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1

Greenhouse Gases  

MedlinePLUS

... are greenhouse gases? Many chemical compounds present in Earth's atmosphere behave as 'greenhouse gases'. These are gases ... direct sunlight (relative shortwave energy) to reach the Earth's surface unimpeded. As the shortwave energy (that in ...

2

Greenhouse Gases  

MedlinePLUS

... were not for naturally occurring greenhouse gases, the earth would be too cold to support life as ... the greenhouse effect, the average temperature of the earth would be about -2°F rather than the ...

3

Greenhouse Gases  

NSDL National Science Digital Library

This is a lesson where learners engage in a radiating heat activity and an activity that measures temperature in models with and without greenhouse gases. Learners will draw conclusions about the effect of greenhouse gases on temperature and on human life and kinesthetically model the absorbing and re-radiation of heat. The lesson models scientific inquiry using the 5E instructional model and includes teacher notes, prerequisite concepts, common misconceptions, student journal and reading. This is lesson 3 in the Astro-Venture Atmospheric Science Training Unit. The purpose of the unit is to increase students’ awareness of and interest in astrobiology and the many career opportunities that utilize science, math and technology skills. The lessons are designed for educators to use in conjunction with the Astro-Venture multimedia modules.

2012-08-03

4

The state of greenhouse gases in the atmosphere using global observations through 2012  

NASA Astrophysics Data System (ADS)

The Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) provides a framework for global observations and assessment of the state and development of atmospheric composition, including greenhouse gases. It puts stringent requirements on the quality of the observations. These requirements are reviewed by the greenhouse gas science and measurement community at biennial WMO/IAEA Meetings on Carbon Dioxide, Other Greenhouse Gases, and Related Tracer Measurement Techniques. The 17th meeting was held in Beijing, China, on 10 - 14 June 2013 (http://ggmt-2013.cma.gov.cn/dct/page/1). Results of global analysis of the observational data are reported annually in the WMO/GAW Annual Greenhouse Gas Bulletin. Bulletin No. 9 represents an update of the results for the year 2012 (extended version is available at http://www.wmo.int/pages/prog/arep/gaw/ghg/ghg9-en-online.html). The cover story of this bulletin presents the attribution of methane sources in the context of the renewed growth of the global average methane mole fraction in 2007. The bulletin is prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/www/CBS/Lists_WorkGroups/CAS/opag-epac/gaw%20sag%20ghg) in collaboration with the World Data Center for Greenhouse Gases. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) derived from this network reached new highs in 2012, with CO2 at 393.1±0.1 ppm, CH4 at 1819±1 ppb and N2O at 325.1±0.1 ppb. These values constitute 141%, 260% and 120% of pre-industrial (before 1750) levels, respectively. The increase of the annual mean CO2 mole fraction from 2011 to 2012 amounted to 2.2 ppm, which is greater than the average growth rate for the 1990s (~1.5 ppm yr-1) and for the past decade (~2.0 ppm yr-1). The globally averaged CH4 mole fraction increased by 6 ppb from 2011 to 2012. The growth rate of CH4 decreased from ~13 ppb yr-1 during the early 1980s to near zero during 1999-2006. Since 2007, atmospheric CH4 has been increasing again, averaging ~5 ppb yr-1. The growth rate of N2O in 2012 was 0.9 ppb yr-1, which is greater than the average growth rate over the last 10 years (0.75 ppb yr-1). The NOAA Annual Greenhouse Gas Index (AGGI) has been defined as the ratio of total radiative forcing due to long-lived greenhouse gases for any year for which adequate global measurements exist to that which was present in 1990. The AGGI in 2012 was 1.32 (corresponding to 2.87 W m-2 of global radiative forcing, relative to 1750, of all long-lived greenhouse gases). The AGGI indicates an increase in radiative forcing by all long-lived greenhouse gases of 32% since 1990 and of 1.2% from 2011 to 2012, while the radiative forcing by all long-lived greenhouse gases in 2012 corresponded to a CO2-equivalent mole fraction of 475.6 ppm (http://www.esrl.noaa.gov/gmd/aggi).

Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Edward; Montzka, Stephen A.; Butler, James H.

2014-05-01

5

Regulating Greenhouse Gases  

NSDL National Science Digital Library

This video highlights the work of climate scientists in the Amazon who research the relationship between deforestation, construction of new dams, and increased amounts of greenhouse gases being exchanged between the biosphere and the atmosphere.

KQED

6

Hyper-spectral observations of greenhouse gases in Three Gorges Reservoir Region, China  

NASA Astrophysics Data System (ADS)

The Three Gorges Reservoir (TGR) is the most ambitious hydroelectric and flood control project in human history. Its riparian zone has areas of ~300 km2 with water levels fluctuating between 175m above the sea in winter and 145m in summer, and is a special type of wetlands at the low water levels. These wetlands may release CO2 and CH4 with significantly spatial and temporal variations, and have been misleadingly described as a “methane menace” and caused a worldwide concern. A joint research program for TGR greenhouse gases monitoring is operated by several institutions and based at Yangtze Normal Univ. in Fuling of Chongqing. It is characterized by the combined satellite, airship, and ground-based hyper-spectral observations, which serve to simultaneously measure various eco-environmental parameters in a large area with high spatial and spectral resolutions, and to model the status and key dynamic processes of the TGR greenhouse gases. In this talk, the retrieval algorithm of the gas species from satellite near-infrared observations is discussed with special attentions paid to the mountainous and foggy TGR region. The distributions and variations of TGR greenhouse gases are studied by using the AIRS and SCIAMACHY monthly means of multiple years. The airship and ground-based observation system is outlined and expected to provide unique data needed to address the TGR environmental issues, and to evolve towards operational service.

Wang, Ding Yi; Zhang, Chun-ming; Qin, Lin; Zhang, Lu; Wang, Xiang-hong; Li, Hong-qun; Yang, Fu-Mo; Chen, Gang-Cai; Wang, Shu-peng; Zhang, Xing-ying; Zhang, Peng

7

The state of greenhouse gases in the atmosphere using global observations through 2011  

NASA Astrophysics Data System (ADS)

The Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) provides a framework for global observations and assessment of the state and development of atmospheric composition, including greenhouse gases. It puts stringent requirements on the quality of the observations, and these requirements are evaluated every two years. Results of global analysis of the observational data are reported annually in the WMO/GAW Annual Greenhouse Gas Bulletin. Bulletin No. 8 represents the results for the year 2011. This bulletin highlights the importance of carbon sinks (ocean and terrestrial biosphere) for anthropogenic CO2 emissions. Observations used for global analysis are collected at more than 100 sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) reached new highs in 2011, with CO2 at 390.9 ± 0.1 ppm, CH4 at 1813 ± 2 ppb and N2O at 324.2 ± 0.1 ppb. These values constitute 140%, 259% and 120% of pre-industrial (before 1750) levels, respectively. The increase of the annual mean CO2 mole fraction from 2010 to 2011 amounted to 2.0 ppm, which is greater than the average growth rate for the 1990s (~ 1.5 ppm/yr) and is equal to the average for the past decade (~ 2.0 ppm/yr). The globally averaged CH4 mole fraction increased by 5 ppb from 2010 to 2011. The growth rate of CH4 decreased from ~ 13 ppb/yr during the early 1980s to near zero during 1999-2006. Since 2007, atmospheric CH4 has been increasing again, averaging ~ 5 ppb/yr. The growth rate of N2O in 2011 was 1.0 ppb/yr, which is substantially greater than the average over the last 10 years (0.75 ppb/yr). The NOAA Annual Greenhouse Gas Index (AGGI) has been defined as the ratio of total radiative forcing due to long-lived greenhouse gases for any year for which adequate global measurements exist to that which was present in 1990. The AGGI in 2011 was 1.30 (corresponding to 2.84 W-m2 of global radiative forcing, relative to 1750, of all long-lived greenhouse gases). The AGGI indicates an increase in radiative forcing by all long-lived greenhouse gases of 30% since 1990 and of 1.2% from 2010 to 2011, while the radiative forcing by all long-lived greenhouse gases in 2011 corresponded to a CO2-equivalent mole fraction of 473 ppm (http://www.esrl.noaa.gov/gmd/aggi).

Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Ed; Montzka, Stephen A.; Griffith, David; Brunke, Ernst; Scheel, Hans-Eckhart; Laurila, Tuomas; Weller, Rolf; Butler, James H.

2013-04-01

8

Greenhouse Gases Exposed  

NSDL National Science Digital Library

In this activity, students learn about the relationship between greenhouse gases and global warming through a simple teacher demo or hands-on lab activity. Everyday materials are used: beakers, baking soda, vinegar, candle, thermometers, heat source such as a goose-necked lamp, etc. Students shine a light onto three thermometers: a control, an upside down beaker w/ a thermometer and air, and a beaker in which CO2 had been poured.

Victoria Babcock

9

Global CO2 Distributions over Land from the Greenhouse Gases Observing Satellite (GOSAT)  

NASA Technical Reports Server (NTRS)

January 2009 saw the successful launch of the first space-based mission specifically designed for measuring greenhouse gases, the Japanese Greenhouse gases Observing SATellite (GOSAT). We present global land maps (Level 3 data) of column-averaged CO2 concentrations (X(sub CO2)) derived using observations from the GOSAT ACOS retrieval algorithm, for July through December 2009. The applied geostatistical mapping approach makes it possible to generate maps at high spatial and temporal resolutions that include uncertainty measures and that are derived directly from the Level 2 observations, without invoking an atmospheric transport model or estimates of CO2 uptake and emissions. As such, they are particularly well suited for comparison studies. Results show that the Level 3 maps for July to December 2009 on a lO x 1.250 grid, at six-day resolution capture much of the synoptic scale and regional variability of X(sub CO2), in addition to its overall seasonality. The uncertainty estimates, which reflect local data coverage, X(sub CO2) variability, and retrieval errors, indicate that the Southern latitudes are relatively well-constrained, while the Sahara Desert and the high Northern latitudes are weakly-constrained. A probabilistic comparison to the PCTM/GEOS-5/CASA-GFED model reveals that the most statistically significant discrepancies occur in South America in July and August, and central Asia in September to December. While still preliminary, these results illustrate the usefulness of a high spatiotemporal resolution, data-driven Level 3 data product for direct interpretation and comparison of satellite observations of highly dynamic parameters such as atmospheric CO2.

Hammerling, Dorit M.; Michalak, Anna M.; O'Dell, Christopher; Kawa, Randolph S.

2012-01-01

10

Greenhouse Gases: A Closer Look  

NSDL National Science Digital Library

This lesson covers different aspects of the major greenhouse gases - water vapor, carbon dioxide, methane, nitrous oxides and CFCs - including some of the ways in which human activities are affecting the atmospheric concentrations of these key greenhouse gases. This is lesson six in a nine-lesson module about climate change.

King's Centre for Visualization in Science

11

Voluntary Reporting of Greenhouse Gases  

EIA Publications

The Voluntary Reporting of Greenhouse Gases Program was suspended May 2011. It was a mechanism by which corporations, government agencies, individuals, voluntary organizations, etc., could report to the Energy Information Administration, any actions taken that have or are expected to reduce/avoid emissions of greenhouse gases or sequester carbon.

2011-01-01

12

GREENHOUSE GASES AND AGRICULTURE  

EPA Science Inventory

Agriculture ranks third in its contribution to Earth's anthropogenically nhanced greenhouse effect. Energy use and production and chlorofluorocarbons are anked first and second, respectively.) pecifically, greenhouse gas sources and inks are increased, and sinks are decreased, by...

13

GREENHOUSE GASES AND GLOBAL WARMING  

Microsoft Academic Search

Summary Global warming is an important environmental issue which is rapidly becoming a part of popular culture. This paper provides an account of the science associated with this important issue. Historical evidence for past climate change is discussed. The difference between weather and climate is highlighted. The physics of the greenhouse effect and the concept of greenhouse gases are presented.

Timothy J. Wallington; Jayaraman Srinivasan; Ole John Nielsen; Ellie J. Highwood

14

Atmospheric Chemistry, Carbon Cycle, and Climate (AC4): Observational Constraints on Sources and Sinks of Aerosols and Greenhouse Gases  

E-print Network

of aerosols and greenhouse gases, and (4) measure emissions from oil and gas extraction of the following: 1. Greenhouse gas emissions from oil and gas extraction 2. Emissions of aerosols, greenhouse uncertain. Recent increases in emissions from oil and gas extraction are becoming significant

15

Greenhouse gases thinning the thermosphere  

NSDL National Science Digital Library

Orbital decay rates of satellites and other objects that have flown continually for more than 30 years were analyzed to determine the concentrations of greenhouse gases in the thermosphere. A decrease of 25 percent per decade was found in the thermosphere's density since 1966. Implications are discussed.

Emmert et al.

16

Greenhouse Gases: The Overlooked Sources  

NSDL National Science Digital Library

This radio broadcast, which took place during the Kyoto Conference on global warming, discusses well-known and more obscure sources of greenhouse gases. Solutions to reduce carbon emissions are discussed, including creating fuel with less carbon in it (biomass fuels); reducing driving by increasing the cost of fuel; and improving vehicle fuel economy. The broadcast then introduces the topic of methane as a greenhouse gas; although less is emitted, it is about fifty times more effective than carbon dioxide at warming the planet. Cattle are a major source of methane; some ideas are introduced for monitoring and reducing their emissions. There is also discussion of whether global warming could be a result of natural variability as opposed to the result of a human-caused greenhouse effect. The broadcast is 49 minutes and 39 seconds in length.

17

Climate Change and Greenhouse Gases  

NASA Technical Reports Server (NTRS)

The American Geophysical Union (AGU), as a scientific organization devoted to research on the Earth and space sciences, provides current scientific information to the public on issues pertinent to geophysics. The Council of the AGU approved a position statement on Climate Change and Greenhouse Gases in December 1998. The statement, together with a short summary of the procedures that were followed in its preparation, review, and adoption were published in the February 2, 1999 issue of Eos ([AGU, 1999]. The present article reviews scientific understanding of this issue as presented in peer-reviewed publications that serves as the underlying basis of the position statement.

Ledley, Tamara S.; Sundquist, Eric; Schwartz, Stephen; Hall, Dorothy K.; Fellows, Jack; Killeen, Timothy

1999-01-01

18

Comparing greenhouse gases for policy purposes  

E-print Network

In order to derive optimal policies for greenhouse gas emissions control, the discounted marginal damages of emissions of different gases must be compared. The greenhouse warming potential (GWP) index, which is most often ...

Schmalensee, Richard

1993-01-01

19

CARIBIC observations of greenhouse gases and non-methane hydrocarbons on flights between Germany and South Africa  

NASA Astrophysics Data System (ADS)

Since May 2005 the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container, www.caribic-atmospheric.com) has made near-monthly deployments of an atmospheric observatory making measurements from aboard a Lufthansa Airbus A340-600 during routine passenger flights. Flights originate in Frankfurt, Germany and serve a large number of destinations, among them Cape Town and Johannesburg in South Africa. On these flights, which took place primarily during northern hemisphere winter 2010/2011, a near-meridional profile was obtained over Europe and Africa, in similar fashion to HIPPO flight tracks over the Pacific, be it without vertical profiles. Over Central Africa, deep convection transports boundary layer air to the free troposphere, linking observations at cruise altitude to surface emissions and allowing for the investigation of emissions and sources of atmospherically relevant species in Africa. Mixing ratios of greenhouse gases (methane, carbon dioxide, sulfur hexafluoride and nitrous oxide) and a suite of C2-C8 non-methane hydrocarbons (NMHC) are measured from flask samples collected at cruise altitude during flight. Several tracers, for example methane, carbon monoxide, and various NMHC, exhibit enhanced mixing ratios over tropical Africa. Using tracer-tracer correlations to characterize methane emissions from Africa, we find that biomass burning made a major contribution to the methane burden, but that also biogenic sources, such as wetlands, play a significant role. We also compare these measurements to those conducted earlier over India, which were used to investigate sources and emissions of greenhouse gases during the South Asian summer monsoon.

Brenninkmeijer, C. A.; Schuck, T. J.; Baker, A. K.; van Velthoven, P.

2012-12-01

20

Interferometric Monitor for Greenhouse Gases (IMG)  

NASA Astrophysics Data System (ADS)

A satellite borne FTIR called IMG(Interferometric Monitor for Greenhouse Gases) was developed by JAROS (Japan Resources Observation System Organization) deputed by MITI (Ministry of International Trade and Industry). It was installed on ADEOS (Advanced Earth Observing Satellite) which was launched on Aug. 1966 by NASDA (National Space Development Agency of Japan). IMG is a very high spectral resolution (0.1cm-1) spectrometer that covers a wide range of infrared spectrum (3.3 - 15 ?m). With these features, IMG could detect and monitor spatial and vertical distribution of greenhouse effect gases such as CO2, CH4, 03, etc. over the entire Earth. Unfortunately, ADEOS stopped its operation on 30, June 1997, but about 8 months of data have been collected. IMG sensor characteristics and some of the initial scientific results are described

Shimoda, H.; Ogawa, T.

21

Emission Verification of Greenhouse Gases on the Sub-continental Scale Using Tall Tower Observations and Inverse Trajectory Modeling  

NASA Astrophysics Data System (ADS)

Inert (on the time scale of several days) greenhouse gases like CH4, N2O and SF6 are almost ideal gases to model in trajectory models, as (photo)chemistry and uptake processes can be neglected. The forward and backward (inverse) calculations of atmospheric transport presented here have been performed by using a simple trajectory model, utilizing 3D 96 hour backward trajectory data based on ECMWF analysed windfields. The trajectories were calculated using the FLEXTRA model v3.3 (Stohl et al., 1999). The most important factor determining the atmospheric concentrations besides the greenhouse gas emission strengths obviously is the atmospheric mixing layer height. This mixing height is determined in the model by following a critical Richardson number scheme. We used a long time series of 3 years of continuous high precision vertical concentration gradient measurements of CH4 and N2O at the tall tower of Cabauw in the center of the Netherlands to derive estimates of the West European spatial distribution of emissions of these gases and the corresponding trends. The forward and inverse calculations and the high resolution vertical concentration gradient data provide maps of both the local and more remote distribution of the sources. The inverse calculation uses the SVD matrix inversion technique to determine the best fitting solution to the overdetermined system that follows from the combination of the source receptor matrix derived from the trajectory model and the observed concentration data. The resulting best estimate for the emissions of CH4 are for most parts of Western Europe in agreement with the current inventory data. The inherent uncertainty of the transport model and measurements and how these uncertainties translate into the uncertainty of the inverse calculated emissions is estimated by using a Monte Carlo error analysis technique. Other error estimations are determined from using ensemble trajectories with horizontal and vertical deviations. Several problems related to solving overdetermined problems still remain and options to overcome these will be discussed. References Stohl, A., L. Haimberger, M.P. Scheele, and H. Wernli (1999): An intercomparison of results from three trajectory models. Meteorol. Applications 8, 127-135.

Vermeulen, A. T.; Hensen, A.; Bulk, P. V.; Erisman, J.

2003-12-01

22

Voluntary reporting of greenhouse gases, 1995  

SciTech Connect

The Voluntary Reporting Program for greenhouse gases is part of an attempt by the U.S. Government to develop innovative, low-cost, and nonregulatory approaches to limit emissions of greenhouse gases. It is one element in an array of such programs introduced in recent years as part of the effort being made by the United States to comply with its national commitment to stabilize emissions of greenhouse gases under the Framework Convention on Climate Change. The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report to the Energy Information Administration (EIA) on actions taken that have reduced or avoided emissions of greenhouse gases.

NONE

1996-07-01

23

Where do California's greenhouse gases come from?  

ScienceCinema

Last March, more than two years after California passed legislation to slash greenhouse gas emissions 25 percent by 2020, Lawrence Berkeley National Laboratory scientist Marc Fischer boarded a Cessna loaded with air monitoring equipment and crisscrossed the skies above Sacramento and the Bay Area. Instruments aboard the aircraft measured a cocktail of greenhouse gases: carbon dioxide from fossil fuel use, methane from livestock and landfills, CO2 from refineries and power plants, traces of nitrous oxide from agriculture and fuel use, and industrially produced other gases like refrigerants. The flight was part of the Airborne Greenhouse Gas Emissions Survey, a collaboration between Berkeley Lab, the National Oceanic and Atmospheric Administration, and the University of California, and UC Davis to pinpoint the sources of greenhouse gases in central California. The survey is intended to improve inventories of the states greenhouse gas emissions, which in turn will help scientists verify the emission reductions mandated by AB-32, the legislation enacted by California in 2006.

Fischer, Marc

2013-05-29

24

IMG, interferometric measurement of greenhouse gases from space  

NASA Astrophysics Data System (ADS)

A Michelson interferometer is under development as a payload of the ADEOS satellite. It will measure the spectra of terrestrial thermal infrared radiation with a nadir view in 700-3,000 cm-1 wavenumber region with an apodized resolution of 0.1 cm-1. Using those measured spectra, we will retrieve the altitude profiles of atmospheric temperature and the concentrations of greenhouse gases such as H2O, CO2, CH4, N2O, CO and O3. Our final goal is to observe horizontal structure in greenhouse gas concentrations and to infer the global distribution of the emission sources of greenhouse gases.

Ogawa, T.; Shimoda, H.; Hayashi, M.; Imasu, R.; Ono, A.; Nishinomiya, S.; Kobayashi, H.

1994-01-01

25

Thermal efficiency of the principal greenhouse gases  

NASA Astrophysics Data System (ADS)

Atmospheric gases are ranked according to the efficiency with which they absorb and radiate longwave radiation. The open international HITRAN database of gaseous absorption lines of high resolution together with inverse Fourier transform were used. The autocorrelation functions of the total dipole moment of the basic greenhouse gases molecules such as H2O, CO2, O3, N2O, and CH4 were obtained. Absorption coefficient spectra and emission power spectra of infrared radiation of these gases were calculated. Analysis of the emissive ability of all gases under consideration was carried out. Compared to CO2, all the gases under investigation have more effective emission except ozone. An efficiency criterion of IR absorption and emission is defined and is calculated for each studied gas, and the gases are ranked accordingly as follows (from strong to weak): H2O, CH4, CO2, N2O, and O3.

Y. Galashev, A.; R. Rakhmanova, O.

2015-01-01

26

Curbing Greenhouse Gases: Agriculture's Role  

E-print Network

be changed by the presence of a market or other means to mitigate greenhouse gas? The Kyoto Protocol called Kyoto Protocol after the Japanese conference place. Developing countries negotiated emission and nitrous oxide. Agriculture, emissions and sinks - Treatment in the Kyoto Protocol The Protocol mentions

McCarl, Bruce A.

27

16 Rangelands educing concentrations of greenhouse gases  

E-print Network

sequestration or decrease carbon loss will be especially important. The Terrestrial Carbon Cycle Prior the current amount of carbon being stored in an area. In the terrestrial carbon cycle (Supplemental Material and the atmosphere. Carbon dioxide (CO2 ) is one of the primary anthropogenic greenhouse gases. Reductions

28

How Greenhouse Gases Absorb Heat  

NSDL National Science Digital Library

In this experiment, students will observe two model atmospheres: one with normal atmospheric composition and another with an elevated concentration of carbon dioxide. These two contained atmospheres will be exposed to light energy from a sunny window or from a lamp. The carbon dioxide is produced by a simple reaction and tested using bromothymol blue (BTB).

American Museum of Natural History

29

Voluntary reporting of greenhouse gases 1997  

SciTech Connect

The Voluntary Reporting of Greenhouse Gases Program, required by Section 1605(b) of the Energy Policy Act of 1992, records the results of voluntary measures to reduce, avoid, or sequester greenhouse gas emissions. In 1998, 156 US companies and other organizations reported to the Energy information Administration that, during 1997, they had achieved greenhouse gas emission reductions and carbon sequestration equivalent to 166 million tons of carbon dioxide, or about 2.5% of total US emissions for the year. For the 1,229 emission reduction projects reported, reductions usually were measured by comparing an estimate of actual emissions with an estimate of what emissions would have been had the project not been implemented.

NONE

1999-05-01

30

Critical UN Conference on Greenhouse Gases Begins  

NSDL National Science Digital Library

Yesterday at the Hague, delegates from over 160 nations began meeting to try to hammer out details of the 1997 Kyoto agreement which mandated that nations reduce their greenhouse gas emissions to pre-1990 levels by the year 2012. This sixth session of the UN's Framework Convention on Climate Change will have to overcome significant obstacles if delegates are to emerge with an agreement within the conference's scheduled two weeks. To begin with, there is disagreement between the European Union and the United States on the use of "clean development mechanisms" (CDMs), which give states a number of ways of reaching the treaty's targets without actually reducing emissions. Among these is a proposal to allow for the trading of emissions credits -- disparagingly viewed by most environmentalists as licenses to pollute -- and the possibility of states with high emissions investing in reforestation projects in developing countries that would serve as "Carbon sinks" to absorb these emissions. Naturally, the US, responsible for 24 percent of the world's greenhouse gases, favors such measures, while the EU -- believing its recent coastal flood to be greenhouse-related -- opposes them in favor of across-the-board reductions and tough sanctions for noncompliance. The US is also concerned that the current draft allows developing nations, including China and India, to pledge to reach emissions limits in the future, but does not hold them to any legal obligation for failure to do so. The United Kingdom has stated that an effective agreement can be reached with or without US support. However, given that the US is the main producer of greenhouse gases, most analysts feel that an agreement without US cooperation is liable to have little long-term consequence.

Charbonneau, David D.

31

Carbon dioxide and other greenhouse gases  

SciTech Connect

The authors address the issue of the impact of the greenhouse gases on the earth's climate. It is characterized by two equally challenging facts. The first is that a climatic change must occur, since it is impossible to perturb the earth's radiation budget without perturbing the system of which that budget is a key element. The second is that no one can say at present when exactly that change will occur, whether it will take place at the same rate everywhere on earth, what changes will be involved at a regional scale, nor whether it may even be beneficial in some ways. They suggest policy actions necessary to counteract these adverse consequences.

Fantechi, R.; Ghazi, A.

1989-01-01

32

Observations of production and emission of greenhouse gases and ammonia during storage of solids separated from pig slurry: Effects of covering  

Microsoft Academic Search

Separation of slurry produces a solid fraction that is stored in manure heaps before being used as a fertiliser in crop production. Considerable amounts of ammonia (NH3) and greenhouse gases may be emitted during storage, which has deleterious environmental effects. The emission levels can be expected to depend on oxygenation level inside the bulk of the stored manure and therefore

M. N. Hansen; K. Henriksen; S. G. Sommer

2006-01-01

33

Transport of Greenhouse Gases in Trees  

NASA Astrophysics Data System (ADS)

Emissions of greenhouse gases methane (CH4) and nitrous oxide (N2O) have been measured in cultivated and natural regions, quantifying overall emissions for croplands, wetlands, and forests. However, segregation between soil and plant emissions is less clear, and the dynamics behind each respective emission type differs. Better defined plant transport mechanisms will yield more accurate determination of greenhouse gas flux, contributing to a comprehensive theory quantifying greenhouse gas emissions globally. While the mechanisms of CH4 and N2O emissions from rice have not been fully identified, for trees these mechanisms are virtually unknown. CH4 and N2O emissions from several species of tree (Alnus rubra, Populus trichocarpa, Thuja plicata, Fraxinus latifolia) native to the Pacific Northwest have been measured. To identify mechanisms of gas transport, correlation of emissions and stomatal conductance, transpiration, and photosynthesis has been tested. A synthesis between plant physiological data and emissions is sought to elucidate the role plant physiology plays in the production and transport of CH4 and N2O. This research was supported by the Office of Science (BER), U. S. Department of Energy, Grant No. DE-FG02-08ER64515.

Kutschera, E.; Khalil, A. K.; Shearer, M.; Rosenstiel, T.

2009-12-01

34

Comparisons of aircraft measurements of greenhouse gases with GOSAT data  

NASA Astrophysics Data System (ADS)

Vertical profiles of greenhouse gases (GHGs) and ozone were measured using the Alpha Jet research aircraft as part of the Alpha Jet Atmospheric eXperiment (AJAX). Airborne instruments measuring GHGs (Picarro Inc. G2301-m) and ozone (2B Technologies Inc., model 205) are installed in a wing pod and operated from NASA Ames Research Center at Moffett Field, CA (37.415°N, 120.050°W). The in situ measurement instruments mounted on the aircraft yield precise and accurate vertical profiles of atmospheric GHGs and ozone. The purpose of this work is to validate GOSAT data and estimate from Alpha Jet measurements the contribution of GHGs from urban areas. We show the result of comparison of GOSAT and Alpha Jet measurements over Railroad Valley, NV and urban areas in Northern California. The Alpha Jet aircraft performs a measurement over the Railroad Valley (RRV) desert playa, Nevada (38.497°N, 115.691°W, 1437m above mean sea level) once a month for the comparison with Greenhouse gases Observing Satellite (GOSAT) measurements from 2011. The GOSAT was developed to measure concentrations of CO2 and CH4 from space and has been in operation from 2009. The instruments onboard GOSAT are the Thermal And Near-infrared Sensor for carbon Observation Fourier Transform Spectrometer (TANSO-FTS) and the TANSO Cloud and Aerosol Imager (TANSO-CAI) (Kuze et al., 2009). The RRV playa is a flat, high altitude desert site and an area where local sources and sinks of carbon-species are expected to be minimal. The playa has virtually no vegetation and an overall size of 15 km× 15 km, which includes GOSAT's field of view. Reference Akihiko Kuze, Hiroshi Suto, Masakatsu Nakajima, and Takashi Hamazaki. Thermal and near infrared sensor for carbon observation Fourier-transform spectrometer on the Greenhouse Gases Observing Satellite for greenhouse gases monitoring. App. Opt., 48, 6716-6733, 2009.

Tanaka, T.; Yates, E. L.; Iraci, L. T.; Loewenstein, M.; Gore, W.; Tadic, J.; Lopez, J. P.; Shiomi, K.; Kawakami, S.; kuze, A.; Yokota, T.

2013-12-01

35

Orbital insolation, ice volume, and greenhouse gases  

Microsoft Academic Search

The SPECMAP models of orbital-scale climate change (Imbrie et al., Paleoceanography 7 (1992) 701, Paleoceanography 8 (1993) 699) are the most comprehensive to date: all major climatic observations were analyzed within the framework of the three orbital signals. Subsequently, tuning of signals in Vostok ice to insolation forcing has fixed the timing of greenhouse-gas changes closely enough to permit an

William F. Ruddiman

2003-01-01

36

Orbital insolation, ice volume, and greenhouse gases  

NASA Astrophysics Data System (ADS)

The SPECMAP models of orbital-scale climate change (Imbrie et al., Paleoceanography 7 (1992) 701, Paleoceanography 8 (1993) 699) are the most comprehensive to date: all major climatic observations were analyzed within the framework of the three orbital signals. Subsequently, tuning of signals in Vostok ice to insolation forcing has fixed the timing of greenhouse-gas changes closely enough to permit an assessment of their orbital-scale climatic role. In addition, evidence from several sources has suggested changes in the SPECMAP ? 18O time scale. This new information indicates that the timing of CO 2 changes at the periods of precession and obliquity does not fit the 1992 SPECMAP model of a "train" of responses initiated in the north, propagated to the south, and later returning north to force the ice sheets. In addition, analysis of the effects of rectification on 100,000-year climatic signals reveals that all have a phase on or near that of eccentricity. This close clustering of phases rules out the long time constants for 100,000-year ice sheets required by the 1993 SPECMAP model. A new hypotheses presented here revives elements of an earlier CLIMAP view (Hays et al., Science 194 (1976a) 1121) but adds a new assessment of the role of greenhouse gases. As proposed by Milankovitch, summer (mid-July) insolation forces northern hemisphere ice sheets at the obliquity and precession periods, with an ice time constant derived here of 10,000 years. Changes in ice volume at 41,000 years drive ice-proximal signals (SST, NADW, dust) that produce a strong positive CO 2 feedback and further amplify ice-volume changes. At the precession period, July insolation forces ice sheets but it also drives fast and early responses in CH 4 through changes in tropical monsoons and boreal wetlands, and variations in CO 2 through southern hemisphere processes. These CH 4 and CO 2 responses enhance insolation forcing of ice volume. Climatic responses at 100,000 years result from eccentricity pacing of forced processes embedded in obliquity and precession cycles. Increased modulation of precession by eccentricity every 100,000 years produces 23,000-year CO 2 and CH 4 maxima that enhance ablation caused by summer insolation and drive climate deeper into an interglacial state. When eccentricity modulation decreases at the 100,000-year cycle, ice sheets grow larger in response to obliquity forcing and activate a 41,000-year CO 2 feedback that drives climate deeper into a glacial state. Alternation of these forced processes because of eccentricity pacing produces the 100,000-year cycle. The 100,000-year cycle began 0.9 Myr ago because gradual global cooling allowed ice sheets to survive during weak precession insolation maxima and grow large enough during 41,000-year ice-volume maxima to generate strong positive CO 2 feedback. The natural orbital-scale timing of these processes indicates that ice sheets should have appeared 6000-3500 years ago and that CO 2 and CH 4 concentrations should have fallen steadily from 11,000 years ago until now. But new ice did not appear, and CO 2 and CH 4 began anomalous increases at 8000 and 5000 years ago, respectively. Human generation of CO 2 and CH 4 is implicated in these anomalous trends and in the failure of ice sheets to appear in Canada.

Ruddiman, William F.

2003-07-01

37

Measuring the Heat Capacity of Greenhouse Gases  

NSDL National Science Digital Library

This quantitative experiment involves lab teams in comparing a sample of room air with one of the greenhouse gases - carbon dioxide, nitrous oxide, or methane - and measuring their heat capacity. The activity requires an infrared heat source, such as a heat lamp, two 2L beverage bottles, #4 one hole rubber stoppers, and a thermometer or temperature probe, volumetric flasks, a graduated cylinder, and tubing. Nitrous oxide can be obtained from a dentist, methane from gas jets in a chemistry lab, and becomes CO² can be generated using vinegar and baking soda. A worksheet guides student calculations of heat capacity of the different samples. The investigation s is supported by the textbook, Climate Change, part of the Global System Science, an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

38

Radiative forcings and global warming potentials of 39 greenhouse gases  

Microsoft Academic Search

The radiative forcings and global warming potentials for 39 greenhouse gases are evaluated using narrowband and broadband radiative transfer models. Unlike many previous studies, latitudinal and seasonal variations are considered explicitly, using distributions of major greenhouse gases from a combination of chemical-transport model results and Upper Atmosphere Research Satellite (UARS) measurements and cloud statistics from the International Satellite Cloud Climatology

Atul K. Jain; Bruce P. Briegleb; K. Minschwaner; Donald J. Wuebbles

2000-01-01

39

Emissions of Greenhouse Gases in the United States 1999  

NSDL National Science Digital Library

EIA's annual report on human-caused greenhouse gases in the US shows an annual average increase of 1.1 percent over the past ten years. In 1999, the total emission of greenhouse gases in the US is estimated at 1,833 million metric tons of carbon equivalent, 0.8 percent higher than the estimated level in 1998.

40

Effects of atmospheric light scattering on spectroscopic observations of greenhouse gases from space: Validation of PPDF-based CO2 retrievals from GOSAT  

NASA Astrophysics Data System (ADS)

This report describes a validation study of Greenhouse gases Observing Satellite (GOSAT) data processing using ground-based measurements of the Total Carbon Column Observing Network (TCCON) as reference data for column-averaged dry air mole fractions of atmospheric carbon dioxide (XCO2). We applied the photon path length probability density function method to validate XCO2retrievals from GOSAT data obtained during 22 months starting from June 2009. This method permitted direct evaluation of optical path modifications due to atmospheric light scattering that would have a negligible impact on ground-based TCCON measurements but could significantly affect gas retrievals when observing reflected sunlight from space. Our results reveal effects of optical path lengthening over Northern Hemispheric stations, essentially from May-September of each year, and of optical path shortening for sun-glint observations in tropical regions. These effects are supported by seasonal trends in aerosol optical depth derived from an offline three-dimensional aerosol transport model and by cirrus optical depth derived from space-based measurements of the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument. Removal of observations that were highly contaminated by aerosol and cloud from the GOSAT data set resulted in acceptable agreement in the seasonal variability of XCO2 over each station as compared with TCCON measurements. Statistical comparisons between GOSAT and TCCON coincident measurements of CO2column abundance show a correlation coefficient of 0.85, standard deviation of 1.80 ppm, and a sub-ppm negative bias of -0.43 ppm for all TCCON stations. Global distributions of monthly mean retrieved XCO2 with a spatial resolution of 2.5° latitude × 2.5° longitude show agreement within ˜2.5 ppm with those predicted by the atmospheric tracer transport model.

Oshchepkov, Sergey; Bril, Andrey; Yokota, Tatsuya; Morino, Isamu; Yoshida, Yukio; Matsunaga, Tsuneo; Belikov, Dmitry; Wunch, Debra; Wennberg, Paul; Toon, Geoffrey; O'Dell, Christopher; Butz, André; Guerlet, Sandrine; Cogan, Austin; Boesch, Hartmut; Eguchi, Nawo; Deutscher, Nicholas; Griffith, David; Macatangay, Ronald; Notholt, Justus; Sussmann, Ralf; Rettinger, Markus; Sherlock, Vanessa; Robinson, John; Kyrö, Esko; Heikkinen, Pauli; Feist, Dietrich G.; Nagahama, Tomoo; Kadygrov, Nikolay; Maksyutov, Shamil; Uchino, Osamu; Watanabe, Hiroshi

2012-06-01

41

Greenhouse gases: What is their role in climate change  

SciTech Connect

This paper summarizes information relevant to understanding the role of greenhouse gases in the atmosphere. It examines the nature of the greenhouse effect, the Earth's radiation budget, the concentrations of these gases in the atmosphere, how these concentrations have been changing, natural processes which regulate these concentrations of greenhouse gases, residence times of these gases in the atmosphere, and the rate of release of gases affecting atmospheric composition by human activities. We address the issue of the greenhouse effect itself in the first section. In the second section we examine trends in atmospheric concentration of greenhouse gases and emissions sources. In the third section, we examine the natural carbon cycle and its role in determining the atmospheric residence time of carbon dioxide (CO{sub 2}). In the fourth section, we examine the role atmospheric chemistry plays in the determining the concentrations of greenhouse gases. This paper is not intended to be an exhaustive treatment of these issues. Exhaustive treatments can be found in other volumes, many of which are cited throughout this paper. Rather, this paper is intended to summarize some of the major findings, unknowns, and uncertainties associated with the current state of knowledge regarding the role of greenhouse gases in the atmosphere. 57 refs., 11 figs., 11 tabs.

Edmonds, J.A.; Chandler, W.U. (Pacific Northwest Lab., Richland, WA (USA)); Wuebbles, D. (Lawrence Livermore National Lab., CA (USA))

1990-12-01

42

The Orbiting Carbon Observatory (OCO-2) Mission and Experience Gained from the Greenhouse gases Observing Satellite (GOSAT)  

NASA Astrophysics Data System (ADS)

The NASA Orbiting Carbon Observatory (OCO-2) will make space-based measurements of atmospheric CO2 with the precision, resolution, and coverage needed to characterize CO2 sources and sinks on regional scales and quantify their variability over the seasonal cycle. The OCO-2 mission will be a 'carbon copy' of the OCO mission, to minimize schedule and cost risks. The OCO-2 instrument has been built and is undergoing testing and characterization. OCO-2 will carry a single instrument that incorporates 3 high resolution grating spectrometers that will make bore-sighted measurements of reflected sunlight in near-infrared CO2 and molecular oxygen (O2) absorption bands. These measurements will be combined to provide spatially resolved estimates of the column-averaged CO2 dry air mole fraction, XCO2. The instrument collects 12 to 24 XCO2 soundings/second over the sunlit portion of the orbit, yielding 200 to 400 soundings per degree of latitude, or 0.5 to 1 million soundings every day. Thick clouds and aerosols will reduce the number of soundings available for XCO2 retrievals by 80-90%, but the remaining data is expected to yield XCO2 estimates with accuracies of ~0.3 to 0.5% (1 to 2 ppm) on regional scales every month. To verify the accuracy of the space-based XCO2 data, the OCO-2 validation program will use ground-based, solar-viewing Fourier Transform Spectrometers (FTS) in the Total Carbon Column Observing Network (TCCON) to tie the space-based XCO2 with the World Meteorological Organization (WMO) standard for atmospheric CO2, which is based on in situ observations of CO2 from flask measurements, tall towers, and aircraft. In preparation for the OCO-2 mission, we are using the OCO-2 algorithm to retrieve XCO2 from GOSAT measurements. We now retrieved XCO2 from GOSAT data from April 2009 to present. These retrievals are being validated with the TCCON network. This presentation will provide an overview of OCO-2 mission, including science objectives, instrument, algorithm, and validation plans as well as recent results from the GOSAT retrievals.

Eldering, A.; Gunson, M.; Crisp, D.; Miller, C. E.

2012-04-01

43

Trace Gases, CO2, Climate, and the Greenhouse Effect.  

ERIC Educational Resources Information Center

Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

Aubrecht, Gordon J., II

1988-01-01

44

Emissions of Greenhouse Gases in the United States 1997  

NSDL National Science Digital Library

The Emissions of Greenhouse Gases in the United States 1997 publication was prepared under the guidance of Mary Hutzler, Director of the Office of Integrated Analysis and Forecasting, Energy Information Administration. This report "presents the latest estimates of emissions for carbon dioxide, methane, nitrous oxide, and other greenhouse gases." The paper states that 82% of U.S. greenhouse gas emissions are caused by coal, petroleum, and natural gas. Gases such as hydroflourocarbons (HFCs), perflourocarbons (PFCs), sulfur hexafluoride, nitrous oxide, methane, and other carbon dioxide gases comprise the other 18% of U.S. emissions. The paper provides an in-depth analysis of Carbon Dioxide Emissions, Methane Emissions, Nitrous Oxide Emissions, Halocarbons and Other Gases, and Land Use Issues, among others.

