and traceability Reference fibres and calibration artefacts Ribbon fibres Mechanical and environmental testing Fibre reliability Polarimetric measurements Passive components characterization: Splices and connectors Couplers, splitters, taps and WDMs Optical fibres and isolators WDM technologies and applications: WDM technologies Tunable optical filters Fibre amplifiers and sources: Performances and characterization Design and standards Nonlinear effects Subsystem design and standards: Design and fabrication techniques Performance degradation and reliability Evaluation of costs/performance/technology Sensors IR - optical fibres Plastic fibres Instrumentation Registration Participation free of charge for postgraduate students, with some grants available for travel and lodging expenses. All correspondence should be addressed to: Secretariat, Trends in Optical Fibre Metrology and Standards, a/c Prof. Olivério D D Soares, Centro de Ciências e Tecnologias Opticas, Lab. Fisica - Faculdade de Ciências, Praça Gomes Teixeira, P-4000 Porto, Portugal. Tel: 351-2-310290, 351-2-2001648; Fax: 351-2-319267.

  5. Highlights of TOMS Version 9 Total Ozone Algorithm

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan; Haffner, David

    2012-01-01

    benefit of this algorithm is that it is considerably simpler than the present algorithm that uses a database of 1512 profiles to retrieve total ozone. These profiles are tedious to construct and modify. Though conceptually similar to the SBUV V8 algorithm that was developed about a decade ago, the SBUV and TOMS V9 algorithms differ in detail. The TOMS algorithm uses 3 wavelengths to retrieve the profile while the SBUV algorithm uses 6-9 wavelengths, so TOMS provides less profile information. However both algorithms have comparable total ozone information and TOMS V9 can be easily adapted to use additional wavelengths from instruments like GOME, OMI and OMPS to provide better profile information at smaller SZAs. The other significant difference between the two algorithms is that while the SBUV algorithm has been optimized for deriving monthly zonal means by making an appropriate choice of the a priori error covariance matrix, the TOMS algorithm has been optimized for tracking short-term variability using month and latitude dependent covariance matrices.

  6. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Lawson, S. J.; Selleck, P. W.; Galbally, I. E.; Keywood, M. D.; Harvey, M. J.; Lerot, C.; Helmig, D.; Ristovski, Z.

    2014-08-01

    mechanism. Glyoxal surface observations from both sites were converted to vertical columns and compared to average vertical column densities (VCDs) from GOME-2 satellite retrievals. Both satellite columns and in situ observations are higher in summer than winter, however satellite vertical column densities exceeded the surface observations by more than 1.5 × 1014 molecules cm-2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption, or use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much needed data to verify the presence of these short lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

  7. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Lawson, S. J.; Selleck, P. W.; Galbally, I. E.; Keywood, M. D.; Harvey, M. J.; Lerot, C.; Helmig, D.; Ristovski, Z.

    2015-01-01

    , respectively, highlighting a significant but as yet unknown production mechanism. Surface-level glyoxal observations from both sites were converted to vertical columns and compared to average vertical column densities (VCDs) from GOME-2 satellite retrievals. Both satellite columns and in situ observations are higher in summer than winter; however, satellite vertical column densities exceeded the surface observations by more than 1.5 × 1014 molecules cm-2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or it may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption or the use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much-needed data to verify the presence of these short-lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

  8. 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

    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.

  9. NMMB/BSC-DUST: model validation at regional scale in Northern Africa

    NASA Astrophysics Data System (ADS)

    Haustein, Karsten; Pérez, Carlos; Jorba, Oriol; María Baldasano, José; Janjic, Zavisa; Black, Tom; Slobodan, Nickovic; Prigent, Catherine; Laurent, Benoit

    2010-05-01

    up of 5 days in advance. Dust columnal load, dust concentration at the surface, AOD and extinction coefficient are extracted for two time periods: March 2005 - corresponding with BoDEx campaign [Todd et al., 2008] - and May/June 2006 - corresponding with SAMUM I field campaign [Haustein et al., 2009]. Several model simulations were run with dust RRTM longwave and shortwave radiative feedback switched on or off, with dust vertical flux after Marticorena and Bergametti [1995] or after Alfaro and Gomez [2001], including viscous sublayer approach [Janjic, 1994] applied or not, and with or without preferential sources following Ginoux [2001]. Additionally, two new observational datasets of surface "aeolian" roughness length [Laurent, 2006; Prigent, 2005] are applied either for drag partition correction, or as substitution for the empirical model roughness length. These simulations are compared with detailed observational data. The atmospheric wind field is analyzed in terms of its capability to reproduce the low level jet in the Bodélé. References: Alfaro, S. C. and L. Gomes (2001). Modeling mineral aerosol production by eind erosion: Emission intensities and aerosol size distribution in source areas. Journal of Geophysical Research 106, D16, 18075-18084. Ginoux, P. et al. (2001). Sources and distribution of dust aerosols simulated with the GOCART model. J. Geophys. Res., 106, D17, 20255-20273. Haustein, K. et al. (2009). Regional dust model performance during SAMUM-I 2006. Geophysical Research Letters 36, L03812, doi:10.1029/2008GL036463. Janjic, Z. I. (1994). The Step-Mountain Eta Coordinate Model: Further Developments of the Convection, Viscous Sublayer, and Turbulence Closure Schemes. Monthly Weather Review 122, 927-945. Janjic, Z. I. (2005). A unified model approach from meso to global scales. Geophysical Research Abstracts 7, 05582, 2005, EGU05-A-05582. Laurent, B. Et al. (2006). Modeling mineral dust emissions from Chinese and Mongolian deserts. Global and

  10. Estimation of transboundary SO2 fluxes in Siberia and Russian Far East using EANET and OMI observations

    NASA Astrophysics Data System (ADS)

    Trifonova-Yakovleva, Alisa; Gromov, Sergey S.; Gromov, Sergey A.

    2017-04-01

    ozone concentrations over EANET station areas based on remote sensing GOME2 high-resolution ozone profile datasets, EANET Science Bulletin, v.4 (October 2016), ISSN 1883-3608.

  11. Model Evaluation with Multi-wavelength Satellite Observations Using a Neural Network

    NASA Astrophysics Data System (ADS)

    Kolassa, Jana; Jimenez, Carlos; Aires, Filipe

    2013-04-01

    Pereira, J. (2012), Soil moisture Retrieval from Multi-instrument Observations: Information Content Analysis and Retrieval Methodology (2012), J. Geophys. Res., de Rosnay, P., Polcher, J., Bruen, M., Laval, K. (2002), Impact of a physically based soil water flow and soil-plant interaction representation for modeling large-scale land surface processes, J. Geophys. Res., 107, D11, 4118, 10.1029/2001JD000634 Weedon, G.P., Gomes, S., Viterbo, P., Shuttleworth, W.J., Blyth, E., O ̈sterle, H., Adam, J.C., Bellouin, N., Boucher, O., and Best, M. (2011), Creation of the WATCH Forcing Data and its use to assess global and regional reference crop evaporation over land during the twentieth century, J. Hydrometeorology,12, 5, pp. 823-848.

  12. Total ozone patterns over the southern mid-latitudes: spatial correlations, extreme events and dynamical contributions

    NASA Astrophysics Data System (ADS)

    Rieder, Harald E.; di Rocco, Stefania; Staehelin, Johannes; Maeder, Jörg A.; Ribatet, Mathieu; Peter, Thomas; Davison, Anthony C.

    2010-05-01

    influence of major volcanic eruptions (e.g. Mt. Pinatubo) and ozone depleting substances (ODS) on column ozone over the southern mid-latitudes is analyzed for the time period 1979-2007. References: Bodeker, G.E., J.C. Scott, K. Kreher, and R.L. McKenzie, Global ozone trends in potential vorticity coordinates using TOMS and GOME intercompared against the Dobson network: 1978-1998, J. Geophys. Res., 106 (D19), 23029-23042, 2001. Coles, S.: An Introduction to Statistical Modeling of Extreme Values, Springer Series in Statistics, ISBN:1852334592, Springer, Berlin, 2001. Müller, R., Grooß, J.-U., Lemmen, C., Heinze, D., Dameris, M., and Bodeker, G.: Simple measures of ozone depletion in the polar stratosphere, Atmos. Chem. Phys., 8, 251-264, 2008. Ribatet, M.: POT: Modelling peaks over a threshold, R News, 7, 34-36, 2007. Rieder ,H.E., Staehelin, J., Maeder, J.A., Ribatet, M., Stübi, R., Weihs, P., Holawe, F., Peter, T., and A.D., Davison (2010): Extreme events in total ozone over Arosa - Part I: Application of extreme value theory, to be submitted to ACPD. Rieder, H.E., Staehelin, J., Maeder, J.A., Ribatet, M., Stübi, R., Weihs, P., Holawe, F., Peter, T., and A.D., Davison (2010): Extreme events in total ozone over Arosa - Part II: Fingerprints of atmospheric dynamics and chemistry and effects on mean values and long-term changes, to be submitted to ACPD. Rieder, H.E., Jancso, L.M., Staehelin, J., Maeder, J.A., Ribatet, Peter, T., and A.D., Davison (2010): Extreme events in total ozone over the northern mid-latitudes: A case study based on long-term data sets from 5 ground-based stations, in preparation. Staehelin, J., Kegel, R., and Harris, N. R.: Trend analysis of the homogenized total ozone series of Arosa (Switzerland), 1929-1996, J. Geophys. Res., 103(D7), 8389-8400, doi:10.1029/97JD03650, 1998a. Staehelin, J., Renaud, A., Bader, J., McPeters, R., Viatte, P., Hoegger, B., Bugnion, V., Giroud, M., and Schill, H.: Total ozone series at Arosa (Switzerland): Homogenization