45

Sun and dust versus greenhouse gases - An assessment of their relative roles in global climate change  

NASA Technical Reports Server (NTRS)

Many mechanisms, including variations in solar radiation and atmospheric aerosol concentrations, compete with anthropogenic greenhouse gases as causes of global climate change. Comparisons of available data show that solar variability will not counteract greenhouse warming and that future observations will need to be made to quantify the role of tropospheric aerosols, for example.

Hansen, James E.; Lacis, Andrew A.

1990-01-01

46

Sun and dust versus greenhouse gases: an assessment of their relative roles in global climate change  

Microsoft Academic Search

Many mechanisms, including variations in solar radiation and atmospheric aerosol concentrations, compete with anthropogenic greenhouse gases as causes of global climate change. Comparisons of available data show that solar variability will not counteract greenhouse warming and that future observations will need to be made to quantify the role of tropospheric aerosols, for example.

James E. Hansen; Andrew A. Lacis

1990-01-01

47

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The mitigation of noncarbon dioxide (non-CO2) greenhouse gas emissions can be a relatively inexpensive supplement to CO2-only mitigation strategies. The non-CO2 gases include methane (CH4), nitrous oxide (N2O), and a number of high global warming potential (high- GWP) or fluorinated gases. These ga...

48

Air Pollution, Greenhouse Gases and Climate Change  

NASA Astrophysics Data System (ADS)

The global build up of greenhouse gases (GHGs), is the most significant environmental issue facing the planet. GHGs warm the surface and the atmosphere with significant implications for, rainfall, retreat of glaciers and sea ice, sea level, among other factors. What is less recognized, however, is a comparably major global problem dealing with air pollution. Until about ten years ago, air pollution was thought to be just an urban or a local problem. But new data have revealed that, due to fast long range transport, air pollution is transported across continents and ocean basins, resulting in trans-oceanic and trans-continental plumes of atmospheric brown clouds (ABCs) containing sub micron size particles, i.e, aerosols. ABCs intercept sunlight by absorbing as well as reflecting it, both of which lead to a large surface dimming. The dimming effect is enhanced further because aerosols nucleate more cloud drops which makes the clouds reflect more solar radiation. While the solar heating at the surface is reduced by aerosols in ABCs, the atmospheric solar heating increases due to soot solar absorption. The net difference between the dimming and the atmospheric solar heating is estimated be negative which contributes to a global cooling effect. The global cooling from this negative ABC forcing may have masked as much as 50% of the warming due to GHGs. We will identify regional and mega-city hot spots of ABCs. Long range transport from these hot spots gives rise to wide spread plumes over the adjacent oceans. Such a pattern of regionally concentrated surface dimming and atmospheric solar heating, accompanied by wide spread dimming over the oceans, gives rise to large regional effects. Only during the last decade, we have begun to comprehend the surprisingly large regional impacts. The large north-south gradient in the ABC dimming has altered the north-south gradients in sea surface temperatures, which in turn has been shown by models to decrease rainfall over the continents. The uncertainties in our understanding of the ABC effects are large, but we are discovering new ways in which human activities are changing the climate and the environment.

Ramanathan, V.

2007-12-01

49

76 FR 37300 - Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems: Revisions to Best...  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems: Revisions to...monitoring methods in regulations for Petroleum and Natural Gas Systems of the Greenhouse...Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems....

2011-06-27

50

Remote Sensing of Greenhouse Gases and Their Sources and Sinks  

NASA Astrophysics Data System (ADS)

The man-made emissions of the greenhouse gases carbon dioxide (CO2) and methane (CH4) are considered the main drivers of anthropogenically induced climate change. Major uncertainties persist when it comes to quantifying regional scale surface fluxes of these gases or predicting the evolution of the relevant source/sink processes in a changing climate. Remote sensing of the atmospheric greenhouse gas concentrations from space-borne and ground-based platforms offers the opportunity to significantly advance our knowledge on spatial and temporal scales that are suitable for process attribution and mitigation actions. Overall, the most promising remote-sensing strategy exploits the rotational-vibrational absorption of CO2 and CH4 in sunlight penetrating the Earth's atmosphere. Typically, satellite sounders such as GOSAT (Greenhouse Gases Observing Satellite), OCO-2 (Orbiting Carbon Observatory), and S5P (Sentinel-5 precursor) as well as the ground-based spectrometers of the TCCON (Total Carbon Column Observing Network) cover various CO2, CH4, and O2 absorption bands in the near and shortwave infrared spectral range between 0.75 micron (13400cm-1) and 2.5 micron (4000cm-1). Accuracy of the inferred gas concentrations is contingent on the accuracy of the adopted spectroscopic parameters and spectroscopic models available in these spectral regions. Here, I will report on recent achievements and challenges within our greenhouse-gas remote-sensing activities mainly focusing on the GOSAT observational record. Since its launch in early 2009, the Fourier Transform Spectrometer onboard GOSAT delivers solar absorption spectra with good spectral resolution and high signal-to-noise. It has been shown that the CO2 and CH4 retrievals from these observations can achieve an accuracy on the order of fractions of a percent which makes them suitable for tracking regional scale source/sink processes and their response to climate events. In order to achieve the required accuracy, it is crucial to develop highly accurate radiative-transfer algorithms and to validate the satellite soundings by ground-based observations. I will illustrate some cases where the excellent quality of the absorption spectra collected by GOSAT reveals spectroscopic deficiencies and inconsistencies among the various absorption bands covered. As such, lessons learned from GOSAT can be used as a feedback to the spectroscopy community. Beyond GOSAT, future satellite missions such as S5P or the planned S5 (Sentinel-5, launch ˜2020) will cover spectral ranges which have not yet been spectroscopically optimized for remote-sensing purposes. In that case, simulations and studies based on ground-based observations show that spectroscopic uncertainties constitute a dominant contribution to the error budget of the retrieved gas concentrations. Therefore, further improvements of spectroscopic parameters and line-shape models is of paramount interest for remote sensing of greenhouse gases.

Butz, Andre; Babenhauserheide, Arne; Bertleff, Marco; Checa-Garcia, Ramiro; Hahne, Philipp; Hase, Frank; Klappenbach, Friedrich; Kostinek, Julian; Aben, Ilse; Hasekamp, Otto; Landgraf, Jochen; Galli, Andre; Basu, Sourish

2014-06-01

51

Greenhouse gases dissolved in soil solution - often ignored, but important?  

NASA Astrophysics Data System (ADS)

Flux measurements of climate-relevant trace gases from soils are frequently undertaken in contemporary ecosystem studies and substantially contribute to our understanding of greenhouse gas balances of the biosphere. While the great majority of such investigations builds on closed chamber and eddy covariance measurements, where upward gas fluxes to the atmosphere are measured, fewest concurrently consider greenhouse gas dissolution in the seepage and leaching of dissolved gases via the vadose zone to the groundwater. Here we present annual leaching losses of dissolved N2O and CO2 from arable, grassland, and forest lysimeter soils from three sites differing in altitude and climate. We aim to assess their importance in comparison to direct N2O emission, soil respiration, and further leaching parameters of the C- and N cycle. The lysimeters are part of the Germany-wide lysimeter network initiative TERENO-SoilCan, which investigates feedbacks of climate change to the pedosphere on a long-term scale. Soil water samples were collected weekly from different depths of the profiles by means of suction cups. A laboratory pre-experiment proved that no degassing occurred under those sampling conditions. We applied the headspace equilibration technique to determine dissolved gas concentrations by gas chromatography. The seepage water of all lysimeters was consistently supersaturated with N2O and CO2 compared to water equilibrated ambient air. In terms of N2O, leaching losses increased in the ascending order forest, grassland, and arable soils, respectively. In case of the latter soils, we observed a strong variability of N2O, with dissolved concentrations up to 23 ?g N L-1. However, since seepage discharge of the arable lysimeters was comparatively small and mostly limited to the hydrological winter season, leached N2O appeared to be less important than direct N2O emissions. In terms of dissolved CO2,our measurements revealed considerable leaching losses from the mountainous forest and grassland soils, based on concentrations up to 24 mg C L-1 and high seepage discharge. Such losses turned out to be similarly important like soil respiration, particularly during winter when temperature-dependent soil respiration declined. In conclusion, the results of the first year of our measurements provide evidence that dissolved greenhouse gases should be considered in studies which aim to assess full greenhouse gas balances, particularly in ecosystems where hydrological conditions favour microbial activity and high leaching losses.

Weymann, Daniel; Brueggemann, Nicolas; Puetz, Thomas; Vereecken, Harry

2014-05-01

52

From the First Measurements of Atmospheric Carbon Dioxide During the IGY to the Global Annual Greenhouse Gas Index in 2006: The Evolution of the Global Observing Network for Greenhouse Gases.  

NASA Astrophysics Data System (ADS)

During the International Geophysical Year, Dr. Charles "Dave" Keeling instituted both air sample collections at the South Pole in Antarctica and continuous carbon dioxide measurements with an infrared analyzer at the Mauna Loa Observatory in Hawaii. Both of these locations were later to become Observatories of the U.S. National Oceanic and Atmospheric Administration (NOAA), following its formation in 1970, and the pioneering measurements of Dave Keeling continued to be supported by NOAA at these sites until this day. In addition to instituting Observatories at key background locations (Pt. Barrow, Alaska; American Samoa; and more recently Trinidad Head, California, in addition to the Hawaii and Antarctic sites) the forerunners of NOAA/ESRL also began a global cooperative air sampling network in the late 1960's. The air samples were analyzed for carbon dioxide and other gases in the Boulder, Colorado laboratories. With the help of many people in many nations, this network has grown to the largest such effort in the world, numbering about 90 sites, including three ship routes, at present. In 1996, data from this network and from other networks around the world formed the basis of GLOBALVIEW, a web-based collection of carbon dioxide and methane data used extensively with transport models to determine global carbon dioxide sources and sinks. This data set is available at http://www.cmdl.noaa.gov/ccgg/globalview/index.html . In 2004, the global measurements of all the long-lived greenhouse gases, including carbon dioxide, methane, nitrous oxide, the chlorofluorocarbons, and ten minor halogen gases were condensed into a simple index, the "Annual Greenhouse Gas Index" (AGGI) by summing their radiative climate forcing since the pre-industrial era (taken as 1750). The NOAA AGGI is designed to enhance the connection between scientists and society by providing a normalized standard that can be easily understood and followed. The contribution of long-lived greenhouse gases to climate forcing is well understood by scientists and has been reported through a range of national and international assessments. Nevertheless, the language of scientists (for example, watts per square meter per year) often eludes policy makers, educators, and the general public. This index is designed to help bridge that gap.

Hofmann, D. J.; Butler, J. H.; Dlugokencky, E. J.; Elkins, J. W.; Masarie, K.; Montzka, S. A.; Tans, P. P.

2006-05-01

53

Emissions of greenhouse gases in the United States 1997  

SciTech Connect

This is the sixth annual report on aggregate US national emissions of greenhouse gases. It covers emissions over the period 1990--1996, with preliminary estimates of emissions for 1997. Chapter one summarizes some background information about global climate change and the greenhouse effect. Important recent developments in global climate change activities are discussed, especially the third Conference of the Parties to the Framework Convention on Climate Change, which was held in December of 1997 in Kyoto, Japan. Chapters two through five cover emissions of carbon dioxide, methane, nitrous oxide, halocarbons and related gases, respectively. Chapter six describes potential sequestration and emissions of greenhouse gases as a result of land use changes. Six appendices are included in the report. 96 refs., 38 tabs.

NONE

1998-10-01

54

Greenhouse effect of chlorofluorocarbons and other trace gases  

NASA Technical Reports Server (NTRS)

A comparison is made of the radiative (greenhouse) forcing of the climate system due to changes of atmospheric chlorofluorocarbons and other trace gases. It is found that CFCs, defined to include chlorofluorocarbons, chlorocarbons, and fluorocarbons, now provide about one-quater of current annual increases in anthropogenic greenhouse climate forcing. If the growth rates of CFC production in the early 1970s had continued to the present, current annual growth of climate forcing due to CFCs would exceed that due to CO2.

Hansen, James; Lacis, Andrew; Prather, Michael

1989-01-01

55

Welcome to Greenhouse Gases: Science and Technology: Editorial  

SciTech Connect

This editorial introduces readers and contributors to a new online journal. Through the publication of articles ranging from peer-reviewed research papers and short communications, to editorials and interviews on greenhouse gas emissions science and technology, this journal will disseminate research results and information that address the global crisis of anthropogenic climate change. The scope of the journal includes the full spectrum of research areas from capture and separation of greenhouse gases from flue gases and ambient air, to beneficial utilization, and to sequestration in deep geologic formations and terrestrial (plant and soil) systems, as well as policy and technoeconomic analyses of these approaches.

Oldenburg, C.M.; Maroto-Valer, M.M.

2011-02-01

56

Observational determination of the greenhouse effect  

Microsoft Academic Search

Satellite measurements are used to quantify the atmospheric greenhouse effect, defined here as the infrared radiation energy trapped by atmospheric gases and clouds. The greenhouse effect is found to increase significantly with sea surface temperature. The rate of increase gives compelling evidence for the positive feedback between surface temperature, water vapor and the greenhouse effect; the magnitude of the feedback

A. Raval; V. Ramanathan

1989-01-01

57

Biomass Burning and the Production of Greenhouse Gases. Chapter 9  

NASA Technical Reports Server (NTRS)

Biomass burning is a source of greenhouse gases, carbon dioxide, methane, and nitrous oxide. In addition, biomass burning is a source of chemically active gases, including carbon monoxide, nonmethane hydrocarbons, and nitric oxide. These gases, along with methane, lead to the chemical production of tropospheric ozone (another greenhouse gas) as well as control the concentration of the hydroxyl radical, which regulates the lifetime of almost every atmospheric gas. Following biomass burning, biogenic emissions of nitrous oxide, nitric oxide, and methane are significantly enhanced. It is hypothesized that enhanced postburn biogenic emissions of these gases are related to fire-induced changes in soil chemistry and/or microbial ecology. Biomass burning, once believed to be a tropical phenomenon, has been demonstrated by satellite imagery to also be a regular feature of the world's boreal forests. One example of biomass burning is the extensive 1987 fire that destroyed more than 12 million acres of boreal forest in the People's Republic of China and across its border in the Soviet Union. Recent estimates indicate that almost all biomass burning is human-initiated and that it is increasing with time. With the formation of greenhouse and chemically active gases as direct combustion products and a longer-term enhancement of biogenic emissions of gases, biomass burning may be a significant driver for global change.

Levine, Joel S.

1994-01-01

58

OPTIONS FOR ABATING GREENHOUSE GASES FROM EXHAUST STREAMS.  

SciTech Connect

This report examines different alternatives for replacing, treating, and recycling greenhouse gases. It is concluded that treatment (abatement) is the only viable short-term option. Three options for abatement that were tested for use in semiconductor facilities are reviewed, and their performance and costs compared. This study shows that effective abatement options are available to the photovoltaic (PV) industry, at reasonable cost.

FTHENAKIS,V.

2001-12-01

59

GREENHOUSE GASES FROM DEFORESTATION IN BRAZILIAN AMAZONIA: NET COMMITTED EMISSIONS  

Microsoft Academic Search

Deforestation in Brazilian Amazonia is a significant source of greenhouse gases today and, with almost 90% of the originally forested area still uncleared, is a very large potential source of future emissions. The 1990 rate of loss of forest (13.8 × 103 km2\\/year) and cerrado savanna (approximately 5 × 103 km2\\/year) was responsible for releasing approximately 261 × 106 metric

PHILIP M. Fearnside

1997-01-01

60

The greenhouse gases HFCs, PFCs Danish consumption and emissions, 2007  

E-print Network

The greenhouse gases HFCs, PFCs and SF6 Danish consumption and emissions, 2007 Tomas Sander Poulsen og Ida Bode PlanMiljø Environmental Project No. 1284 2009 Miljøprojekt #12;The Danish Environmental research and development projects financed via the Danish EPA. Please note that publication does

61

Atmospheric Modelling of Greenhouse Gases and Air Quality  

E-print Network

values at the urban sites (blue box) #12;Model: formula3on Grid/les 25th-75th percen/les mean Model Observa/ons C (ppm) #12;UrbanAtmospheric Modelling of Greenhouse Gases and Air Quality John C. Lin Courtenay Strong University

Tipple, Brett

62

Emissions Of Greenhouse Gases From Rice Agriculture  

SciTech Connect

This project produced detailed data on the processes that affect methane and nitrous oxide emissions from rice agriculture and their inter-relationships. It defines the shifting roles and potential future of these gases in causing global warming and the benefits and tradeoffs of reducing emissions. The major results include: 1). Mechanisms and Processes Leading to Methane Emissions are Delineated. Our experiments have tested the standard model of methane emissions from rice fields and found new results on the processes that control the flux. A mathematical mass balance model was used to unravel the production, oxidation and transport of methane from rice. The results suggested that when large amounts of organic matter are applied, the additional flux that is observed is due to both greater production and reduced oxidation of methane. 2). Methane Emissions From China Have Been Decreasing Over the Last Two Decades. We have calculated that methane emissions from rice fields have been falling in recent decades. This decrease is particularly large in China. While some of this is due to reduced area of rice agriculture, the bigger effect is from the reduction in the emission factor which is the annual amount of methane emitted per hectare of rice. The two most important changes that cause this decreasing emission from China are the reduced use of organic amendments which have been replaced by commercial nitrogen fertilizers, and the increased practice of intermittent flooding as greater demands are placed on water resources. 3). Global Methane Emissions Have Been Constant For More Than 20 Years. While the concentrations of methane in the atmosphere have been leveling off in recent years, our studies show that this is caused by a near constant total global source of methane for the last 20 years or more. This is probably because as some anthropogenic sources have increased, others, such as the rice agriculture source, have fallen. Changes in natural emissions appear small. 4). Nitrous Oxide Emissions From Rice Fields Increase as Methane Emissions Drop. Inundated conditions favor anaerobic methane production with high emission rates and de-nitrification resulting in modest nitrous oxide emissions. Under drier conditions such as intermittent flooding, methane emissions fall and nitrous oxide emissions increase. Increased nitrogen fertilizer use increases nitrous oxide emissions and is usually accompanied by reduced organic matter applications which decreases methane emissions. These mechanisms cause a generally inverse relationship between methane and nitrous oxide emissions. Reduction of methane from rice agriculture to control global warming comes with tradeoffs with increased nitrous oxide emissions. 5). High Spatial Resolution Maps of Emissions Produced. Maps of methane and nitrous oxide emissions at a resolution of 5 min × 5 min have been produced based on the composite results of this research. These maps are necessary for both scientific and policy uses.

M. Aslam K. Khalil

2009-07-16

63

Radiative forcings for 28 potential Archean greenhouse gases  

NASA Astrophysics Data System (ADS)

Despite reduced insolation in the late Archean, evidence suggests a~warm climate which was likely sustained by a stronger greenhouse effect, the so-called faint young sun problem (FYSP). CO2 and CH4 are generally thought to be the mainstays of this enhanced greenhouse, though many other gases have been proposed. We present high accuracy radiative forcings for CO2, CH4, and 26 other gases, performing the radiative transfer calculations at line-by-line resolution and using HITRAN 2012 line data for background pressures of 0.5, 1, and 2 bar of atmospheric N2. For CO2 to resolve the FYSP alone at 2.8 Gyr BP (80% of present solar luminosity), 0.32 bar is needed with 0.5 bar of atmospheric N2, 0.20 bar with 1 bar of atmospheric N2, or 0.11 bar with 2 bar of atmospheric N2. For CH4, we find that near-infrared absorption is much stronger than previously thought, arising from updates to the HITRAN database. CH4 radiative forcing peaks at 10.3, 9, or 8.3 W m-2 for background pressures of 0.5, 1, or 2 bar, likely limiting the utility of CH4 for warming the Archean. For the other 26 HITRAN gases, radiative forcings of up to a few to 10 W m-2 are obtained from concentrations of 0.1-1 ppmv for many gases. For the 20 strongest gases, we calculate the reduction in radiative forcing due to overlap. We also tabulate the modern sources, sinks, concentrations, and lifetimes of these gases and summaries the literature on Archean sources and concentrations. We recommend the forcings provided here be used both as a first reference for which gases are likely good greenhouse gases, and as a standard set of calculations for validation of radiative forcing calculations for the Archean.

Byrne, B.; Goldblatt, C.

2014-10-01

64

Greenhouse Gases and the Kyoto Protocol  

NSDL National Science Digital Library

The United Nations Environment Programme UNEP/ GRID Arendal Website (described in the June 24, 1998 Scout Report for Science & Engineering) summarizes greenhouse gas emissions for 1998 and provides projections for 2010. The maps and statistics presented here are based on data collected by the UN Framework Convention on Climate Change (UNFCCC) for the international summit in The Hague, November 2000. Units for totals are "thousands of metric tonnes of Carbon Dioxide (CO2) equivalent units," and for emissions per capita, the units are "tonnes of Carbon Dioxide (CO2) equivalent per person." In every case, emissions from industrialized nations are what the viewer might expect. Nevertheless, the comparison of 1998 and projected future levels is certainly instructive. A series of links provides access to additional related information.

2001-01-01

65

Radiative forcings for 28 potential Archean greenhouse gases  

NASA Astrophysics Data System (ADS)

Despite reduced insolation in the late Archean, evidence suggests a warm climate which was likely sustained by a stronger greenhouse effect, the so-called Faint Young Sun Problem (FYSP). CO2 and CH4 are generally thought to be the mainstays of this enhanced greenhouse, though many other gases have been proposed. We present high accuracy radiative forcings for CO2, CH4 and 26 other gases, performing the radiative transfer calculations at line-by-line resolution and using HITRAN 2012 line data for background pressures of 0.5, 1, and 2 bar. For CO2 to resolve the FYSP alone, 0.21 bar is needed with 0.5 bar of atmospheric pressure, 0.13 bar with 1 bar of atmospheric pressures, or 0.07 bar with 2 bar of atmospheric pressure. For CH4, we find that near-infrared absorption is much stronger than previously thought, arising from updates to the HITRAN database. CH4 radiative forcing peaks at 10.3, 9, or 8.3 W m-2 for background pressures of 0.5, 1 or 2 bar, likely limiting the utility of CH4 for warming the Archean. For the other 26 HITRAN gases, radiative forcings of up to a few to 10 W m-2 are obtained from concentrations of 0.1-1 ppmv for many gases. We further calculate the reduction of radiative forcing due to gas overlap for the 20 strongest gases. We recommend the forcings provided here be used both as a first reference for which gases are likely good greenhouse gases, and as a standard set of calculations for validation of radiative forcing calculations for the Archean.

Byrne, B.; Goldblatt, C.

2014-05-01

66

76 FR 22825 - Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems AGENCY: Environmental...30, 2010 EPA promulgated Subpart W: Petroleum and Natural Gas Systems of the Greenhouse...calculating greenhouse gas emissions for the petroleum and natural gas systems source...

2011-04-25

67

What are greenhouse gases? Many chemical compounds in the atmosphere act as  

E-print Network

What are greenhouse gases? Many chemical compounds in the atmosphere act as greenhouse gases the atmosphere1 . They absorb some and radiate it back down to the Earth. This phenomenon, called the greenhouse. Without the greenhouse effect, the Earth's average surface temperature would be about 60° Fahrenheit

68

Greenhouse effect of trace gases, 1970-1980  

NASA Technical Reports Server (NTRS)

Increased abundances were measured for several trace atmospheric gases in the decade 1970-1980. The equilibrium greenhouse warming for the measured increments of CH4, chlorofluorocarbons and N2O is between 50% and 100% of the equilibrium warming for the measured increase of atmospheric CO2 during the same 10 years. The combined warming of CO2 and trace gases should exceed natural global temperature variability in the 1980's and cause the global mean temperature to rise above the maximum of the late 1930's.

Lacis, A.; Hansen, J.; Lee, P.; Lebedeff, S.; Mitchell, T.

1981-01-01

69

Mitigation of greenhouse gases by adoption of improved biomass cookstoves  

Microsoft Academic Search

Greenhouse gases especially CO2 can be reduced with the help of improved biomass cookstoves. This paper deals with the design and development of biomass\\u000a stoves (single pot and double pot) with better efficiency for meeting household cooking energy requirement. Thermal performance,\\u000a flue gas emission of carbon monoxide (CO) and carbon dioxide (CO2) have been investigated. It was seen from the

N. L. Panwar; A. K. Kurchania; N. S. Rathore

2009-01-01

70

Annual emissions of greenhouse gases from sheepfolds in Inner Mongolia  

Microsoft Academic Search

Sheepfolds represent significant hot spot sources of greenhouse gases (GHG) in semi-arid grassland regions, such as Inner\\u000a Mongolia in China. However, the annual contribution of sheepfolds to regional GHG emissions is still unknown. In order to\\u000a quantify its annual contribution, we conducted measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes at two sheepfold sites in the

Weiwei Chen; Benjamin Wolf; Nicolas Brüggemann; Klaus Butterbach-Bahl; Xunhua Zheng

2011-01-01

71

Ozone depletion, greenhouse gases, and climate change  

NASA Technical Reports Server (NTRS)

This symposium was organized to study the unusual convergence of a number of observations, both short and long term that defy an integrated explanation. Of particular importance are surface temperature observations and observations of upper atmospheric temperatures, which have declined significantly in parts of the stratosphere. There has also been a dramatic decline in ozone concentration over Antarctica that was not predicted. Significant changes in precipitation that seem to be latitude dependent have occurred. There has been a threefold increase in methane in the last 100 years; this is a problem because a source does not appear to exist for methane of the right isotopic composition to explain the increase. These and other meteorological global climate changes are examined in detail.

Mooney, Harold A.; Baker, D. James, Jr.; Bretherton, Francis P.; Burke, Kevin C.; Clark, William C.; Davis, Margaret B.; Dickinson, Robert E.; Imbrie, John; Malone, Thomas F.; Mcelroy, Michael B.

1989-01-01

72

Emissions of greenhouse gases in the United States 1996  

SciTech Connect

The Energy Information Administration (EIA) is required by the Energy Policy Act of 1992 to prepare a report on aggregate US national emissions of greenhouse gases for the period 1987--1990, with annual updates thereafter. This report is the fifth annual update, covering national emissions over the period 1989--1995, with preliminary estimates of emissions for 1996. The estimates contained in this report have been revised from those in last year`s report. Emissions estimates for carbon dioxide are reported in metric tons of carbon; estimates for other gases are reported in metric tons of gas. Chapter 1 of this report briefly recapitulates some background information about global climate change and the greenhouse effect and discusses important recent developments in global climate change activities. Chapter 2 through 6 cover emissions of carbon dioxide, methane, nitrous oxide, halocarbons, and criteria pollutants, respectively. Chapter 7 describes potential sequestration and emissions of greenhouse gases as a result of land use changes. Five appendixes are included with this report. 216 refs., 11 figs., 38 tabs.

NONE

1997-10-01

73

Greenhouse Gases in Intensive Agriculture: Contributions of Individual Gases to the Radiative Forcing of the Atmosphere  

Microsoft Academic Search

Agriculture plays a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide, and methane. From 1991 to 1999, we measured gas fluxes and other sources of global warming potential (GWP) in cropped and nearby unmanaged ecosystems. Net GWP (grams of carbon dioxide equivalents per square meter per year) ranged from 110 in our conventional tillage

G. Philip Robertson; Eldor A. Paul; Richard R. Harwood

2000-01-01

74

Analyzers Measure Greenhouse Gases, Airborne Pollutants  

NASA Technical Reports Server (NTRS)

In complete darkness, a NASA observatory waits. When an eruption of boiling water billows from a nearby crack in the ground, the observatory s sensors seek particles in the fluid, measure shifts in carbon isotopes, and analyze samples for biological signatures. NASA has landed the observatory in this remote location, far removed from air and sunlight, to find life unlike any that scientists have ever seen. It might sound like a scene from a distant planet, but this NASA mission is actually exploring an ocean floor right here on Earth. NASA established a formal exobiology program in 1960, which expanded into the present-day Astrobiology Program. The program, which celebrated its 50th anniversary in 2010, not only explores the possibility of life elsewhere in the universe, but also examines how life begins and evolves, and what the future may hold for life on Earth and other planets. Answers to these questions may be found not only by launching rockets skyward, but by sending probes in the opposite direction. Research here on Earth can revise prevailing concepts of life and biochemistry and point to the possibilities for life on other planets, as was demonstrated in December 2010, when NASA researchers discovered microbes in Mono Lake in California that subsist and reproduce using arsenic, a toxic chemical. The Mono Lake discovery may be the first of many that could reveal possible models for extraterrestrial life. One primary area of interest for NASA astrobiologists lies with the hydrothermal vents on the ocean floor. These vents expel jets of water heated and enriched with chemicals from off-gassing magma below the Earth s crust. Also potentially within the vents: microbes that, like the Mono Lake microorganisms, defy the common characteristics of life on Earth. Basically all organisms on our planet generate energy through the Krebs Cycle, explains Mike Flynn, research scientist at NASA s Ames Research Center. This metabolic process breaks down sugars for energy to fuel cellular functions. "We think this chemical process did not exist when life first formed on Earth," he says, "because it is based on oxygen being available, and there was little oxygen available on the early Earth." It is possible that there are anaerobic regions beneath the sea floor in which life forms like those early non-Krebs Cycle microbes may yet exist. To detect and potentially collect samples of life emerging from hydrothermal vents, Flynn and his colleagues created Medusa, a multi-sensor instrument designed for long-term observation of diked vents on the ocean floor. When the vents erupt, Medusa assesses indicators of life within the expelled water. If the results are positive, the observatory collects samples and detaches from the ocean floor, making the long journey to the surface for retrieval by scientists. One of the indicators Medusa measures is the ratio of carbon isotopes in the water, namely carbon-12 and carbon-13. Living organisms preferentially take up carbon-12, Flynn says, so examining the ratio of these isotopes can help to determine the source of carbon in an environment as either biological or non-biological. "On Mars, there is evidence of localized methane in the atmosphere, and that methane could come from biological sources or from geochemical ones," Flynn says. "Determining the background planetary carbon isotope ratios and then evaluating the specific carbon ratios in this methane would help to determine how it was formed." A long-duration observatory similar to Medusa could one day provide essential evidence for or against the presence of life on the Red Planet or beneath the ice-crusted oceans of Europa.

2012-01-01

75

Observational determination of the greenhouse effect  

NASA Technical Reports Server (NTRS)

Satellite measurements are used to quantify the atmospheric greenhouse effect, defined here as the infrared radiation energy trapped by atmospheric gases and clouds. The greenhouse effect is found to increase significantly with sea surface temperature. The rate of increase gives compelling evidence for the positive feedback between surface temperature, water vapor and the greenhouse effect; the magnitude of the feedback is consistent with that predicted by climate models. This study demonstrates an effective method for directly monitoring, from space, future changes in the greenhouse effect.

Raval, A.; Ramanathan, V.

1989-01-01

76

75 FR 22699 - Mandatory Reporting of Greenhouse Gases: Minor Harmonizing Changes to the General Provisions  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Reporting of Greenhouse Gases: Minor Harmonizing...provisions for the Mandatory Greenhouse Gas (GHG) Reporting...Division, Office of Atmospheric Programs (MC-6207J...rule would not take effect and we would publish...practice and procedure, Greenhouse gases,...

2010-04-30

77

Laser remote sensing of greenhouse gases at NIST  

NASA Astrophysics Data System (ADS)

The National Institute of Standards and Technology is pursuing optical technologies for remote sensing of greenhouse gases in support of mitigation efforts and climate research. We will describe the development of a rapid, integrated-path differential absorption LIDAR (DIAL) system at our Boulder site as well as the development and testing of an indoor, range-resolved DIAL system on our Gaithersburg site. Our eventual goal is the measurement of greenhouse gas emission rates from distributed sources covering areas of 1 km2 to 10 km2. Such measurements require simultaneous wind and gas density measurements. The presentation will describe our progress toward these measurements as well as development of LIDAR laser sources and implementation of various direct and heterodyne detection schemes.

Maxwell, Stephen; Douglass, Kevin; Plusquellic, David

2014-05-01

78

Emissions of greenhouse gases in the United States 1995  

SciTech Connect

This is the fourth Energy Information Administration (EIA) annual report on US emissions of greenhouse gases. This report presents estimates of US anthropogenic (human-caused) emissions of carbon dioxide, methane, nitrous oxide, and several other greenhouse gases for 1988 through 1994. Estimates of 1995 carbon dioxide, nitrous oxide, and halocarbon emissions are also provided, although complete 1995 estimates for methane are not yet available. Emissions of carbon dioxide increased by 1.9% from 1993 to 1994 and by an additional 0.8% from 1994 to 1995. Most carbon dioxide emissions are caused by the burning of fossil fuels for energy consumption, which is strongly related to economic growth, energy prices, and weather. The US economy grew rapidly in 1994 and slowed in 1995. Estimated emissions of methane increased slightly in 1994, as a result of a rise in emissions from energy and agricultural sources. Estimated nitrous oxide emissions increased by 1.8% in 1995, primarily due to increased use of nitrogen fertilizers and higher output of chemicals linked to nitrous oxide emissions. Estimated emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), which are known to contribute to global warming, increased by nearly 11% in 1995, primarily as a result of increasing substitution for chlorofluorocarbons (CFCs). With the exception of methane, the historical emissions estimates presented in this report are only slightly revised from those in last year`s report.

NONE

1996-10-01

79

Integrated model shows that atmospheric brown clouds and greenhouse gases have reduced rice harvests in India  

SciTech Connect

Previous studies have found that atmospheric brown clouds partially offset the warming effects of greenhouse gases. This finding suggests a tradeoff between the impacts of reducing emissions of aerosols and greenhouse gases. Results from a statistical model of historical rice harvests in India, coupled with regional climate scenarios from a parallel climate model, indicate that joint reductions in brown clouds and greenhouse gases would in fact have complementary, positive impacts on harvests. The results also imply that adverse climate change due to brown clouds and greenhouse gases contributed to the slowdown in harvest growth that occurred during the past two decades.

Auffhammer, M. [Univ. of California, Berkeley, CA (United States). Dept. of Agricultural and Resource Economics; Ramanathan, V. [Scripps Institution of Oceanography, San Diego, CA (United States); Vincent, J.R. [Univ. of California, San Diego, CA (United States). Graduate School of International Relations and Pacific Studies

2007-12-26

80

Direct and ozone-mediated forcing of the Southern Annular Mode by greenhouse gases  

NASA Astrophysics Data System (ADS)

We assess the roles of long-lived greenhouse gases and ozone depletion in driving meridional surface pressure gradients in the southern extratropics; these gradients are a defining feature of the Southern Annular Mode. Stratospheric ozone depletion is thought to have caused a strengthening of this mode during summer, with increasing long-lived greenhouse gases playing a secondary role. Using a coupled atmosphere-ocean chemistry-climate model, we show that there is cancelation between the direct, radiative effect of increasing greenhouse gases by the also substantial indirect—chemical and dynamical—feedbacks that greenhouse gases have via their impact on ozone. This sensitivity of the mode to greenhouse gas-induced ozone changes suggests that a consistent implementation of ozone changes due to long-lived greenhouse gases in climate models benefits the simulation of this important aspect of Southern Hemisphere climate.

Morgenstern, Olaf; Zeng, Guang; Dean, Sam M.; Joshi, Manoj; Abraham, N. Luke; Osprey, Annette

2014-12-01

81

Effects of atmospheric light scattering on spectroscopic observations of greenhouse gases from space. Part 2: Algorithm intercomparison in the GOSAT data processing for CO2 retrievals over TCCON sites  

NASA Astrophysics Data System (ADS)

This report is the second in a series of companion papers describing the effects of atmospheric light scattering in observations of atmospheric carbon dioxide (CO2) by the Greenhouse gases Observing SATellite (GOSAT), in orbit since 23 January 2009. Here we summarize the retrievals from six previously published algorithms; retrieving column-averaged dry air mole fractions of CO2 (XCO2) during 22 months of operation of GOSAT from June 2009. First, we compare data products from each algorithm with ground-based remote sensing observations by Total Carbon Column Observing Network (TCCON). Our GOSAT-TCCON coincidence criteria select satellite observations within a 5° radius of 11 TCCON sites. We have compared the GOSAT-TCCON XCO2 regression slope, standard deviation, correlation and determination coefficients, and global and station-to-station biases. The best agreements with TCCON measurements were detected for NIES 02.xx and RemoTeC. Next, the impact of atmospheric light scattering on XCO2 retrievals was estimated for each data product using scan by scan retrievals of light path modification with the photon path length probability density function (PPDF) method. After a cloud pre-filtering test, approximately 25% of GOSAT soundings processed by NIES 02.xx, ACOS B2.9, and UoL-FP: 3G and 35% processed by RemoTeC were found to be contaminated by atmospheric light scattering. This study suggests that NIES 02.xx and ACOS B2.9 algorithms tend to overestimate aerosol amounts over bright surfaces, resulting in an underestimation of XCO2 for GOSAT observations. Cross-comparison between algorithms shows that ACOS B2.9 agrees best with NIES 02.xx and UoL-FP: 3G while RemoTeC XCO2 retrievals are in a best agreement with NIES PPDF-D.

Oshchepkov, Sergey; Bril, Andrey; Yokota, Tatsuya; Wennberg, Paul O.; Deutscher, Nicholas M.; Wunch, Debra; Toon, Geoffrey C.; Yoshida, Yukio; O'Dell, Christopher W.; Crisp, David; Miller, Charles E.; Frankenberg, Christian; Butz, André; Aben, Ilse; Guerlet, Sandrine; Hasekamp, Otto; Boesch, Hartmut; Cogan, Austin; Parker, Robert; Griffith, David; Macatangay, Ronald; Notholt, Justus; Sussmann, Ralf; Rettinger, Markus; Sherlock, Vanessa; Robinson, John; Kyrö, Esko; Heikkinen, Pauli; Feist, Dietrich G.; Morino, Isamu; Kadygrov, Nikolay; Belikov, Dmitry; Maksyutov, Shamil; Matsunaga, Tsuneo; Uchino, Osamu; Watanabe, Hiroshi

2013-02-01

82

Observing megacity greenhouse gas emissions from space  

NASA Astrophysics Data System (ADS)

Emissions of greenhouse gases (GHG) from megacities represent a significant and increasing contributor to anthropogenic GHG release. In efforts aimed at mitigation, some cities have enacted emissions reduction policies, but lack observation-based methods for verifying their efficacy. Atmospheric abundances in and around megacities are strongly impacted by anthropogenic GHG emissions, and therefore have the potential to provide objective, independent assessment of GHG emissions trends. Here we demonstrate the potential of satellites to provide accurate global monitoring of megacity GHG emissions. Specifically, we find GOSAT observations of column averaged CO2 and CH4 dry air mole fractions exhibit statistically significant enhancements over some representative megacities. We will discuss how these enhancements can be exploited to track anthropogenic emission trends with time. We will additionally examine the impact of these findings on regional and global flux inversions using satellite observations. Finally, we will discuss the limitations of current space-based observations, and the potential of future satellite missions to monitor global megacity emissions.

Kort, E. A.; Frankenberg, C.; Miller, C. E.; Oda, T.

2012-12-01

83

Use of 222Rn for estimation of greenhouse gases emissions at Russian territory  

Microsoft Academic Search

It is well known that 222Rn is widely used as a tracer for studying different atmospheric processes including estimations of greenhouse gases emissions. Calculation of 222Rn fluxes from the soil into the atmosphere allows quantitative estimation of greenhouse gases emissions having the soil origin or sources of which are located near the surface. For accurate estimation of 222Rn fluxes detailed

E. V. Berezina; N. F. Elansky

2009-01-01

84

Future climate change in the Southern Hemisphere: Competing effects of ozone and greenhouse gases  

E-print Network

Future climate change in the Southern Hemisphere: Competing effects of ozone and greenhouse gases J in the Southern Hemisphere: Competing effects of ozone and greenhouse gases, Geophys. Res. Lett., 38, L02701, doi in the Southern Hemisphere is likely to be driven by two opposing effects, stratospheric ozone recovery

Arblaster, Julie

85

75 FR 12489 - Mandatory Reporting of Greenhouse Gases: Minor Harmonizing Changes to the General Provisions  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Reporting of Greenhouse Gases: Minor Harmonizing...provisions for the Mandatory Greenhouse Gas (GHG) Reporting...Division, Office of Atmospheric Programs (MC-6207J...action on the Mandatory Greenhouse Gas Reporting Rule...and it will not take effect. We are not...

2010-03-16

86

Adaptation to Impacts of Greenhouse Gases on the Ocean (Invited)  

NASA Astrophysics Data System (ADS)

Greenhouse gases are producing changes in ocean temperature and circulation, and these changes are already adversely affecting marine biota. Furthermore, carbon dioxide is absorbed by the oceans from the atmosphere, and this too is already adversely affecting some marine ecosystems. And, of course, sea-level rise affects both what is above and below the waterline. Clearly, the most effective approach to limit the negative impacts of climate change and acidification on the marine environment is to greatly diminish the rate of greenhouse gas emissions. However, there are other measures that can be taken to limit some of the negative effects of these stresses in the marine environment. Marine ecosystems are subject to multiple stresses, including overfishing, pollution, and loss of coastal wetlands that often serve as nurseries for the open ocean. The adaptive capacity of marine environments can be improved by limiting these other stresses. If current carbon dioxide emission trends continue, for some cases (e.g., coral reefs), it is possible that no amount of reduction in other stresses can offset the increase in stresses posed by warming and acidification. For other cases (e.g., blue-water top-predator fisheries), better fisheries management might yield improved population health despite continued warming and acidification. In addition to reducing stresses so as to improve the adaptive capacity of marine ecosystems, there is also the issue of adaptation in human communities that depend on this changing marine environment. For example, communities that depend on services provided by coral reefs may need to locate alternative foundations for their economies. The fishery industry will need to adapt to changes in fish abundance, timing and location. Most of the things we would like to do to increase the adaptive capacity of marine ecosystems (e.g., reduce fishing pressure, reduce coastal pollution, preserve coastal wetlands) are things that would make sense to do even in the absence of threats from climate change and ocean acidification. Therefore, these measures represent “no regrets” policy options for the marine environment. Nevertheless, even with adaptive policies in place, continued greenhouse gas emissions increasingly risk damaging marine ecosystems and the human communities that depend on them.

Caldeira, K.

2010-12-01

87

In-Situ Microbial Conversion of Sequestered Greenhouse Gases  

SciTech Connect

The objectives of the project are to use microbiological in situ bioconversion technology to convert sequestered or naturally-occurring greenhouse gases, including carbon dioxide and carbon monoxide, into methane and other useful organic compounds. The key factors affecting coal bioconversion identified in this research include (1) coal properties, (2) thermal maturation and coalification process, (3) microbial population dynamics, (4) hydrodynamics (5) reservoir conditions, and (6) the methodology of getting the nutrients into the coal seams. While nearly all cultures produced methane, we were unable to confirm sustained methane production from the enrichments. We believe that the methane generation may have been derived from readily metabolized organic matter in the coal samples and/or biosoluble organic material in the coal formation water. This raises the intriguing possibility that pretreatment of the coal in the subsurface to bioactivate the coal prior to the injection of microbes and nutrients might be possible. We determined that it would be more cost effective to inject nutrients into coal seams to stimulate indigenous microbes in the coal seams, than to grow microbes in fermentation vats and transport them to the well site. If the coal bioconversion process can be developed on a larger scale, then the cost to generate methane could be less than $1 per Mcf

Scott, A R; Mukhopadhyay, M; Balin, D F

2012-09-06

88

Potential Source Regions of Halogenated Greenhouse Gases Measured At A High Alpine Site (jungfraujoch)  

NASA Astrophysics Data System (ADS)

Since January 2000 halogenated greenhouse gases are measured continuously at the high Alpine station Jungfraujoch (3580 m asl.) in Switzerland in the frame of a Swiss National project and the EU-project SOGE (System for Observation of Halogenated Greenhouse Gases in Europe). Emissions of such compounds from both Switzer- land and from different regions in Europe contribute to immissions measured at the Jungfraujoch. In addition to the inhomogeneous distribution of the emission sources, variable and weather dependent transport of air pollution can be observed. As a deci- sion basis for the air pollution control politics, the support and verification of existing inventories is of fundamental importance. The results can be used to assess compliance with the international protocols regulating the emissions (Montreal, Kyoto), and they will be utilised to define criteria for future monitoring in Europe. Therefore, in-situ measurements and meteorological information provided by the Swiss Meteorological Office (MeteoSwiss) are combined to investigate potential source areas. The first ap- proach was the use of trajectories associated with large concentration values monitored at the Jungfraujoch, showing that for some species high concentrations are often linked to air masses with specific geographical origin. In a second step, trajectory statistics was used to localise potential source regions. Hereby receptor data were combined with air mass histories to perform source apportionment. First results will be shown indicating that Po-valley, Southern France, Germany and the Benelux countries are the most important source regions of halogenated greenhouse gases measured at the Jungfraujoch. An improvement of the results is expected by taking into consideration additional information about source regions and the incorporation of the data of the other SOGE-observation sites located at Mace Head (Ireland), Spitsbergen (Norway), and at Monte Cimone (Italy).

Schaub, D.; Stemmler, K.; Reimann, S.; Weiss, A. K.

89

Increasing greenhouse gases lead to dramatic thinning of the upper atmosphere  

NSDL National Science Digital Library

Scientists at the Naval Research Laboratory (NRL) analyzed changes in the orbits of selected objects to derive the yearly average density encountered by each object in different levels of the atmosphere. After adjusting for other factors, the data from every object indicated a long-term decline in the density of the thermosphere. It was found that the observed decrease in density with increased distance in the troposphere depends on height in the same way as predicted by the theoretical simulations, indicating that greenhouse gases are a likely source of the change.

AGU

90

The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation  

NSDL National Science Digital Library

This page explains concepts related to the interaction between greenhouse gasses, transportation, and government regulations. A list of links is given for three main categories: greenhouse gasses, regulated emissions, and transportation energy use.

Shipvehicles, Auto C.

91

Use of 222Rn for estimation of greenhouse gases emissions at Russian territory  

NASA Astrophysics Data System (ADS)

It is well known that 222Rn is widely used as a tracer for studying different atmospheric processes including estimations of greenhouse gases emissions. Calculation of 222Rn fluxes from the soil into the atmosphere allows quantitative estimation of greenhouse gases emissions having the soil origin or sources of which are located near the surface. For accurate estimation of 222Rn fluxes detailed investigations of spatial and temporal variations of its concentrations are necessary. 222Rn concentrations data in the atmospheric surface layer over continental Russia from Moscow to Vladivostok obtained during the six TROICA (Transcontinental Observations Into the Chemistry of the Atmosphere) expeditions of the mobile laboratory along the Trans-Siberian railroad are analyzed. Spatial distribution, diurnal and seasonal variations of surface 222Rn concentrations along the Trans-Siberian railroad are investigated. According to the obtained data surface 222Rn concentration values above continental Russia vary from 0.5 to 75 Bq/m3 depending on meteorological conditions and geological features of the territory with the average value being 8.42 ± 0.10 Bq/m3. The average 222Rn concentration is maximum in the autumn expedition and minimum in the spring one. The factors mostly influencing 222Rn concentration variations are studied: surface temperature inversions, geological features of the territory, precipitations. 222Rn accumulation features in the atmospheric surface layer during night temperature inversions are analyzed. It was noted that during night temperature inversions the surface 222Rn concentration is 7 - 8 times more than the one during the nights without temperature inversions. Since atmospheric stratification determines accumulation and diurnal variations of many atmospheric pollutants as well as greenhouse gases its features are analyzed in detail. Surface temperature inversions were mainly observed from 18:00-19:00 to 06:00-07:00 in the warm season and from 16:00 to 08:00-09:00 in the cold season. During this time 222Rn accumulated in the surface atmospheric layer with its maximum concentration values being observed near sunrise. 222Rn fluxes from the soil into the atmosphere from Moscow to Vladivostok during surface temperature inversions are estimated taking into account geological factors. 222Rn accumulation layer depth in the lower atmosphere is calculated. Using the data of CO2, CH4 and 222Rn concentrations obtained in the expeditions we analyzed correlations between the greenhouse gases and 222Rn. There are significant positive correlations between CO2, CH4 and 222Rn concentrations during night temperature inversions especially in summer and in autumn. It indicates similar accumulation both 222Rn and the greenhouse gases in the surface layer during atmospheric stability. On the basis of the regressions between 222Rn, CO2 and CH4 concentrations the greenhouse gases night time fluxes in the surface layer from Moscow to Vladivostok are estimated using the calculated values of 222Rn fluxes. Acknowledgments. The work was supported by International Science and Technology Center (ISTC) under contract No. 2770 and by Russian Basic Research Foundation (project No. 08-05-13589, 07-05-12063 and 07-05-00428). The authors thank I. B. Belikov for preparation and carrying out the TROICA experiments.

Berezina, E. V.; Elansky, N. F.

2009-04-01

92

40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

Code of Federal Regulations, 2013 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 70.2. (b) Further...

2013-07-01

93

40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).  

...of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 52.21. (b) Further...

2014-07-01

94

40 CFR 71.13 - Enforceable commitments for further actions addressing Greenhouse Gases (GHGs)  

Code of Federal Regulations, 2011 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 71.2. (b) Further...

2011-07-01

95

40 CFR 71.13 - Enforceable commitments for further actions addressing Greenhouse Gases (GHGs)  

Code of Federal Regulations, 2012 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 71.2. (b) Further...

2012-07-01

96

40 CFR 71.13 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 71.2. (b) Further...

2014-07-01

97

40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 70.2. (b) Further...

2014-07-01

98

40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

Code of Federal Regulations, 2010 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 70.2. (b) Further...

2010-07-01

99

40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).  

Code of Federal Regulations, 2013 CFR

...of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 52.21. (b) Further...

2013-07-01

100

40 CFR 71.13 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

Code of Federal Regulations, 2013 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 71.2. (b) Further...

2013-07-01

101

40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).  

Code of Federal Regulations, 2011 CFR

...of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 52.21. (b) Further...

2011-07-01

102

40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).  

Code of Federal Regulations, 2010 CFR

...of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 52.21. (b) Further...

2010-07-01

103

40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).  

Code of Federal Regulations, 2012 CFR

...of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 52.21. (b) Further...

2012-07-01

104

40 CFR 71.13 - Enforceable commitments for further actions addressing Greenhouse Gases (GHGs)  

Code of Federal Regulations, 2010 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 71.2. (b) Further...

2010-07-01

105

40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

Code of Federal Regulations, 2012 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 70.2. (b) Further...

2012-07-01

106

40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).  

Code of Federal Regulations, 2011 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. (2) All other terms used in this section shall have the meaning given in § 70.2. (b) Further...

2011-07-01

107

76 FR 61293 - Extension of Public Comment Period: Mandatory Reporting of Greenhouse Gases: Technical Revisions...  

Federal Register 2010, 2011, 2012, 2013

...the Electronics Manufacturing and the Petroleum and Natural Gas Systems Categories of...the Electronics Manufacturing and the Petroleum and Natural Gas Systems Categories of...Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems....

2011-10-04

108

76 FR 59533 - Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems: Revisions to Best...  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems: Revisions to...available monitoring methods for the Petroleum and Natural Gas Systems source category...final rule affects owners or operators of petroleum and natural gas systems. Regulated...

2011-09-27

109

EVALUATION OF GREENHOUSE GASES EMISSION FROM SOILS AMENDED WITH SEWAGE SLUDGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increase in concentration of various greenhouse gases and their possible contributions to the global warming have received considerable research intrest. Agricultural practices, fossil fuel burning, deforestation, industrial emissions, and wetlands have contributed to atmospheric increases of carbo...

110

Quantifying emissions of greenhouse gases from South Asia through a targeted measurement campaign  

E-print Network

Methane (CH 4 ), nitrous oxide (N20) and sulfur hexafluoride (SF6) are powerful greenhouse gases with global budgets that are well-known but regional distributions that are not adequately constrained for the purposes of ...

Ganesan, Anita Lakshmi

2013-01-01

111

Sedimentary basins and greenhouse gases: a serendipitous association  

Microsoft Academic Search

There is a natural association of sedimentary basins and fossil fuels. Therefore, we should expect a relation between the sedimentary basin, the exploitation of its fossil fuels, and the resulting greenhouse gas emissions. Carbon dioxide is the dominant greenhouse gas resulting from the burning of fossil fuels, and it comprises more than half of all man-made greenhouse gas emissions. Among

Brian Hitchon; W. D. Gunter; Thomas Gentzis; R. T. Bailey

1999-01-01

112

Measurements of Greenhouse Gases around the Sacramento Area: The Airborne Greenhouse Emissions Survey (AGES) Campaign  

NASA Astrophysics Data System (ADS)

The state of California is leading the United States by enacting legislation (AB-32) to reduce greenhouse gas emissions to 1990 levels by 2020. The success of reduction efforts can be gauged with accurate emissions inventories and potentially verified with atmospheric measurements of greenhouse gases (GHGs) over time. Measurements of multiple GHGs and associated trace gas species in a specific region also provide information on emissions ratios for source apportionment. We conducted the Airborne Greenhouse Emissions Survey (AGES) campaign to determine emissions signature ratios for the sources that exist in the San Francisco Bay and Sacramento Valley areas. Specifically, we attempt to determine the emissions signatures of sources that influence ongoing measurements made at a tall-tower measurement site near Walnut Grove, CA. For two weeks in February and March of 2009, a Cessna 210 was flown throughout the Sacramento region, making continuous measurements of CO2, CH4, and CO while also sampling discrete flasks for a variety of additional tracers, including SF6, N2O, and 14C in CO2 (?14CO2). Flight paths were planned using wind predictions for each day to maximize sampling of sources whose emissions would also be sampled contemporaneously by the instrumentation at the Walnut Grove tower (WGC), part of the ongoing California Greenhouse Gas Emissions Measurement (CALGEM) project between NOAA/ESRL’s Carbon Cycle group and Lawrence Berkeley National Laboratory (LBNL). Flights were performed in two distinct patterns: 1) flying across a plume upwind and downwind of the Sacramento urban area, and 2) flying across the Sacramento-San Joaquin Delta from Richmond to Walnut Grove, a region consisting of natural wetlands as well as several power plants and refineries. Results show a variety of well-correlated mixing ratio signals downwind of Sacramento, documenting the urban signature emission ratios, while emissions ratios in the Delta region were more variable, likely due to the both natural and anthropogenic sources in that region. Periodic flask measurements of ?14CO2 provide additional insight regarding the partitioning of CO2 emissions due to fossil fuel (deficient in 14C) from those of biospheric sources. A strong correlation between fossil-fuel CO2 and CO was measured downwind of Sacramento, suggesting that the continuous measurements of CO can be used to estimate a continuous profile of fossil-fuel CO2 enhancement in this region.

Karion, A.; Fischer, M. L.; Turnbull, J. C.; Sweeney, C.; Faloona, I. C.; Zagorac, N.; Guilderson, T. P.; Saripalli, S.; Sherwood, T.

2009-12-01

113

Emissions of greenhouse gases in the United States, 1985--1990  

SciTech Connect

The Earth`s capacity to support life depends on the moderating influences of gases that envelop the planet and warm its surface and protect it from harmful radiation. These gases are referred to as ``greenhouse gases.`` Their warming capacity, called ``the greenhouse effect,`` is essential to maintaining a climate hospitable to all plant, animal, and human life. In recent years, however, there has been increasing concern that human activity may be affecting the intricate balance between the Earth`s absorption of heat from the sun and its capacity to reradiate excess heat back into space. Emissions of greenhouse gases from human activities may be an important mechanism that affects global climate. Thus, research is intensifying to improve our understanding of the role human activities might play in influencing atmospheric concentrations of greenhouse gases. On the basis of scientific findings of the past few decades, the US Government and the international community at large are now taking steps toward stabilizing greenhouse gas emissions. This report contributes to that process. Mandated by Congress this report provides estimates of US emissions of the principal greenhouse gases--carbon dioxide, methane, nitrous oxide, chlorofluorcarbons, carbon monoxide, nitrogen oxides, and nonmethane volatile organic compounds. Estimates are for the period 1985 to 1990. Preliminary estimates for 1991 have also been included, whenever data were available.

Not Available

1993-11-10

114

Global Mitigation Of Non-CO2 Greenhouse Gases: 2010-2030  

EPA Science Inventory

This report illustrates the abatement potential of non-CO2 greenhouse gases, by sector and by region, from 2010-2030. This peer-reviewed update provides economists and policymakers with improved data to better understand the costs and opportunities for reducing non-CO2 greenhouse...

115

77 FR 10434 - Mandatory Reporting of Greenhouse Gases Rule: Confidentiality Determinations and Best Available...  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Reporting of Greenhouse Gas Emissions Final...issues related to such effects. D. Unfunded Mandates...health or environmental effects of their programs...health or environmental effects on minority or low-income...practice and procedure, Greenhouse gases, Reporting...

2012-02-22

116

The relative roles of sulfate aerosols and greenhouse gases in climate forcing  

Microsoft Academic Search

Calculations of the effects of both natural and anthropogenic tropospheric sulfate aerosols indicate that the aerosol climate forcing is sufficiently large in a number of regions of the Northern Hemisphere to reduce significantly the positive forcing from increased greenhouse gases. Summer sulfate aerosol forcing in the Northern Hemisphere completely offsets the greenhouse forcing over the eastern United States and central

J. T. Kiehl; B. P. Briegleb

1993-01-01

117

Evaluation of headspace equilibration methods for quantifying greenhouse gases in groundwater.  

PubMed

The objective of the study was to evaluate the different headspace equilibration methods for the quantification of dissolved greenhouse gases in groundwater. Groundwater samples were collected from wells with contrasting hydrogeochemical properties and degassed using the headspace equilibration method. One hundred samples from each well were randomly selected, treatments were applied and headspace gases analysed by gas chromatography. Headspace equilibration treatments varied helium (He):water ratio, shaking time and standing time. Mean groundwater N(2)O, CO(2) and CH(4) concentrations were 0.024 mg N L(-1), 13.71 mg C L(-1) and 1.63 ?g C L(-1), respectively. All treatments were found to significantly influence dissolved gas concentrations. Considerable differences in the optimal He:water ratio and standing time were observed between the three gases. For N(2)O, CO(2) and CH(4) the optimum operating points for He:water ratio was 4.4:1, 3:1 and 3.4:1; shaking time was 13, 12 and 13 min; and standing time was 63, 17 and 108 min, respectively. The headspace equilibration method needs to be harmonised to ensure comparability between studies. The experiment reveals that He:water ratio 3:1 and shaking time 13 min give better estimation of dissolved gases than any lower or higher ratios and shaking times. The standing time 63, 17 and 108 min should be applied for N(2)O, CO(2) and CH(4), respectively. PMID:22922500

Jahangir, M M R; Johnston, P; Khalil, M I; Grant, J; Somers, C; Richards, K G

2012-11-30

118

Remote Sensing of Spatial Distributions of Greenhouse Gases in the Los Angles Basin  

Microsoft Academic Search

The Los Angeles air basin is a significant anthropogenic source of greenhouse gases and pollutants including CO2, CO, CH4 and N2O, contributing significantly to regional and global climate change. Recent legislation in California, the California Global Warming Solutions Act (AB32), established a statewide cap for greenhouse gas emissions for 2020 based on 1990 emissions. Verifying the effectiveness of regional greenhouse

D. Fu; S. P. Sander; T. J. Pongetti; R. Cheung; J. Stutz

2010-01-01

119

Towards European organisation for integrated greenhouse gas observation system  

NASA Astrophysics Data System (ADS)

Climate change is one the most challenging problems that humanity will have to cope with in the coming decades. The perturbed global biogeochemical cycles of the greenhouse gases (carbon dioxide, methane and nitrous oxide) are a major driving force of current and future climate change. Deeper understanding of the driving forces of climate change requires full quantification of the greenhouse gas emissions and sinks and their evolution. Regional greenhouse gas budgets, tipping-points, vulnerabilities and the controlling mechanisms can be assessed by long term, high precision observations in the atmosphere and at the ocean and land surface. ICOS RI is a distributed infrastructure for on-line, in-situ monitoring of greenhouse gases (GHG) necessary to understand their present-state and future sinks and sources. ICOS RI provides the long-term observations required to understand the present state and predict future behaviour of the global carbon cycle and greenhouse gas emissions. Linking research, education and innovation promotes technological development and demonstrations related to greenhouse gases. The first objective of ICOS RI is to provide effective access to coherent and precise data and to provide assessments of GHG inventories with high temporal and spatial resolution. The second objective is to provide profound information for research and understanding of regional budgets of greenhouse gas sources and sinks, their human and natural drivers, and the controlling mechanisms. ICOS is one of several ESFRI initiatives in the environmental science domain. There is significant potential for structural and synergetic interaction with several other ESFRI initiatives. ICOS RI is relevant for Joint Programming by providing the data access for the researchers and acting as a contact point for developing joint strategic research agendas among European member states. The preparatory phase ends in March 2013 and there will be an interim period before the legal entity will be set up. International negotiations have been going on for two years during which the constitutional documents have been processed and adopted. The instrument for the ICOS legal entity is the ERIC (European Research Infrastructure Consortium) steered by the General Assembly of its Members. ICOS is a highly distributed research infrastructure where three operative levels (ICOS National Networks, ICOS Central Facilities and ICOS ERIC) interact on several fields of research and governance. The governance structure of ICOS RI needs to reflect this complexity while maintaining the common vision, strategy and principles.

Kaukolehto, Marjut; Vesala, Timo; Sorvari, Sanna; Juurola, Eija; Paris, Jean-Daniel

2013-04-01

120

Managing agricultural greenhouse gases: The basis of GRACEnet  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since 2002, USDA Agricultural Research Service has been engaged in a national project called GRACEnet (Greenhouse gas Reduction through Agricultural Carbon Enhancement network). Goals of the project are to (1) evaluate soil organic carbon status and change, (2) assess net greenhouse gas emissions (...

121

The contribution from emissions of different gases to the enhanced greenhouse effect. Appendix B  

SciTech Connect

The main purpose of this paper is to compare the different contributions, that mankind has made to perturbing the atmosphere`s radiative balance. We have, and will continue to perturb both the balance of outgoing long-wave radiation and the balance of incoming short-wave radiation. Human activities since preindustrial times have caused a substantial enhancement of the greenhouse effect, a process involving the absorption of outgoing long-wave radiation which leads to a warming of the lower atmosphere. Because the atmosphere`s short-wave radiative balance is affected by the presence of small particles (aerosols) produced by the oxidation of sulphur compounds, anthropogenic emissions of sulphur dioxide (SO{sub 2}) have also caused a perturbation of the overall balance. The greenhouse gases we will consider are, in order of importance: carbon dioxide (CO{sub 2}), Methane (CH{sub 4}), nitrous oxide (N{sub 2}O) and the halocarbons. We use observed and model-based concentration data together with the most recent information relating concentrations to radiative forcing to estimate the individual contributions of the different gases to the changing radiative balance of the atmosphere. We also estimate the ranges of uncertainty in each of these estimates. We base all results on the 1992 IPCC emissions scenarios IS92a-f. We begin with a summary of 1990 conditions, then consider each gas separately (but lumping the halocarbons into a single group), to compare their relative importance.

Wigley, T.M.L.

1993-01-01

122

Global budgets for non-CO 2 greenhouse gases  

Microsoft Academic Search

The most abundant gases in dry air, N 2 (~ 78.1% by volume) and O 2 (~ 20.95% by volume), represent the equilibrium state of global biogeochemical processes that have operated on time scales of many millions of years. Among the remaining gases, the noble gas argon (~- 0.93 % by volume) is by far most abundant. Because of their

Paul J. Crutzen

1994-01-01

123

Greenhouse gases accounting and reporting for waste management - A South African perspective  

SciTech Connect

This paper investigates how greenhouse gases are accounted and reported in the waste sector in South Africa. Developing countries (including South Africa) do not have binding emission reduction targets, but many of them publish different greenhouse gas emissions data which have been accounted and reported in different ways. Results show that for South Africa, inventories at national and municipal level are the most important tools in the process of accounting and reporting greenhouse gases from waste. For the development of these inventories international initiatives were important catalysts at national and municipal levels, and assisted in developing local expertise, resulting in increased output quality. However, discrepancies in the methodology used to account greenhouse gases from waste between inventories still remain a concern. This is a challenging issue for developing countries, especially African ones, since higher accuracy methods are more data intensive. Analysis of the South African inventories shows that results from the recent inventories can not be compared with older ones due to the use of different accounting methodologies. More recently the use of Clean Development Mechanism (CDM) procedures in Africa, geared towards direct measurements of greenhouse gases from landfill sites, has increased and resulted in an improvement of the quality of greenhouse gas inventories at municipal level.

Friedrich, Elena, E-mail: Friedriche@ukzn.ac.z [University of KwaZulu-Natal, CRECHE, School of Civil Engineering, Surveying and Construction, Howard College Campus, Durban (South Africa); Trois, Cristina [University of KwaZulu-Natal, CRECHE, School of Civil Engineering, Surveying and Construction, Howard College Campus, Durban (South Africa)

2010-11-15

124

Estimation of pathways of the production of greenhouse gases in the tropical swamp forest in Thailand by stable isotope investigation  

Microsoft Academic Search

Dynamics of greenhouse gases (N2O and CH4) with the dry–wet cycle along with the variation of oxidation–reduction boundaries were investigated in the tropical wetland in monsoon Asia. It was clarified that the production of N2O and CH4 was closely related to the development of a redox boundary in the Bang Nara River systems. An intermittent increase in N2O was observed

Narin Boontanon; Shingo Ueda; Eitaro Wada

2008-01-01

125

Carbon and Conservation: Cropping systems and greenhouse gases  

Technology Transfer Automated Retrieval System (TEKTRAN)

Quantifying and predicting soil carbon sequestration and greenhouse gas emissions from agricultural systems have been research goals for numerous institutions, especially since the turn of the millennium. Cost, time, and politics are variables that have limited the rapid development of robust quant...

126

Biomass burning and the production of greenhouse gases  

NASA Technical Reports Server (NTRS)

The present discussion of related aspects of biomass burning describes a technique for estimating the instantaneous emission of trace gases generated by such fires on the basis of satellite imagery, and notes that burning results in significantly enhanced biogenic emissions of N2O, NO, and CH4. Biomass burning therefore has both immediate and long-term impacts on the trace-gas content of the atmosphere. The effects of Kuwait's oil fires, which encompass both combustion gases and particulates, are compared with those of the more general problem.

Levine, Joel S.

1991-01-01

127

Changes in the Seasonality of Tropical Precipitation in Response to Greenhouse Gases: Local and Remote Forcings  

Microsoft Academic Search

When forced with increasing greenhouse gases, all of the CMIP3 models project a delay of the annual cycle of global precipitation and SST. This global phase shift has important regional manifestations, that are quite robust across the CMIP3 ensemble. At regional scales, though, rainfall and temperature anomalies may be more complex than a simple shift and, in places, are better

M. Biasutti; A. H. Sobel; D. S. Battisti

2009-01-01

128

Evaluation of Emission of Greenhouse Gases from Soils Amended with Sewage Sludge  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increase in concentrations of various greenhouse gases originated by various human activities, including agricultural origin, could contribute to climate change. Anthropogenic activities such as cultivation of flooded rice and application of waste materials, such as sewage sludge which are rich in ...

129

THE IMPACTS OF BIOFUELS ON GREENHOUSE GASES: HOW LAND USE CHANGE ALTERS THE EQUATION  

Microsoft Academic Search

Summary: The environmental benefits derived from biofuels results from the plants used to engineer them. Plants take carbon dioxide out of the atmo- sphere. But it takes land to grow these plants, and using land for biofuels sacrifices other benefits of keeping land in its existing use. New analyses are now showing that the loss of greenhouse gases from direct

Tim Searchinger

2008-01-01

130

Climate changes predicted by climate models for the increase of greenhouse gases  

Microsoft Academic Search

Climate models have been used to predict climate changes caused by the increase of greenhouse gases. Models predict physical states of the upper part of the earth including the atmosphere, the ocean, the land surface and the cryosphere with the use of physical laws. When atmospheric concentration of C02 is doubled, globally averaged surface temperature is predicted to increase 1.5

T Tokioka

1995-01-01

131

Ozone-depleting substances and the greenhouse gases HFCs, PFCs and  

E-print Network

Ozone-depleting substances and the greenhouse gases HFCs, PFCs and SF6 Danish consumption contribution to the debate on environmental policy in Denmark. #12;3 Contents 1 SUMMARY 5 1.1 OZONE OZONE-DEPLETING SUBSTANCES 18 3.1 IMPORTS AND EXPORTS 18 3.1.1 CFCs 18 3.1.2 Tetrachloromethane 19 3

132

Greenhouse gases emission from municipal waste management: The role of separate collection  

SciTech Connect

The municipal solid waste management significantly contributes to the emission in the atmosphere of greenhouse gases (e.g. CO{sub 2}, CH{sub 4}, N{sub 2}O) and therefore the management process from collection to treatment and disposal has to be optimized in order to reduce these emissions. In this paper, starting from the average composition of undifferentiated municipal solid waste in Italy, the effect of separate collection on greenhouse gases emissions from municipal waste management has been assessed. Different combinations of separate collection scenarios and disposal options (i.e. landfilling and incineration) have been considered. The effect of energy recovery from waste both in landfills and incinerators has also been addressed. The results outline how a separate collection approach can have a significant effect on the emission of greenhouse gases and how wise municipal solid waste management, implying the adoption of Best Available Technologies (i.e. biogas recovery and exploitation system in landfills and energy recovery system in Waste to Energy plants), can not only significantly reduce greenhouse gases emissions but, in certain cases, can also make the overall process a carbon sink. Moreover it has been shown that separate collection of plastic is a major issue when dealing with global warming relevant emissions from municipal solid waste management.

Calabro, Paolo S. [Dipartimento di Meccanica e Materiali, Universita degli Studi Mediterranea di Reggio Calabria, via Graziella - loc. Feo di Vito, 89122 Reggio Calabria (Italy)], E-mail: paolo.calabro@unirc.it

2009-07-15

133

Emissions of greenhouse gases in the United States, 1987--1994  

SciTech Connect

The Energy Information Administration (EIA) is required by the Energy Policy Act of 1992 to prepare a report on aggregate US national emissions of greenhouse gases for the period 1987--1992, with annual updates thereafter. This is the third annual update report,covering national emissions over the period 1987--1993, with preliminary estimates of US carbon dioxide and halocarbon emissions for 1994. Calculating national aggregate emissions(or ``national inventories``) of greenhouse gases is a recently developed form of intellectual endeavor. Greenhouse gas emissions are rarely measured directly or reported to statistical agencies. Thus, to prepare emissions inventories usually requires inferring emissions indirectly from information collected for other purposes. Both the available information and the inferences drawn may be of varying reliability. Chapter 1 of this report briefly recapitulates some background information about global climate change and the greenhouse effect and discusses important recent developments in global climate change activities. Chapters 2 through 6 cover emissions of carbon dioxide, methane, nitrous oxide, halocarbons, and criteria pollutants, respectively. Chapter 7 describes potential sequestration and emissions of greenhouse gases as a result of land use changes.

NONE

1995-09-25

134

Effect of noble gases on an atmospheric greenhouse /Titan/.  

NASA Technical Reports Server (NTRS)

Several models for the atmosphere of Titan have been investigated, taking into account various combinations of neon and argon. The investigation shows that the addition of large amounts of Ne and/or Ar will substantially reduce the hydrogen abundance required for a given greenhouse effect. The fact that a large amount of neon should be present if the atmosphere is a relic of the solar nebula is an especially attractive feature of the models, because it is hard to justify appropriate abundances of other enhancing agents.

Cess, R.; Owen, T.

1973-01-01

135

Miniaturized Laser Heterodyne Radiometer (LHR) for Measurements of Greenhouse Gases in the Atmospheric Column  

NASA Technical Reports Server (NTRS)

This passive laser heterodyne radiometer (LHR) instrument simultaneously measures multiple trace gases in the atmospheric column including carbon dioxide (CO2) and methane (CH4), and resolves their concentrations at different altitudes. This instrument has been designed to operate in tandem with the passive aerosol sensor currently used in AERONET (an established network of more than 450 ground aerosol monitoring instruments worldwide). Because aerosols induce a radiative effect that influences terrestrial carbon exchange, simultaneous detection of aerosols with these key carbon cycle gases offers a uniquely comprehensive measurement approach. Laser heterodyne radiometry is a technique for detecting weak signals that was adapted from radio receiver technology. In a radio receiver, a weak input signal from a radio antenna is mixed with a stronger local oscillator signal. The mixed signal (beat note, or intermediate frequency) has a frequency equal to the difference between the input signal and the local oscillator. The intermediate frequency is amplified and sent to a detector that extracts the audio from the signal. In the LHR instrument described here, sunlight that has undergone absorption by the trace gas is mixed with laser light at a frequency matched to a trace gas absorption feature in the infrared (IR). Mixing results in a beat signal in the RF (radio frequency) region that can be related to the atmospheric concentration. For a one-second integration, the estimated column sensitivities are 0.1 ppmv for CO2, and <1 ppbv for CH4. In addition to producing a standalone ground measurement product, this instrument could be used to calibrate/validate four Earth observing missions: ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons), OCO-2 (Orbiting Carbon Observatory), OCO-3, and GOSAT (Greenhouse gases Observational SATellite). The only network that currently measures CO2 and CH4 in the atmospheric column is TCCON (Total Carbon Column Observing Network), and only two of its 16 operational sites are in the United States. TCCON data is used for validation of GOSAT data, and will be used for OCO-2 validation. While these Fourier-transform spectrometers (FTS) can measure the largest range of trace gases, the network is severely limited due to the high cost and extreme size of these instruments (these occupy small buildings and require personnel for operation). The LHR/AERONET instrument offers a significantly smaller (carry-on luggage size) autonomous instrument that can be incorporated into AERONET s much larger (450 instruments) global network.

Steel, Emily; McLinden, Matthew

2012-01-01

136

Greenhouse warming by minor gases on early Mars  

NASA Astrophysics Data System (ADS)

The early atmospheres of Earth and Mars were non-oxidizing mixtures likely derived from volcanic outgassing of a silicate mantle, with some fraction of the volatiles also contributed by impacting comets and meteorites. Here the authors investigate the potential of minor atmospheric constituents produced by ultraviolet and auroral chemistry to contribute to the thermal opacity of early Earth and Mars atmospheres. Using a very simple two-stream thermal opacity model, the authors show that HCN at 10 parts per million (ppm) and N2O at 100 ppm can each block radiation in thermal infrared windows sufficiently to increase the surface temperature by 7 K separately, or 14 K together. Small quantities of other species are also produced in such experiments. Some of these have especially complex infrared spectra and should be further investigated for their potential to help close windows in the CO2 + H2O infrared transmission. Enhancement of greenhouse warming by minor atmospheric species different from those present in today's atmosphere may have played important roles in the climate of early Earth and Mars.

Heinrich, M. N.; Thompson, W. R.; Sagan, C.

1992-12-01

137

Evaluation of emission of greenhouse gases from soils amended with sewage sludge.  

PubMed

Increase in concentrations of various greenhouse gases and their possible contributions to the global warming are becoming a serious concern. Anthropogenic activities such as cultivation of flooded rice and application of waste materials, such as sewage sludge which are rich in C and N, as soil amendments could contribute to the increase in emission of greenhouse gases such as methane (CH(4)) and nitrous oxide (N(2)O) into the atmosphere. Therefore, evaluation of flux of various greenhouse gases from soils amended with sewage sludge is essential to quantify their release into the atmosphere. Two soils with contrasting properties (Candler fine sand [CFS] from Florida, and Ogeechee loamy sand [OLS] from Savannah, GA) were amended with varying rates (0, 24.7, 49.4, 98.8, and 148.3 Mg ha(-1)) of 2 types of sewage sludge (industrial [ISS] and domestic [DSS] origin. The amended soil samples were incubated in anaerobic condition at field capacity soil water content in static chamber (Qopak bottles). Gas samples were extracted immediately after amending soils and subsequently on a daily basis to evaluate the emission of CH(4), CO(2) and N(2)O. The results showed that emission rates and cumulative emission of all three gases increased with increasing rates of amendments. Cumulative emission of gases during 25-d incubation of soils amended with different types of sewage sludge decreased in the order: CO(2) > N(2)O > CH(4). The emission of gases was greater from the soils amended with DSS as compared to that with ISS. This may indicate the presence of either low C and N content or possible harmful chemicals in the ISS. The emission of gases was greater from the CFS as compared to that from the OLS. Furthermore, the results clearly depicted the inhibitory effect of acetylene in both soils by producing more N(2)O and CH(4) emission compared to the soils that did not receive acetylene at the rate of 1 mL g(-1) soil. Enumeration of microbial population by fluorescein diacetate (FDA) and most probable number (MPN) procedure at the end of 25-d incubation demonstrated a clear relationship between microbial activity and the emission of gases. The results of this study emphasize the need to consider the emission of greenhouse gases from soils amended with organic soil amendments such as sewage sludge, especially at high rates, and their potential contribution to global warming. PMID:18172810

Paramasivam, S; Fortenberry, Gamola Z; Julius, Afolabi; Sajwan, Kenneth S; Alva, A K

2008-02-01

138

Air Surface Temperature Correlation with Greenhouse Gases by Using Airs Data Over Peninsular Malaysia  

NASA Astrophysics Data System (ADS)

The main objective of this study is to develop algorithms for calculating the air surface temperature (AST). This study also aims to analyze and investigate the effects of greenhouse gases (GHGs) on the AST value in Peninsular Malaysia. Multiple linear regression is used to achieve the objectives of the study. Peninsular Malaysia has been selected as the research area because it is among the regions of tropical Southeast Asia with the greatest humidity, pockets of heavy pollution, rapid economic growth, and industrialization. The predicted AST was highly correlated ( R = 0.783) with GHGs for the 6-year data (2003-2008). Comparisons of five stations in 2009 showed close agreement between the predicted AST and the observed AST from AIRS, especially in the wet season (within 1.3 K). The in situ data ranged from 1 to 2 K. Validation results showed that AST ( R = 0.776-0.878) has values nearly the same as the observed AST from AIRS. We found that O3 during the wet season was indicated by a strongly positive beta coefficient (0.264-0.992) with AST. The CO2 yields a reasonable relationship with temperature with low to moderate beta coefficient (-0.065 to 0.238). The O3, CO2, and environmental variables experienced different seasonal fluctuations that depend on weather conditions and topography. The concentration of gases and pollution were the highest over industrial zones and overcrowded cities, and the dry season was more polluted compared with the wet season. These results indicate the advantage of using the satellite AIRS data and a correlation analysis to investigate the effect of atmospheric GHGs on AST over Peninsular Malaysia. An algorithm that is capable of retrieving Peninsular Malaysian AST in all weather conditions with total uncertainties ranging from 1 to 2 K was developed.

Rajab, Jasim Mohammed; MatJafri, M. Z.; Lim, H. S.

2014-08-01

139

Greenhouse effects due to man-made perturbations of trace gases  

NASA Technical Reports Server (NTRS)

Nitrous oxide, methane, ammonia, and a number of other trace constituents of the earth's atmosphere have infrared absorption bands in the spectral range from 7 to 14 microns. Despite their small amounts, these gases can have a significant effect on the thermal structure of the atmosphere by transmitting most of the thermal radiation from the earth's surface to the lower atmosphere. In the present paper, this greenhouse effect is computed for a number of trace gases. The nature and climatic implications of possible changes in the concentrations of N2O, CH4, NH3, and HNO3 are discussed.

Wang, W. C.; Yung, Y. L.; Lacis, A. A.; Mo, T.; Hansen, J. E.

1976-01-01

140

Are Greenhouse Gases Changing ENSO Precursors in the Western North Pacific?  

SciTech Connect

Using multiple observational and modeling datasets, we document a strengthening relationship between boreal winter sea surface temperature anomalies (SSTA) in the western North Pacific (WNP) and the development of the El Nino-Southern Oscillation (ENSO) one year later. The increased WNP-ENSO association emerged in the mid 20th century and has grown through the present, reaching correlation coefficients as high as ~0.70 in recent decades. Fully coupled climate experiments with the Community Earth System Model (CESM) replicate the WNP-ENSO association and indicate that greenhouse gases (GHG) are largely responsible for the observed increase. We speculate that shifts in the location and amplitudes of positive SST trends in the subtropical-tropical western Pacific impacts the low-level circulation so that WNP variability is increasingly influencing the development of ENSO one year later. A strengthened GHG-driven relationship between the WNP and ENSO provides an example of how anthropogenic climate change can potentially improve the skill of intraseasonal-to-interannual climate prediction.

Wang, S-Y (Simon); Heureux, Michelle L.; Yoon, Jin-Ho

2013-09-01

141

Counteracting the climate effects of volcanic eruptions using short-lived greenhouse gases  

NASA Astrophysics Data System (ADS)

large volcanic eruption might constitute a climate emergency, significantly altering global temperature and precipitation for several years. Major future eruptions will occur, but their size or timing cannot be predicted. We show, for the first time, that it may be possible to counteract these climate effects through deliberate emissions of short-lived greenhouse gases, dampening the abrupt impact of an eruption. We estimate an emission pathway countering a hypothetical eruption 3 times the size of Mount Pinatubo in 1991. We use a global climate model to evaluate global and regional responses to the eruption, with and without counteremissions. We then raise practical, financial, and ethical questions related to such a strategy. Unlike the more commonly discussed geoengineering to mitigate warming from long-lived greenhouse gases, designed emissions to counter temporary cooling would not have the disadvantage of needing to be sustained over long periods. Nevertheless, implementation would still face significant challenges.

Fuglestvedt, Jan S.; Samset, Bjørn H.; Shine, Keith P.

2014-12-01

142

On the additivity of radiative forcing between land use change and greenhouse gases  

NASA Astrophysics Data System (ADS)

scientific and policy contexts, radiative forcing—an external change in Earth's mean radiative balance—has been suggested as a metric for evaluating the strength of climate perturbations resulting from different climate change drivers such as greenhouse gases and surface physical effects of land use change. However, the utility of this approach has been questioned given the spatially concentrated and sometimes nonradiative nature of land use climate disturbances. Here we show that when negative forcing from agricultural expansion is approximately balanced by a radiatively equivalent increase in atmospheric carbon dioxide, significant changes in temperature, precipitation, and the timing of climate change result. These idealized experiments demonstrate the nonadditivity of radiative forcing from land use change and greenhouse gases and point to the need for new climate change metrics or the development of climate policies and assessment protocols that do not rely on single dimensional metrics.

Jones, Andrew D.; Collins, William D.; Torn, Margaret S.

2013-08-01

143

Exchanges of Greenhouse Gases, Water Vapor, and Heat at the Earth's Surface  

NSDL National Science Digital Library

This report provides an overview of the exchange of greenhouse gases, their influences on climate, viability of ecosystems, distribution of biomes, quantities of surface- and ground-water, and some research projects in place to investigate these influences. Topics include lake-atmosphere carbon dioxide exchange, sequestering and exchange of atmospheric carbon dioxide in boreal and subalpine forests, volcanic carbon dioxide emissions, and the use of the eddy covariance method to measure these exchanges.

144

Integrated Modeling & Development of Emission Scenarios for Methane and Key Indirect Greenhouse Gases  

SciTech Connect

This report outlines main accomplishments on the development of Emission inventories and Scenarios for Key Indirect Greenhouse Gases (CO, VOCs, NOx) and methane supported by Office of Science (BER), US Department of Energy. This research produced 3 journal articles, 1 book chapter, and 4 research articles/abstracts in conference proceedings. In addition, this grant supported two PhD students and one undergraduate student at UIUC.

Jain, Atul K.