  13. Remote Sensing of Marine Life and Submerged Target Motions with Ocean Waveguide Acoustics

    NASA Astrophysics Data System (ADS)

    Gong, Zheng

    the roughly 2-week experiment, consistent with the steep roll-offs expected for sub-resonance scattering from fish with air-filled swimbladders. A numerical Monte-Carlo model is developed to determine the statistical moments of the broadband matched filtered scattered returns from fish groups spanning over multiple range and cross-range resolution cells of a waveguide remote sensing system. It uses the parabolic equation to simulate acoustic field propagation in a random range-dependent ocean waveguide. The effects of (1) multiple scattering, (2) attenuation due to scattering, and (3) fish group 3D spatial configuration on fish population density imaging are examined. The model is applied to investigate (a) population density imaging of shoaling Atlantic herring during the 2006 Gulf of Maine Experiment (GOME06) and (b) examine the wide-area imaging of sparse aggregation of ground fish species, such as Atlantic Cod, in Ipswich Bay continental shelf environment using the waveguide remote sensing system. Incoherent intensities are shown to dominate the total scattered returns from distributed fish groups making single scattering assumption valid for inferring fish areal population densities from their matched filtered scattered intensities. Multiple scattering, attenuation, fish group 3D spatial configuration, and coherent effects, such as resonance shift, sub- and super-local-maxima are found to be negligible at the imaging frequencies employed and for the herring densities observed. Similar results are obtained for the sparsely aggregated cod, but coherent effects such as the double-peak in school resonance can be prominent at much lower fish densities. Attenuation due to scattering can be significant when the fish flesh viscosity is high, especially true for cod. We also investigate approaches for instantaneous long-range passive source localization and tracking with a towed horizontal line-array in a random range-dependent ocean waveguide using passive waveguide

  14. FOREWORD International Conference on Defects in Insulating Materials

    NASA Astrophysics Data System (ADS)

    Valerio, Mário Ernesto Giroldo; Jackson, R. A.

    2010-11-01

    M Suszynska, Poland I Tale, Latvia M E G Valerio, Brasil R T Williams, USA Programme Committee Robert A Jackson (Chair), University of Keele, UK R M Montereali, ENEA C.R. Frascati, Rome, Italy M Moreno, University of Cantabria, Spain Ch Pedrini, University Lyon, France Klaus W H Krambrock, UFMG, MG, Brasil Volkmar Dierolf, Lehigh University, USA Laszlo Kovács, Hungarian Academy of Sciences, Hungary M E G Valerio, UFS, SE, Brasil Local Organizing Committee M E G Valerio, UFS, SE, Brasil Sonia L Baldochi, IPEN, SP, Brasil Klaus W H Krambrock, UFMG, MG, Brasil Livio Amaral, UFRGS, RS, Brasil Ana R Blak, USP, SP, Brasil Marco Cremona, PUC-RJ, RJ, Brasil Anderson S L Gomes, UFPE, PE, Brasil Spero Penha Morato, LaserTools, SP, Brasil Alejandro Ayala, UFC, CE, Brasil ICDIM2008 Sponsors: Sponsors

  15. GlobVolcano pre-operational services for global monitoring active volcanoes

    NASA Astrophysics Data System (ADS)

    Tampellini, Lucia; Ratti, Raffaella; Borgström, Sven; Seifert, Frank Martin; Peltier, Aline; Kaminski, Edouard; Bianchi, Marco; Branson, Wendy; Ferrucci, Fabrizio; Hirn, Barbara; van der Voet, Paul; van Geffen, J.