2005-09-30

145

The impact of greenhouse gases on past changes in tropospheric ozone  

E-print Network

. Olsen,2,3 A. R. Douglass,3 Q. Liang,3,4 J. E. Nielsen,3,5 L. D. Oman,3 S. Pawson,3 and R. S. Stolarski1 velocities and water vapor. Citation: Lang, C., D. W. Waugh, M. A. Olsen, A. R. Douglass, Q. Liang, J. EThe impact of greenhouse gases on past changes in tropospheric ozone C. Lang,1 D. W. Waugh,1 M. A

Waugh, Darryn W.

146

Long Term Monitoring of Greenhouse Gases at NOAA - a Forty Year Record  

Microsoft Academic Search

NOAA's Earth System Research Laboratory and its precursor organizations have been monitoring trends and distributions of greenhouse gases and other climatically relevant constituents in the atmosphere for over 40 years (http:\\/\\/www.esrl.noaa.gov\\/gmd). The focus of these measurements has been to obtain reliable records of global trends and distributions, but the experimental design and use of these measurements have advanced over time

J. H. Butler

2009-01-01

147

Peatlands, carbon storage, greenhouse gases, and the Kyoto Protocol: Prospects and significance for Canada  

Microsoft Academic Search

The Kyoto Protocol accepts terrestrial sinks for greenhouse gases (GHGs) as offsets for fossil fuel emissions. Only carbon\\u000a sequestered in living biomass from re- and afforestation is presently considered, but the Protocol contains a provision for\\u000a the possible future inclusion of other land uses and soils. As a result, the possibility of sequestration of carbon in wetlands,\\u000a and particularly peatlands,

Nigel T. Roulet

2000-01-01

148

Systematical strategies for wastewater treatment and the generated wastes and greenhouse gases in China  

Microsoft Academic Search

China now faces double challenges of water resources shortage and severe water pollution. To resolve Chinese water pollution\\u000a problems and reduce its impacts on human health, economic growth and social development, the situation of wastewater treatment\\u000a was investigated. Excess sludge and greenhouse gases (GHGs) emitted during wastewater treatment were also surveyed. It is\\u000a concluded that Chinese water pollution problems should

Jingbo Guo; Fang Ma; Yuanyuan Qu; Ang Li; Liang Wang

149

Investigating high concentrations of three greenhouse gases in the Los Angeles Basin and San Bernardino Valley  

NASA Astrophysics Data System (ADS)

Following the Montreal Protocol of 1987 calling for the phase-out of CFCs and other ozone depleting substances, HCFCs and HFCs were introduced as alternatives despite still being greenhouse gases with high global warming potentials. In this study, whole air samples were collected during four research flights over Southern California aboard the NASA DC-8 Airborne Science Laboratory as part of the NASA Student Airborne Science Program. These samples were then analyzed by gas chromatography using a suite of detectors for many compounds, including HFC-134a, HCFC-22, and HFC-152a. HCFC-22 is primarily used as a refrigerant, while HFC-134a and HFC-152a are also used as aerosol propellants and foam blowing agents. High concentrations of these three compounds were observed for samples taken at low altitudes over urban areas around Los Angeles and San Bernardino. Exceptionally high concentrations were seen for all three compounds in samples taken near the Ontario and San Bernardino airports. Concentrations of HFC-134a, HCFC-22, and HFC-152a were enhanced above background levels near other airports sampled in the Los Angeles Basin and San Bernardino Valley. It is clear that concentrations of these three gases are higher in the San Bernardino Valley than in the Los Angeles Basin, and locations with exceptionally high concentrations were investigated to identify potential point sources. Concentrations of these three compounds were also compared to data from past SARP missions and data collected at Trinidad Head, California since 2005 as part of the AGAGE network. Comparison of the average values for each of these campaigns reveal that the background concentrations of HFC-134a, HCFC-22, and HFC-152a are all increasing with a strong linear trend in Southern California.

Kirpes, R.; Blake, D. R.; Marrero, J.

2013-12-01

150

Inadequacy of effective CO2 as a proxy in simulating the greenhouse effect of other radiatively active gases  

NASA Astrophysics Data System (ADS)

The use of an 'effective' CO2 concentration to simulate the combined greenhouse effect of CO2 and the trace gases CH4, N2O, CFC-11 and CFC-12 is open to question, because the radiative-forcing behavior of CO2 is very different from that of these other gases. Model simulations show that different radiative forcing can lead to quite different climatic effects. The thermal infrared opacity of these trace gases therefore needs to be explicitly accounted for when attempting to predict the climate response to increasing concentrations of greenhouse gases.

Wang, Wei-Chyung; Dudek, Michael P.; Liang, Xin-Zhong; Kiehl, J. T.

1991-04-01

151

Impact of rising greenhouse gases on mid-latitude storm tracks and associated hydroclimate variability and change  

SciTech Connect

Project Summary This project aimed to advance physical understanding of how and why the mid-latitude jet streams and storm tracks shift in intensity and latitude in response to changes in radiative forcing with an especial focus on rising greenhouse gases. The motivation, and much of the work, stemmed from the importance that these mean and transient atmospheric circulation systems have for hydroclimate. In particular drying and expansion of the subtropical dry zones has been related to a poleward shift of the mid-latitude jets and storm tracks. The work involved integrated assessment of observation and model projections as well as targeted model simulations.

Seager, Richard

2014-12-08

152

Emissions of Greenhouse Gases from Urban Xi'an, China - Direct Measurements by Eddy Covariance  

NASA Astrophysics Data System (ADS)

Throughout the world and especially in Asia, rapid urbanization is resulting in an increasing number of very large cities. In these areas, the rate of development can outpace the perceived need for environmental regulation, and frequently there are inadequate resources available to monitor pollution or enforce compliance with those environmental regulations that do exist. These limitations obviously impact air quality on a local scale, but cities also have significant environmental impacts on regional and even global scales. In order to understand and mitigate these impacts on the surrounding environment, it is first necessary to robustly characterize the pollutant emissions themselves. This can be a significant challenge. Major discrepancies arise when comparing emissions inventories based on bottom-up compilations of source types, number, and activity levels to estimates inferred from satellite observations and other large-scale techniques. Direct measurements of neighborhood-scale emission fluxes via micrometeorological approaches provide a means to resolve these differences. Such measurements can be used to quantify the integrated vertical exchange for a wide variety of greenhouse gases and other pollutants, typically with spatial footprints of tens of square kilometers and with temporal resolutions of ~30 minutes. Here we present the results of an urban flux study conducted in Xi'an, China in August 2011. For the study a 23 m tower was erected atop the ~100 m tall administration building at Xi'an Jiaotong University. From the tower, we employed an eddy covariance approach to measure concentrations and fluxes of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and carbon monoxide (CO). Here we present an analysis of the air-surface exchange of these gases. Results indicate that while our study site in Xi'an was a net source of these species, the greenhouse gas fluxes were significantly smaller than at other sites around the world and exhibited a different diurnal pattern. We attribute these results to two factors: 1) the relatively low traffic density at the Xi'an study site relative to other urban flux sites; and 2) the presence of a large urban park in the northerly sector of the study footprint, where the vegetative sink for CO2 was often greater than anthropogenic sources. Overall the analysis suggests that even in heavily urbanized regions land use and activity profiles can have significant impacts on air pollutant emissions.

VanReken, T. M.; Mwaniki, G. R.; VanderSchelden, G.; O'Keeffe, P.; Waldo, S.; Erickson, M. H.; Lamb, B. K.; Jobson, B. T.; Tie, X.; Cao, J.

2012-12-01

153

Enhancement of greenhouse gases associated with Canadian forest fire using multi sensor data  

NASA Astrophysics Data System (ADS)

Forest fire is a common natural hazard that takes lives of people and billion dollar loss of properties almost every year. In the recent past frequency of forest fires have increased in Canada and throughout the world that is associated with the changes in land use and land cover practice. Multi sensor satellites are now capable in providing information about the land cover, atmosphere and meteorological parameters. The present paper deals with the multi sensor data (AIRS, MODIS, OMI AURA, TOMS) to study the changes in greenhouse and other gases (NOx, O3, CO, water vapor) and aerosol parameters. The detailed analysis of multi sensor data have shown elevated amount of greenhouse gases, total ozone column and aerosol optical depth during summer of 2004 at the time of Canadian forest fire compared to other years. The spatial distribution of greenhouse gas, aerosol optical depth and meteorological conditions are found to change after the onset of forest fire that shows the dynamic nature of the greenhouse gas and associated releases with the dispersion of the plume and smoke from the forest fire. The maximum changes are found from the surface up to a pressure level height 500 hPa, the change occur is found to be very much dependent on the distance from the source (forest fire location) and also on the meteorological conditions.

Singh, Rachita; Singh, Rachita; Chaturvedi, Ritu

154

Greenhouse gases, climate change and the transition from coal to low-carbon electricity  

NASA Astrophysics Data System (ADS)

A transition from the global system of coal-based electricity generation to low-greenhouse-gas-emission energy technologies is required to mitigate climate change in the long term. The use of current infrastructure to build this new low-emission system necessitates additional emissions of greenhouse gases, and the coal-based infrastructure will continue to emit substantial amounts of greenhouse gases as it is phased out. Furthermore, ocean thermal inertia delays the climate benefits of emissions reductions. By constructing a quantitative model of energy system transitions that includes life-cycle emissions and the central physics of greenhouse warming, we estimate the global warming expected to occur as a result of build-outs of new energy technologies ranging from 100 GWe to 10 TWe in size and 1-100 yr in duration. We show that rapid deployment of low-emission energy systems can do little to diminish the climate impacts in the first half of this century. Conservation, wind, solar, nuclear power, and possibly carbon capture and storage appear to be able to achieve substantial climate benefits in the second half of this century; however, natural gas cannot.

Myhrvold, N. P.; Caldeira, K.

2012-03-01

155

European emissions of halogenated greenhouse gases inferred from atmospheric measurements.  

PubMed

European emissions of nine representative halocarbons (CFC-11, CFC-12, Halon 1211, HCFC-141b, HCFC-142b, HCFC-22, HFC-125, HFC-134a, HFC-152a) are derived for the year 2009 by combining long-term observations in Switzerland, Italy, and Ireland with campaign measurements from Hungary. For the first time, halocarbon emissions over Eastern Europe are assessed by top-down methods, and these results are compared to Western European emissions. The employed inversion method builds on least-squares optimization linking atmospheric observations with calculations from the Lagrangian particle dispersion model FLEXPART. The aggregated halocarbon emissions over the study area are estimated at 125 (106-150) Tg of CO(2) equiv/y, of which the hydrofluorocarbons (HFCs) make up the most important fraction with 41% (31-52%). We find that chlorofluorocarbon (CFC) emissions from banks are still significant and account for 35% (27-43%) of total halocarbon emissions in Europe. The regional differences in per capita emissions are only small for the HFCs, while emissions of CFCs and hydrochlorofluorocarbons (HCFCs) tend to be higher in Western Europe compared to Eastern Europe. In total, the inferred per capita emissions are similar to estimates for China, but 3.5 (2.3-4.5) times lower than for the United States. Our study demonstrates the large benefits of adding a strategically well placed measurement site to the existing European observation network of halocarbons, as it extends the coverage of the inversion domain toward Eastern Europe and helps to better constrain the emissions over Central Europe. PMID:22192076

Keller, Christoph A; Hill, Matthias; Vollmer, Martin K; Henne, Stephan; Brunner, Dominik; Reimann, Stefan; O'Doherty, Simon; Arduini, Jgor; Maione, Michela; Ferenczi, Zita; Haszpra, Laszlo; Manning, Alistair J; Peter, Thomas

2012-01-01

156

Emissions of greenhouse gases and air pollutants from commercial aircraft at international airports in Korea  

NASA Astrophysics Data System (ADS)

The emissions of greenhouse gases (GHGs) and air pollutants from aircraft in the boundary layer at four major international airports in Korea over a two-year period (2009-2010) were estimated using the Emissions and Dispersion Modeling System (EDMS) (i.e. activity-based (Landing/Take-Off (LTO) cycle) methodology). Both domestic and international LTOs and ground support equipment at the airports were considered. The average annual emissions of GHGs (CO2, N2O, CH4 and H2O) at all four airports during the study period were 1.11 × 103, 1.76 × 10-2, -1.85 × 10-3 and 3.84 × 108 kt yr-1, respectively. The emissions of air pollutants (NOx, CO, VOCs and particulate matter) were 5.20, 4.12, 7.46 × 10-1 and 3.37 × 10-2 kt yr-1, respectively. The negative CH4 emission indicates the consumption of atmospheric CH4 in the engine. The monthly and daily emissions of GHGs and air pollutants showed no significant variations at all airports examined. The emissions of GHGs and air pollutants for each aircraft operational mode differed considerably, with the largest emission observed in taxi-out mode.

Song, Sang-Keun; Shon, Zang-Ho

2012-12-01

157

The Marginal Damage Costs of Different Greenhouse Gases: An Application of FUND  

SciTech Connect

We use FUND 3.8 to estimate the social cost of four greenhouse gases: carbon dioxide, methane, nitrous oxide, and sulphur hexafluoride emissions. The damage potential for each gas—the ratio of the social cost of the non-carbon dioxide greenhouse gas to the social cost of carbon dioxide—is also estimated. The damage potentials are compared to several metrics, focusing in particular on the global warming potentials, which are frequently used to measure the trade-off between gases in the form of carbon dioxide equivalents. We find that damage potentials could be significantly higher than global warming potentials. This finding implies that previous papers have underestimated the relative importance of reducing non-carbon dioxide greenhouse gas emissions from an economic damage perspective. We show results for a range of sensitivity analyses: carbon dioxide fertilization on agriculture productivity, terrestrial feedbacks, climate sensitivity, discounting, equity weighting, and socioeconomic and emissions scenarios. The sensitivity of the results to carbon dioxide fertilization is a primary focus as it is an important element of climate change that has not been considered in much of the previous literature. We estimate that carbon dioxide fertilization has a large positive impact that reduces the social cost of carbon dioxide with a much smaller effect on the other greenhouse gases. As a result, our estimates of the damage potentials of methane and nitrous oxide are much higher compared to estimates that ignore carbon dioxide fertilization. As a result, our base estimates of the damage potential for methane and nitrous oxide that include carbon dioxide fertilization are twice their respective global warming potentials. Our base estimate of the damage potential of sulphur hexafluoride is similar to the one previous estimate, both almost three times the global warming potential.

Waldhoff, Stephanie T.; Anthoff, David; Rose, Steven K.; Tol, Richard

2014-10-01

158

Greenhouse Gases  

NSDL National Science Digital Library

Explore how the Earth's atmosphere affects the energy balance between incoming and outgoing radiation. Using an interactive model, adjust realistic parameters such as how many clouds are present or how much carbon dioxide is in the air, and watch how these factors affect the global temperature.

2012-07-19

159

Global warming: Experimental study about the effect of accumulation of greenhouse gases in the atmosphere  

NASA Astrophysics Data System (ADS)

The project presented here was developed by fifteen year old students of the Institut Sabadell (Sabadell Secondary School. Spain). The objective of this project was to raise the students awareness' about the problem of climate change, mainly caused by the accumulation of greenhouse gases in the atmosphere. It is also intended that students use the scientific method as an effective system of troubleshooting and that they use the ICTs (Information and Communication Technologies) to elicit data and process information. To develop this project, four lessons of sixty minutes each were needed. The first lesson sets out the role of the atmosphere as an Earth's temperature regulator, highlighting the importance of keeping the levels of carbon dioxide, methane and water steam in balance. The second lesson is focused on the experimental activity that students will develop in the following lesson. In lesson two, students will present and justify their hypothesis about the experiment. Some theoretical concepts, necessary to carry out the experiment, will also be explained. The third lesson involves the core of the project, that is the experiment in the laboratory. The experiment consists on performing the atmosphere heating on a little scale. Four different atmospheres are created inside four plastic boxes heated by an infrared lamp. Students work in groups (one group for each atmosphere) and have to monitor the evolution of temperature by means of a temperature sensor (Multilog software). The first group has to observe the relationship between temperature and carbon dioxide levels increase, mainly caused by the widespread practice of burning fossil fuels by growing human populations. The task of this group is to measure simultaneously the temperature of an empty box (without CO2) and the temperature of a box with high carbon dioxide concentration. The carbon dioxide concentration is the result of the chemical reaction when sodium carbonate mixes with hydrochloric acid. The second group's task is similar to the first. Students have to study how the concentration of methane affects the temperature of their atmosphere box. Similarly, the third group monitors the influence of the water steam (generated by evaporation) on the temperature of their atmosphere box. Results must be carefully analyzed because of possible interferences from water steam. And finally, the forth and last group explores the long term effects that the accumulation of greenhouse gases have on the Earth's temperature. As temperature rises, evaporation increases and more water steam accumulates in the atmosphere. As a greenhouse gas, water absorbs heat, therefore the air gets warmer and, again, more water is evaporated. To develop this project, a previous experiment is needed so that the concentration of carbon dioxide remains constant and water steam levels increase gradually. Thus, the consequences of an uncontrolled increase of temperature can be simulated. Students' aim is to examine the data elicited from the last step of the scientific method experiment. They have to decide either if the experiment supported their hypothesis and, therefore, they can be regarded as true, or the experiment disproved them and, therefore, they are false. Finally, in the last lesson, students perform an oral presentation about their experimental results, establishing relationships amongst the different experiments. All together emphasizes the must of humankind to promote renewable energies.

Molto, Carlos; Mas, Miquel

2010-05-01

160

Estimates of global biomass burning emissions for reactive greenhouse gases (CO, NMHCs, and NOx) and CO2  

E-print Network

, along with biofuel consumption rate data. The estimated global and annual total dry matter (DM) burned burning emissions of these gases. Estimated DM burned associated with domestic biofuel burning is 3,114 TgEstimates of global biomass burning emissions for reactive greenhouse gases (CO, NMHCs, and NOx

Jain, Atul K.

161

A Group Increment Scheme for Infrared Absorption Intensities of Greenhouse Gases  

NASA Technical Reports Server (NTRS)

A molecule's absorption in the atmospheric infrared (IR) window (IRW) is an indicator of its efficiency as a greenhouse gas. A model for estimating the absorption of a fluorinated molecule within the IRW was developed to assess its radiative impact. This model will be useful in comparing different hydrofluorocarbons and hydrofluoroethers contribution to global warming. The absorption of radiation by greenhouse gases, in particular hydrofluoroethers and hydrofluorocarbons, was investigated using ab initio quantum mechanical methods. Least squares regression techniques were used to create a model based on this data. The placement and number of fluorines in the molecule were found to affect the absorption in the IR window and were incorporated into the model. Several group increment models are discussed. An additive model based on one-carbon groups is found to work satisfactorily in predicting the ab initio calculated vibrational intensities.

Kokkila, Sara I.; Bera, Partha P.; Francisco, Joseph S.; Lee, Timothy J.

2012-01-01

162

Radiative Forcing by Long-Lived Greenhouse Gases: Calculations with the AER Radiative Transfer Models  

SciTech Connect

A primary component of the observed, recent climate change is the radiative forcing from increased concentrations of long-lived greenhouse gases (LLGHGs). Effective simulation of anthropogenic climate change by general circulation models (GCMs) is strongly dependent on the accurate representation of radiative processes associated with water vapor, ozone and LLGHGs. In the context of the increasing application of the Atmospheric and Environmental Research, Inc. (AER) radiation models within the GCM community, their capability to calculate longwave and shortwave radiative forcing for clear sky scenarios previously examined by the radiative transfer model intercomparison project (RTMIP) is presented. Forcing calculations with the AER line-by-line (LBL) models are very consistent with the RTMIP line-by-line results in the longwave and shortwave. The AER broadband models, in all but one case, calculate longwave forcings within a range of -0.20 to 0.23 W m{sup -2} of LBL calculations and shortwave forcings within a range of -0.16 to 0.38 W m{sup -2} of LBL results. These models also perform well at the surface, which RTMIP identified as a level at which GCM radiation models have particular difficulty reproducing LBL fluxes. Heating profile perturbations calculated by the broadband models generally reproduce high-resolution calculations within a few hundredths K d{sup -1} in the troposphere and within 0.15 K d{sup -1} in the peak stratospheric heating near 1 hPa. In most cases, the AER broadband models provide radiative forcing results that are in closer agreement with high 20 resolution calculations than the GCM radiation codes examined by RTMIP, which supports the application of the AER models to climate change research.

Collins, William; Iacono, Michael J.; Delamere, Jennifer S.; Mlawer, Eli J.; Shephard, Mark W.; Clough, Shepard A.; Collins, William D.

2008-04-01

163

Relative Contribution of Greenhouse Gases and Ozone Change to Temperature Trends in the Stratosphere: A Chemistry/Climate Model Study  

NASA Technical Reports Server (NTRS)

Long-term changes in greenhouse gases, primarily carbon dioxide, are expected to lead to a warming of the troposphere and a cooling of the stratosphere. We examine the cooling of the stratosphere and compare the contributions greenhouse gases and ozone change for the decades between 1980 and 2000. We use 150 years of simulation done with our coupled chemistry/climate model (GEOS 4 GCM with GSFC CTM chemistry) to calculate temperatures and constituents fiom,1950 through 2100. The contributions of greenhouse gases and ozone to temperature change are separated by a time-series analysis using a linear trend term throughout the period to represent the effects of greenhouse gases and an equivalent effective stratospheric chlorine (EESC) term to represent the effects of ozone change. The temperature changes over the 150 years of the simulation are dominated by the changes in greenhouse gases. Over the relatively short period (approx. 20 years) of ozone decline between 1980 and 2000 changes in ozone are competitive with changes in greenhouse gases. The changes in temperature induced by the ozone change are comparable to, but smaller than, those of greenhouse gases in the upper stratosphere (1-3 hPa) at mid latitudes. The ozone term dominates the temperature change near both poles with a negative temperature change below about 3-5 hPa and a positive change above. At mid latitudes in the upper stratosphere and mesosphere (above about 1 hPa) and in the middle stratosphere (3 to 70 ma), the greenhouse has term dominates. From about 70 hPa down to the tropopause at mid latitudes, cooling due to ozone changes is the largest influence on temperature. Over the 150 years of the simulation, the change in greenhouse gases is the most important contributor to temperature change. Ozone caused a perturbation that is expected to reverse over the coming decades. We show a model simulation of the expected temperature change over the next two decades (2006-2026). The simulation shows a crossover between lower atmospheric heating and upper atmospheric cooling that is located at about 90 hPa in the tropics and 30-40 hPa in the polar regions. This results from the combination of continuing increases in greehouse gases and recovery from ozone depletion.

Stolarski, Richard S.; Douglass, A. R.; Newman, P. A.; Pawson, S.; Schoeberl, M. R.

2006-01-01

164

Perfluoroalkyl Amines: A New Class of Long-Lived Greenhouse Gases?  

NASA Astrophysics Data System (ADS)

Polyfluorinated compounds have the potential to act as potent greenhouse gases, due to absorption of the carbon-fluorine bond in the atmospheric window. Perfluoroalkyl amines are a class of thermally and chemically stable compounds marketed for use in numerous applications, including electronic testing and heat transfer. To assess the potential for climate impact, the radiative efficiency and atmospheric lifetime of perfluorotributyl amine (PFBAm) were determined. PFBAm was shown to have a radiative efficiency of 0.86 W m-2 ppb-1, which is higher than any compound yet detected in the atmosphere. The lifetime of this compound is likely limited by photolysis in the mesosphere, on the timescale of 800 years. The potential for perfluoroalkyl amines to behave as greenhouse gases is only realized if they are present in the atmosphere. The perfluorotripropyl and perfluorotrihexyl amine congeners are listed as high-production chemicals, with production in the range of hundreds of tonnes between 1986 and 2002 (1). An air sampling, extraction and analysis method employing thermal desorption, cryofocusing and GC-MS with negative chemical ionization has been developed to detect perfluoroalkyl amines in the atmosphere. Results and implications of the air sampling study will be discussed. (1)Howard, P. H.; Meylan, W. "EPA Great Lakes Study for Identification of PBTs to Develop Analytical Methods: Selection of Additional PBTs - Interim Report," EPA Contract No. EP-W-04-019, 2007.

Young, C. J.; Mabury, S. A.

2008-12-01

165

A new UK Greenhouse Gas measurement network providing ultra high-frequency measurements of key radiatively active trace gases taken from a network of tall towers  

NASA Astrophysics Data System (ADS)

Monitoring of atmospheric concentrations of gases is important in assessing the impact of international policies related to the atmospheric environment. The effects of control measures on greenhouse gases introduced under the Montreal and Kyoto Protocols are now being observed. Continued monitoring is required to assess the overall success of the Protocols. For over 15 years the UK Government have funded high-frequency measurements of greenhouse gases and ozone depleting gases at Mace Head, a global background measurement station on the west coast of Ireland. These continuous, high-frequency, high-precision measurements are used to estimate regional (country-scale) emissions of greenhouse gases across the UK using an inversion methodology (NAME-Inversion) that links the Met Office atmospheric dispersion model (Numerical Atmospheric dispersion Modelling Environment - NAME) with the Mace Head observations. This unique inversion method acts to independently verify bottom up emission estimates of radiatively active and ozone-depleting trace gases. In 2011 the UK government (DECC) funded the establishment and integration of three new tall tower measurements stations in the UK, to provide enhanced resolution emission maps and decrease uncertainty of regional emission estimates produced using the NAME-Inversion. One station included in this new UK network was already established in Scotland and was used in collaboration with Edinburgh University. The two other new stations are in England and were set-up early in 2012, they contain brand new instrumentation for measurements of greenhouse gases. All three additional stations provide ultra high-frequency (1 sec) data of CO2 and CH4 using the Picarro© Cavity Ring Down Spectrometer and high frequency (20 min) measurements of N2O and SF6 from custom built sample modules with GC-ECD. We will present the new tall tower UK measurement network in detail. Using high-frequency measurements at new operational sites, including Mace Head, we will present the latest inversion results from the new network highlighting the enhanced resolution in regional emission maps for the UK. These results are presented to the UK government periodically and provide independent verification of the emission estimates of radiatively active trace gases. These results also inform policy makers on the accuracy of inventory emissions estimates of radiatively active and ozone-depleting trace gases.

Grant, A.; O'Doherty, S.; Manning, A. J.; Simmonds, P. G.; Derwent, R. G.; Moncrieff, J. B.; Sturges, W. T.

2012-04-01

166

Influence of biochar amendment on greenhouse gases emission and rice production in paddy field, China  

NASA Astrophysics Data System (ADS)

Biochar incorporating into agricultural soils as a strategy to increase soil carbon content and mitigate climate change received great attention. We present a field study about biochar amendment into paddy field in Sichuan province 2010, China. The objective was to evaluate the impacts of biochar incorporation on rice production and greenhouse gas emissions. Biochar used in this study was produced from wheat straw at temperature 350-550°C. Biochar incorporated into paddy field before rice transplanting. Methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) fluxes were measured in situ using closed chamber method during whole rice growing season. Flux of greenhouse gases was monitored at about 7 day's interval. Two rates of N fertilizer (0 and 240 kg N/ha) were applied as urea in combination with 3 biochar rates (0, 20 and 40 t/ha). Amendment of biochar had no influence on rice yield even at the hightest rate of 40 t/ha. However, rice production was greatly relying on chemical N fertilization input. No interact effect was detected between biochar and N fertilizer. Amendment of biochar suppressed N2O emission. During the whole rice growing season, the total N2O emission from chemical fertilizer was reduce by 29% and 53% under biochar amendment rates of 20t/ha and 40t/ha respectively. Total amounts of CO2 and CH4 emitted from paddy fields during whole rice growing season were not greatly increased despite of much carbon brought into soil with biochar. However, biochar amendment slightly increased CO2 emission in the absence of N fertilizer. Our results showed that biochar amendment into paddy field did not increase the global warming potential (GPW) and greenhouse gases emission intensity (GHGI).

Liu, X.; Pan, G. X.; Li, L. Q.; Zhou, T.

2012-04-01

167

Atmospheric Removal of Very Long-lived Greenhouse Gases in the Mesosphere  

NASA Astrophysics Data System (ADS)

Chlorofluorocarbons are known to have serious ozone depleting and global warming potentials. Perfluorinated compounds such as SF6, NF3, SF5CF3 and CF3CF2Cl which have very long lifetimes (ranging from a few centuries to over 3000 years) are too stable to affect stratospheric ozone but do have among the highest per molecule radiative forcing of any greenhouse pollutant, making them extremely potent greenhouse gases. Due to the stability of these gases in the lower atmosphere, mesospheric loss processes could significantly reduce their estimated atmospheric lifetimes and hence, overall climate impact. Potential sinks include reactions with metals and energetic particles such as electrons or short wavelength photons already present in the upper atmosphere. The metals, in this instance iron, sodium or potassium, are produced by meteoric ablation, while background and energetic electrons have the continuous source of photoionization and auroral precipitation, respectively. In this study we investigate the removal potentials of four very long lived gases (SF6, NF3, SF5CF3 and CF3CF2Cl). First, by four metals (Fe, Mg, Na and K), where rate coefficients are measured using the Fast Flow Tube and Pulsed Laser Flash Photolysis / Laser Induced Fluorescence techniques. Second, removal by electron attachment was investigated using a quadrupole mass spectrometer. measurements. Third, Lyman-alpha (121.56 nm) photolysis was measured in a VUV absorption cell. The resulting removal rate coefficients are currently being input into the Whole Atmosphere Community Climate Model (WACCM) to obtain lifetime measurements for these species.

Totterdill, A.; Kovacs, T.; Gomez Martin, J.; FENG, W.; Chipperfield, M.; Plane, J. M.

2013-12-01

168

Using ocean-glint scattered sunlight as a diagnostic tool for satellite remote sensing of greenhouse gases  

NASA Astrophysics Data System (ADS)

Spectroscopic measurements of sunlight backscattered by the Earth's surface is a technique widely used for remote sensing of atmospheric constituent concentrations from space. Thereby, remote sensing of greenhouse gases poses particularly challenging accuracy requirements for instrumentation and retrieval algorithms which, in general, suffer from various error sources. Here, we investigate a method that helps disentangle sources of error for observations of sunlight backscattered from the glint spot on the ocean surface. The method exploits the backscattering characteristics of the ocean surface which is bright for glint geometry but dark for off-glint angles. This property allows for identifying a set of clean scenes where light scattering due to particles in the atmosphere is negligible such that uncertain knowledge of the lightpath can be excluded as a source of error. We apply the method to more than 3 yr of ocean-glint measurements by the Thermal And Near infrared Sensor for carbon Observation (TANSO) - Fourier Transform Spectrometer (FTS) onboard the Greenhouse Gases Observing Satellite (GOSAT) which aims at measuring carbon dioxide (CO2) and methane (CH4) concentrations. The proposed method is able to clearly monitor recent improvements in the instrument calibration of the oxygen (O2) A-band channel and suggests some residual uncertainty in our knowledge about the instrument. We further assess the consistency of CO2 retrievals from several absorption bands between 6400 cm-1 (1565 nm) and 4800 cm-1 (2100 nm) and find that the absorption bands commonly used for monitoring of CO2 dry air mole fractions from GOSAT allow for consistency better than 1.5 ppm. Usage of other bands reveals significant inconsistency among retrieved CO2 concentrations pointing at inconsistency of spectroscopic parameters.

Butz, A.; Guerlet, S.; Hasekamp, O. P.; Kuze, A.; Suto, H.

2013-05-01

169

Using ocean-glint scattered sunlight as a diagnostic tool for satellite remote sensing of greenhouse gases  

NASA Astrophysics Data System (ADS)

Spectroscopic measurements of sunlight backscattered by the Earth's surface is a technique widely used for remote sensing of atmospheric constituent concentrations from space. Thereby, remote sensing of greenhouse gases poses particularly challenging accuracy requirements for instrumentation and retrieval algorithms which, in general, suffer from various error sources. Here, we investigate a method that helps disentangle sources of error for observations of sunlight backscattered from the glint spot on the ocean surface. The method exploits the backscattering characteristics of the ocean surface, which is bright for glint geometry but dark for off-glint angles. This property allows for identifying a set of clean scenes where light scattering due to particles in the atmosphere is negligible such that uncertain knowledge of the lightpath can be excluded as a source of error. We apply the method to more than 3 yr of ocean-glint measurements by the Thermal And Near infrared Sensor for carbon Observation (TANSO) Fourier Transform Spectrometer (FTS) onboard the Greenhouse Gases Observing Satellite (GOSAT), which aims at measuring carbon dioxide (CO2) and methane (CH4) concentrations. The proposed method is able to clearly monitor recent improvements in the instrument calibration of the oxygen (O2) A-band channel and suggests some residual uncertainty in our knowledge about the instrument. We further assess the consistency of CO2 retrievals from several absorption bands between 6400 cm-1 (1565 nm) and 4800 cm-1 (2100 nm) and find that the absorption bands commonly used for monitoring of CO2 dry air mole fractions from GOSAT allow for consistency better than 1.5 ppm. Usage of other bands reveals significant inconsistency among retrieved CO2 concentrations pointing at inconsistency of spectroscopic parameters.

Butz, A.; Guerlet, S.; Hasekamp, O. P.; Kuze, A.; Suto, H.

2013-09-01

170

MAMM (Methane and other greenhouse gases in the Arctic - Measurements, process studies and Modelling) progress report  

NASA Astrophysics Data System (ADS)

MAMM consortium (led by JA Pyle, Univ. Cambridge, with partners from Univ. East Anglia; Univ. Manchester; Royal Holloway, Univ. of London; NERC Centre for Ecology and Hydrology). The UK MAMM project (Methane and other greenhouse gases in the Arctic - Measurements, process studies and Modelling) is designed to improve quantitative knowledge of Arctic methane and other greenhouse gases from various sources (e.g. wetlands, natural gas, clathrates), to determine magnitudes and spatial distributions, and to develop process understanding (e.g. dependence of fluxes on temperature). In Arctic Finland, Sweden, Norway and Spitsbergen, intensive low-level aircraft campaigns (flights in spring, summer, autumn 2012 and 2013, with the UK FAAM BAe146 aircraft) are designed to measure concentrations of CH4 and other gases across the Arctic by time and location, with in situ sampling for ?13CCH4 at selected sites on land (Zeppelin, Pallas, Alert) and Keeling-plot diel determination of wetland source signatures. High altitude flights sampled stratosphere-troposphere exchange in the Arctic to assess the impact of the polar vortex on methane isotope budgets. Methane column profiles are measured by combining ground based eddy covariance and chamber measurements with aircraft measurements, using a landscape-scale box model approach and flying up and downwind of source regions. Airborne remote sensing is being used to retrieve CH4 columns for comparison with in-situ profiles and testing of hyperspectral retrieval methods from satellite platforms. Longer-term time series measurements are also being established in Kjølnes, northern Norway, for a range of greenhouse and related species via continuous or flask/bag sampling. Modelling studies are in progress to assess the overall Arctic influence on the global methane budget, including detailed back-trajectory analysis of the measurements, especially the isotopic data, to identify sources of methane by location, type (e.g. gasfield, wetland, biomass fire, clathrate), and seasonality / event, and also regional source analysis using the NAME particle dispersion model. Chemistry/climate modelling is used to assess the role of the Arctic in recent changes in atmospheric methane and to perform projections for future change.

Nisbet, E. G.; Pyle, J. A.

2012-12-01

171

High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4) during BARCA  

NASA Astrophysics Data System (ADS)

High-accuracy continuous measurements of greenhouse gases (CO2 and CH4) during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS) technique. This analyzer was flown without a drying system or any in-flight calibration gases. Water vapor corrections associated with dilution and pressure-broadening effects for CO2 and CH4 were derived from laboratory experiments employing measurements of water vapor by the CRDS analyzer. Before the campaign, the stability of the analyzer was assessed by laboratory tests under simulated flight conditions. During the campaign, a comparison of CO2 measurements between the CRDS analyzer and a nondispersive infrared (NDIR) analyzer on board the same aircraft showed a mean difference of 0.22±0.09 ppm for all flights over the Amazon rain forest. At the end of the campaign, CO2 concentrations of the synthetic calibration gases used by the NDIR analyzer were determined by the CRDS analyzer. After correcting for the isotope and the pressure-broadening effects that resulted from changes of the composition of synthetic vs. ambient air, and applying those concentrations as calibrated values of the calibration gases to reprocess the CO2 measurements made by the NDIR, the mean difference between the CRDS and the NDIR during BARCA was reduced to 0.05±0.09 ppm, with the mean standard deviation of 0.23±0.05 ppm. The results clearly show that the CRDS is sufficiently stable to be used in flight without drying the air or calibrating in flight and the water corrections are fully adequate for high-accuracy continuous airborne measurements of CO2 and CH4.

Chen, H.; Winderlich, J.; Gerbig, C.; Hoefer, A.; Rella, C. W.; Crosson, E. R.; van Pelt, A. D.; Steinbach, J.; Kolle, O.; Beck, V.; Daube, B. C.; Gottlieb, E. W.; Chow, V. Y.; Santoni, G. W.; Wofsy, S. C.

2009-12-01

172

Recent Trends in Non-CO2 Greenhouse Gases, and their Implications for Emissions and Lifetime Estimates  

NASA Astrophysics Data System (ADS)

We examine trends in non-CO2 greenhouse gases measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) over the last decade. During this time, the concentrations of all the major chlorofluorocarbons (CFCs) declined significantly. In contrast, a large number of replacement gases that have high global warming potentials, hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs), have grown rapidly. Methane (CH4) and nitrous oxide (N2O) levels have continued to increase, but with rates that change inter-annually. Concentrations of very long lived, potent greenhouse gases such as perfluorocarbons (PFCs) and sulfur hexafluoride (SF6) have also grown significantly. Using a model of atmospheric chemistry and transport, and a multi-species inverse method, we make use of the measured trends to infer global lifetimes of CFCs and global emissions of HFCs, HCFCs, CH4, N2O and other gases. We determine lifetimes of 52 (45-61) years for CFC-11 and 106 (85-138) years for CFC-113 that are somewhat higher than current `best' estimates, and a lifetime for CFC-12 in line with current estimates. Emissions estimates reveal substantial emissions growth over the last decade for most of the major long-lived, non-CO2, non-CFC greenhouse gases, highlighting the need for effective measures towards global emission reductions.

Rigby, M.; Prinn, R. G.; O'Doherty, S.; Young, D.; Simmonds, P. G.; Muhle, J.; Salameh, P.; Harth, C. M.; Weiss, R. F.; Steele, P.; Krummel, P. B.; Fraser, P. J.

2012-12-01

173

O(1D) kinetic study of key ozone depleting substances and greenhouse gases.  

PubMed

A key stratospheric loss process for ozone depleting substances (ODSs) and greenhouse gases (GHGs) is reaction with the O((1)D) atom. In this study, rate coefficients, k, for the O((1)D) atom reaction were measured for the following key halocarbons: chlorofluorocarbons (CFCs) CFCl3 (CFC-11), CF2Cl2 (CFC-12), CFCl2CF2Cl (CFC-113), CF2ClCF2Cl (CFC-114), CF3CF2Cl (CFC-115); hydrochlorofluorocarbons (HCFCs) CHF2Cl (HCFC-22), CH3CClF2 (HCFC-142b); and hydrofluorocarbons (HFCs) CHF3 (HFC-23), CHF2CF3 (HFC-125), CH3CF3 (HFC-143a), and CF3CHFCF3 (HFC-227ea). Total rate coefficients, kT, corresponding to the loss of the O((1)D) atom, were measured over the temperature range 217-373 K using a competitive reactive technique. kT values for the CFC and HCFC reactions were >1 × 10(-10) cm(3) molecule(-1) s(-1), except for CFC-115, and the rate coefficients for the HFCs were in the range (0.095-0.72) × 10(-10) cm(3) molecule(-1) s(-1). Rate coefficients for the CFC-12, CFC-114, CFC-115, HFC-23, HFC-125, HFC-143a, and HFC-227ea reactions were observed to have a weak negative temperature dependence, E/R ? -25 K. Reactive rate coefficients, kR, corresponding to the loss of the halocarbon, were measured for CFC-11, CFC-115, HCFC-22, HCFC-142b, HFC-23, HFC-125, HFC-143a, and HFC-227ea using a relative rate technique. The reactive branching ratio obtained was dependent on the composition of the halocarbon and the trend in O((1)D) reactivity with the extent of hydrogen and chlorine substitution is discussed. The present results are critically compared with previously reported kinetic data and the discrepancies are discussed. 2D atmospheric model calculations were used to evaluate the local and global annually averaged atmospheric lifetimes of the halocarbons and the contribution of O((1)D) chemistry to their atmospheric loss. The O((1)D) reaction was found to be a major global loss process for CFC-114 and CFC-115 and a secondary global loss process for the other molecules included in this study. PMID:23441917

Baasandorj, Munkhbayar; Fleming, Eric L; Jackman, Charles H; Burkholder, James B

2013-03-28

174

Tittel: An Alternative to the Global Warming Potential for Comparing Climate Impacts of Emissions of Greenhouse Gases Title: An Alternative to the Global Warming Potential for Comparing Climate Impacts of Emissions of Greenhouse Gases  

Microsoft Academic Search

The Global Warming Potential (GWP) is used within the Kyoto Protocol to the United Nations Framework Convention on Climate Change as a metric for weighting the climatic impact of emissions of different greenhouse gases. The GWP has been subject to many criticisms because of its formulation, but nevertheless it has retained some favour because of the simplicity of its design

Keith P. Shine; Jan S. Fuglestvedt; Nicola Stuber

175

Using STELLA System Dynamic Model to Analyze Greenhouse Gases' Emission From Solid Waste Management in Taiwan  

SciTech Connect

Using a system dynamic model (SDM), such as STELLA, to analyze the waste management policy is a new trial for Taiwan's research communities. We have developed an easy and relatively accurate model for analyzing the greenhouse gases emission for the wastes from animal farming and municipalities. With the local research data of the past decade, we extract the most prominent factors and assemble the SDM. The results and scenarios were compared with the national inventory. By comparing to the past data, we found these models reasonably represent the situation in Taiwan. However, SDM can program many scenarios and produce a lot of prediction data. With the development of many program control tools on STELLA, we believe the models could be further used by researchers or policy-makers to find the needed research topics, to set the future scenarios and to determine the management tools.

Horng, Jao-Jia; Lee, R.F.; Liao, K.Y.

2004-03-31

176

On Road Study of Colorado Front Range Greenhouse Gases Distribution and Sources  

NASA Astrophysics Data System (ADS)

The Global Monitoring Division and Chemical Sciences Division of the NOAA Earth System Research Laboratory have teamed up over the summer 2008 to experiment with a new measurement strategy to characterize greenhouse gases distribution and sources in the Colorado Front Range. Combining expertise in greenhouse gases measurements and in local to regional scales air quality study intensive campaigns, we have built the 'Hybrid Lab'. A continuous CO2 and CH4 cavity ring down spectroscopic analyzer (Picarro, Inc.), a CO gas-filter correlation instrument (Thermo Environmental, Inc.) and a continuous UV absorption ozone monitor (2B Technologies, Inc., model 202SC) have been installed securely onboard a 2006 Toyota Prius Hybrid vehicle with an inlet bringing in outside air from a few meters above the ground. To better characterize point and distributed sources, air samples were taken with a Portable Flask Package (PFP) for later multiple species analysis in the lab. A GPS unit hooked up to the ozone analyzer and another one installed on the PFP kept track of our location allowing us to map measured concentrations on the driving route using Google Earth. The Hybrid Lab went out for several drives in the vicinity of the NOAA Boulder Atmospheric Observatory (BAO) tall tower located in Erie, CO and covering areas from Boulder, Denver, Longmont, Fort Collins and Greeley. Enhancements in CO2, CO and destruction of ozone mainly reflect emissions from traffic. Methane enhancements however are clearly correlated with nearby point sources (landfill, feedlot, natural gas compressor ...) or with larger scale air masses advected from the NE Colorado, where oil and gas drilling operations are widespread. The multiple species analysis (hydrocarbons, CFCs, HFCs) of the air samples collected along the way bring insightful information about the methane sources at play. We will present results of the analysis and interpretation of the Hybrid Lab Front Range Study and conclude with perspectives on how we will adapt the measurement strategy to study CO2 anthropogenic emissions in Denver Basin.

Petron, G.; Hirsch, A.; Trainer, M. K.; Karion, A.; Kofler, J.; Sweeney, C.; Andrews, A.; Kolodzey, W.; Miller, B. R.; Miller, L.; Montzka, S. A.; Kitzis, D. R.; Patrick, L.; Frost, G. J.; Ryerson, T. B.; Robers, J. M.; Tans, P.

2008-12-01

177

Tracing origin and fate of dissolved greenhouse gases in Malaysian peat-draining rivers  

NASA Astrophysics Data System (ADS)

Tropical peatlands are known to store large amounts of organic carbon. Peat-draining rivers in these regions receive considerable amounts of carbon from these soils, yet, its fate remains poorly studied. Although a number of recent studies investigated greenhouse gas production and emission from inland waters, only a small number focused on tropical freshwaters, and data from tropical peat-draining rivers are particularly lacking. We investigated rivers in a peat-dominated catchment in Sarawak, Malaysia. Dissolved greenhouse gases (GHG) were measured with Fourier Transform InfraRed (FTIR) spectroscopy. It allows for the simultaneous and continuous measurement of major GHG (CO2 and ?13C in CO2, CH4, N2O, and CO) with high accuracy and precision. We found that concentrations of dissolved CO, CO2 and CH4 were higher than the respective atmospheric equilibrium concentration, suggesting that those rivers are a source of these GHG to the atmosphere. Enhanced N2O concentrations were only found around some cultivated areas. In order to trace the origin of the GHG, we quantified dissolved organic carbon (DOC), particulate organic carbon (POC), inorganic nutrients and different parameters that describe water chemistry. Stable carbon isotope analysis of dissolved inorganic carbon (DIC) yielded indications of a terrestrial source of inorganic carbon in the river, suggesting that in-situ respiration of organic matter might play an important role.

Müller, Denise; Warneke, Thorsten; Rixen, Tim; Denis, Nastassia; Müller, Moritz; Notholt, Justus

2014-05-01

178

Direct nitrous oxide emissions from agricultural fields in China estimated by the revised 1996 IPPC guidelines for national greenhouse gases  

Microsoft Academic Search

Using revised 1996 IPCC guidelines for national greenhouse gases and statistic data in China Agricultural Yearbook, we estimated the direct nitrous oxide (N2O) emissions from agricultural fields in China for the following years: 1949, 1954, 1960, 1965, 1970, 1975, 1980, 1985, 1990 and 1995. Direct N2O emissions have been increasing continuously, from 26 Gg N in 1949 to 336 Gg

G. X. Xing; X. Y. Yan

1999-01-01

179

Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change  

Microsoft Academic Search

Most prior studies have found that substituting biofuels for gasoline will reduce greenhouse gases because biofuels sequester carbon through the growth of the feedstock. These analyses have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels. By

Timothy Searchinger; Ralph Heimlich; R. A. Houghton; Fengxia Dong; Amani Elobeid; Jacinto F. Fabiosa; Simla Tokgoz; Dermot J. Hayes; Tun-Hsiang Yu

2008-01-01

180

Definition of yearly emission factor of dust and greenhouse gases through continuous measurements in swine husbandry  

NASA Astrophysics Data System (ADS)

The object of this study was to develop an accurate estimation method to evaluate the contribution of the various compartments of swine husbandry to dust and GHG (greenhouse gases, CO 2, CH 4 and N 2O) emission into the atmosphere during one year of observation. A weaning, a gestation, a farrowing and a fattening room in an intensive pig house were observed in three different periods (Autumn-Winter, Springtime and Summer, monitoring at least 60% of each period (20% at the beginning, in the middle and at the end) of each cycle). During monitoring, live weight, average live weight gain, number of animals and its variation, type of feed and feeding time were taken into account to evaluate their influence on PM 10, or the fraction of suspended particulate matter with an aerodynamic diameter less than or equal to 10 ?m [Emission Inventory Guidebook, 2007. B1100 Particle Emissions from Animal Husbandry Activities. Available from: (accessed October 2008)] and to define GHG emission. The selected piggery had a ventilation control system using a free running impeller to monitor continuously real-time environmental and management parameters with an accuracy of 5%. PM 10 concentration was monitored by a sampler (Haz Dust EPAM 5000), either continuously or through traditional gravimetric technique, and the mean value of dust amount collected on the membranes was utilized as a correction factor to be applied to continuously collected data. PM 10 concentration amount incoming from inlets was removed from PM 10 emission calculation, to estimate the real contribution of pig house dust pollution into atmosphere. Mean yearly emission factor of PM 10 was measured in 2 g d -1 LU -1 for the weaning room, 0.09 g d -1 LU -1 for the farrowing room, 2.59 g d -1 LU -1 for the fattening room and 1.23 g d -1 LU -1 for the gestation room. The highest PM 10 concentration and emission per LU was recorded in the fattening compartment while the lowest value was recorded in the farrowing room. CO 2, CH 4 and N 2O concentrations were continuously measured in the exhaust ducts using an infrared photoacoustic detector IPD (Brüel & Kjaer, Multi-gas Monitor Type 1302, Multipoint Sampler and Doser Type 1303) sampling data every 15 min, for the 60% of the cycles. Yearly emission factor for CO 2 was measured in 5997 g d -1 LU -1 for the weaning room, 1278 g d -1 LU -1 for the farrowing room, 13,636 g d -1 LU -1 for the fattening room and 8851 g d -1 LU -1 for the gestation room. Yearly emission factor for CH 4 was measured in 24.57 g d -1 LU -1 for the weaning room, 4.68 g d -1 LU -1 for the farrowing room, 189.82 g d -1 LU -1 for the fattening room and 132.12 g d -1 LU -1 for the gestation room. Yearly emission factor for N 2O was measured in 3.62 g d -1 LU -1 for the weaning room, 0.66 g d -1 LU -1 for the farrowing room, 3.26 g d -1 LU -1 for the fattening room and 2.72 g d -1 LU -1 for the gestation room.

Costa, Annamaria; Guarino, Marcella

181

Retrieval of greenhouse gases from GOSAT SWIR data processing with PPDF-based method of atmospheric light scattering correction  

NASA Astrophysics Data System (ADS)

With the launch of the Greenhouse Gases Observing Satellite (GOSAT) that is in orbit since 23rd January, 2009, one of the key issues of a large volume of near-infrared highly resolved spectra processing is the accurate and rapid determination of CO2 level. Algorithms for oper-ational satellite data processing of solar spectral observations of ground surface reflection must properly account for atmospheric light scattering. Aerosol and thin upper tropospheric clouds that affect the optical path through the atmosphere could be significant sources of error in greenhouse gas retrievals We present initial results on actual GOSAT SWIR data processing with PPDF-based method that corrects atmospheric light scattering through account for optical pathlength modification (PPDF is an abbreviation for "photon pathlength probability density function). The retrieval procedure includes constrained minimization of the residual between the modeled and observed GOSAT spectra. The constraints are mainly imposed on gas vertical profiles within the maximum a posteriori method using covariance matrices based on NIES atmo-spheric tracer transport model. The state vector includes vertical profiles of gas mixing ratios; correction factors for prior temperature and water vapor profiles; altitudes of the cirrus and aerosol layers parameters. Surface pressure is taken from climatological data set. In addition, we retrieve three polynomial coefficients for each spectral region to account for low-frequency part of the spectra and stretch factor to allow for wave number grid variations. Two spectral regions were utilized (6200 -6270 cm-1 from band 2 and 4800 -4880 cm-1 from band 3) for CO2 estimation depending on the retrieval strategy. The tapping of both regions permits si-multaneous gas and PPDF retrievals. The case of Band 2 only required independent PPDF estimations that were obtained on the base of three-dimensional aerosol transport radiation model SPRINTERS.

Oshchepkov, Sergey; Andrey, Bril; Yoshida, Yukio; Isamu, Morino; Yokota, Tatsuya

182

Have greenhouse gases intensified the contrast between wet and dry regions?  

NASA Astrophysics Data System (ADS)

While changes in land precipitation during the last 50 years have been attributed in part to human influences, results vary by season, are affected by data uncertainty and do not account for changes over ocean. One of the more physically robust responses of the water cycle to warming is the expected amplification of existing patterns of precipitation minus evaporation. Here, precipitation changes in wet and dry regions are analyzed from satellite data for 1988-2010, covering land and ocean. We derive fingerprints for the expected change from climate model simulations that separately track changes in wet and dry regions. The simulations used are driven with anthropogenic and natural forcings combined, and greenhouse gas forcing or natural forcing only. Results of detection and attribution analysis show that the fingerprint of combined external forcing is detectable in observations and that this intensification of the water cycle is partly attributable to greenhouse gas forcing.

Polson, D.; Hegerl, G. C.; Allan, R. P.; Sarojini, B. Balan

2013-09-01

183

Wood decomposition in Amazonian hydropower reservoirs: An additional source of greenhouse gases  

NASA Astrophysics Data System (ADS)

Amazonian hydroelectric reservoirs produce abundant carbon dioxide and methane from large quantities of flooded biomass that decompose anaerobically underwater. Emissions are extreme the first years after impounding and progressively decrease with time. To date, only water-to-air fluxes have been considered in these estimates. Here, we investigate in two Amazonian reservoirs (Balbina and Petit Saut) the fate of above water standing dead trees, by combining a qualitative analysis of wood state and density through time and a quantitative analysis of the biomass initially flooded. Dead wood was much more decomposed in the Balbina reservoir 23 years after flooding than in the Petit Saut reservoir 10 years after flooding. Termites apparently played a major role in wood decomposition, occurring mainly above water, and resulting in a complete conversion of this carbon biomass into CO2 and CH4 at a timescale much shorter than reservoir operation. The analysis of pre-impounding wood biomass reveals that above-water decomposition in Amazonian reservoirs is a large, previously unrecognized source of carbon emissions to the atmosphere, representing 26-45% of the total reservoir flux integrated over 100 years. Accounting for both below- and above-water fluxes, we could estimate that each km2 of Amazonian forest converted to reservoir would emit over 140 Gg CO2-eq in 100 years. Hydropower plants in the Amazon should thus generate 0.25-0.4 MW h per km2 flooded area to produce lower greenhouse gas emissions than gas power plants. They also have the disadvantage to emit most of their greenhouse gases the earliest years of operation.

Abril, Gwenaël; Parize, Marcelo; Pérez, Marcela A. P.; Filizola, Naziano

2013-07-01

184

POTENTIAL OF GREENHOUSE GASES REDUCTION BY FUEL CROP CULTIVATION UTILIZING SEWAGE SLUDGE IN JAPAN  

NASA Astrophysics Data System (ADS)

Potential of greenhouse gases (GHG) reduction was estimated and compared in six scenarios of fuel crop cultivation by utilizing sewage sludge in Japan. Bioethanol from corn and biodiesel fuel from soybean was selected as biofuel produced. When all the sludge discharged from sewage treatment plants in 18 major cities was utilized for soybean cultivation and subsequent biodiesel fuel production, produced biofuel corresponded to 4.0% of GHG emitted from sewage treatment in Japan. On the other hand, cultivation area for fuel crop cultivation was found to be the regulating factor. When fuel crop was cultivated only in abandoned agricultural fields, produced biofuel corresponded to 0.60% and 0.62%, respectively, in the case that corn and soybean was cultivated. Production of biodiesel fuel from soybean was estimated to have more net reduction potential than bioehanol production from corn when sludge production is limited, because required sewage sludge compost was 2.5-times larger in corn although reduction potential per crop area was 2-times larger in bioethanol production from corn.

Honda, Ryo; Fukushi, Kensuke

185

Greenhouse gases, radiative forcing, global warming potential and waste management--an introduction.  

PubMed

Management of post-consumer solid waste contributes to emission of greenhouse gases (GHGs) representing about 3% of global anthropogenic GHG emissions. Most GHG reporting initiatives around the world utilize two metrics proposed by the Intergovernmental Panel on Climate Change (IPCC): radiative forcing (RF) and global warming potential (GWP). This paper provides a general introduction of the factors that define a GHG and explains the scientific background for estimating RF and GWP, thereby exposing the lay reader to a brief overview of the methods for calculating the effects of GHGs on climate change. An objective of this paper is to increase awareness that the GWP of GHGs has been re-adjusted as the concentration and relative proportion of these GHGs has changed with time (e.g., the GWP of methane has changed from 21 to 25 CO(2)-eq). Improved understanding of the indirect effects of GHGs has also led to a modification in the methodology for calculating GWP. Following a presentation of theory behind GHG, RF and GWP concepts, the paper briefly describes the most important GHG sources and sinks in the context of the waste management industry. The paper serves as a primer for more detailed research publications presented in this special issue of Waste Management & Research providing a technology-based assessment of quantitative GHG emissions from different waste management technologies. PMID:19748948

Scheutz, Charlotte; Kjeldsen, Peter; Gentil, Emmanuel

2009-11-01

186

Effect of the greenhouse gases (CO2, H2O, SO2) on Martian paleoclimate  

NASA Technical Reports Server (NTRS)

There is general agreement that certain surface features on Mars are indicative of the presence of liquid water at various times in the geologic past. In particular, the valley networks are difficult to explain by a mechanism other than the flow of liquid water. It has been suggested in several studies that a thick CO2 atmosphere on Mars early in its history could have provided a greenhouse warming that would have allowed the flow of water either on the surface or just below the surface. However, this effect was examined with a detailed radiation model, and it was found that if reduced solar luminosity early in the history of the solar system is taken into account, even three bars of CO2 will not provide sufficient greeenhouse warming. The addition of water vapor and sulflur dioxide (both plausible gases that may have been emitted by Martian volcanoes) to the atmosphere also fail to warm the surface above 273 K for reduced solar luminosity conditions. The increase in temperature may be large enough, however, for the formation of these features by brines.

Postawko, S. E.; Kuhn, W. R.

1986-01-01

187

Emissions of greenhouse gases from the use of transportation fuels and electricity. Volume 1, Main text  

SciTech Connect

This report presents estimates of full fuel-cycle emissions of greenhouse gases from using transportation fuels and electricity. The data cover emissions of carbon dioxide (CO{sub 2}), methane, carbon monoxide, nitrous oxide, nitrogen oxides, and nonmethane organic compounds resulting from the end use of fuels, compression or liquefaction of gaseous transportation fuels, fuel distribution, fuel production, feedstock transport, feedstock recovery, manufacture of motor vehicles, maintenance of transportation systems, manufacture of materials used in major energy facilities, and changes in land use that result from using biomass-derived fuels. The results for electricity use are in grams of CO{sub 2}-equivalent emissions per kilowatt-hour of electricity delivered to end users and cover generating plants powered by coal, oil, natural gas, methanol, biomass, and nuclear energy. The transportation analysis compares CO{sub 2}-equivalent emissions, in grams per mile, from base-case gasoline and diesel fuel cycles with emissions from these alternative- fuel cycles: methanol from coal, natural gas, or wood; compressed or liquefied natural gas; synthetic natural gas from wood; ethanol from corn or wood; liquefied petroleum gas from oil or natural gas; hydrogen from nuclear or solar power; electricity from coal, uranium, oil, natural gas, biomass, or solar energy, used in battery-powered electric vehicles; and hydrogen and methanol used in fuel-cell vehicles.

DeLuchi, M.A. [California Univ., Davis, CA (United States)

1991-11-01

188

Emissions of greenhouse gases from the use of transportation fuels and electricity  

SciTech Connect

This report presents estimates of full fuel-cycle emissions of greenhouse gases from using transportation fuels and electricity. The data cover emissions of carbon dioxide (CO{sub 2}), methane, carbon monoxide, nitrous oxide, nitrogen oxides, and nonmethane organic compounds resulting from the end use of fuels, compression or liquefaction of gaseous transportation fuels, fuel distribution, fuel production, feedstock transport, feedstock recovery, manufacture of motor vehicles, maintenance of transportation systems, manufacture of materials used in major energy facilities, and changes in land use that result from using biomass-derived fuels. The results for electricity use are in grams of CO{sub 2}-equivalent emissions per kilowatt-hour of electricity delivered to end users and cover generating plants powered by coal, oil, natural gas, methanol, biomass, and nuclear energy. The transportation analysis compares CO{sub 2}-equivalent emissions, in grams per mile, from base-case gasoline and diesel fuel cycles with emissions from these alternative- fuel cycles: methanol from coal, natural gas, or wood; compressed or liquefied natural gas; synthetic natural gas from wood; ethanol from corn or wood; liquefied petroleum gas from oil or natural gas; hydrogen from nuclear or solar power; electricity from coal, uranium, oil, natural gas, biomass, or solar energy, used in battery-powered electric vehicles; and hydrogen and methanol used in fuel-cell vehicles.

DeLuchi, M.A. (California Univ., Davis, CA (United States))

1991-11-01

189

Simulations of greenhouse trace gases using the Los Alamos chemical tracer model  

SciTech Connect

Through three-dimensional global model studies on atmospheric composition and transport, we are improving our quantitative understanding of the origins and behavior of trace gases that affect Earth`s radiative energy balance and climate. We will focus, in this paper, on the simulations of three individual trace gases including CFC-11, methyl chloroform, and methane. We first used our chemical tracer model to study the global distribution and trend of chemically inert CFC-11 observed by the Atmospheric Lifetime Experiment. The results show that the model has the ability to reproduce the time-series of the observations. The purpose of this CFC-11 simulation was to test the transport of the model. We then used to model introduce methyl chloroform into the atmosphere according to the known emission patterns and iteratively varied OH fields so that the observed concentrations of methyl chloroform from the observations could be simulated well. The rationale behind this approach is that the reaction with OH is the dominant sink for metyl chloroform and the transport of the model has been tested in the previous CFC-11 study. Finally, using the inferred OH distributions, we conducted a steady-state simulation to reproduce the current methane distribution. The general agreement between the modeled an observed methane surface concentrations has laid a foundation for the simulation of the transient increase of methane.

Kao, C.Y.J.; Morz, E. [Los Alamos National Lab., NM (United States); Tie, X. [Scripps Institution of Oceanography, San Diego, CA (United States)

1991-11-01

190

Simulations of greenhouse trace gases using the Los Alamos chemical tracer model  

SciTech Connect

Through three-dimensional global model studies on atmospheric composition and transport, we are improving our quantitative understanding of the origins and behavior of trace gases that affect Earth's radiative energy balance and climate. We will focus, in this paper, on the simulations of three individual trace gases including CFC-11, methyl chloroform, and methane. We first used our chemical tracer model to study the global distribution and trend of chemically inert CFC-11 observed by the Atmospheric Lifetime Experiment. The results show that the model has the ability to reproduce the time-series of the observations. The purpose of this CFC-11 simulation was to test the transport of the model. We then used to model introduce methyl chloroform into the atmosphere according to the known emission patterns and iteratively varied OH fields so that the observed concentrations of methyl chloroform from the observations could be simulated well. The rationale behind this approach is that the reaction with OH is the dominant sink for metyl chloroform and the transport of the model has been tested in the previous CFC-11 study. Finally, using the inferred OH distributions, we conducted a steady-state simulation to reproduce the current methane distribution. The general agreement between the modeled an observed methane surface concentrations has laid a foundation for the simulation of the transient increase of methane.

Kao, C.Y.J.; Morz, E. (Los Alamos National Lab., NM (United States)); Tie, X. (Scripps Institution of Oceanography, San Diego, CA (United States))

1991-11-01

191

The relationship between air surface temperature and greenhouse gases in Peninsular Malaysia during 2003–2008 retrieved from AIRS data  

Microsoft Academic Search

The damage resulting from global warming was faster than any experts have predicted or anticipated. Global mean temperature has increased by 0.3-0.6 C during the past 100 years, and warming has been accelerating at a rate of 0.15 since the mid-1970s. The result of an increase of temperature is the greenhouse gases (GHGs). Results from the analysis of the retrieved

Jasim Mohammed Rajab; M. Z. MatJafri; H. S. Lim; K. Abdullah; Faez M. Hassan

2011-01-01

192

Evaluating Changes in Organic C and Emission of Greenhouse Gases in a California Agricultural Landscape.  

NASA Astrophysics Data System (ADS)

A major question in CA agriculture is how much C may be sequestered in soil of irrigated, minimum tillage systems. Our main research goals are to identify and quantify the underlying mechanisms and processes controlling the rate of CO2 and other greenhouse gas emissions versus soil C stabilization as affected by tillage operations. A landscape research approach is used to increase our mechanistic understanding of the biotic and abiotic processes that govern C dynamics under standard and minimum tillage practices. We have selected an irrigated, laser leveled agricultural site in the CA Central Valley for this study. The 70-acre site, located approximately 10 miles northwest of Davis, has been split into two fields. Beginning in the fall of 2003, one field has been managed under standard tillage (ST) and the other under minimum tillage (MT). Each field is instrumented with 1) an eddy-covariance mast to measure field-scale CO2 fluxes, 2) with a 0.62-m2 automated chamber to assess the temporal pattern of CO2 and N2O fluxes, 3) with 36 506-cm2 portable PVC chambers to evaluate the spatial characteristics of CO2, N2O and NO fluxes, 4) with 4 subsurface soil gas probes to measure CO2 and N2O concentrations with depth and 5) with multiple piezometers and tensiometers to monitor the movement of soil water throughout the growing season. Round-up Ready corn was planted in both fields in April 2004. Results from this growing season indicate that the various methods of CO2 measurement compare well with one another. There was no notable difference in soil CO2 flux between tillage treatments, but the eddy-covariance towers measured differences in net CO2 flux between treatments based on differential crop growth patterns. The MT treatment had slightly higher N2O emissions than ST, but N2O and NO emissions were primarily restricted to areas and time periods of fertilizer application. Preliminary results from the 2005 growing season (sunflower crop) indicate similar results. MT corn yield was 73% of that in the ST treatment. Patterns of soil texture, ground water movement, and treatment effects are being explored to help explain the yield gap and other spatial patterns in the data. Upcoming years of the project include continued monitoring of greenhouse gases and soil C dynamics in the two tillage systems, comparison of field data with DNDC and Daycent models, and economic evaluation of the two systems. These results will help provide a realistic assessment of the role CA agriculture can play in C sequestration when land is converted from standard to minimum tillage.

Rolston, D. E.; Hopmans, J. W.; van Kessel, C.; Six, J.; Paw U, K.; Plant, R. E.; Hsiao, T. C.; Poch, R. M.; Shaver, G.; Ideris, A. J.; Lee, J.; Louie, D. T.; MacIntyre, J. L.; Matista, T. A.; Evatt, K. J.; King, A. P.

2005-12-01

193

Geologic Storage of Greenhouse Gases: Multiphase andNon-isothermal Effects, and Implications for Leakage Behavior  

SciTech Connect

Storage of greenhouse gases, primarily CO2, in geologic formations has been proposed as a means by which atmospheric emissions of such gases may be reduced (Bachu et al., 1994; Orr, 2004). Possible storage reservoirs currently under consideration include saline aquifers, depleted or depleting oil and gas fields, and unmineable coal seams (Baines and Worden, 2004). The amount of CO2 emitted from fossil-fueled power plants is very large, of the order of 30,000 tons per day (10 million tons per year) for a large 1,000 MW coal-fired plant (Hitchon,1996). In order to make a significant impact on reducing emissions, very large amounts of CO2 would have to be injected into subsurface formations, resulting in CO2 disposal plumes with an areal extent of order 100 km2 or more (Pruess et al., 2003). It appears inevitable, then, that such plumes will encounter imperfections in caprocks, such as fracture zones or faults, that would allow CO2 to leak from the primary storage reservoir. At typical subsurface conditions of temperature and pressure, CO2 is always less dense than aqueous fluids; thus buoyancy forces will tend to drive CO2 upward, towards the land surface, whenever adequate (sub-)vertical permeability is available. Upward migration of CO2 could also occur along wells, including pre-existing wells in sedimentary basins where oil and gas exploration and production may have been conducted (Celia et al., 2004), or along wells drilled as part of a CO2 storage operation. Concerns with leakage of CO2 from a geologic storage reservoir include (1) keeping the CO2 contained and out of the atmosphere, (2) avoiding CO2 entering groundwater aquifers, (3)asphyxiation hazard if CO2 is released at the land surface, and (4) the possibility of a self-enhancing runaway discharge, that may culminate in a ''pneumatic eruption'' (Giggenbach et al., 1991). The manner in which CO2 may leak from storage reservoirs must be understood in order to avoid hazards and design monitoring systems.

Pruess, Karsten

2005-08-05

194

Emissions of ammonia and greenhouse gases during combined pre-composting and vermicomposting of duck manure.  

PubMed

Combined pre-composting and vermicomposting has shown potential for reclamation of solid wastes, which is a significant source of ammonia (NH3), and greenhouse gases (GHG), including nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2). Earthworms and amendments may both affect physico-chemical characteristics that control gas-producing processes, and thus affect NH3 and GHG emissions. Here, we used two-way ANOVA to test the effects of addition of reed straw and combined addition of reed straw and zeolite on NH3 and GHG emissions during pre-composting of duck manure, either with or without a follow-up phase of vermicomposting. Results showed that cumulative N2O, CH4, and CO2 emissions during pre-composting and vermicomposting ranged from 92.8, 5.8, and 260.6 mg kg(-)(1) DM to 274.2, 30.4, and 314.0 mg kg(-1) DM, respectively. Earthworms and amendments significantly decreased N2O and CH4 emissions. Emission of CO2 was not affected by earthworms, but increased in responses to addition of reed straw. Cumulative NH3 emission ranged from 3.0 to 8.1 g kg(-1) DM, and was significantly decreased by reed straw and zeolite addition. In conclusion, combined pre-composting and vermicomposting with reed straw and zeolite addition would be strongly recommended in mitigating emissions of N2O, CH4, and NH3 from duck manure. Moreover, this method also provides nutrient-rich products that can be used as a fertilizer. PMID:24835490

Wang, Jinzhi; Hu, Zhengyi; Xu, Xingkai; Jiang, Xia; Zheng, Binghui; Liu, Xiaoning; Pan, Xubin; Kardol, Paul

2014-08-01

195

Climatic consequences of observed ozone loss in the 1980s: Relevance to the greenhouse problem  

NASA Technical Reports Server (NTRS)

Recently published findings using satellite and ground-based observations indicate a large winter and summertime decrease in the column abundance of ozone at high and middle latitudes during the last decade. Using a simple ozone depletion profile reflecting the observed decrease in ozone column abundance, Ramaswamy et al. (1992) showed that the negative radiative forcing that results from the ozone decrease between 1979 and 1990 approximately balanced the greenhouse climate forcing due to the chlorofluorocarbons emitted during the same period. Here, we extend the forcing analyses by calculating the equilibrium surface temperature response explicitly, using an updated version of the Atmospheric and Environmental Research two-dimensional radiative-dynamical seasonal model. The calculated steady state responses suggest that the surface cooling due to the ozone depletion in the lower stratosphere offsets about 30% of the surface warming due to greenhouse gases emitted during the same decade. The temperature offset is roughly a factor of 2 larger than the corresponding offset obtained from forcing intercomparisons. This result appears to be related to the climate feedback mechanisms operating in the model troposphere, most notably that associated with atmospheric meridional heat transport. Thus a comprehensive assessment of ozone change effects on the predicted greenhouse warming cannot be accomplished based on forcing evaluations alone. Our results also show that calculations adopting a seasonally and latitudinally dependent ozone depletion profile produce a negative forcing about 50% smaller than that calculated for the depletion profile used by Ramaswamy et al. (1992).

Molnar, G. I.; Ko, M. K. W.; Zhou, S.; Sze, N. D.

1994-01-01

196

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 94, NO. D13, PAGES 16,417-16,421,NOVEMBER 20, 1989 Greenhouse Effect of Chlorofluorocarbons and Other Trace Gases  

E-print Network

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 94, NO. D13, PAGES 16,417-16,421,NOVEMBER 20, 1989 Greenhouse Effect of Chlorofluorocarbons and Other Trace Gases JAMESHANSEN,ANDREW LACIS,AND MICHAEL PRATHER NASA GoddardSpaceFlightCenter,Institutefor SpaceStudies,New York We comparetheradiative(greenhouse

Fridlind, Ann

197

Ionic composition and greenhouse gases evaluation in Tietê River sediment and mud landfill  

NASA Astrophysics Data System (ADS)

There are 39 cities composing the Metropolitan Area of São Paulo (MASP) which has grown seven times during the last sixty years, reaching, in 2011, 19.3 million inhabitants. This fact associated with a strong industrial development provoked, among other consequences, a disordered urbanization along the most important river of the region: Tietê. About 100 Km of its 1,150 Km full extension crosses MASP and, during the 60's, Marginal Tietê roadway was constructed, occupying the river banks as access routes. Tietê River was straightened and several landfills were created with its deposit (sediment and mud). EACH-USP (46.50 W, 23.48 S) lies nowadays in one of these areas, where this work has been developed. Therefore, the goal is to evaluate the chemical composition (ionic and gases) and its variability in function of the depth levels using three wells, from 0.60 to 9.0 m of depth. The wells were perforated in September 2011, end of the dry weather. Each well owns a homemade multiport sampling device (HMSD), being possible to push gas and/or water up from 15 available ports. The gases measurements were carried out using a GEM-2000 plus (Landtec) portable analyzer. Aqueous samples containing solid material were taken at each level depth from ports of the HMSD. However, no water was found in some levels. All samples were kept cooled until analysis procedures. After decantation of the solid material, the supernatant liquid was divided in two portions, being its conductivity (Micronal conductimeter) and pH (pH-meter Metrohm 654 with combined glass electrode) measured with the former and ionic analysis with the latter, in which all samples were filtered (Millex 0.22 micrometer pores) before each ionic chromatographic analysis, using Metrohm 850 System, for the ions: sodium, ammonium, potassium, calcium, magnesium, chloride, nitrate and sulfate. The first sampling stage was carried out during November and December 2011 in the beginning of rainy season in the mid Spring. From all the analysis performed, a large variability of the results may be observed for both gases and ionic composition not only among the wells, but also among the different depth levels. Vertically, one of the wells (W2) showed the same percentage of gases, methane 55% and carbon dioxide 45%, at all depth levels, while the other two wells (W1 and W3) presented these gases percentages only under 5.0 m deep. Concerning oxygen, 25% of this gas was detected at 1.0 m under the surface in W1 and W3. In relation to aqueous samples, the most acidity was observed near the surface (0.60 m deep, W1), pH 4.65, while pH 7.88 was obtained under 5.0 m deep (W3). For ionic concentrations a large range was observed considering all wells, being the lowest values for sulfate, from 0.60 to 20 mg/l, and the highest values for ammonium, between 14 and 53 mg/l. These results variability can be associated to the different soil composition layers, as well as to the biodegradation process and the time confinement of the river material deposit.

La-Scalea, M. A.; Fornaro, A.; Abreu, E. L.; Mendonça, C. A.

2012-04-01

198

A Next-Generation Space Geodetic Technique: Profiling of Greenhouse Gases and Climate by Microwave and Infrared-Laser Occultation  

NASA Astrophysics Data System (ADS)

Since the pioneering GNSS radio occultation (GRO) mission GPS/Met in the mid-1990ties, and fostered by many missions since then such as CHAMP, Formosat-3/COSMIC and others, the GRO method was firmly established as a leading space geodetic technique. GRO provides vital contributions to meteorology and climate applications, like numerical weather prediction and climate change monitoring, and a range of those are covered in this session. Building on this success, further advanced techniques for future missions and science applications emerge beyond GRO. In particular, next-generation occultation between Low Earth Orbit satellites (LEO-LEO) uses GNSS-type coherent signals beyond the GRO decimeter waves at centimeter, millimeter, and micrometer wavelengths. This new technique, termed LEO-LEO microwave and infrared-laser occultation (LMIO), enables to vastly expand from the GRO refractivity-based sounding of the thermodynamic structure to a complete set of weather and climate variables, including thermodynamic ones (pressure, temperature, water vapor), greenhouse gases, wind speed, and others (Kirchengast and Schweitzer, GRL, 38, L13701, 2011; www.agu.org/pubs/crossref/2011/2011GL047617.shtml). LMIO combines microwave occultation signals at cm and mm wavelengths (within 8-25 GHz and 175-200 GHz) for thermodynamic state profiling with infrared-laser occultation signals within 2 to 2.5 ?m for greenhouse gas and line-of-sight wind profiling; greenhouse gases include water vapor (H2O), the three key long-lived ones (CO2, CH4, N2O) and others. We present the fundamentals and discuss the estimated performance of LMIO-based thermodynamic state and greenhouse gas profiling, including from quasi-realistic end-to-end performance simulations considering also clouds and aerosols. To indicate the performance, we found monthly-mean temperature and greenhouse gas profiles, assuming 30 to 40 native profiles averaged per climatological "grid cell" per month, accurate to

Kirchengast, G.; Schweitzer, S.; Proschek, V.

2012-04-01

199

The effect of water oxygen content on the production of greenhouse gases from shallow pond sediments  

NASA Astrophysics Data System (ADS)

Shallow lakes and ponds, including those commonly found in agricultural landscapes are often only a few metres deep, with surface areas <1ha. Despite this, landscapes may contain a high number of these ponds, amounting to a considerable cumulative surface area. Many of these features, both naturally formed and man-made, receive and trap runoff with high nutrient and sediment loadings. As such, the potential for the production of greenhouse gases (GHGs) through biogeochemical cycling in the pond sediments may be significant. Furthermore, the abundance of available nutrients coupled with the shallow physical characteristics of these systems, mean that short, irregular eutrophic episodes during the summer are common, causing large fluctuations in the oxygen content of the overlying water column. The oxygen content of the water column is often cited as key factor in the production of GHGs in large lake and reservoir systems. Given the limited research focusing on shallow ponds/lakes, and potential for these systems to be important sources of GHGs, the impacts of variable water oxygen content should be investigated. Here we present the results from a sediment microcosm experiment utilising sediment cores from an agricultural pond system in Cumbria, UK. Intact sediment cores were incubated in the dark at in-situ temperature and continuously fed with filtered pond water for 2 weeks. During this time the oxygen content of the water was manipulated between fully oxygenated and anaerobic. Measurements of GHG release were based on calculated dissolved gas concentrations present in the water columns of these cores. Results indicated that during times of water column anoxia, production of methane and carbon dioxide increased significantly, despite the presence of substantial quantities of nitrate in the water columns. No change in N2O production was detected. These results indicate that while representing a significant cumulative carbon store in agricultural landscapes, shallow pond and lake systems can contribute to emission of GHGs. Furthermore, the physical and ecological characteristics of these systems have the potential to significantly increase the quantity of gas produced. This understanding will be valuable when constraining both freshwater and agricultural GHG budgets.

Freer, Adam; Quinton, John; Surridge, Ben; McNamara, Niall

2014-05-01

200

Understanding the Greenhouse Effect Using Clear vs Cloudy Sky Diurnal Temperature Observations  

Microsoft Academic Search

Standard meteorological observations from local airports can provide a tangible example of how the greenhouse effect is a part of everyday life. In the exercise outlined here, students plot diurnal temperature observations to compare the relative magnitude of the greenhouse effect under clear and cloudy-sky conditions, gaining insight into the strength of the greenhouse effect. Contemplation of the relation of

S. V. Tayor

2006-01-01

201

Optimization Model for Reducing Emissions of Greenhouse Gases from Automobiles (OMEGA)  

EPA Science Inventory

The EPA Vehicle Greenhouse Gas (VGHG) model is used to apply various technologies to a defined set of vehicles in order to meet a specified GHG emission target, and to then calculate the costs and benefits of doing so....

202

Assessing Greenhouse Gas emissions in the Greater Toronto Area using atmospheric observations (Invited)  

NASA Astrophysics Data System (ADS)

Urban areas are said to be responsible for approximately 75% of anthropogenic Greenhouse Gases (GHGs) emissions while comprising only two percent of the land area [1]. This limited spatial expansion should facilitate a monitoring of anthropogenic GHGs from atmospheric observations. As major sources of emissions, cities also have a huge potential to drive emissions reductions. To effectively manage emissions, cities must however, first measure and report these publicly [2]. Modelling studies and measurements of CO2 from fossil fuel burning (FFCO2) in densely populated areas does, however, pose several challenges: Besides continuous in-situ observations, i.e. finding an adequate atmospheric transport model, a sufficiently fine-grained FFCO2 emission model and the proper background reference observations to distinguish the large-scale from the local/urban contributions to the observed FFCO2 concentration offsets ( ?FFCO2) are required. Pilot studies which include the data from two 'sister sites*' in the vicinity of Toronto, Canada helped to derive flux estimates for Non-CO2 GHGs [3] and improve our understanding of urban FFCO2 emissions. Our 13CO2 observations reveal that the contribution of natural gas burning (mostly due to domestic heating) account for 80%×7% of FFCO2 emissions in the Greater Toronto Area (GTA) during winter. Our 14CO2 observations in the GTA, furthermore, show that the local offset of CO2 (?CO2) between our two sister sites can be largely attributed to urban FFCO2 emissions. The seasonal cycle of the observed ?FFCO2 in Toronto, combined with high-resolution atmospheric modeling, helps to independently assess the contribution from different emission sectors (transportation, primary energy and industry, domestic heating) as predicted by a dedicated city-scale emission inventory, which deviates from a UNFCCC-based inventory. [1] D. Dodman. 2009. Blaming cities for climate change? An analysis of urban greenhouse gas emissions inventories. Environment and Urbanization, 21,185. [2] Arikan Y., Desaim R., Bhatia P. and W. K. Fong, 2012 Global Protocol for Community-Scale Greenhouse Gas Emissions (GPC), C40 Cities Climate Leadership group, available at: http://www.c40.org [3] Vogel, F. R., Ishizawa, M., Chan, E., Chan, D., Hammer, S., Levin, I., & Worthy, D. E. J. (2012). Regional non-CO2 greenhouse gas fluxes inferred from atmospheric measurements in Ontario, Canada. Journal of Integrative Environmental Sciences, 9(1), 41-55. *The term 'sister sites' refers to sites that share a common background signal (i.e. common large scale influence), while significantly differing sensitivities to urban GHG emissions. In our case: Egbert, Ontario and Downsview, Toronto, Ontario.

Vogel, F. R.; Chan, E.; Huang, L.; Levin, I.; Worthy, D.

2013-12-01

203

Greenhouse gases in the South Atlantic Ocean: recent trends and anomalies from continuous island and shipboard measurements  

NASA Astrophysics Data System (ADS)

In-situ observation of tropical and southern Atlantic greenhouse gases is still limited. Continuous high-precision greenhouse gas measurement by CRDS in the South Atlantic started in 2010 on Ascension Is. (8° S) and near Stanley on East Falkland Is. (52° S), and in 2012 on the British Antarctic Survey ship RRS James Clark Ross, which sails annually from the UK to Antarctica and back. Both the Ascension and Falklands records show sustained inter-annual growth in both CO2 and CH4. NOAA data from a small number of stations indicate that Southern Tropical Methane has been increasing since 2007 but that growth is now slowing. This is confirmed by our new data. Strong CH4 growth of 11 ppb was observed on Ascension between July 2010 and July 2011 (winter to winter), of 7 ppb/yr from Jan 2011 to Jan 2012 (summer-to-summer) and decreased further to 4 ppb from July 2011 to July 2012. This compares with a fairly constant growth of 4-5 ppb/yr for the Falklands site. Isotopic evidence for the causes of the 2010-11 southern hemisphere sub-tropical methane anomaly is inconclusive. A slight depletion in 13C on Ascension during the period of growth might indicate that wetland emissions are the dominant cause of the anomaly, fitting with much higher than average sub-tropical rainfall during recent years, but a much longer data set is required to isolate the anomaly from the long-term trend. On 23 April 2011, Ascension experienced a 20-year event when the ITCZ moved far south of its normal position. In very clean marine air, in the space of 3 minutes the methane jumped from a normal autumn southern hemisphere level of 1763 ppb to 1795 ppb, closer to the concentrations of northern hemisphere spring, settling near to 1800 ppb for six hours, after which it rapidly fell back to 1760 ppb. Simultaneously CO2 rose from 389 to about 392 ppm, then to 396 ppm before falling back to 388 ppm. During this period there was very heavy rainfall, with nearly 300 mm on the slopes of Green Mountain and more than 200 mm in surrounding desert areas. The 35 ppb magnitude of this methane switch compares with a magnitude of 55 ppb (1825 to 1770 ppb) observed by continuous measurement on-board the James Clark Ross when crossing the ITCZ from 8° N to 8° S in October 2010. In this event, high altitude Northern hemisphere air was moving SE over NW moving trade winds until the storm brought high level air to ground level. The observations highlight the usefulness of continuous measurement at such a site and demonstrate that the meteorological boundary between the hemispheres can on occasion be very sharp.