    2010-05-01

    ), Stromboli and Volcano (Italy), Hilo (Hawai), Mt. St. Helens (United States), CTM (Coherent Target Monitoring): Cumbre Vieja (La Palma) To generate products either Envisat ASAR, Radarsat 1or ALOS PALSAR data have been used. Surface Thermal Anomalies Volcanic hot-spots detection, radiant flux and effusion rate (where applicable) calculation of high temperature surface thermal anomalies such as active lava flow, strombolian activity, lava dome, pyroclastic flow and lava lake can be performed through MODIS (Terra / Aqua) MIR and TIR channels, or ASTER (Terra), HRVIR/HRGT (SPOT4/5) and Landsat family SWIR channels analysis. ASTER and Landsat TIR channels allow relative radiant flux calculation of low temperature anomalies such as lava and pyroclastic flow cooling, crater lake and low temperature fumarolic fields. MODIS, ASTER and SPOT data are processed to detect and measure the following volcanic surface phenomena: Effusive activity Piton de la Fournaise (Reunion Island); Mt Etna (Italy). Lava dome growths, collapses and related pyroclastic flows Soufrière Hills (Montserrat); Arenal - (Costa Rica). Permanent crater lake and ephemeral lava lake Karthala (Comores Islands). Strombolian activity Stromboli (Italy). Low temperature fumarolic fields Nisyros (Greece), Vulcano (Italy), Mauna Loa (Hawaii). Volcanic Emission The Volcanic Emission Service is provided to the users by a link to GSE-PROMOTE - Support to Aviation Control Service (SACS). The aim of the service is to deliver in near-real-time data derived from satellite measurements regarding SO2 emissions (SO2 vertical column density - Dobson Unit [DU]) possibly related to volcanic eruptions and to track the ash injected into the atmosphere during a volcanic eruption. SO2 measurements are derived from different satellite instruments, such as SCIAMACHY, OMI and GOME-2. The tracking of volcanic ash is accomplished by using SEVIRI-MSG data and, in particular, the following channels VIS 0.6 and IR 3.9, and along with IR8.7, IR 10

  16. PREFACE: 11th International Conference on Nucleus-Nucleus Collisions (NN2012)

    NASA Astrophysics Data System (ADS)

    Li, Bao-An; Natowitz, Joseph B.

    2013-03-01

    Nuclear Science and Technologies 6. Nuclear Reactions and Structure of Unstable Nuclei 7. Equation of State of Neutron-Rich Nuclear Matter, Clusters in Nuclei and Nuclear Reactions 8. Fusion and Fission 9. Nuclear Astrophysics 10. New Facilities and Detectors We would like to thank Texas A&M University and Texas A&M University-Commerce for their organizational support and for providing financial support for many students and postdocs and those who had special need. This support helped assure the success of NN2012. Special thanks also go to all members of the International Advisory Committee and the Local Organizing Committee (listed below) for their great work in advising upon, preparing and executing the NN2012 scientific program as well as the social events that all together made the NN2012 an enjoyable experience for both the participants and their companions. NN2012 International Advisory Committee N Auerbach (Israel) J Aysto (Finland) C Beck (France) S Cherubini (Italy) L Ferreira (Portugal) C Gagliardi (USA) S Gales (France) C Gale (Canada) W Gelletly (Great Britain) Paulo R S Gomes (Brazil) W Greiner (Germany) W Henning (USA) D Hinde (Australia) S Hofmann (Germany) M Hussein (Brazil) B Jacak (USA) S Kailas (India) W G Lynch (USA) Z Majka (Poland) L McLerran (USA) V Metag (Germany) K Morita (Japan) B Mueller (USA) D G Mueller (France) T Motobayashi (Japan) W Nazarewicz (USA) Y Oganessian (Russia) J Nolen (USA) E K Rehm (USA) N Rowley (France) B Sherrill (USA) J Schukraft (Switzerland) W Q Shen (China) A Stefanini (Italy) H Stoecker (Germany) A Szanto de Toledo (Brazil) U van Kolck (USA) W von Oertzen (Germany) M Wiescher (USA) N Xu (USA) N V Zamfir (Romania) W L Zhan (China) H Q Zhang (China) NN2012 Local Organizing Committee Marina Barbui Carlos Bertulani Robert Burch Jr Cheri Davis Cody Folden Kris Hagel John Hardy Bao-An Li (Co-Chair and Scientific Secretary) Joseph Natowitz (Co-Chair) Ralf Rapp Livius Trache Sherry Yennello Editors of NN2012 Proceedings Bao