Lowry, David; Fisher, Rebecca; Lanoisellé, Mathias; France, James; Nisbet, Euan

2013-04-01

204

The early faint sun paradox: Organic shielding of ultraviolet-labile greenhouse gases  

Microsoft Academic Search

Atmospheric mixing ratios of â¼10{sup -5 {+-}1} for ammonia on the early Earth would have been sufficient, through the resulting greenhouse warming, to counteract the temperature effects of the faint early sun. One argument against such model atmospheres has been the short time scale for ammonia photodissociation by solar ultraviolet light. Here it is shown that ultraviolet absorption by steady-state

C. Sagan; C. Chyba

1997-01-01

205

Life-cycle analysis of dryland greenhouse gases affected by cropping sequence and nitrogen fertilization  

Technology Transfer Automated Retrieval System (TEKTRAN)

Little information is available about management practices effect on net global warming potential (GWP) and greenhouse gas intensity (GHGI) under dryland cropping systems. We evaluated the effects of cropping sequences (conventional till malt barley-fallow [CTB-F], no-till malt barley-pea [NTB-P], a...

206

Contributions of solar and greenhouse gases forcing during the present warm period  

NASA Astrophysics Data System (ADS)

Due to the dramatic increase in the global mean surface temperature (GMST) during the twentieth century, the climate science community has endeavored to determine which mechanisms are responsible for global warming. By analyzing a millennium simulation (the period of 1000-1990 ad) of a global climate model and global climate proxy network dataset, we estimate the contribution of solar and greenhouse gas forcings on the increase in GMST during the present warm period (1891-1990 ad). Linear regression analysis reveals that both solar and greenhouse gas forcing considerably explain the increase in global mean temperature during the present warm period, respectively, in the global climate model. Using the global climate proxy network dataset, on the other hand, statistical approach suggests that the contribution of greenhouse gas forcing is slightly larger than that of solar forcing to the increase in global mean temperature during the present warm period. Overall, our result indicates that the solar forcing as well as the anthropogenic greenhouse gas forcing plays an important role to increase the global mean temperature during the present warm period.

Lim, Hyung-Gyu; Yeh, Sang-Wook; Kim, Ji-Won; Park, Rokjin; Song, Chang-Keun

2014-10-01

207

Halogenated greenhouse gases at the Swiss High Alpine Site of Jungfraujoch (3580 m asl): Continuous measurements and their use for regional European source allocation  

Microsoft Academic Search

At the high Alpine site of Jungfraujoch (3580 m asl), 23 halogenated greenhouse gases are measured quasi-continuously by gas chromatography-mass spectrometry (GCMS). Measurement data from the years 2000-2002 are analyzed for trends and pollution events. Concentrations of the halogenated trace gases, which are already controlled in industrialized countries by the Montreal Protocol (e.g., CFCs) were at least stable or declining.

Stefan Reimann; Daniel Schaub; Konrad Stemmler; Doris Folini; Matthias Hill; Peter Hofer; Brigitte Buchmann; Peter G. Simmonds; Brian R. Greally; Simon O'Doherty

2004-01-01

208

Halogenated greenhouse gases at the Swiss High Alpine Site of Jungfraujoch (3580 m asl): Continuous measurements and their use for regional European source allocation  

Microsoft Academic Search

At the high Alpine site of Jungfraujoch (3580 m asl), 23 halogenated greenhouse gases are measured quasi-continuously by gas chromatography-mass spectrometry (GCMS). Measurement data from the years 2000–2002 are analyzed for trends and pollution events. Concentrations of the halogenated trace gases, which are already controlled in industrialized countries by the Montreal Protocol (e.g., CFCs) were at least stable or declining.

Stefan Reimann; Daniel Schaub; Konrad Stemmler; Doris Folini; Matthias Hill; Peter Hofer; Brigitte Buchmann; Peter G. Simmonds; Brian R. Greally; Simon O'Doherty

2004-01-01

209

GREENHOUSE GASES FROM BIOMASS AND FOSSIL FUEL STOVES IN DEVELOPING COUNTRIES: A MANILA PILOT STUDY  

EPA Science Inventory

Samples were taken of the combustion gases released by household cookstoves in Manila, Philippines. In a total of 24 samples, 14 cookstoves were tested. These were fueled by liquefied petroleum gas (LPG), kerosene (three kinds of stoves), charcoal, and wood. Ambient samples were ...

210

Greenhouse gases from biomass and fossil fuel stoves in developing countries: A Manila pilot study  

Microsoft Academic Search

Samples were taken of the combustion gases released by household cookstoves in Manila, Philippines. In a total of 24 samples, 14 cookstoves were tested. These were fueled by liquefied petroleum gas (LPG), kerosene (three kinds of stoves), charcoal, and wood. Ambient samples were also taken. All samples were analyzed for CO 2, CO, CH 4, NzO, and total non-methane organic

K. R. Smith; M. A. K. KhaliP; R. A. Rasmussen; S. A. Thorneloe; F. Manegdeg; M. Apte

1993-01-01

211

GREENHOUSE GASES FROM SMALL-SCALE COMBUSTION IN DEVELOPING COUNTRIES -- A PILOT STUDY IN MANILA  

EPA Science Inventory

The report gives results of sampling of combustion gases released by household cookstoves in Manila, Philippines. n a total of 24 samples, 14 cookstoves were tested, fueled by liquefied petroleum gas (LPG), kerosene (three kinds of stoves), charcoal, and wood. Five ambient sample...

212

Air-water greenhouse gases exchange in two coastal systems in Cadiz Bay (SW Spain)  

NASA Astrophysics Data System (ADS)

Coastal areas are subject to a great anthropogenic pressure because more than half of the world's population lives in its vicinity, causing organic matter inputs, which intensifies greenhouse gas emissions into the atmosphere. Water surface greenhouse gas concentrations (CH4 and N2O) have been estimated in two aquatic systems of Cadiz Bay Natural Park: Rio San Pedro Creek and Sancti Petri Channel Water renewal in Rio San Pedro Creek is tidally controlled. Due to its little freshwater input, the Creek is essentially a marine system. Several fish farms are distributed on its banks discharging effluents without previous treatment. Nine sampling stations are distributed along this system 12 Km length. Sancti Petri Channel is a flow channel-ebb tides extending from the inner Cadiz Bay to the Atlantic Ocean along 17 Km. Organic matter pollution sources in this environment are straggly. There exist anthropogenic inputs such as aquaculture effluents and sewage discharges coming through the Iro River, which flows into the Channel central part. In addition there are natural organic matter inputs from surrounding marshes. It has been established 11 sampling stations crossing this system. Sampling was conducted seasonally during 2013. CH4 and N2O concentrations were obtained though a gas chromatograph connected to an equilibration system. Greenhouse gas values vary between 24 and 295 nM and 16 and 27 nM for CH4 and N2O, respectively. Gas concentrations increase close to the fish farm effluent in Rio San Pedro Creek, and next to Iro River's mouth in Sancti Petri tidal Channel. Both environments act as greenhouse gas sources into the atmosphere, showing seasonal variations. It has been estimated mean fluxes of 75.3 ?mol m-2 d-1 of CH4 and 31.9 ?mol m-2 d-1 of N2O for both systems.

Burgos, Macarena; Ortega, Teodora; Forja, Jesús

2014-05-01

213

Changes of Pacific decadal variability in the twentieth century driven by internal variability, greenhouse gases, and aerosols  

NASA Astrophysics Data System (ADS)

paper explores the contributions of internal variability, greenhouse gases (GHGs), and anthropogenic aerosols (AAs) in driving the magnitude and evolution of Pacific Decadal Variability (PDV) during the twentieth century by analyzing 129 Coupled Model Intercomparison Project Phase 5 model realizations. Evidence shows that PDV phase transition is dominated by internal variability, but it is also significantly affected by external forcing agents such as GHGs and aerosols. The combined effects of GHGs and AAs favor the positive phase of PDV with stronger ocean warming in the tropics than the extratropical Pacific. The GHG forcing induces the increased surface downward longwave radiation, especially over the tropical Pacific, and results in stronger warming in that area. The AA forcing results in a stronger cooling in the North Pacific region, due to the reduced surface downward shortwave radiation via cloud-aerosol interaction: this offsets the substantial warming caused by GHG forcing.

Dong, Lu; Zhou, Tianjun; Chen, Xiaolong

2014-12-01

214

Ecological effects of overshooting stabilization targets for greenhouse gases for California plant species  

NASA Astrophysics Data System (ADS)

Stabilization of global greenhouse gas (GHG) concentrations at or below 350 ppm may be required to avoid catastrophic changes to the climate system. Although the level of stabilization is a primary concern, the pathway to reaching the target should also be considered as some pathways in reaching these goals could have more "dangerous impacts" than others. Since atmospheric GHG stands at 385pppm, achieving a 350ppm target will require overshoot - an exceedance of the target for several decades, followed by a gradual decline back to target levels. The UN Framework Convention on Climate Change aims to stabilize greenhouse gas concentrations to avoid dangerous interference with the climate. The EU has set a goal of 2 C warming. However the current trajectory of greenhouse gas emissions and associated temperature change suggest we are in danger of exceeding these goals and are committed to a certain degree of warming. Ecosystems are one benchmark of acceptable change in international policy, so are a relevant test of the value of low stabilization targets. The biological consequences of overshoot are unknown. Here we simulate the ecological effects of an overshoot strategy for the first time, for a series of California plants. We find that the portion of the species' range defined by the bioclimatic envelope is an important factor in determining the effects of an overshoot scenario and varies between species.

Ries, L. P.; Hannah, L.; Thorne, J.; Seo, C.

2008-12-01

215

Radiative forcing by well-mixed greenhouse gases: Estimates from climate models in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4)  

Microsoft Academic Search

The radiative effects from increased concentrations of well-mixed greenhouse gases (WMGHGs) represent the most significant and best understood anthropogenic forcing of the climate system. The most comprehensive tools for simulating past and future climates influenced by WMGHGs are fully coupled atmosphere-ocean general circulation models (AOGCMs). Because of the importance of WMGHGs as forcing agents it is essential that AOGCMs compute

W. D. Collins; V. Ramaswamy; M. D. Schwarzkopf; Y. Sun; R. W. Portmann; Q. Fu; S. E. B. Casanova; J.-L. Dufresne; D. W. Fillmore; P. M. D. Forster; V. Y. Galin; L. K. Gohar; W. J. Ingram; D. P. Kratz; M.-P. Lefebvre; J. Li; P. Marquet; V. Oinas; Y. Tsushima; T. Uchiyama; W. Y. Zhong

2006-01-01

216

Atmospheric science is a fascinating area of study. From sunny spells and scattered showers, to climate change and greenhouse gases, a wide range of meteorological  

E-print Network

, to climate change and greenhouse gases, a wide range of meteorological and climate topics are examined during the M.Sc. course in Meteorology. Students get scientific training in theoretical and applied meteorology and learn about the geomagnetic and seismological work in addition to the meteorological programme

217

The early faint sun paradox: organic shielding of ultraviolet-labile greenhouse gases  

NASA Technical Reports Server (NTRS)

Atmospheric mixing ratios of approximately 10(-5 +/- 1) for ammonia on the early Earth would have been sufficient, through the resulting greenhouse warming, to counteract the temperature effects of the faint early sun. One argument against such model atmospheres has been the short time scale for ammonia photodissociation by solar ultraviolet light. Here it is shown that ultraviolet absorption by steady-state amounts of high-altitude organic solids produced from methane photolysis may have shielded ammonia sufficiently that ammonia resupply rates were able to maintain surface temperatures above freezing.

Sagan, C.; Chyba, C.

1997-01-01

218

Designing optimal greenhouse gas observing networks that consider performance and cost  

NASA Astrophysics Data System (ADS)

Emission rates of greenhouse gases (GHGs) entering into the atmosphere can be inferred using mathematical inverse approaches that combine observations from a network of stations with forward atmospheric transport models. Some locations for collecting observations are better than others for constraining GHG emissions through the inversion, but the best locations for the inversion may be inaccessible or limited by economic and other non-scientific factors. We present a method to design an optimal GHG observing network in the presence of multiple objectives that may be in conflict with each other. As a demonstration, we use our method to design a prototype network of six stations to monitor summertime emissions in California of the potent GHG 1,1,1,2-tetrafluoroethane (CH2FCF3, HFC-134a). We use a multiobjective genetic algorithm to evolve network configurations that seek to jointly maximize the scientific accuracy of the inferred HFC-134a emissions and minimize the associated costs of making the measurements. The genetic algorithm effectively determines a set of "optimal" observing networks for HFC-134a that satisfy both objectives (i.e., the Pareto frontier). The Pareto frontier is convex, and clearly shows the tradeoffs between performance and cost, and the diminishing returns in trading one for the other. Without difficulty, our method can be extended to design optimal networks to monitor two or more GHGs with different emissions patterns, or to incorporate other objectives and constraints that are important in the practical design of atmospheric monitoring networks.

Lucas, D. D.; Yver Kwok, C.; Cameron-Smith, P.; Graven, H.; Bergmann, D.; Guilderson, T. P.; Weiss, R.; Keeling, R.

2014-12-01

219

Intensive flux measurements and analysis of greenhouse gases from an upland cabbage field at Kunsan, Korea  

NASA Astrophysics Data System (ADS)

It has been recognized that intensively managed agricultural soil is a dominant source of atmospheric N2O through increase in use of nitrogen fertilizer and soil microbial processes, contributing to about 57% (9Tg y-1) of total N2O annual global emission. Organic carbons in soil and wetland sediment including tidal flat affect the CO2 and CH4 emission in such environments depending on their physicochemical conditions. From October 2009 to June 2010, CO2, CH4, and N2O (GHG) soil emission measurements were conducted from upland cabbage field at Kunsan (35o56’23’’N, 126o43’14’’E), Korea by using closed static chamber method. During the experimental period, hourly GHG emissions were conducted mostly from 1000 to 1800LST in each field measurement day (total 28 days). After placing each chamber over soil surface of two neighboring plots, 50 ml of air sample inside the chambers was taken for every 15 min over a 30 min period by using plastic syringes (total of three samples). GHG concentrations were simultaneously analyzed in the laboratory by using a GC equipped with a methanizer, FID and ECD (Varian CP3800). The GHG fluxes were calculated from a linear regression of the changes in the concentrations. Negative values indicate GHG uptake by the soil surface, and positive values indicate GHG emission to the atmosphere. In addition, soil parameters (e.g. soil moisture, temperature, pH, organic C, soil N) were measured at the sampling plot. The average soil pH and soil moisture during the experimental period was ~pH5.4±0.4 and 70.0±19.7 %WFPS, respectively. The average fluxes and ranges of GHG during the experimental period were -0.004±0.032 mg-m-2 hr-1 (-0.087 ~ 0.045 mg-m-2 hr-1) for CH4, 5.32±57.63 mg-m-2 hr-1 (-92.96 ~ 139.38 mg-m-2 hr-1) for CO2, and 1.119±1.918 mg-m-2 hr-1 (0.077 ~ 8.409 mg-m-2 hr-1) for N2O, respectively. Monthly base flux measurement results revealed that monthly means of CO2 and CH4 flux during October (fall) was positive and significantly higher than those (negative value) during January (winter) when sub soil have low temperature and relatively high moisture due to snow during the winter measurement period. Averages of soil temperature and moisture during these months were 17.5±1.2oC, 45.7±8.2%WFPS for October; and 1.4±1.3oC, 89.9±8.8%WFPS for January. It may indicate that soil temperature and moisture have significant role in determining whether the CO2 and CH4 emission or uptake take place. Low temperature and high moisture above a certain optimum level during winter could weaken microbial activity and the gas diffusion in soil matrix, and then make soil GHG emission to the atmosphere decrease. Other soil parameters were also correlated with GHG emissions and discussed. Both positive and negative gas fluxes in CH4 and CO2 were observed during these measurements, but not for N2O. CH4 and CO2 gases seem to be emitted from soil surface or up taken by the soil depending on other factors such as background concentrations and physicochemical soil conditions. However, still there are many uncertainties and large scarcities in both their determination methods and soil GHG flux data. Improvement of measurement techniques and well-understanding of relationships between gas emission and controlling factors in such environments need to be required.

Kim, D.; Na, U.

2010-12-01

220

Applications of fiber lasers for remote sensing of atmospheric greenhouse gases  

NASA Astrophysics Data System (ADS)

In 2004 ITT Exelis developed the Multifunctional Fiber Laser Lidar (MFLL) for measuring atmospheric CO2. This lidar relies on high efficiency telecom laser components and Erbium Doped Fiber Amplifiers (EDFA's) to implement a unique Continuous Wave (CW) Intensity Modulated (IM) differential absorption lidar measurement. This same approach has also been used to measure atmospheric O2 by replacing the EDFA's with fiber Raman amplifier technology. The use of all fiber coupled components results in a highly reliable, flexible and robust instrument. The general architecture of the MFLL, its implementation for greenhouse gas measurements, and as a pseudorandom noise encoded altimeter system is reviewed. Results from a 2011 flight campaign on the NASA DC-8 aircraft which included CO2, O2, and PN altimetry using a single receiver for all three measurements are also discussed. In addition, an introduction to a novel variation of this approach that will enable greenhouse gas monitoring from a geostationary orbit is given. This paper provides a general overview of a set of applications for fiber lasers in the area of active remote sensing that have been developed by Exelis over the past several years.

Dobler, Jeremy T.; Braun, Michael; Nagel, James; Temyanko, Valery L.; Zaccheo, T. Scott; Harrison, F. Wallace; Browell, Edward V.; Kooi, Susan A.

2013-02-01

221

Greenhouse Gases in the South Atlantic: Testing and Automation of Instrumentation for Long-Term Monitoring  

NASA Astrophysics Data System (ADS)

Understanding ocean uptake of atmospheric CO2 by the Southern Ocean is important for modelling of future global warming scenarios, particularly since it was recently proposed that this sink was reducing (Le Quéré, et al., 2007). To help our understanding of this problem a new project aims to flask sample air from 5 South Atlantic sites and set up continuous monitoring at the 2 most accessible of these: Ascension Island and the Falklands. Flask sample measurements will include CO2 and CH4 mixing ratios and the ^13C measurement of both of these gases using the rapid continuous flow trace gas analysis system at Royal Holloway, University of London (RHUL). Routine precisions are ±0.03 per mil and ±0.05 per mil for CO2 and CH4, respectively (Fisher et al., 2006). A time series of ^13C in CH4 was maintained for Ascension Island from 2000-2005 and a time series for methane isotopes commenced for the Falkland Islands in autumn 2007. To meet the continuous monitoring requirements of the new project, three Picarro G1301 CO2 / CH4 / H2O Cavity Ring Down Spectrometers (CRDS) were installed at RHUL in October 2008 for testing, calibration and the development of an automated air inlet system suitable for analysis of calibration gases at the remote sites. Initial testing included calibration with NOAA calibrated and target gases, validation of the Picarro-defined H2O-correction of CO2, and derivation of an H2O-correction for CH4. Continuing checks on the H2O correction are made by having 2 instruments side-by-side taking air from the same inlet, but one having a combined Nafion / Mg-perchlorate drying system that utilizes the analysis system exhaust gas for the reverse flow through the Nafion and maintains water-levels at 0.05% for more than 2 weeks. These instruments are connected to the same air inlet as a GC measuring CH4 mixing ratio and a LiCor 6252 measuring CO2 mixing ratio at 30-minute and 1-minute intervals respectively. The third CRDS instrument is connected to a separate airline and can be switched between inlets that are within 1m of grass lawn at ground level or within 5 m of a large oak tree at canopy level. Flow rates vary between the internal pumps of the CRDS instruments, but within the range 260-300 cc/min when inlet valves are fully opened. Controlling flows below 200 cc/min significantly increases stabilisation time for cylinder gases. Likewise setting outlet pressures for NOAA and target gases at 4 psi and allowing the instrument pumps to control flow speeds up stabilization. Currently the instruments are measuring CO2, CH4 and H2O at 5-second intervals. Precisions (1 SD) of NOAA tanks, based on the final 10 minutes of a 30-minute analysis period are better than ±0.03 ppm for CO2 and ±0.3 ppb for CH4. Automated inlets and automated data retrieval will be tested during spring, for deployment on the South Atlantic islands later in 2009. Fisher, R., Lowry, D., Wilkin, O., Sriskantharajah S. & Nisbet. E.G. (2006) High-precision, automated stable isotope analysis of atmospheric methane and carbon dioxide using continuous-flow isotope-ratio mass spectrometry. Rapid Comm. Mass. Spec. 20, 200-208. Le Quéré, C., C. Rödenbeck, E. T. Buitenhuis, T. J. Conway, R. Langenfelds, A. Gomez, C. Labuschagne, M. Ramonet, T. Nakazawa, N. Metzl, N. Gillett, and M. Heimann, Saturation of the Southern Ocean CO2 sink due to recent climate change, Science, 316, 1735-1738, 2007.

Lowry, D.; Fisher, R.; Sriskantharajah, S.; Lanoisellé, M.; Etchells, A.; Manning, A.; Nisbet, E.

2009-04-01

222

Observations of atmospheric trace gases by MAX-DOAS in the coastal boundary layer over Jiaozhou Bay  

NASA Astrophysics Data System (ADS)

Atmospheric trace gases exist in the atmosphere of the earth rarely. But the atmospheric trace gases play an important role in the global atmospheric environment and ecological balance by participating in the global atmospheric cycle. And many environmental problems are caused by the atmospheric trace gases such as photochemical smog, acid rain, greenhouse effect, ozone depletion, etc. So observations of atmospheric trace gases become very important. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) developed recently is a kind of promising passive remote sensing technology which can utilize scattered sunlight received from multiple viewing directions to derive vertical column density of lower tropospheric trace gases like ozone, sulfur dioxide and nitrogen dioxide. It has advantages of simple structure, stable running, passive remote sensing and real-time online monitoring automatically. A MAX-DOAS has been developed at Shandong Academy of Sciences Institute of Oceanographic Instrumentation (SDIOI) for remote measurements of lower tropospheric trace gases (NO2, SO2, and O3). In this paper, we mainly introduce the stucture of the instrument, calibration and results. Detailed performance analysis and calibration of the instrument were made at Qingdao. We present the results of NO2, SO2 and O3 vertical column density measured in the coastal boundary layer over Jiaozhou Bay. The diurnal variation and the daily average value comparison of vertical column density during a long-trem observation are presented. The vertical column density of NO2 and SO2 measured during Qingdao oil pipeline explosion on November 22, 2013 by MAX-DOAS is also presented. The vertical column density of NO2 reached to a high value after the explosion. Finally, the following job and the outlook for future possible improvements are given. Experimental calibration and results show that the developed MAX-DOAS system is reliable and credible.

Li, Xianxin; Wang, Zhangjun; Meng, Xiangqian; Zhou, Haijin; Du, Libin; Qu, Junle; Chen, Chao; An, Quan; Wu, Chengxuan; Wang, Xiufen

2014-11-01

223

Greenhouse gases generated from the anaerobic biodegradation of natural offshore asphalt seepages in southern California  

NASA Astrophysics Data System (ADS)

Significant offshore asphaltic deposits with active seepage occur in the Santa Barbara Channel offshore southern California. The composition and isotopic signatures of gases sampled from the oil and gas seeps reveal that the coexisting oil in the shallow subsurface is anaerobically biodegraded, generating CO2 with secondary CH4 production. Biomineralization can result in the consumption of as much as 60% by weight of the original oil, with 13C enrichment of CO2. Analyses of gas emitted from asphaltic accumulations or seeps on the seafloor indicate up to 11% CO2 with 13C enrichment reaching +24.8‰. Methane concentrations range from less than 30% up to 98% with isotopic compositions of -34.9 to -66.1‰. Higher molecular weight hydrocarbon gases are present in strongly varying concentrations reflecting both oil-associated gas and biodegradation; propane is preferentially biodegraded, resulting in an enriched 13C isotopic composition as enriched as -19.5‰. Assuming the 132 million barrels of asphaltic residues on the seafloor represent ~40% of the original oil volume and mass, the estimated gas generated is 5.0×1010 kg (~76×109 m3) CH4 and/or 1.4×1011 kg CO2 over the lifetime of seepage needed to produce the volume of these deposits. Geologic relationships and oil weathering inferences suggest the deposits are of early Holocene age or even younger. Assuming an age of ~1,000 years, annual fluxes are on the order of 5.0×107 kg (~76×106 m3) and/or 1.4×108 kg for CH4 and CO2, respectively. The daily volumetric emission rate (2.1×105 m3) is comparable to current CH4 emission from Coal Oil Point seeps (1.5×105 m3/day), and may be a significant source of both CH4 and CO2 to the atmosphere provided that the gas can be transported through the water column.

Lorenson, Thomas D.; Wong, Florence L.; Dartnell, Peter; Sliter, Ray W.

2014-06-01

224

Increased spring flooding of agricultural fields will exhibit altered production of greenhouse gases  

NASA Astrophysics Data System (ADS)

The U.S. Corn Belt currently is a net source of carbon dioxide and nitrous oxide to the atmosphere, but is also a sink of methane. Among the proposed effects of climate change in the North American Midwest region is an increase in the frequency and duration of spring flooding events. This would cause ponding in fields which may change the greenhouse gas balance of the region, especially by providing a suitable anoxic environment for the proliferation of methanogens, increasing methane emissions. To determine whether methanogenesis occurs in flooded agricultural soils of the Midwest and how other gas fluxes are affected, we installed collars into the ground of a research field located in central Illinois. The control group was maintained at the same conditions as the surrounding field. Two groups of collars were sustained with water flooding the headspaces via a drip irrigation system; one treatment was analyzed for gas fluxes of CH4, N2O, and CO2 evolving from the collars, and a separate treatment of flooded collars was used for soil sampling. Comparing flooded soils versus control we measured reduced N2O fluxes (-3.12 x 10-6 × 6.8 x 10-7 g N m-2 min-1), reduced CO2 fluxes (-6.13 x 10-3 × 9.3 x 10-4 g CO2 m-2 min-1), and increased methane fluxes (+2.72 x 10-6 × 5.8 x 10-7 g CH4 m-2 min-1). After only one week of treatment the flooded soils switched from being sinks to sources of methane, which continued across the duration of the experiment. These preliminary results indicate that methanogenesis occurs in flooded agricultural fields, and suggest including regional modeling into further study. Although the global warming potential of methane is 25 times greater than CO2, our measured rates of methane production were compensated by reductions in nitrous oxide and CO2 fluxes, reducing the total 100-year horizon global warming potential of the flooded soils we studied by 64.8%. This indicates that accounting for more frequent seasonal ponding would significantly revise the estimates of future greenhouse gas emissions for Midwest agroecology.

Paul, R. F.; Smith, C. M.; Smyth, E. M.; Kantola, I. B.; DeLucia, E. H.

2013-12-01

225

Inspection of non-CO2 greenhouse gases from emission sources and in ambient air by Fourier-transform-infrared-spectrometry: Measurements with FTIS-MAPS.  

PubMed

Infrared spectrometry is a versatile basis to analyse greenhouse gases in the atmosphere. A multicomponent air pollution software (MAPS) was developed for retrieval of gas concentrations from radiation emission as well as absorption measurements. Concentrations of CO, CH4, N2O, and H2O as well as CO2, NO, NO2, NH3, SO2, HCl, HCHO, and the temperature of warm gases are determined on-line. The analyses of greenhouse gases in gaseous emission sources and in ambient air are performed by a mobile remote sensing system using the double-pendulum interferometer K300 of the Munich company Kayser-Threde. Passive radiation measurements are performed to retrieve CO, N2O, and H2O as well as CO2, NO, SO2, and HCl concentrations in smoke stack effluents of thermal power plants and municipal incinerators and CO and H2O as well as CO2 and NO in exhausts of aircraft engines. Open-path radiation measurements are used to determine greenhouse gas concentrations at different ambient air conditions and greenhouse gas emission rates of diffusive sources as garbage deposits, open coal mining, stock farming together with additional compounds (e.g. NH3), and from road traffic together with HCHO. Some results of measurements are shown. A future task is the verification of emission cadastres by these inspection measurements. PMID:24213905

Schäfer, K; Haus, R; Heland, J

1994-05-01

226

Relevance of emissions timing in biofuel greenhouse gases and climate impacts.  

PubMed

Employing life cycle greenhouse gas (GHG) emissions as a key performance metric in energy and environmental policy may underestimate actual climate change impacts. Emissions released early in the life cycle cause greater cumulative radiative forcing (CRF) over the next decades than later emissions. Some indicate that ignoring emissions timing in traditional biofuel GHG accounting overestimates the effectiveness of policies supporting corn ethanol by 10-90% due to early land use change (LUC) induced GHGs. We use an IPCC climate model to (1) estimate absolute CRF from U.S. corn ethanol and (2) quantify an emissions timing factor (ETF), which is masked in the traditional GHG accounting. In contrast to earlier analyses, ETF is only 2% (5%) over 100 (50) years of impacts. Emissions uncertainty itself (LUC, fuel production period) is 1-2 orders of magnitude higher, which dwarfs the timing effect. From a GHG accounting perspective, emissions timing adds little to our understanding of the climate impacts of biofuels. However, policy makers should recognize that ETF could significantly decrease corn ethanol's probability of meeting the 20% GHG reduction target in the 2007 Energy Independence and Security Act. The added uncertainty of potentially employing more complex emissions metrics is yet to be quantified. PMID:21866889

Schwietzke, Stefan; Griffin, W Michael; Matthews, H Scott

2011-10-01

227

Co-control of urban air pollutants and greenhouse gases in Mexico City.  

PubMed

This study addresses the synergies of mitigation measures to control urban air pollutant and greenhouse gas (GHG) emissions, in developing integrated "co-control" strategies for Mexico City. First, existing studies of emissions reduction measures--PROAIRE (the air quality plan for Mexico City) and separate GHG studies--are used to construct a harmonized database of options. Second, linear programming (LP) is developed and applied as a decision-support tool to analyze least-cost strategies for meeting co-control targets for multiple pollutants. We estimate that implementing PROAIRE measures as planned will reduce 3.1% of the 2010 metropolitan CO2 emissions, in addition to substantial local air pollutant reductions. Applying the LP, PROAIRE emissions reductions can be met at a 20% lower cost, using only the PROAIRE measures, by adjusting investments toward the more cost-effective measures; lower net costs are possible by including cost-saving GHG mitigation measures, but with increased investment. When CO2 emission reduction targets are added to PROAIRE targets, the most cost-effective solutions use PROAIRE measures for the majority of local pollutant reductions, and GHG measures for additional CO2 control. Because of synergies, the integrated planning of urban-global co-control can be beneficial, but we estimate that for Mexico City these benefits are often small. PMID:15296295

West, J Jason; Osnaya, Patricia; Laguna, Israel; Martínez, Julia; Fernández, Adrián

2004-07-01

228

Greenhouse gases and other airborne pollutants from household stoves in China: a database for emission factors  

NASA Astrophysics Data System (ADS)

Emissions from household stoves, especially those using solid fuels, can contribute significantly to greenhouse gas (GHG) inventories and have adverse health impacts. Few data are available on emissions from the numerous types of cookstoves used in developing countries. We have systematically measured emissions from 56 fuel/stove combinations in India and China, a large fraction of the combinations in use world-wide. A database was generated containing emission factors of direct and indirect GHGs and other airborne pollutants such as CO 2, CO, CH 4, TNMHC, N 2O, SO 2, NO x, TSP, etc. In this paper, we report on the 28 fuel/stove combinations tested in China. Since fuel and stove parameters were measured simultaneously along with the emissions, the database allows construction of complete carbon balances and analyses of the trade-off of emissions per unit fuel mass and emissions per delivered energy. Results from the analyses show that the total emissions per unit delivered energy were substantially greater from burning the solid fuels than from burning the liquid or gaseous fuels, due to lower thermal and combustion efficiencies for solid-fuel/stove combinations. For a given biomass fuel type, increasing overall stove efficiency tends to increase emissions of products of incomplete combustion. Biomass fuels are typically burned with substantial production of non-CO 2 GHGs with greater radiative forcing, indicating that biomass fuels have the potential to produce net global warming commitments even when grown renewably.

Zhang, J.; Smith, K. R.; Ma, Y.; Ye, S.; Jiang, F.; Qi, W.; Liu, P.; Khalil, M. A. K.; Rasmussen, R. A.; Thorneloe, S. A.

229

Quantified estimates of total GWPs for greenhouse gases taking into account tropospheric chemistry  

SciTech Connect

The purpose of this report is to give interim account of the progress being made at Lawrence Livermore National Laboratory (LLNL) in developing an improved capability for assessing the direct and indirect effects on Global Warming Potentials. Much of our current efforts are being devoted to improving the capability for modeling of global tropospheric processes in our state-of-the-art zonally-averaged chemical-radiative-transport model of the troposphere and stratosphere. These efforts are in preparation for an improved evaluation and better quantification of the indirect GWPs resulting from effects on tropospheric ozone from ethane and other gases with significant human-related emissions. There are three major findings that should result from this project that should have significant impacts on EPA and its programs. First, the current and ongoing studies of the direct and indirect GWPs should have a significant influence on the continuing national and international assessments of climate change. Second, the improved capability for modeling of chemical and physical processes should lead to enhanced understanding of the controlling factors influencing ozone, hydroxyl and other key tropospheric constituents. Third, the enhanced modeling capability should be important to future studies of human-related influences on tropospheric and stratospheric chemical processes.

Wuebbles, D.J.; Tamaresis, J.S.; Patten, K.O.

1993-11-01

230

Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions.  

PubMed

Important greenhouse gas (GHG) emissions related to waste incineration and co-combustion of waste were identified and considered relative to critical aspects such as: the contents of biogenic and fossil carbon, N(2)O emissions, fuel and material consumptions at the plants, energy recovery, and solid residues generated. GHG contributions were categorized with respect to direct emissions from the combustion plant as well as indirect upstream contributions (e.g. provision of fuels and materials) and indirect downstream contributions (e.g. substitution of electricity and heat produced elsewhere). GHG accounting was done per tonne of waste received at the plant. The content of fossil carbon in the input waste, for example as plastic, was found to be critical for the overall level of the GHG emissions, but also the energy conversion efficiencies were essential. The emission factors for electricity provision (also substituted electricity) affected the indirect downstream emissions with a factor of 3-9 depending on the type of electricity generation assumed. Provision of auxiliary fuels, materials and resources corresponded to up to 40% of the direct emission from the plants (which were 347-371 kg CO(2)-eq. tonne( -1) of waste for incineration and 735-803 kg CO(2)-eq. tonne(-1) of waste for co-combustion). Indirect downstream savings were within the range of -480 to -1373 kg CO(2)eq. tonne(-1) of waste for incineration and within -181 to -2607 kg CO(2)-eq. tonne(- 1) of waste for co-combustion. N(2)O emissions and residue management did not appear to play significant roles. PMID:19748939

Astrup, Thomas; Møller, Jacob; Fruergaard, Thilde

2009-11-01

231

Anaerobic digestion and digestate use: accounting of greenhouse gases and global warming contribution.  

PubMed

Anaerobic digestion (AD) of source-separated municipal solid waste (MSW) and use of the digestate is presented from a global warming (GW) point of view by providing ranges of greenhouse gas (GHG) emissions that are useful for calculation of global warming factors (GWFs), i.e. the contribution to GW measured in CO(2)-equivalents per tonne of wet waste. The GHG accounting was done by distinguishing between direct contributions at the AD facility and indirect upstream or downstream contributions. GHG accounting for a generic AD facility with either biogas utilization at the facility or upgrading of the gas for vehicle fuel resulted in a GWF from -375 (a saving) to 111 (a load) kg CO(2)-eq. tonne(-1) wet waste. In both cases the digestate was used for fertilizer substitution. This large range was a result of the variation found for a number of key parameters: energy substitution by biogas, N(2)O-emission from digestate in soil, fugitive emission of CH( 4), unburned CH(4), carbon bound in soil and fertilizer substitution. GWF for a specific type of AD facility was in the range -95 to -4 kg CO(2)-eq. tonne(-1) wet waste. The ranges of uncertainty, especially of fugitive losses of CH(4) and carbon sequestration highly influenced the result. In comparison with the few published GWFs for AD, the range of our data was much larger demonstrating the need to use a consistent and robust approach to GHG accounting and simultaneously accept that some key parameters are highly uncertain. PMID:19748957

Møller, Jacob; Boldrin, Alessio; Christensen, Thomas H

2009-11-01

232

Potential effects of clean coal technologies on acid precipitation, greenhouse gases, and solid waste disposal  

SciTech Connect

The US Department of Energy`s (DOE`s) Clean Coal Technology Demonstration Program (CCTDP) was initially funded by Congress to demonstrate more efficient, economically feasible, and environmentally acceptable coal technologies. Although the environmental focus at first was on sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) because their relationship to acid precipitation, the CCTDP may also lead to reductions in carbon dioxide (CO{sub 2}) emissions and in the volume of solid waste produced, compared with conventional technologies. The environmental effects of clean coal technologies (CCTs) depend upon which (if any) specific technologies eventually achieve high acceptance in the marketplace. In general, the repowering technologies and a small group of retrofit technologies show the most promise for reducing C0{sub 2} emissions and solid waste. These technologies also compare favorably with other CCTs in terms of SO{sub 2} and NO{sub x} reductions. The upper bound for CO{sup 2} reductions in the year 2010 is only enough to reduce global ``greenhouse`` warming potential by about 1%. However, CO{sub 2} emissions come from such variety of sources around the globe that no single technological innovation or national policy change could realistically be expected to reduce these emissions by more than a few percent. Particular CCTs can lead to either increases or decreases in the amount of solid waste produced. However, even if decreases are not achieved, much of the solid waste from clean coal technologies would be dry and therefore easier to dispose of than scrubber sludge.

Blasing, T.J.; Miller, R.L.; McCold, L.N.

1993-11-01

233

Atmospheric Feedbacks By Greenhouse Gases From Baltic Bogs During Late Holocene Reconstructed Using Wetness Anomalies  

NASA Astrophysics Data System (ADS)

Climate changes are documented in multiple proxies in sediments such as peat. At the same time, information on ecosystem feedbacks in terms of greenhouse gas balances can be derived from the proxies. As part of the EU-project ACCROTELM, we headed to building peat-based multi-proxy datasets from Finnish and Estonian sites over the past 4500 years. The cores were 14C-dated using AMS, and the high resolution age-depth curves were assumed by wiggle matching. We sampled the peat cores with a resolution of 1 cm at least every at 4th cm and analyzed plant macrofossils, testate amoebae, and carbon accumulation rates. At least a decadal resolution was obtained for the 1 cm sample slices throughout the cores. We also sampled current testate amoebae communities at different microsites of vegetation varying in moisture conditions, in order to compile a transfer function for water tables. These reconstructions were attributed with spatial proportions of mire microsites, derived in GIS from aerial images. We reviewed the methane emission and carbon accumulation history of the bog landscape as GWP using the time series of GHG balances over the 4,5 millennia. Special attention was paid for the periods of rapid climatic excursions with wet or dry shifts. The climatic feedbacks, i.e. CO2 deposition from bulk density and C content, and CH4 modeled as function of wetness, were combined in CO2 equivalents. Although the bogs were carbon sinks, the apparent impact was net atmospheric warming, through the dynamics of CH4 release. Burning of peat in the fires located in the sediment cores must have increased the net warming effect. The temporal correlations between the bogs south and north from the Gulf of Finland are inspected.

Alm, J.; Sillasoo, Ü.; Endjärv, E.; Lode, E.; Blundell, A.; Charman, D.; Väliranta, M.; Laine, J. K.; Tuittila, E.; Seppä, H.; Korhola, A.; Karofeld, E.

2006-12-01

234

Carbon and nitrogen dynamics and greenhouse gases emissions in constructed wetlands: a review  

NASA Astrophysics Data System (ADS)

The nitrogen (N) removal efficiency of constructed wetlands (CWs) is very inconsistent and does not alone explain if the removed species are reduced by physical attenuation or if they are transformed to other reactive forms (pollution swapping). There are many pathways for the removed N to remain in the system: accumulation in the sediments, leaching to groundwater (nitrate-NO3- and ammonium-NH4+), emission to atmosphere via nitrous oxide- N2O and ammonia and/or conversion to N2 gas and adsorption to sediments. The kinetics of these pathways/processes varies with CWs management and therefore needs to be studied quantitatively for the sustainable use of CWs. For example, the quality of groundwater underlying CWs with regards to the reactive N (Nr) species is largely unknown. Equally, there is a dearth of information on the extent of Nr accumulation in soils and discharge to surface waters and air. Moreover, CWs are rich in dissolved organic carbon (DOC) and produce substantial amounts of CO2 and CH4. These dissolved carbon (C) species drain out to ground and surface waters and emit to the atmosphere. The dynamics of dissolved N2O, CO2 and CH4 in CWs is a key "missing piece" in our understanding of global greenhouse gas budgets. In this review we provide an overview of the current knowledge and discussion about the dynamics of C and N in CWs and their likely impacts on aquatic and atmospheric environments. We suggest that the fate of various N species in CWs and their surface emissions and subsurface drainage fluxes need to be evaluated in a holistic way to better understand their potential for pollution swapping. Research on the process based N removal and balancing the end products into reactive and benign forms are critical to assess environmental impacts of CWs. Thus we strongly suggest that in situ N transformation and fate of the transformation products with regards to pollution swapping requires further detailed examination.

Jahangir, M. M. R.; Fenton, O.; Gill, L.; Müller, C.; Johnston, P.; Richards, K. G.

2014-07-01

235

Evaluation of process conditions triggering emissions of green-house gases from a biological wastewater treatment system.  

PubMed

In this study, methane (CH4) and nitrous oxide (N2O) emission dynamics of a plug-flow bioreactor located in a municipal full-scale wastewater treatment plant were monitored during a period of 10 weeks. In general, CH4 and N2O gas emissions from the bioreactor accounted for 0.016% of the influent chemical oxygen demand (COD) and 0.116% of the influent total Kjeldahl nitrogen (TKN) respectively. In order to identify the emission patterns in the different zones, the bioreactor was divided in six different sampling sites and the gas collection hood was placed for a period of 2-3 days in each of these sites. This sampling strategy also allowed the identification of different process perturbations leading to CH4 or N2O peak emissions. CH4 emissions mainly occurred in the first aerated site, and were mostly related with the influent and reject wastewater flows entering the bioreactor. On the other hand, N2O emissions were given along all the aerated parts of the bioreactor and were strongly dependant on the occurrence of process disturbances such as periods of no aeration or nitrification instability. Dissolved CH4 and N2O concentrations were monitored in the bioreactor and in other parts of the plant, as a contribution for the better understanding of the transport of these greenhouse gases across the different stages of the treatment system. PMID:24954560

Rodriguez-Caballero, A; Aymerich, I; Poch, M; Pijuan, M

2014-09-15

236

An environmental and economic evaluation of pyrolysis for energy generation in Taiwan with endogenous land greenhouse gases emissions.  

PubMed

Taiwan suffers from energy insecurity and the threat of potential damage from global climate changes. Finding ways to alleviate these forces is the key to Taiwan's future social and economic development. This study examines the economic and environmental impacts when ethanol, conventional electricity and pyrolysis-based electricity are available alternatives. Biochar, as one of the most important by-product from pyrolysis, has the potential to provide significant environmental benefits. Therefore, alternative uses of biochar are also examined in this study. In addition, because planting energy crops would change the current land use pattern, resulting in significant land greenhouse gases (GHG) emissions, this important factor is also incorporated. Results show that bioenergy production can satisfy part of Taiwan's energy demand, but net GHG emissions offset declines if ethanol is chosen. Moreover, at high GHG price conventional electricity and ethanol will be driven out and pyrolysis will be a dominant technology. Fast pyrolysis dominates when ethanol and GHG prices are low, but slow pyrolysis is dominant at high GHG price, especially when land GHG emissions are endogenously incorporated. The results indicate that when land GHG emission is incorporated, up to 3.8 billion kWh electricity can be produced from fast pyrolysis, while up to 2.2 million tons of CO2 equivalent can be offset if slow pyrolysis is applied. PMID:24619159

Kung, Chih-Chun; McCarl, Bruce A; Chen, Chi-Chung

2014-03-01

237

Greenhouse gases emissions accounting for typical sewage sludge digestion with energy utilization and residue land application in China  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer GHGs emissions from sludge digestion + residue land use in China were calculated. Black-Right-Pointing-Pointer The AD unit contributes more than 97% of total biogenic GHGs emissions. Black-Right-Pointing-Pointer AD with methane recovery is attractive for sludge GHGs emissions reduction. - Abstract: About 20 million tonnes of sludge (with 80% moisture content) is discharged by the sewage treatment plants per year in China, which, if not treated properly, can be a significant source of greenhouse gases (GHGs) emissions. Anaerobic digestion is a conventional sewage sludge treatment method and will continue to be one of the main technologies in the following years. This research has taken into consideration GHGs emissions from typical processes of sludge thickening + anaerobic digestion + dewatering + residue land application in China. Fossil CO{sub 2}, biogenic CO{sub 2}, CH{sub 4,} and avoided CO{sub 2} as the main objects is discussed respectively. The results show that the total CO{sub 2}-eq is about 1133 kg/t DM (including the biogenic CO{sub 2}), while the net CO{sub 2}-eq is about 372 kg/t DM (excluding the biogenic CO{sub 2}). An anaerobic digestion unit as the main GHGs emission source occupies more than 91% CO{sub 2}-eq of the whole process. The use of biogas is important for achieving carbon dioxide emission reductions, which could reach about 24% of the total CO{sub 2}-eq reduction.

Niu Dongjie, E-mail: niudongjie@tongji.edu.cn [Key Laboratory of Yangtze Aquatic Environment, Ministry of Education, College of Environmental Science and Engineering of Tongji University, 1239 Siping Road, Shanghai 200092 (China); UNEP-Tongji Institute of Environment for Sustainable Development, 1239 Siping Road, Shanghai 200092 (China); Huang Hui [Key Laboratory of Yangtze Aquatic Environment, Ministry of Education, College of Environmental Science and Engineering of Tongji University, 1239 Siping Road, Shanghai 200092 (China); Dai Xiaohu [Key Laboratory of Yangtze Aquatic Environment, Ministry of Education, College of Environmental Science and Engineering of Tongji University, 1239 Siping Road, Shanghai 200092 (China); National Engineering Research Center for Urban Pollution Control, Shanghai 200092 (China); Zhao Youcai [Key Laboratory of Yangtze Aquatic Environment, Ministry of Education, College of Environmental Science and Engineering of Tongji University, 1239 Siping Road, Shanghai 200092 (China)

2013-01-15

238

Attribution of Ozone Changes in the Near Future: Nonlinear Feedbacks between Ozone Depleting Substances and Greenhouse Gases  

NASA Astrophysics Data System (ADS)

In the first half of the 21st century the stratospheric burden of ozone depleting substances (ODSs) is predicted to decrease due to the regulations in the Montreal Protocol and its amendments. Concomitantly, the concentrations of well-mixed greenhouse gases (GHGs) will continue to rise. As the removal of the ODSs from the stratosphere is also affected by changes in the Brewer-Dobson Circulation, the decrease of halogens will also depend on the rate of the GHG increase. Furthermore, the increasing concentrations of the GHGs methane (CH4) and nitrous oxide (N2O) can modify the halogen-ozone chemistry. Therefore, a non-linear contribution has to be included in the attribution analysis of the ozone changes to ODS and GHG changes. In this study we detect and analyze this non-linear term in a set of appropriately defined timeslice simulations for the year 2045 with the Chemistry-Climate-Model EMAC. The causal processes of the non-linear interactions are studied in more detail by separating the relative ozone changes in the contribution from chemistry (production and loss) and transport. This allows us to identify not only feedbacks between chemistry and temperature but also between chemistry and dynamics, i.e. ozone transport.

Meul, Stefanie; Oberländer, Sophie; Langematz, Ulrike

2014-05-01

239

Do Agricultural Soils of California have the Potential to Sequester Carbon and Mitigate Greenhouse Gases?  

NASA Astrophysics Data System (ADS)

Agricultural ecosystems play a major role in the global carbon cycle and can be both sources of carbon emissions to the atmosphere and also carbon sinks which may be used to offset any future greenhouse gas (GHG) emissions. In California, climate change predictions indicate major impacts and substantial alterations of agricultural systems over the next decades. In 2006, California passed the California Global Warming Solutions Act of 2006 (AB 32) that requires reduction of the three major GHG's (CO2, N2O and CH4) to 1990 levels by 2020. We surveyed and synthesized available data from recent studies describing the potential to sequester carbon and reduce other GHG emissions in California agricultural soils. The studies evaluated various management practices in both annual row and perennial cropping systems, with other studies focusing upon biogeochemical model predictions for carbon sequestration and GHG mitigation calibrated towards California agriculture. Management practices considered included minimum or no tillage, cover cropping, organic residue (low and high inputs) and nitrogen fertilizer management. Though practices involving inputs of carbon, such as cover cropping and organic amendments, were often associated with increases in soil organic carbon (SOC) in the top soil layer (0-20 cm), results were not consistent across farming systems. Several studies indicated that conservation tillage, alone, increased above-ground biomass, especially when used with a cover crop. However, the reduced soil disturbance from conservation tillage merely resulted in a redistribution of the soil carbon rather than an overall accumulation, when compared with standard tillage and cover cropping practices together. Predictions from biogeochemical models indicated that increased inputs of manure and increased organic residues led to substantial carbon sequestration but did not consistently reduce non-CO2 related GHG emissions. The most effective way to reduce non-CO2 GHG emissions, and simultaneously add organic matter to soil, was to employ reduced tillage techniques and low input farming which is based upon the reduction of chemical fertilizers, pesticides and herbicides without their complete elimination and to also add carbon to the soils through the addition and incorporation of organic amendments and cover crops.

Suddick, E. C.; Scow, K. M.; Six, J. W.

2008-12-01

240

Observations of seasonal variations in atmospheric greenhouse trapping and its enhancement at high sea surface temperature  

NASA Technical Reports Server (NTRS)

Greenhouse trapping is examined theoretically using a version of the radiative transfer equations that demonstrates how atmospheric greenhouse trapping can vary. Satellite observations of atmospheric greenhouse trapping are examined for four months representing the various seasons. The cause of the super greenhouse effect at the highest SSTs is examined, and four processes are found to contribute. The middle and upper troposphere must be particularly moist and the temperature lapse rate must be increasingly unstable over the warmest regions to explain the observed distribution of atmospheric greenhouse trapping. Since the highest SSTs are generally associated with deep convection, this suggests that deep convection acts to moisten the middle and upper troposphere in regions of the highest SSTs relative to other regions. The tropical atmospheric circulation acts to both increase the temperature lapse rate and greatly increase the atmospheric water vapor concentration with spatially increasing SST.

Hallberg, Robert; Inamdar, Anand K.

1993-01-01

241

Development and Deployment of Mobile Emissions Laboratory for Continuous Long-Term Unattended Measurements of Greenhouse Gases, Fluxes, Isotopes and Pollutants  

Microsoft Academic Search

Development and Deployment of Mobile Emissions Laboratory for Continuous Long-Term Unattended Measurements of Greenhouse Gases, Fluxes, Isotopes and Pollutants A. Gardner(1), D. Baer (1), T. Owano (1), R. Provencal (1), V. Parsotam (1), P. Graves (1), M. Gupta (1), Allen Goldstein (2), Abhinav Guha (2) (1) Los Gatos Research, 67 East Evelyn Avenue, Suite 3, Mountain View, CA 94041-1529 (2)

A. Gardner; D. S. Baer; T. G. Owano; R. A. Provencal; M. Gupta; V. Parsotam; P. Graves; A. Goldstein; A. Guha

2010-01-01

242

Outflow of Greenhouse Gases and Tracer Species from the San Francisco Metropolitan Area at a New Measurement Site in Livermore, California  

NASA Astrophysics Data System (ADS)

A 'top down' approach to estimating greenhouse gas emissions from urban areas will be critical for verifying progress toward reductions targets and identifying the effectiveness of local emissions reduction policies. Measurements of gases and particulates that are co-emitted with greenhouse gases may provide important constraints on the emissions from different sectors. In order to study the emissions from a major urban area, we are measuring a variety of tracers, atmospheric parameters, and greenhouse gases in the outflow from the San Francisco Bay area. The measurement tower is located in the eastern end of the Livermore Valley, and samples drawn from 30 m above the ground are continuously analyzed for CO2, CO2 stable isotopes, CH4, H2O, CO, NOx, NOy, SO2, O3, and VOC mixing ratios. Additionally, the local temperature, pressure, and humidity are measured along with ceilometer-derived boundary layer parameters. Patterns in measurements made in Livermore are analyzed and compared to estimates made using the Weather Research and Forecasting model, Vulcan fossil-fuel emissions inventory, and a Lagrangian particle dispersion model. Comparisons are made with measurements from other locations in the San Francisco Bay area and interpreted with the help of emission inventories and atmospheric transport modeling.

Bambha, R.; Schrader, P. E.; Dansson, M. A.; Liu, Z.; Michelsen, H. A.

2013-12-01

243

Changes in the Arctic Oscillation under increased1 atmospheric greenhouse gases  

E-print Network

-industrial level and at the late 20th century level, for November to16 March. The change in the linear AO pattern the extratropical25 Northern Hemisphere [Thompson and Wallace, 1998, 2001]. Through principal component analysis26 Hemisphere SLP trends were39 consistent with observations, the simulated Northern Hemisphere SLP trends were

Hsieh, William

244

Truck Stop Electrification as a Strategy To Reduce Greenhouse Gases, Fuel Consumption and Pollutant Emissions  

E-print Network

, and carbon dioxide (CO2) emissions by 2.1 tons. The paper provides both observed and modeled results periods of time that drivers spend resting and sleeping in the cabs of their trucks. As a consequence on a daily basis nationwide due to extended idling (1). In addition, about 140,000 tons of carbon dioxide (CO

245

Uncertainty in predictions of the climate response to rising levels of greenhouse gases  

Microsoft Academic Search

The range of possibilities for future climate evolution needs to be taken into account when planning climate change mitigation and adaptation strategies. This requires ensembles of multi-decadal simulations to assess both chaotic climate variability and model response uncertainty. Statistical estimates of model response uncertainty, based on observations of recent climate change, admit climate sensitivities-defined as the equilibrium response of global

D. A. Stainforth; T. Aina; C. Christensen; M. Collins; N. Faull; D. J. Frame; J. A. Kettleborough; S. Knight; A. Martin; J. M. Murphy; C. Piani; D. Sexton; L. A. Smith; R. A. Spicer; A. J. Thorpe; M. R. Allen

2005-01-01

246

AIRS: Improving Weather Forecasting and Providing New Data on Greenhouse Gases  

NASA Technical Reports Server (NTRS)

This paper discusses the performance of AIRS and examines how it is meeting its operational and research objectives based on the experience of more than 2 yr with AIRS data. We describe the science background and the performance of AIRS in terms of the accuracy and stability of its observed spectral radiances. We examine the validation of the retrieved temperature and water vapor profiles against collocated operational radiosondes, and then we assess the impact thereof on numerical weather forecasting of the assimilation of the AIRS spectra and the retrieved temperature. We close the paper with a discussion on the retrieval of several minor tropospheric constituents from AIRS spectra.

Chahine, Moustafa T.; Pagano, Thomas S.; Aumann, Hartmut H.; Atlas, Robert; Barnet, Christopher; Blaisdell, John; Chen, Luke; Divakarla, Murty; Fetzer, Eric J.; Goldberg, Mitch; Gautier, Catherine; Granger, Stephanie; Hannon, Scott; Irion, Fredrick W; Kakar, Ramesh; Kalnay, Eugenia; Lambrigtsen, Bjorn H.; Lee, Sung-Yung; Marshall, John Le; McMillan, W. Wallace; McMillin, Larry; Olsen, Edward T.; Revercomb, Henry; Rosenkranz, Philip; Smith, William L.

2006-01-01

247

Emissions of Greenhouse Gases and Fine Particles (PM2.5) from Wildland Fires in the United States from 2003 to 2011  

NASA Astrophysics Data System (ADS)

Wildland fires not only affect adjacent communities, but also produce smoke that can travel long distances and significantly impact downwind communities, alter weather patterns, and contribute to global climate change. As air quality standards have tightened, smoke from wildland fires has faced greater scrutiny from the air quality management community. Wildland fire emissions in the United States from 2003 to 2011 were estimated using the SmartFire2 system and the BlueSky Smoke Modeling Framework. Based on various sources of observational fire activity data, including ground-based incident reports and satellite-derived fire perimeters, fire information was reconciled and passed through a chain of models that estimate fuel loading, fuel consumption, and smoke emissions. While the spatial and temporal distributions of prescribed fires follow a stable pattern, wildfires are difficult to predict and their effects vary greatly from fire to fire. We analyzed the area burned and the emissions of select greenhouse gases (carbon dioxide and methane) and fine particles (PM2.5) from the model outputs to characterize long-term temporal and spatial variations. We will present these results, discuss factors that cause variability and uncertainty, and make comparisons to typical global modeling methods.

Huang, S.; Larkin, N. K.; Raffuse, S. M.

2013-12-01

248

The effect of land-use change on the net exchange rates of greenhouse gases: a meta-analytical approach  

NASA Astrophysics Data System (ADS)

One of the environmental impacts of land-use change (LUC) is a change in the net exchange of the greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Here we summarize findings based on a new global database containing data sets of changes in soil organic carbon stocks and soil CH4 and N2O fluxes. We combine that with estimates of biomass carbon stock changes and enteric CH4 emissions following LUC. Data were expressed in common units by converting net CH4 and N2O fluxes to CO2 equivalents (CO2 eq) using established global warming potentials, and carbon-stock changes were converted to annual net fluxes by averaging stock changes over 100 yr. Conversion from natural forest to cropland resulted in the greatest increase in net GHG fluxes, while conversion of cropland to secondary forest resulted in the greatest reduction in net GHG emissions. Specifically, LUC from natural forest to crop and grasslands led to net fluxes of 6.2 ± 1.6 (Mean ± 95% confidence intervals) and 4.8 ± 1.6 t CO2 eq ha-1 yr-1 to the atmosphere, respectively. Conversely, conversion from crop and grasslands to secondary forest reduced net emissions by 6.1 ± 4.1 and 3.9 ± 1.2 t CO2 eq ha-1 yr-1, respectively. Land-use change impacts were generally dominated by changes in biomass carbon. A retrospective analysis indicated that LUC from natural forests to agricultural lands contributed a cumulative 1326 ± 449 Gt CO2 eq between 1765 and 2005, which is equivalent to average emissions of 5.5 ± 1.6 Gt CO2 eq yr-1. This study demonstrates how specific LUCs can positively or negatively affect net GHG fluxes to the atmosphere.

Kim, D.-G.; Kirschbaum, M. U. F.

2014-01-01

249

Greenhouse Gases Life Cycle Assessment (GHGLCA) as a decision support tool for municipal solid waste management in Iran  

PubMed Central

Background One of the most problems in developing countries is the integrated waste management and the effects on Greenhouse Gases (GHG) emission, Life Cycle Assessment (LCA) is used in this paper as a decision supporting tool in planning Municipal Solid Waste (MSW) managements. Methods In this paper the EPA’s Waste Reduction Model (WARM) that provide GHG emission factors for waste stream components that are based on life Cycle Inventory (LCI) framework were used and The MSW management methods comprised in seven scenarios. Results The amount of GHG which was generated from Iran’s waste sector estimated about 17836079 Metric Tons of Carbon dioxide Equivalents (MT CO2e) in this study. The lowest amount of GHG was generated by LFG capture system with energy recovery (557635 MT CO2e), while Incineration of materials being sent to landfill (1756823 MT CO2e), Landfill Gas (LFG) capture system with flaring (2929150 MT CO2e) and Improved source reduction and recycling (4780278 MT CO2e) emitted fewer GHG than the other scenarios. Lowest levels of gross energy consumption occur in source reduction with recycling and composting (-89356240 Mega British Thermal Unit, M BTU), recycling and composting (-86772060 M BTU) as well as Improved source reduction with recycling and composting (-54794888 M BTU). Conclusions It appears that recycling and composting each offer significant GHG emissions and energy consumption reductions (scenarios 4, 5 and 6). Upon of the GHG emission and energy consumption results concluded that improved source reduction and recycling scenario has been the Balanced and appropriate technology for handling the solid waste streams in municipalities. PMID:24910776

2014-01-01

250

Dissolved greenhouse gases (nitrous oxide and methane) associated with the natural iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean  

NASA Astrophysics Data System (ADS)

The concentrations of greenhouse gases (GHGs) like nitrous oxide (N2O) and methane (CH4) were measured in the Kerguelen Plateau Region (KPR), an area with annual microalgal bloom caused by natural Fe fertilization, which may stimulate microbes involved in GHG cycling. This study was carried out during the KEOPS 2 cruise during the austral spring of 2011. Two transects were sampled along and across the KRP, the north-south (N-S) transect (46-51° S, 72° E meridian) and the west-east (W-E) transect (66-75° E, 48.3° S latitude), both associated with the presence of a plateau, polar fronts and other mesoscale features. The W-E transect had N2O levels ranging from equilibrium (105%) to light supersaturation (120%) with respect to the atmosphere. CH4 levels fluctuated dramatically, with intense supersaturations (120-970%) in areas close to the coastal waters of Kerguelen Island and in the polar front (PF). There, Fe and nutrient fertilization seem to promote high total chlorophyll a (TChl a) levels. The distribution of both gases was more homogenous in the N-S transect, but CH4 peaked at southeastern stations of the KPR (A3 stations), where phytoplankton bloom was observed. Both gases responded significantly to the patchy distribution of particulate matter as Chl a, stimulated by Fe supply by complex mesoscale circulation. While CH4 appears to be produced mainly at the pycnoclines, N2O seems to be consumed superficially. Air-sea fluxes for N2O (from -10.5 to 8.65, mean 1.71 ?mol m-2d-1), and for CH4 (from 0.32 to 38.1, mean 10.07 ?mol m-2d-1) reflected sink and source behavior for N2O and source behavior for CH4, with considerable variability associated with a highly fluctuating wind regime and, in the case of CH4, due to its high superficial levels that had not been reported before in the Southern Ocean and may be caused by an intense microbial CH4 cycling.

Farías, L.; Florez-Leiva, L.; Besoain, V.; Fernández, C.

2014-08-01

251

Comparative Climate Responses of Anthropogenic Greenhouse Gases, All Major Aerosol Components, Black Carbon, and Methane, Accounting for the Evolution of the Aerosol Mixing State and of Clouds/Precipitation from Multiple Aerosol Size Distributions  

NASA Astrophysics Data System (ADS)

Several modeling studies to date have simulated the global climate response of anthropogenic greenhouse gases and bulk (non-size-resolved) sulfate or generic aerosol particles together, but no study has examined the climate response of greenhouse gases simultaneously with all major size- and composition resolved aerosol particle components. Such a study is important for improving our understanding of the effects of anthropogenic pollutants on climate. Here, the GATOR-GCMOM model is used to study the global climate response of (a) all major greenhouse gases and size-resolved aerosol components, (b) all major greenhouse gases alone, (c) fossil-fuel soot (black carbon, primary organic matter, sulfuric acid, bisulfate, sulfate), and (d) methane. Aerosol components treated in all simulations included water, black carbon, primary organic carbon, secondary organic carbon, sulfuric acid, bisulfate, sulfate, nitrate, chloride, ammonium, sodium, hydrogen ion, soil dust, and pollen/spores. Fossil-fuel soot (FFS) was emitted into its own size distribution. All other components, including biofuel and biomass soot, sea-spray, soil dust, etc., were emitted into a second distribution (MIX). The FFS distribution grew by condensation of secondary organic matter and sulfuric acid, hydration of water, and dissolution of nitric acid, ammonia, and hydrochloric acid. It self-coagulated and heterocoagulated with the MIX distribution, which also grew by condensation, hydration, and dissolution. Treatment of separate distributions for FFS allowed FFS to evolve from an external mixture to an internal mixture. In both distributions, black carbon was treated as a core component for optical calculations. Both aerosol distributions served as CCN during explicit size-resolved cloud formation. The resulting clouds grew by coagulation and condensation, coagulated with interstitial aerosol particles, and fell to the surface as rain and snow, carrying aerosol constituents with them. Thus, cloud evolution accounted for the first and second indirect effects and the mixing state of aerosol particles. The optical properties of clouds were found by treating black carbon inclusions surrounded by a shell of water. The albedos of snow, sea ice, and water were calculated with radiative transfer solutions, assuming black carbon inclusions in the case of snow and sea ice. The simulations accounted for 3-D energy diffusion to the deep ocean and 2-D ocean circulation. Major conclusions are (a) the most important constituents of global warming, in terms of climate response, appear to be, in order, carbon dioxide, black carbon, and methane, (b) aerosol particles (all together) appear to act on top of greenhouse gases to enhance extremes in both regional cooling and regional warming, (b) the combination of important greenhouse gases and aerosol particles can explain observed major regions of historic warming and cooling, and (d) eliminating all anthropogenic aerosol emission could more than double current global warming but would have less of an effect than independently doubling carbon dioxide.

Jacobson, M. Z.

2005-12-01

252

Control of greenhouse gases emission by radiation-induced formation of useful products. Utilization of CO 2  

NASA Astrophysics Data System (ADS)

Carbon dioxide (CO 2) is produced in enormous quantities by combustion of fossil fuels in power plants and heavy industries. It is strongly influencing the environment and the climate. However, it can be separated from the exhaust gases and utilized as row material for making value-added products by irradiation. Results of experiments in laboratory scale showed, e.g. that amino acids and short chain proteins can be produced by carboxylation of amines, whereas salicylic acid results from phenol and malonic acid formation is observed from acetic acid. The yield dependence from various experimental factors as well as the reaction mechanisms of the studied systems are discussed and an outlook of future developments is given.

Getoff, Nikola

2006-04-01

253

Future Climate Impacts of Direct Radiative Forcing Anthropogenic Aerosols, Tropospheric Ozone, and Long-lived Greenhouse Gases  

NASA Technical Reports Server (NTRS)

Long-lived greenhouse gases (GHGs) are the most important driver of climate change over the next century. Aerosols and tropospheric ozone (O3) are expected to induce significant perturbations to the GHG-forced climate. To distinguish the equilibrium climate responses to changes in direct radiative forcing of anthropogenic aerosols, tropospheric ozone, and GHG between present day and year 2100, four 80-year equilibrium climates are simulated using a unified tropospheric chemistry-aerosol model within the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 110. Concentrations of sulfate, nitrate, primary organic (POA) carbon, secondary organic (SOA) carbon, black carbon (BC) aerosols, and tropospheric ozone for present day and year 2100 are obtained a priori by coupled chemistry-aerosol GCM simulations, with emissions of aerosols, ozone, and precursors based on the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenario (SRES) A2. Changing anthropogenic aerosols, tropospheric ozone, and GHG from present day to year 2100 is predicted to perturb the global annual mean radiative forcing by +0.18 (considering aerosol direct effects only), +0.65, and +6.54 W m(sup -2) at the tropopause, and to induce an equilibrium global annual mean surface temperature change of +0.14, +0.32, and +5.31 K, respectively, with the largest temperature response occurring at northern high latitudes. Anthropogenic aerosols, through their direct effect, are predicted to alter the Hadley circulation owing to an increasing interhemispheric temperature gradient, leading to changes in tropical precipitation. When changes in both aerosols and tropospheric ozone are considered, the predicted patterns of change in global circulation and the hydrological cycle are similar to those induced by aerosols alone. GHG-induced climate changes, such as amplified warming over high latitudes, weakened Hadley circulation, and increasing precipitation over the Tropics and high latitudes, are consistent with predictions of a number of previous GCM studies. Finally, direct radiative forcing of anthropogenic aerosols is predicted to induce strong regional cooling over East and South Asia. Wintertime rainfall over southeastern China and the Indian subcontinent is predicted to decrease because of the increased atmospheric stability and decreased surface evaporation, while the geographic distribution of precipitation is also predicted to be altered as a result of aerosol-induced changes in wind flow.

Chen, Wei-Ting; Liao, Hong; Seinfeld, John H.

2007-01-01

254

In Situ Measurements of Halocarbons and Greenhouse Gases from the Trans-Siberian Railway During Summer 2001  

NASA Astrophysics Data System (ADS)

During June 27 - July 10, 2001, over 11,000 in situ measurements of CFC-12, halon-1211, N2O, SF6, and 5000 measurements of CFC-11, CFC-113, CHCl3, CH3CCl3, CCl4, CH4 and H2 were made along 17,000 km of the trans-Siberian railway between Moscow and Khabarovsk, Russia. Also measured by in situ analyzers were CO, CO2, O3, NOx, and standard meterological parameters. These measurements were part of the seventh Trans-Siberian Observations in the Chemistry of the Atmosphere (TROICA-7) scientific expedition, a collaboration between U.S., Russian, and German scientists. Most of these gases were detected at elevated concentrations along some sections of the fully-electrified railway, typically in proximity to the larger cities. Specifically, spikes of CFC-12, halon-1211, CHCl3 and CH4 were frequently encountered during both the eastward and westward transects of the expedition. Attempts to identify the sources of these emissions are based on analyses of their correlations with the other measured gases. Chloroform emissions are generally uncorrelated with anthropogenic tracers, and are believed to be associated with the bleaching of wood pulp from Siberian forests. CFC-12 and halon-1211 emissions are mostly uncorrelated with one another, and accurate identification of their sources is difficult but extremely important in view of the Montreal Protocol. CH4 emissions were detected as short-term spikes and, in some regions, broader increases in the background CH4 concentration. Possible sources for CH4 emissions include biomass burning, leaks from natural gas transmission lines, and wetlands.

Hurst, D. F.; Hurst, D. F.; Romashkin, P. A.; Romashkin, P. A.; Elkins, J. W.; Oberlander, E. A.; Elansky, N. F.; Belikov, I. B.; Granberg, I. G.; Golitsyn, G. S.; Brenninkmeijer, C. A.; Crutzen, P. J.

2001-12-01

255

Measurements and modeling of greenhouse gases and the planetary boundary layer for the Boston metro area and the Northeastern Megalopolis  

NASA Astrophysics Data System (ADS)

The accuracy of greenhouse gas (GHG) emission and air quality simulations reflects the fidelity of the atmospheric transport model employed that in turn is highly dependent on the accuracy of the meteorological input data. We begin by describing a multi-scale measurement network and model-data analysis framework for the Boston Metro region, with extension to the mid-Atlantic urban corridor. Observations include a network of automated concentrations of CO2 and CH4 inside and outside the urban domain, near the surface, on towers and tall buildings, total column measurements using the sun as a source, aerosol LiDAR data defining atmospheric structure, and meteorological data. The model-data analysis framework includes a Lagrangian particle dispersion model (LPDM), the Stochastic Time-Inverted Lagrangian Transport (STILT), driven by meteorological fields from the North American Regional Reanalysis (NARR) and Weather Research and Forecasting (WRF) model, and an inversion framework. We show examples of data and discuss the observational network's sampling design and a plan for extension to the NE urban corridor of the US. These urban studies are demonstrating the feasibility and value of incorporating advanced instrumentation such as the Mini Micro Pulse LiDAR to evaluate and improve the fidelity of the WRF simulations of atmospheric transport and structure in the planetary boundary layer. We also present examples of inverse analyses assessing anthropogenic emission rates for CH4 and CO2 in the urban region of metro Boston and along the urban-rural gradient.

DeCola, Philip; Jones, Taylor; Wofsy, Steven; McKain, Kathryn; Chen, Jia; Bererra, Yanina; Gottlieb, Elaine; Nehrkorn, Thomas; Hegarty, Jennifer; Eluszkiewicz, Janusz; Henderson, John; Mountain, Marikate; Hutyra, Lucy; Callahan, William

2014-05-01

256

A game of climate chicken : can EPA regulate greenhouse gases before the U.S. Senate ratifies the Kyoto Protocol?  

E-print Network

EPA's legal authority to regulate greenhouse gas emissions under the Clean Air Act is reviewed. While EPA clearly does not have the authority to implement the precise terms of the Kyoto Protocol, arguments could be put ...

Bugnion, Véronique.; Reiner, David M.

257

Final report on activities and findings under DOE grant “Interactive Photochemistry in Earth System Models to Assess Uncertainty in Ozone and Greenhouse Gases  

SciTech Connect

Atmospheric chemistry controls the abundances and hence climate forcing of important greenhouse gases including N2O, CH4, HFCs, CFCs, and O3. Attributing climate change to human activities requires, at a minimum, accurate models of the chemistry and circulation of the atmosphere that relate emissions to abundances. This DOE-funded research provided realistic, yet computationally optimized and affordable, photochemical modules to the Community Earth System Model (CESM) that augment the CESM capability to explore the uncertainty in future stratospheric-tropospheric ozone, stratospheric circulation, and thus the lifetimes of chemically controlled greenhouse gases from climate simulations. To this end, we have successfully implemented Fast-J (radiation algorithm determining key chemical photolysis rates) and Linoz v3.0 (linearized photochemistry for interactive O3, N2O, NOy and CH4) packages in LLNL-CESM and for the first time demonstrated how change in O2 photolysis rate within its uncertainty range can significantly impact on the stratospheric climate and ozone abundances. From the UCI side, this proposal also helped LLNL develop a CAM-Superfast Chemistry model that was implemented for the IPCC AR5 and contributed chemical-climate simulations to CMIP5.

Prather, Michael J. [UCI

2014-11-07

258

Biogeochemistry, transport fluxes and emission of greenhouse gases from the Ogooué River (west central Africa): preliminary results after two years of monitoring  

NASA Astrophysics Data System (ADS)

The Ogooué River is the fourth largest river in Africa by discharge. The Ogooué Basin mostly consists of undisturbed rainforest with some savanna grassland. Yet, there is no information on the biogeochemistry, transport fluxes and greenhouse gases in this river. Here, we report initial results of a monitoring campaign whereby 2-weekly samples were collected at Lambaréné (Gabon) [10.24°E 0.69°S] between April 2012 and March 2014 for a suite of physico-chemical and biogeochemical characteristics, including total suspended matter (TSM) concentrations, concentration and stable isotope composition of particulate organic carbon (POC and ?13C-POC) and particulate nitrogen (PN and ?15N-PN), chromophoric dissolved organic matter (CDOM), dissolved organic carbon (DOC and ?13C-DOC), dissolved inorganic carbon (DIC and ?13C-DIC), concentration of greenhouse gases (GHGs) (CO2, CH4 and N2O), as well as major elements, total alkalinity, and oxygen isotope signatures of water (?18O-H2O). This dataset allows us to construct annual budgets for particulate and dissolved carbon fluxes, nutrient exports, as well as a first seasonally resolved characterisation of the GHGs emitted to the atmosphere by the Ogooué River.

Darchambeau, François; Bouillon, Steven; Mbega, Jean-Daniel; Lambert, Thibault; Borges, Alberto V.

2014-05-01

259

Development and integration of a solar powered unmanned aerial vehicle and a wireless sensor network to monitor greenhouse gases.  

PubMed

Measuring gases for environmental monitoring is a demanding task that requires long periods of observation and large numbers of sensors. Wireless Sensor Networks (WSNs) and Unmanned Aerial Vehicles (UAVs) currently represent the best alternative to monitor large, remote, and difficult access areas, as these technologies have the possibility of carrying specialized gas sensing systems. This paper presents the development and integration of a WSN and an UAV powered by solar energy in order to enhance their functionality and broader their applications. A gas sensing system implementing nanostructured metal oxide (MOX) and non-dispersive infrared sensors was developed to measure concentrations of CH4 and CO2. Laboratory, bench and field testing results demonstrate the capability of UAV to capture, analyze and geo-locate a gas sample during flight operations. The field testing integrated ground sensor nodes and the UAV to measure CO2 concentration at ground and low aerial altitudes, simultaneously. Data collected during the mission was transmitted in real time to a central node for analysis and 3D mapping of the target gas. The results highlights the accomplishment of the first flight mission of a solar powered UAV equipped with a CO2 sensing system integrated with a WSN. The system provides an effective 3D monitoring and can be used in a wide range of environmental applications such as agriculture, bushfires, mining studies, zoology and botanical studies using a ubiquitous low cost technology. PMID:25679312

Malaver, Alexander; Motta, Nunzio; Corke, Peter; Gonzalez, Felipe

2015-01-01

260

An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons  

E-print Network

A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on ...

Stohl, A.

261

Nitric oxide and greenhouse gases emissions following the application of different cattle slurry particle size fractions to soil  

NASA Astrophysics Data System (ADS)

The application to soil of different slurry particle size fractions may lead to variable gaseous soil emissions and associated differential environmental impacts. An incubation experiment was carried out during 70 d to assess the influence on nitric oxide (NO) and greenhouse gas (GHG; i.e. nitrous oxide, carbon dioxide and methane) emissions following incorporation of 4 particle size fractions, obtained through laboratorial separation from cattle slurry, to agricultural sandy loam soil (Dystric Cambisol). The response to these applied slurry fractions (>2000 ?m, 2000-500 ?m, 500-100 ?m, <100 ?m) was compared to other experimental treatments, including whole slurry (WS), ammonium sulphate (AS) and an unamended control (CON). The highest value of cumulated NO emissions (6.3 mg NO-N kg -1 dry soil) were observed from the AS treatment. The cumulated amount of NO emitted (˜1 mg NO-N kg -1 dry soil) was not significantly different between slurry fractions, thereby indicating that slurry particle size had no effect on NO emissions. The largest slurry fraction (>2000 ?m) induced significantly higher N 2O emissions (1.8 mg N 2O-N kg -1 dry soil) compared to the other smaller sized fractions (1.0 mg N 2O-N kg -1 dry soil). The >2000 ?m, fraction, being more than 55% of the slurry by weight, was the major contributor to daily and cumulative N 2O emissions. Hence, for N 2O, the application of WS to agricultural soil is a better option that amendment with the >2000 ?m, fraction. Low CH 4 emissions (<200 ?g CH 4-C kg -1 dry soil d -1) were observed, but only in treatments amended with slurry or its fractions. The CH 4 emissions were short-lived and rates returned to control levels within 3 d after the slurry application. Higher CO 2 emissions were observed in soils amended with slurry fractions when compared to application with whole slurry. Clearly, slurry separation can increase soil CO 2 emissions relative to whole slurry application. Overall, N 2O contributed 10-30% to total GHG emissions, while that of methane was negligible. The present study suggested that mechanical separation of slurry into fractions and targeted application of the finest fractions to soil is a potential suitable management tool to reduce GHG emissions. However, the largest fractions have to be used for other purposes as anaerobic digestion rather than applied to soil.

Fangueiro, David; Coutinho, João; Cabral, Fernanda; Fidalgo, Paula; Bol, Roland; Trindade, Henrique

2012-02-01

262

Development and Deployment of Mobile Emissions Laboratory for Continuous Long-Term Unattended Measurements of Greenhouse Gases, Fluxes, Isotopes and Pollutants  

NASA Astrophysics Data System (ADS)

Development and Deployment of Mobile Emissions Laboratory for Continuous Long-Term Unattended Measurements of Greenhouse Gases, Fluxes, Isotopes and Pollutants A. Gardner(1), D. Baer (1), T. Owano (1), R. Provencal (1), V. Parsotam (1), P. Graves (1), M. Gupta (1), Allen Goldstein (2), Abhinav Guha (2) (1) Los Gatos Research, 67 East Evelyn Avenue, Suite 3, Mountain View, CA 94041-1529 (2) Department of Environmental Science, Policy, and Management, University of California at Berkeley Quantifying the Urban Fossil Fuel Plume: Convergence of top-down and bottom-up approaches (Session A54). We report on the design, development and deployment of a novel Mobile Emissions Laboratory, consisting of innovative laser-based gas analyzers, for rapid measurements of multiple greenhouse gases and pollutants. Designed for real-time mobile and stationery emissions monitoring, the Mobile Emissions Laboratory was deployed at several locations during 2010, including CalNEX 2010, Caldecott Tunnel (Oakland, CA), and Altamont Landfill (Livermore, CA), to record real-time continuous measurements of isotopic CO2 (?13C, CO2), methane (CH4), acetylene (C2H2), nitrous oxide (N2O), carbon monoxide (CO), and isotopic water vapor (H2O; ?18O, ?2H). The commercial gas analyzers are based on novel cavity-enhanced laser absorption spectroscopy. The portable analyzers provide measurements in real time, require about 150 watts (each) of power and do not need liquid nitrogen to operate. These instruments have been applied in the field for applications that require high data rates (for eddy correlation flux), wide dynamic range (e.g., for chamber flux and other applications with concentrations that can be 10-1000 times higher than typical ambient levels) and highest accuracy (atmospheric monitoring stations). The Mobile Emissions Laboratory, which contains onboard batteries for long-term unattended measurements without access to mains power, can provide regulatory agencies, monitoring stations, scientists and researchers with temporally and spatially resolved data (including measurements of important greenhouse gases, isotopes and pollutants) necessary for compliance monitoring, hot-spot detection, as well as cap and trade, at any location. Details of extended measurement campaigns (including lessons learned) at the various field sites (urban and rural environments) will be presented.

Gardner, A.; Baer, D. S.; Owano, T. G.; Provencal, R. A.; Gupta, M.; Parsotam, V.; Graves, P.; Goldstein, A.; Guha, A.

2010-12-01

263

High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4) using the cavity ring-down spectroscopy (CRDS) technique  

NASA Astrophysics Data System (ADS)

High-accuracy continuous measurements of greenhouse gases (CO2 and CH4) during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS) technique. This analyzer was flown without a drying system or any in-flight calibration gases. Water vapor corrections associated with dilution and pressure-broadening effects for CO2 and CH4 were derived from laboratory experiments employing measurements of water vapor by the CRDS analyzer. Before the campaign, the stability of the analyzer was assessed by laboratory tests under simulated flight conditions. During the campaign, a comparison of CO2 measurements between the CRDS analyzer and a nondispersive infrared (NDIR) analyzer on board the same aircraft showed a mean difference of 0.22±0.09 ppm for all flights over the Amazon rain forest. At the end of the campaign, CO2 concentrations of the synthetic calibration gases used by the NDIR analyzer were determined by the CRDS analyzer. After correcting for the isotope and the pressure-broadening effects that resulted from changes of the composition of synthetic vs. ambient air, and applying those concentrations as calibrated values of the calibration gases to reprocess the CO2 measurements made by the NDIR, the mean difference between the CRDS and the NDIR during BARCA was reduced to 0.05±0.09 ppm, with the mean standard deviation of 0.23±0.05 ppm. The results clearly show that the CRDS is sufficiently stable to be used in flight without drying the air or calibrating in flight and the water corrections are fully adequate for high-accuracy continuous airborne measurements of CO2 and CH4.

Chen, H.; Winderlich, J.; Gerbig, C.; Hoefer, A.; Rella, C. W.; Crosson, E. R.; van Pelt, A. D.; Steinbach, J.; Kolle, O.; Beck, V.; Daube, B. C.; Gottlieb, E. W.; Chow, V. Y.; Santoni, G. W.; Wofsy, S. C.