  17. Proceedings of the Eleventh International Conference on Calorimetry in Particle Physics

    NASA Astrophysics Data System (ADS)

    Cecchi, Claudia

    The Pamela silicon tungsten calorimeter / G. Zampa -- Design and development of a dense, fine grained silicon tungsten calorimeter with integrated electronics / D. Strom -- High resolution silicon detector for 1.2-3.1 eV (400-1000 nm) photons / D. Groom -- The KLEM high energy cosmic rays collector for the NUCLEON satellite mission / M. Merkin (contribution not received) -- The electromagnetic calorimeter of the Hera-b experiment / I. Matchikhilian -- The status of the ATLAS tile calorimeter / J. Mendes Saraiva -- Design and mass production of Scintillator Pad Detector (SPD) / Preshower (PS) detector for LHC-b experiment / E. Gushchin -- Study of new FNAL-NICADD extruded scintillator as active media of large EMCal of ALICE at LHC / O. Grachov -- The CMS hadron calorimeter / D. Karmgard (contribution not received) -- Test beam study of the KOPIO Shashlyk calorimeter prototype / A. Poblaguev -- The Shashlik electro-magnetic calorimeter for the LHCb experiment / S. Barsuk -- Quality of mass produced lead-tungstate crystals / R. Zhu -- Status of the CMS electromagnetic calorimeter / J. Fay -- Scintillation detectors for radiation-hard electromagnetic calorimeters / H. Loehner -- Energy, timing and two-photon invariant mass resolution of a 256-channel PBWO[symbol] calorimeter / M. Ippolitov -- A high performance hybrid electromagnetic calorimeter at Jefferson Lab / A. Gasparian -- CsI(Tl) calorimetry on BESHI / T. Hu (contribution not received) -- The crystal ball and TAPS detectors at the MAMI electron beam facility / D. Watts -- Front-end electronics of the ATLAS tile calorimeter / R. Teuscher -- The ATLAS tilecal detector control system / A. Gomes -- Performance of the liquid argon final calibration board / C. de la Taille -- Overview of the LHCb calorimeter electronics / F. Machefert -- LHCb preshower photodetector and electronics / S. Monteil -- The CMS ECAL readout architecture and the clock and control system / K. Kloukinas -- Test of the CMS-ECAL trigger

  18. Physics of Unstable Nuclei

    NASA Astrophysics Data System (ADS)

    Khoa, Dao Tien; Egelhof, Peter; Gales, Sydney; Giai, Nguyen Van; Motobayashi, Tohru

    2008-04-01

    ]C([symbol], n)[symbol]O by the transfer reaction [symbol]C([symbol]Li, t)[symbol]O / F. Hammache et al. -- SPIRAL2 at GANIL: a world of leading ISOL facility for the physics of exotic nuclei / S. Gales -- Magnetic properties of light neutron-rich nuclei and shell evolution / T. Suzuki, T. Otsuka -- Multiple scattering effects in elastic and quasi free proton scattering from halo nuclei / R. Crespo et al. -- The dipole response of neutron halos and skins / T. Aumann -- Giant and pygmy resonances within axially-symmetric-deformed QRPA with the Gogny force / S. Péru, H. Goutte -- Soft K[symbol] = O+ modes unique to deformed neutron-rich unstable nuclei / K. Yoshida et al. -- Synthesis, decay properties, and identification of superheavy nuclei produced in [symbol]Ca-induced reactions / Yu. Ts. Oganessian et al. -- Highlights of the Brazilian RIB facility and its first results and hindrance of fusion cross section induced by [symbol]He / P. R. S. Gomes et al. -- Search for long fission times of super-heavy elements with Z = 114 / M. Morjean et al. -- Microscopic dynamics of shape coexistence phenomena around [symbol]Se and [symbol]Kr / N. Hinohara et al. -- [symbol]-cluster states and 4[symbol]-particle condensation in [symbol]O / Y. Funaki et al. -- Evolution of the N = 28 shell closure far from stability / O. Sorlin et al. -- Continuum QRPA approach and the surface di-neutron modes in nuclei near the neutron drip-line / M. Matsuo et al. -- Deformed relativistic Hartree-Bogoliubov model for exotic nuclei / S. G. Zhou et al. -- Two- and three-body correlations in three-body resonances and continuum states / K. Katō, K. Ikeda -- Pion- and Rho-Meson effects in relativistic Hartree-Fock and RPA / N. V. Giai et al. -- Study of the structure of neutron rich nuclei by using [symbol]-delayed neutron and gamma emission method / Y. Ye et al. -- Production of secondary radioactive [symbol] Na beam for the study of [symbol]Na([symbol], p)[symbol]Mg stellar reaction / D. N. Binh et al

  19. Nanotechnology in paper electronics

    NASA Astrophysics Data System (ADS)

    Demming, Anna; Österbacka, Professor Ronald; Han, Jin-Woo, Dr

    2014-03-01

    R 2014 Nanoparticle composites for printed electronics Nanotechnology 25 094004 [11] Costa M N, Veigas B, Jacob J M, Santos D S, Gomes J, Baptista P V, Martins R, Inácio J and Fortunato E 2014 Low cost, safe, disposable, rapid and self-sustainable paper based platform for diagnostic testing: lab-on-paper Nanotechnology 25 094006 [12] Bollström R, Pettersson F, Dolietis P, Preston J, Österbacka R and Toivakka M 2014 Impact of humidity on functionality of on-paper printed electronics Nanotechnology 25 094003 [13] Purandare S, Gomez E F and Steckl A J 2014 High brightness phosphorescent organic light emitting diodes on transparent and flexible cellulose films Nanotechnology 25 094012 [14] Kim J-H, Mun S, Ko H-U, Yun G-Y and Kim J 2014 Disposable chemical and biosensors made on cellulose paper Nanotechnology 25 092001 [15] Zinsser W 1976 Introduction On Writing Well 5th edn, p vii

  20. PREFACE: Introduction to the proceedings of Dynamics Days South America 2010

    NASA Astrophysics Data System (ADS)

    Macau, Elbert E. N.; Pereira, Tiago; Prado, Antonio F. B. A.; Turci, Luiz F. R.; Winter, Othon C.

    2011-03-01

    Merida - Venezuela Othon Cabo WinterUNESP - "Júlio de Mesquisa Filho"Guaratinguetá - SP - Brazil Ricardo Luiz VianaUniversidade Federal do ParanáCuritiba - PA - Brazil Silvina Ponce DawsonUniversidad de Buenos AiresBuenos Aires - Argentina Vivian M GomesINPE - Instituto Nacional de Pesquisas EspaciaisSão José dos Campos - SP - Brazil Realization INPE logo Promotion ABCM logo   SBA logo SBF logo   SBMAC logo Sponsorship CAPES logo   CNPq logo FAPESP logo   ICTP logo Claf logo   SOARD AFOSR logo TAM logo

  1. Software Uncertainty in Integrated Environmental Modelling: the role of Semantics and Open Science

    NASA Astrophysics Data System (ADS)

    de Rigo, Daniele

    2013-04-01

    undiscovered mistakes in the software used to calculate and present those results" [65]. Despite the ubiquity of software errors [62-70], the structural role of scientific software uncertainty seems dramatically underestimated [2,53]. Semantic D- TM modularization might help to catch at least a subset of silent faults, when misusing intermediate data outside the expected semantic context of a given D- TM module (b). Where the complexity and scale of WSTMe may lead unavoidable software-uncertainty to induce or worsen deep-uncertainty [2], techniques such as ensemble modelling may be recommendable [11-13]. Adapting those techniques for glancing at the software-uncertainty of a given WSTMe would imply availability of multiple instances (implementations) of the same abstract WSTMe. Independently re-implementing the same WSTMe (design diversity [71]) might of course be extremely expensive. However, partly independent re-implementations of critical D- TM modules may be more affordable and examples of comparison between supposedly equivalent D- TM algorithms seem to corroborate the interest of this research option [59,72,51]. References Casagrandi, R., Guariso, G., 2009. Impact of ICT in environmental sciences: A citation analysis 1990-2007. Environmental Modelling & Software 24 (7), 865-871. http://dx.doi.org/10.1016/j.envsoft.2008.11.013 de Rigo, D., 2013. Behind the horizon of reproducible integrated environmental modelling at European scale: ethics and practice of scientific knowledge freedom. F1000 Research. To appear as discussion paper Gomes, C. P., 2009. Computational sustainability: Computational methods for a sustainable environment, economy, and society. The Bridge 39 (4), 5-13. http://www.nae.edu/File.aspx?id=17673 Easterbrook, S. M., Johns, T. C., 2009. Engineering the software for understanding climate change. Computing in Science & Engineering 11 (6), 65-74. http://dx.doi.org/10.1109/MCSE.2009.193 Hamarat, C., Kwakkel, J. H., Pruyt, E., 2012. Adaptive robust design