2010-03-01

264

The RCP greenhouse gas concentrations and their extensions from 1765 to 2300  

Microsoft Academic Search

We present the greenhouse gas concentrations for the Representative Concentration Pathways (RCPs) and their extensions beyond\\u000a 2100, the Extended Concentration Pathways (ECPs). These projections include all major anthropogenic greenhouse gases and are\\u000a a result of a multi-year effort to produce new scenarios for climate change research. We combine a suite of atmospheric concentration\\u000a observations and emissions estimates for greenhouse gases

Malte Meinshausen; Steven J. Smith; Katherine V. Calvin; John S. Daniel; M. L. T. Kainuma; J.-F. Lamarque; Ken ichi Matsumoto; S. A. Montzka; S. C. B. Raper; Keywan Riahi; Allison M. Thomson; G. J. M. Velders; Detlef Van Vuuren

2011-01-01

265

How will greenhouse gas observations meet changing requirements, laws, and demands?  

NASA Astrophysics Data System (ADS)

Recent efforts to develop a global greenhouse gas information system (GHGIS) have been driven by an anticipated need to support future national emission reduction policies or international treaties with observations. Such an effort would be similar to that done in support of the Montreal Protocol on Substances that Deplete Ozone, but more complex. However, greenhouse gas emissions are much more difficult to manage and may not be controlled by international agreement. The Kyoto Protocol has been fraught with political and practical difficulties, not the least of which is the absence of an independent observation and analysis requirement. Nevertheless, no unifying agreement was reached at the much heralded 2009 Conference of Parties (COP-15) in Copenhagen. Thus, it is quite possible (likely?) that greenhouse gas emissions may be reduced owing to other, uncoordinated policies that have their own merits, e.g., energy efficiency, alternative energy development, air quality improvement, forest development, agricultural practices, etc. If this is the future, then what observations and observation system design are needed and to what end? This presentation will discuss those needs in light of critical observations, analytical approaches, and evolving, disparate policies.

Butler, J. H.; Tans, P. P.; Sweeney, C.; Andrews, A. E.; Miller, J. B.; Montzka, S. A.

2010-12-01

266

Greenhouse gases emission and carbon sequestration in agro-ecosystems under long-term no-till: implications for global warming mitigation  

NASA Astrophysics Data System (ADS)

No-till (NT) management has gained wide acceptance in US agriculture, and could contribute to global warming mitigation by offsetting fossil fuel emission. While C sequestration in NT systems is fairly well documented, the dynamics of greenhouse gases (GHG) emission is less well understood. However, the literature abounds with viewpoints and assumptions. Because of crop residue accumulation on NT surface and generally higher soil moisture, it is often assumed that production of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) is greater in NT systems compared to conventional tillage (MP). But it is also possible that long-term implementation of NT could increase soil macro-porosity, lead to the evolution of an active population of methanotrophs, and ultimately result in enhanced CH4 uptake. Field data are needed to reconcile these conflicting assumptions. A 2-year (2009-2011) study was conducted to quantify C sequestration, and compare GHG fluxes in adjacent forest and cropland under MP and long-term NT (9, 13, 36 and 48 years). The study sites were located across Ohio on soil series with similar drainage characteristics (moderately well drained, MWD) so that duration of NT management is the experimental factor. We also included a site under NT for 48 years but located on somewhat poorly-drained soil (SPD) in order to assess the impact of soil drainage. Results revealed marked effect of NT duration and soil drainage characteristics on GHG fluxes. As hypothesized, we found a positive impact of NT on CH4 uptake, but significant difference with MP management was noted at sites under NT for > 10 years. At the sites under NT for 48 years, CH4 uptake rate was 10-12 times higher in MWD than in SPD soils. When data from all sites were pooled, N2O fluxes were significantly higher under MP (2.01 mg N2O-N m-2 d-1) than under NT (0.73), but the trend varied with NT duration. While at recent (<10 y) NT sites, N2O emission was significantly lower than under MP, the reverse was observed at sites under NT for > 30 years. At these older NT sites, N2O emissions accounted for 40-60 % of the global warming potential (GWP, sum of all GHG expressed as CO2 equivalents). These findings suggest that the viability of NT farming as a climate warming mitigation strategy hinges on the adoption of N fertilizer management practices (timing, amount, type and method of application) that minimize N2O emissions from cropland under long-term NT.

Jacinthe, P.; Dick, W. A.; Lal, R.; Shrestha, R. K.; Bilen, S.

2011-12-01

267

Gradient anaysis of biomass in Costa Rica and a first estimate of total emissions of greenhouse gases from biomass burning  

SciTech Connect

One important component of sustainable development for a nation is the degree to which it can balance greenhouse gas (GHG) exchange with the atmosphere. Scientists at NHEERL-WED recently estimated the release of such GHGs from the conversion of a range of forest types in Costa Rica between 1940-1983. They also evaluated the influence of environmental gradients that affect the rates and patterns of deforestation and the carbon pools of the forest cleared on GHG emissions.

Helmer, E.H.; Brown, S.

1997-12-31

268

The enhancement of clear sky greenhouse effect in HIRS  

Microsoft Academic Search

The High-resolution Infrared Radiation Sounder (HIRS) observations are used to understand the atmospheric response at the top of the atmosphere, induced by the anthropogenic emission of greenhouse gases. The HIRS brightness temperature channels are used to regress the Outgoing Longwave Radiation (OLR), and the greenhouse effect, in clear sky conditions, over the period 1981-2004. Here, we find that since 1981,

Guillaume Gastineau; Brian Soden; Darren Jackson; Chris O'Dell; Graeme Stephens

2010-01-01

269

Does recent global warming suggest an enhanced greenhouse effect?  

Microsoft Academic Search

Considerable controversy has been generated by the observation that the Earth's climate has warmed over the last century. Public policy decisions hinge on the question of whether this trend is natural climate variability or the result of the increase in atmospheric concentrations of greenhouse gases. The strength of the enhanced greenhouse effect depends, in large part, on the uncertain value

Haroon S. Kheshgi; Benjamin S. White

1993-01-01

270

What do near-term observations tell us about long-term developments in greenhouse gas emissions?  

Microsoft Academic Search

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible\\u000a long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy\\u000a system, land-use and the emissions associated with these systems. The phenomena that determine these long-term developments\\u000a (several decades or even centuries) are very different than

Detlef P. van Vuuren; James A. Edmonds; Steven J. Smith; Katherine V. Calvin; Joseph F. Karas; Mikiko Kainuma; Nebojsa Nakicenovic; Keywan Riahi; Bas J. van Ruijven; Robert Swart; Allison M. Thomson

2010-01-01

271

Switching to a U.S. hydrogen fuel cell vehicle fleet: The resultant change in emissions, energy use, and greenhouse gases  

NASA Astrophysics Data System (ADS)

This study examines the potential change in primary emissions and energy use from replacing the current U.S. fleet of fossil-fuel on-road vehicles (FFOV) with hybrid electric fossil fuel vehicles or hydrogen fuel cell vehicles (HFCV). Emissions and energy usage are analyzed for three different HFCV scenarios, with hydrogen produced from: (1) steam reforming of natural gas, (2) electrolysis powered by wind energy, and (3) coal gasification. With the U.S. EPA's National Emission Inventory as the baseline, other emission inventories are created using a life cycle assessment (LCA) of alternative fuel supply chains. For a range of reasonable HFCV efficiencies and methods of producing hydrogen, we find that the replacement of FFOV with HFCV significantly reduces emission associated with air pollution, compared even with a switch to hybrids. All HFCV scenarios decrease net air pollution emission, including nitrogen oxides, volatile organic compounds, particulate matter, ammonia, and carbon monoxide. These reductions are achieved with hydrogen production from either a fossil fuel source such as natural gas or a renewable source such as wind. Furthermore, replacing FFOV with hybrids or HFCV with hydrogen derived from natural gas, wind or coal may reduce the global warming impact of greenhouse gases and particles (measured in carbon dioxide equivalent emission) by 6, 14, 23, and 1%, respectively. Finally, even if HFCV are fueled by a fossil fuel such as natural gas, if no carbon is sequestered during hydrogen production, and 1% of methane in the feedstock gas is leaked to the environment, natural gas HFCV still may achieve a significant reduction in greenhouse gas and air pollution emission over FFOV.

Colella, W. G.; Jacobson, M. Z.; Golden, D. M.

272

Observational constraints on U.S. emissions of climate-active and ozone-depleting trace gases from a tall-tower and aircraft sampling network  

NASA Astrophysics Data System (ADS)

Air samples have been regularly collected at a number of tall tower sites and from aircraft profiling locations across the U.S. and Canada during the past 4 to 5 years. Measurements of approximately 50 trace gases in these samples provide a rich dataset of chemical markers related to urban, industrial, oceanic, biomass burning, fossil-fuel burning, atmospheric mixing, photosynthesis, and soil influences. Anthropogenic emission signals are readily apparent in the halocarbon and hydrocarbon data, upon which this talk will focus. Measured correlations between different halocarbons (especially hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs)) show variations as a function of season that are qualitatively consistent with the expected regional and seasonal patterns of use and emission of these industrially-produced chemicals. In some instances, annual mean correlation slopes between different trace gases are well described by the U.S. EPA Greenhouse Gas Emission Inventories, but for others, large differences are observed. Furthermore, interannual changes in correlation slopes are expected for gases that are being phased out (i.e., HCFCs) compared to those for which emissions may be increasing (i.e., HFCs) in the US. This presentation will focus on the regional, seasonal, and interannual variations in trace gas emissions implied from a straightforward analysis of this extensive measurement record.

Montzka, S. A.; Miller, B. R.; Siso, C.; Sweeney, C.; Andrews, A. E.; Karion, A.; Neff, D.; Fischer, M. L.; Higgs, J.

2010-12-01

273

Radiative Forcing by Well-Mixed Greenhouse Gases: Estimates from Climate Models in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4)  

NASA Technical Reports Server (NTRS)

The radiative effects from increased concentrations of well-mixed greenhouse gases (WMGHGs) represent the most significant and best understood anthropogenic forcing of the climate system. The most comprehensive tools for simulating past and future climates influenced by WMGHGs are fully coupled atmosphere-ocean general circulation models (AOGCMs). Because of the importance of WMGHGs as forcing agents it is essential that AOGCMs compute the radiative forcing by these gases as accurately as possible. We present the results of a radiative transfer model intercomparison between the forcings computed by the radiative parameterizations of AOGCMs and by benchmark line-by-line (LBL) codes. The comparison is focused on forcing by CO2, CH4, N2O, CFC-11, CFC-12, and the increased H2O expected in warmer climates. The models included in the intercomparison include several LBL codes and most of the global models submitted to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). In general, the LBL models are in excellent agreement with each other. However, in many cases, there are substantial discrepancies among the AOGCMs and between the AOGCMs and LBL codes. In some cases this is because the AOGCMs neglect particular absorbers, in particular the near-infrared effects of CH4 and N2O, while in others it is due to the methods for modeling the radiative processes. The biases in the AOGCM forcings are generally largest at the surface level. We quantify these differences and discuss the implications for interpreting variations in forcing and response across the multimodel ensemble of AOGCM simulations assembled for the IPCC AR4.

Collins, W. D.; Ramaswamy, V.; Schwarzkopf, M. D.; Sun, Y.; Portmann, R. W.; Fu, Q.; Casanova, S. E. B.; Dufresne, J.-L.; Fillmore, D. W.; Forster, P. M. D.; Galin, V. Y.; Gohar, L. K.; Ingram, W. J.; Kratz, D. P.; Lefebvre, M.-P.; Li, J.; Marquet, P.; Oinas, V.; Tsushima, Y.; Uchiyama, T.; Zhong, W. Y.

2006-01-01

274

Evaluation of the potentialities to reduce greenhouse gases (GHG) emissions resulting from various treatments of municipal solid wastes (MSW) in moist tropical climates: application to Yaounde.  

PubMed

The authors here analyse the emission of greenhouse gases (GHG) resulting from the various treatment of municipal solid waste found in the town of Yaounde. Four management systems have been taken as the basis for analyses. System 1 is the traditional collection and landfill disposal, while in system 2 the hiogas produced in the landfill is recuperated to produce electricity. In systems 3 and 4, in addition to the collection, we have introduced a centralised composting or biogas plant before the landfilling disposal of refuse. A Life Cycle Inventory (LCI) of the four systems was made; this enable us to quantify the flux of matter and of energy, consumed or produced by the systems. Following this, only the greenhouse effect was taken into account to evaluate the ecological consequences of the MSW management systems. The method used to evaluate this impact takes into consideration on the one hand, GHG emissions or avoided emission following the substitution of fuel with methane recovered from landfills or produced in the digesters, and on the other hand, sequestrated carbon in the soil following the regular deposit of compost. Landfilling without recuperation of methane is the most emitting solution for greenhouse gas: it leads to the emission of 1.7 ton of carbon dioxide equivalent (tCO2E) per ton of household waste. Composting and methanisation allow one to have a comparable level of emission reduction, either respectively 1.8 and 2 tCO2E/t of MSW. In order to reduce the emission of GHG in the waste management systems, it is advisable to avoid first of all the emissions of methane coming from the landfills. System 2 seems to be a solution that would reduce the emissions of GHG at low cost (2.2 to 4 $/tCO2E). System 2 is calculated as the most effective at the environmental and economic level in the context of Yaounde. Therefore traditional collection, landfill disposal and biogas recuperation to produce electricity is preferable in moist tropical climates. PMID:12549662

Ngnikam, Emmanuel; Tanawa, Emile; Rousseaux, Patrick; Riedacker, Arthur; Gourdon, Rémy

2002-12-01

275

Global and regional emissions of HFC-125 (CHF[subscript 2]CF[subscript 3]) from in situ and air archive atmospheric observations at AGAGE and SOGE observatories  

E-print Network

High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and System for Observation of halogenated Greenhouse gases in Europe (SOGE) networks for the period 1998 to 2008, combined ...

O'Doherty, S.

276

Analysis of potential for reducing emissions of greenhouse gases in municipal solid waste in Brazil, in the state and city of Rio de Janeiro  

SciTech Connect

Highlights: ? We constructed future scenarios of emissions of greenhouse gases in waste. ? Was used the IPCC methodology for calculating emission inventories. ? We calculated the costs of abatement for emissions reduction in landfill waste. ? The results were compared to Brazil, state and city of Rio de Janeiro. ? The higher the environmental passive, the greater the possibility of use of biogas. - Abstract: This paper examines potential changes in solid waste policies for the reduction in GHG for the country of Brazil and one of its major states and cities, Rio de Janeiro, from 2005 to 2030. To examine these policy options, trends in solid waste quantities and associated GHG emissions are derived. Three alternative policy scenarios are evaluated in terms of effectiveness, technology, and economics and conclusions posited regarding optimal strategies for Brazil to implement. These scenarios are been building on the guidelines for national inventories of GHG emissions (IPCC, 2006) and adapted to Brazilian states and municipalities’ boundaries. Based on the results, it is possible to say that the potential revenue from products of solid waste management is more than sufficient to transform the current scenario in this country into one of financial and environmental gains, where the negative impacts of climate change have created a huge opportunity to expand infrastructure for waste management.

Loureiro, S.M., E-mail: saulo@lima.coppe.ufrj.br [Department of Energy Planning, Federal University of Rio de Janeiro, C.P. 68565, CEP 21949-972 Rio de Janeiro, RJ (Brazil); Rovere, E.L.L., E-mail: emilio@ppe.ufrj.br [Department of Energy Planning, Federal University of Rio de Janeiro, C.P. 68565, CEP 21949-972 Rio de Janeiro, RJ (Brazil); Mahler, C.F., E-mail: mahler0503@yahoo.com [Department of Civil Engineering, Federal University of Rio de Janeiro, C.P. 68506, CEP 21945-970, Rio de Janeiro, RJ (Brazil)

2013-05-15

277

Biogeochemistry, transport fluxes and emission of greenhouse gases from the Niger River (West Africa): preliminary results after two years of monitoring  

NASA Astrophysics Data System (ADS)

The Niger River is Africa's third longest river and drains an area of ~2,120,000 km2. It encompasses six hydrographic regions and crosses almost all possible ecosystem zones in West Africa. Yet, there is surprisingly little or no information on carbon (C) and nitrogen (N) cycling in this river. Here, we report initial results of a monitoring campaign whereby 2-weekly samples have been collected at Niamey (Niger) [2.01° E 13.57° N] between April 2011 and March 2013 for a suite of physico-chemical and biogeochemical characteristics, including total suspended matter (TSM) concentrations, quantification and stable isotope composition of particulate organic carbon (POC and ?13C-POC) and particulate nitrogen (PN and ?15N-PN), dissolved organic carbon (DOC ?13C-DOC) and dissolved inorganic carbon (DIC and ?13C-DIC), concentration of greenhouse gases (GHGs) (partial pressure of CO2, CH4 and N2O), as well as major elements, total alkalinity, and oxygen isotope signatures of water (?18O-H2O). This dataset allows us to construct an annual budget for both particulate and dissolved carbon fluxes, as well as a first seasonally resolved characterisation of the matter transported by the Niger River and of the GHGs emitted to the atmosphere.

Darchambeau, François; Bouillon, Steven; Alhou, Bassirou; Borges, Alberto V.

2013-04-01

278

New proofs of the recent climate warming over the Tibetan Plateau as a result of the increasing greenhouse gases emissions  

Microsoft Academic Search

A striking climate warming over the Tibetan Plateau during the last decades has been revealed by many studies, but evidence\\u000a linking it to human activity is insufficient. By using historical observations, here we show that the in situ climate warming is accompanied by a distinct decreasing trend of the diurnal range of surface air temperature. The ERA40\\u000a reanalysis further indicates

Anmin Duan; Guoxiong Wu; Qiong Zhang; Yimin Liu

2006-01-01

279

Transport fluxes and emission of greenhouse gases of the Middle Niger River (west Africa): disproprotionate importance of the recent red floods in the Niamey region  

NASA Astrophysics Data System (ADS)

The Niger River is Africa's third longest river and drains an area of ~2,120,000 km². It encompasses six hydrographic regions and crosses almost all possible ecosystem zones in West Africa. Since few decades, the Middle Niger River presents a two flood hydrograph, the local flood, or red flood, occurring during the rainy season being the more pronounced one. Here, we report initial results of a monitoring campaign whereby 2-weekly samples were collected at Niamey (Niger) [2.01°E 13.57°N] between April 2011 and March 2013 for a suite of physico-chemical and biogeochemical characteristics, including total suspended matter (TSM) concentrations, concentration and stable isotope composition of particulate organic carbon (POC and ?13C-POC) and particulate nitrogen (PN and ?15N-PN), chromophoric dissolved organic matter (CDOM), dissolved organic carbon (DOC and ?13C-DOC), dissolved inorganic carbon (DIC and ?13C-DIC), concentration of greenhouse gases (GHGs) (CO2, CH4 and N2O), as well as major elements, total alkalinity, and oxygen isotope signatures of water (?18O-H2O). This dataset allows us to construct seasonal budgets for particulate and dissolved carbon fluxes, nutrient exports, as well as a first seasonally resolved characterisation of the GHGs emitted to the atmosphere by the Middle Niger River. The red flood, concentrated on 2 months (August-September), contributed to more than 80% of the annual transport fluxes of TSM and POC and to approximately 30% of the annual transport fluxes of DIC and DOC.

Darchambeau, François; Bouillon, Steven; Alhou, Bassirou; Lambert, Thibault; Borges, Alberto V.

2014-05-01

280

CO2, CO and CH4 measurements from the NOAA Earth System Research Laboratory's Tall Tower Greenhouse Gas Observing Network: instrumentation, uncertainty analysis and recommendations for future high-accuracy greenhouse gas monitoring efforts  

NASA Astrophysics Data System (ADS)

A robust in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Tall Tower Greenhouse Gas Observing Network. The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary layer trace gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2, 6 ppb for CO, and 0.5 ppb for CH4, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures and flow rates that are inputs for automated alerts and quality control algorithms. These algorithms provide detailed and time-dependent uncertainty estimates for all of the gases and could be adapted to other species or analysis systems. The design emphasizes use of off the shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.

Andrews, A. E.; Kofler, J. D.; Trudeau, M. E.; Williams, J. C.; Neff, D. H.; Masarie, K. A.; Chao, D. Y.; Kitzis, D. R.; Novelli, P. C.; Zhao, C. L.; Dlugokencky, E. J.; Lang, P. M.; Crotwell, M. J.; Fischer, M. L.; Parker, M. J.; Lee, J. T.; Baumann, D. D.; Desai, A. R.; Stanier, C. O.; de Wekker, S. F. J.; Wolfe, D. E.; Munger, J. W.; Tans, P. P.

2013-02-01

281

Evaluating greenhouse gas emissions inventories for agricultural burning using satellite observations of active fires.  

PubMed

Fires in agricultural ecosystems emit greenhouse gases and aerosols that influence climate on multiple spatial and temporal scales. Annex 1 countries of the United Nations Framework Convention on Climate Change (UNFCCC), many of which ratified the Kyoto Protocol, are required to report emissions of CH4 and N2O from these fires annually. In this study, we evaluated several aspects of this reporting system, including the optimality of the crops targeted by the UNFCCC globally and within Annex 1 countries, and the consistency of emissions inventories among different countries. We also evaluated the success of individual countries in capturing interannual variability and long-term trends in agricultural fire activity. In our approach, we combined global high-resolution maps of crop harvest area and production, derived from satellite maps and ground-based census data, with Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) measurements of active fires. At a global scale, we found that adding ground nuts (e.g., peanuts), cocoa, cotton and oil palm, and removing potato, oats, rye, and pulse other from the list of 14 crops targeted by the UNFCCC increased the percentage of active fires covered by the reporting system by 9%. Optimization led to a different recommended list for Annex 1 countries, requiring the addition of sunflower, cotton, rapeseed, and alfalfa and the removal of beans, sugarcane, pulse others, and tuber-root others. Extending emissions reporting to all Annex 1 countries (from the current set of 19 countries) would increase the efficacy of the reporting system from 6% to 15%, and further including several non-Annex 1 countries (Argentina, Brazil, China, India, Indonesia, Thailand, Kazakhstan, Mexico, and Nigeria) would capture over 55% of active fires in croplands worldwide. Analyses of interannual trends from the United States and Australia showed the importance of both intensity of fire use and crop production in controlling year-to-year variations in agricultural fire emissions. Remote sensing provides an effective means for evaluating some aspects of the current UNFCCC emissions reporting system; and, if combined with census data, field experiments and expert opinion, has the potential to improve the robustness of the next generation inventory system. PMID:22827140

Lin, Hsiao-Wen; Jin, Yufang; Giglio, Louis; Foley, Jonathan A; Randerson, James T

2012-06-01

282

GreenHouse Observations of the Stratosphere and Troposphere (GHOST): a novel shortwave infrared spectrometer developed for the Global Hawk unmanned aerial vehicle  

NASA Astrophysics Data System (ADS)

The tropospheric distribution of greenhouse gases (GHGs) depends on surface flux variations, atmospheric chemistry and transport processes over a range of spatial and temporal scales. Accurate and precise atmospheric concentration observations of GHGs can be used to infer surface flux estimates, though their interpretation relies on unbiased atmospheric transport models. GHOST is a novel, compact shortwave infrared spectrometer which will observe tropospheric columns of CO2, CO, CH4 and H2O (along with the HDO/H2O ratio) during deployment on board the NASA Global Hawk unmanned aerial vehicle. The primary science objectives of GHOST are to: 1) test atmospheric transport models; 2) evaluate satellite observations of GHG column observations over oceans; and 3) complement in-situ tropopause transition layer observations from other Global Hawk instruments. GHOST comprises a target acquisition module (TAM), a fibre slicer and feed system, and a multiple order spectrograph. The TAM is programmed to direct solar radiation reflected by the ocean surface into a fibre optic bundle. Incoming light is then split into four spectral bands, selected to optimise remote observations of GHGs. The design uses a single grating and detector for all four spectral bands. We summarise the GHOST concept and its objectives, and describe the instrument design and proposed deployment aboard the Global Hawk platform.

Humpage, Neil; Bösch, Hartmut; Palmer, Paul I.; Parr-Burman, Phil M.; Vick, Andrew J. A.; Bezawada, Naidu N.; Black, Martin; Born, Andrew J.; Pearson, David; Strachan, Jonathan; Wells, Martyn

2014-10-01

283

Is the additional greenhouse effect already evident in the current climate?  

Microsoft Academic Search

Several greenhouse gases, which are in part or entirely produced by human activities, have accumulated in the atmosphere since approximately the middle of the 19th century. They are assumed to have an additional greenhouse effect causing a further increase of atmospheric temperatures near the ground and a decrease in the layers above approximately 15 km altitude. The currently observed near-surface

E. Raschke

2001-01-01

284

Emissions of air pollutants and greenhouse gases over Asian regions during 2000-2008: Regional Emission inventory in ASia (REAS) version 2  

NASA Astrophysics Data System (ADS)

We have updated the Regional Emission inventory in ASia (REAS) as version 2.1. REAS 2.1 includes most major air pollutants and greenhouse gases from each year during 2000 and 2008 and following areas of Asia: East, Southeast, South, and Central Asia and the Asian part of Russia. Emissions are estimated for each country and region using updated activity data and parameters. Monthly gridded data with a 0.25° × 0.25° resolution are also provided. Asian emissions for each species in 2008 are as follows (with their growth rate from 2000 to 2008): 56.9 Tg (+34%) for SO2, 53.9 Tg (+54%) for NOx, 359.5 Tg (+34%) for CO, 68.5 Tg (+46%) for non-methane volatile organic compounds, 32.8 Tg (+17%) for NH3, 36.4 Tg (+45%) for PM10, 24.7 Tg (+42%) for PM2.5, 3.03 Tg (+35%) for black carbon, 7.72 Tg (+21%) for organic carbon, 182.2 Tg (+32%) for CH4, 5.80 Tg (+18%) for N2O, and 16.0 Pg (+57%) for CO2. By country, China and India were respectively the largest and second largest contributors to Asian emissions. Both countries also had higher growth rates in emissions than others because of their continuous increases in energy consumption, industrial activities, and infrastructure development. In China, emission mitigation measures have been implemented gradually. Emissions of SO2 in China increased from 2000 to 2006 and then began to decrease as flue-gas desulphurization was installed to large power plants. On the other hand, emissions of air pollutants in total East Asia except for China decreased from 2000 to 2008 owing to lower economic growth rates and more effective emission regulations in Japan, South Korea, and Taiwan. Emissions from other regions generally increased from 2000 to 2008, although their relative shares of total Asian emissions are smaller than those of China and India. Tables of annual emissions by country and region broken down by sub-sector and fuel type, and monthly gridded emission data with a resolution of 0.25° × 0.25° for the major sectors are available from the following URL: http://www.nies.go.jp/REAS/.

Kurokawa, J.; Ohara, T.; Morikawa, T.; Hanayama, S.; Janssens-Maenhout, G.; Fukui, T.; Kawashima, K.; Akimoto, H.

2013-11-01

285

Emissions of air pollutants and greenhouse gases over Asian regions during 2000-2008: Regional Emission inventory in ASia (REAS) version 2  

NASA Astrophysics Data System (ADS)

We have updated the Regional Emission inventory in ASia (REAS) as version 2.1. REAS 2.1 includes most major air pollutants and greenhouse gases from each year during 2000 and 2008 and following areas of Asia: East, Southeast, South, and Central Asia and the Asian part of Russia. Emissions are estimated for each country and region using updated activity data and parameters. Monthly gridded data with a 0.25 × 0.25° resolution are also provided. Asian emissions for each species in 2008 are as follows (with their growth rate from 2000 to 2008): 56.9 Tg (+34%) for SO2, 53.9 Tg (+54%) for NOx, 359.5 Tg (+34%) for CO, 68.5 Tg (+46%) for non-methane volatile organic compounds, 32.8 Tg (+17%) for NH3, 36.4 Tg (+45%) for PM10, 24.7 Tg (+42%) for PM2.5, 3.03 Tg (+35%) for black carbon, 7.72 Tg (+21%) for organic carbon, 182.2 Tg (+32%) for CH4, 5.80 Tg (+18%) for N2O, and 16.7 Pg (+59%) for CO2. By country, China and India were respectively the largest and second largest contributors to Asian emissions. Both countries also had higher growth rates in emissions than others because of their continuous increases in energy consumption, industrial activities, and infrastructure development. In China, emission mitigation measures have been implemented gradually. Emissions of SO2 in China increased from 2000 to 2006 and then began to decrease as flue-gas desulfurization was installed to large power plants. On the other hand, emissions of air pollutants in total East Asia except for China decreased from 2000 to 2008 owing to lower economic growth rates and more effective emission regulations in Japan, South Korea, and Taiwan. Emissions from other regions generally increased from 2000 to 2008, although their relative shares of total Asian emissions are smaller than those of China and India. Tables of annual emissions by country and region broken down by sub-sector and fuel type, and monthly gridded emission data with a resolution of 0.25 × 0.25° for the major sectors are available from the following url: http://www.nies.go.jp/REAS/ .

Kurokawa, J.; Ohara, T.; Morikawa, T.; Hanayama, S.; Greet, J.-M.; Fukui, T.; Kawashima, K.; Akimoto, H.

2013-04-01

286

Organic trace gases of oceanic origin observed at South Pole during ISCAT 2000  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) were measured at the South Pole (SP) from late Austral spring to mid-summer 2000 as part of the Investigation of Sulfur Chemistry in the Antarctic Troposphere Program (ISCAT-2000). This paper focuses on VOCs that are directly emitted from the ocean, specifically dimethyl sulfide (DMS), methyl nitrate (CH 3ONO 2), methyl iodide (CH 3I) and bromoform (CHBr 3). A partial seasonal cycle of these gases was also recorded during the year following ISCAT-2000. During the summer, the SP periodically receives relatively fresh marine air containing short-lived oceanic trace gases, such as DMS ( ??1 day). However, DMS was not detected at the SP until January even though DMS emissions from the Southern Ocean typically start peaking in November and elevated levels of other ocean-derived VOCs, including CH 3ONO 2 and CHBr 3, were observed in mid-November. We speculate that in November and December most of the DMS is oxidized before it reaches the SP: a strong correlation between CH 3ONO 2 and methane sulfonate (MSA), an oxidation product of DMS, supports this hypothesis. Based on a limited number of samples taken over the course of one year, CH 3ONO 2 apparently accumulates to a quasi-steady-state level over the SP in winter, most likely due to continuing emissions of the compound coupled with a lower rate of photochemical destruction. Oceanic emissions were concluded to be the dominant source of alkyl nitrates at the SP; this is in sharp contrast to northern high latitudes where total alkyl nitrate mixing ratios are dominated by urban sources.

Swanson, Aaron L.; Davis, Douglas D.; Arimoto, Richard; Roberts, Pauline; Atlas, Elliot L.; Flocke, Frank; Meinardi, Simone; Sherwood Rowland, F.; Blake, Donald R.

287

A Strategy for a Global Observing System for Verification of National Greenhouse Gas Emissions  

E-print Network

With the risks of climate change becoming increasingly evident, there is growing discussion regarding international treaties and national regulations to lower greenhouse gas (GHG) emissions. Enforcement of such agreements ...

Prinn, Ronald G.

288

The detection of climate change due to the enhanced greenhouse effect  

NASA Technical Reports Server (NTRS)

The greenhouse effect is accepted as an undisputed fact from both theoretical and observational considerations. In Earth's atmosphere, the primary greenhouse gas is water vapor. The specific concern today is that increasing concentrations of anthropogenically introduced greenhouse gases will, sooner or later, irreversibly alter the climate of Earth. Detecting climate change has been complicated by uncertainties in historical observations and measurements. Thus, the primary concern for the GEDEX project is how can climate change and enhanced greenhouse effects be unambiguously detected and quantified. Specifically examined are the areas of: Earth surface temperature; the free atmosphere (850 millibars and above); space-based measurements; measurement uncertainties; and modeling the observed temperature record.

Schiffer, Robert A.; Unninayar, Sushel

1991-01-01

289

Profile observations of long-lived trace gases in the Arctic vortex  

SciTech Connect

Five sets of vertical profiles of long-lived trace gases were measured in the stratosphere at high northern latitudes (68{degree}N) during three field campaigns of the CHEOPS-Project. Large whole air samples were collected by means of balloon-borne cryogenic samplers analyzed for their content of N{sub 2}O, CH{sub 4}, CFCl{sub 3}, CF{sub 2}Cl{sub 2}, C{sub 2}F{sub 3}Cl{sub 3}, CCl{sub 4}, CH{sub 3}Cl and CH{sub 3}CCl{sub 3}. The measured polar profiles well be compared with mean vertical distributions derived from a series of observations at midlatitudes (44{degree}N). The difference indicates a pronounced effect of subsidence in the Arctic winter stratosphere with a net downward shift of the Arctic vertical profile by about 7 km over the time period from November until February. Owing to this efficient downward transport, the abundance of chlorine in the form of reservoir and reactive species, is increased in the lower Arctic stratosphere to about twice that observed at mid-latitudes.

Schmidt, U.; Bauer, R.; Khedim, A.; Klein, E.; Kulessa, G.; Schiller, C. (Forschungszentrum Juelich (West Germany))

1991-04-01

290

The Warming Trend and the Greenhouse Effect  

NSDL National Science Digital Library

This video segment produced by ThinkTV explains the greenhouse effect and its connection to the recent rise in Earth's average temperature. Scientists explore the role of human activity in the increase of greenhouse gases and the warming trend.

2010-11-12

291

Photoacoustic measurement of internal quantum efficiency and observation of the exciton effect in GaSe with photoacoustic phase spectra  

Microsoft Academic Search

We studied the room temperature photoacoustic spectra of GaSe single crystals in the vicinity of the energy gap. Exciton formation was observed in both amplitude and phase spectra. The thermal source that arises in the illuminated sample because of optical absorption without free-carrier generation was incorporated in the heat diffusion equation in order to extend the theoretical approach of photoacoustic

Zoran D. Ristovski; Miroslav D. Dramicanin

1997-01-01

292

Mapping Greenhouse Gas Emissions Where You Live  

NSDL National Science Digital Library

In this lesson plan, learners examine some of the of greenhouse gas emissions sources in their community. To investigate the sources of greenhouse gas emissions, learners use the Environmental Protection Agency’s (EPA) Facility Level Information on GreenHouse gases Tool (FLIGHT). The FLIGHT Tool is a publicly accessible repository of data submitted to EPA by power plants, factories, refineries, and other U.S. facilities that emit large amounts of greenhouse gases.

United States Environmental Protection Agency

2014-04-30

293

Earth observations for estimating greenhouse gas emissions from deforestation in developing countries  

Microsoft Academic Search

In response to the United Nations Framework Convention on Climate Change (UNFCCC) process investigating the technical issues surrounding the ability to reduce greenhouse gas (GHG) emissions from deforestation in developing countries, this paper reviews technical capabilities for monitoring deforestation and estimating emissions. Implementation of policies to reduce emissions from deforestation require effective deforestation monitoring systems that are reproducible, provide consistent

Ruth DeFries; Frédéric Achard; Sandra Brown; Martin Herold; Daniel Murdiyarso; Bernhard Schlamadinger; Carlos de Souza

2007-01-01

294

Assessment of ground-based atmospheric observations for verification of greenhouse gas emissions from an urban region.  

PubMed

International agreements to limit greenhouse gas emissions require verification to ensure that they are effective and fair. Verification based on direct observation of atmospheric greenhouse gas concentrations will be necessary to demonstrate that estimated emission reductions have been actualized in the atmosphere. Here we assess the capability of ground-based observations and a high-resolution (1.3 km) mesoscale atmospheric transport model to determine a change in greenhouse gas emissions over time from a metropolitan region. We test the method with observations from a network of CO(2) surface monitors in Salt Lake City. Many features of the CO(2) data were simulated with excellent fidelity, although data-model mismatches occurred on hourly timescales due to inadequate simulation of shallow circulations and the precise timing of boundary-layer stratification and destratification. Using two optimization procedures, monthly regional fluxes were constrained to sufficient precision to detect an increase or decrease in emissions of approximately 15% at the 95% confidence level. We argue that integrated column measurements of the urban dome of CO(2) from the ground and/or space are less sensitive than surface point measurements to the redistribution of emitted CO(2) by small-scale processes and thus may allow for more precise trend detection of emissions from urban regions. PMID:22611187

McKain, Kathryn; Wofsy, Steven C; Nehrkorn, Thomas; Eluszkiewicz, Janusz; Ehleringer, James R; Stephens, Britton B

2012-05-29

295

Greenhouse Observations of the Stratosphere and Troposphere (GHOST): a novel shortwave infrared spectrometer developed for the Global Hawk unmanned aerial vehicle  

NASA Astrophysics Data System (ADS)

The tropospheric distribution of greenhouse gases (GHGs) is dependent on surface flux variations, atmospheric chemistry and transport processes over a wide range of spatial and temporal scales. Errors in assumed atmospheric transport can adversely affect surface flux estimates inferred from surface, aircraft or satellite observations of greenhouse gas concentrations using inverse models. We present a novel, compact shortwave infrared spectrometer (GHOST) for installation on the NASA Global Hawk unmanned aerial vehicle to provide tropospheric column observations of CO2, CO, CH4, H2O and HDO over the ocean to address the need for large-scale, simultaneous, finely resolved measurements of key GHGs. These species cover a range of lifetimes and source processes, and measurements of their tropospheric columns will reflect the vertically integrated signal of their vertical and horizontal transport within the troposphere. The primary science objectives of GHOST are to: 1) provide observations which can be used to test atmospheric transport models; 2) validate satellite observations of GHG column observations over oceans, thus filling a critical gap in current validation capabilities; and 3) complement in-situ tropopause transition layer tracer observations from other instrumentation on board the Global Hawk to provide a link between upper and lower troposphere concentration measurements. The GHOST spectrometer system comprises a target acquisition module (TAM), a fibre slicer and feed system, and a multiple order spectrograph. The TAM design utilises a gimbal behind an optical dome, which is programmed to direct solar radiation reflected by the ocean surface into a fibre optic bundle. The fibre slicer and feed system then splits the light into the four spectral bands using order sorting filters. The fibres corresponding to each band are arranged with a small sideways offset to correctly centre each spectrum on the detector array. The spectrograph design is unique in that a single grating and detector is used for all four spectral bands. The whole instrument is housed within a liquid nitrogen cooled cryostat to ensure thermal stability. We summarise the GHOST project and its objectives, and will provide a detailed overview of the instrument concept, development, and proposed deployment on board the Global Hawk.

Humpage, Neil; Boesch, Hartmut; Palmer, Paul; Parr-Burman, Phil; Vick, Andy; Bezawada, Naidu; Black, Martin; Born, Andy; Pearson, David; Strachan, Jonathan; Wells, Martyn

2014-05-01

296

Observations of Reactive Gases in the Central Siberia in 2007-2009  

NASA Astrophysics Data System (ADS)

There is a considerable shortage of direct observations of atmospheric trace gases in low-populated regions of Siberia. Since March, 2007 till now continuous measurements of O3, NOx, NO and NO2 concentrations have been performed at ZOTTO station in the middle of Krasnoyarsky Krai (60 N, 90 E) with 10 sec timing. Observations are completely automated and are part of scientific program on atmospheric chemistry measurements of ZOTTO Consortium headed by Max Planck Institute for Biogeochemistry, Jena. Variations of ozone concentration reveal vivid seasonal and daily features which have been analyzed and compared to other mid-latitude background stations as well as to data of TROICA train-based observations. These variations are likely to be typical for the Northern Eurasia boreal zone. Seasonal spring maximum (40-50 ppbv) is caused by stratospheric ozone intrusions that are only considerable ozone source. Smaller variations can be induced both by local factors and long-range transport of ozone precursors from pollution sources. The largest ozone formation rate has been observed in summer time from 9 a.m. till 3 p.m. of local time and made up 1-2 ppbv/hour. Such value points out on quite low photochemical activity and ambient air oxidizing ability. NOx concentration does not exceed 1 ppb that is typical for background areas but may vary by order and some more in few hours. Higher surface NOx(=NO+NO2) concentrations during day time generally correspond to higher ozone when NO/NO2 ratio indicates on clean or slightly polluted conditions. Analysis on base of Lagrangian model for evaluation of air parcel trajectories basing on NCEP final analysis meteorological fields and Russian Federation Hydrometeocenter reanalysis fields and residence time statistics has shown that most probable sources of man-made emissions influencing the Central Siberia air are located on south of Siberia (Kemerovo, Novokuznetsk, Krasnoyarsk, Tomsk, Novosibirsk). These results have been verified by CO data provided Max Planck Institute for Chemistry, Mainz, and agreement was very good. Data of TROICA-11, 12, 13 campaigns which occurred correspondingly in summer of 2007, 2008 and 2009 have been used to analyze pollution sources located along the Trans-Siberian Railroad. Measurements of volatile organic compounds by proton mass-spectrometry (PTR-MS) in 2008 and 2009 have been also considered to assess concentrations of biogenic VOCs (isoprene and monoterpenes) for dark-coniferous forests zone. Some of man-made VOCs (aromatic hydrocarbons and formaldehyde) were measured at ZOTTO in 2008 and in 2009 and are also presented in this study. The work was supported by Russian Foundation for Basic Research (Project # 08-05-13589).

Skorokhod, Andrey; Moiseenko, Konstantin; Pankratova, Natalia; Shumsky, Roman; Vivchar, Anastasia; Timkovsky, Joseph; Berezina, Elena

2010-05-01

297

Morphological and chemical modification of mineral dust: Observational insight into the heterogeneous uptake of acidic gases  

Microsoft Academic Search

Aerosol samples were collected in the urban atmosphere of Beijing, China, by deploying a tethered balloon. Coarse particles (d > 1 ?m) were individually analyzed using electron microscopes, to investigate the extent of dust modification by acidic gases in the atmosphere. Based on the elemental composition, irregularly shaped mineral dust was separated into carbonate and silicate groups. Both sulfate and

Atsushi Matsuki; Yasunobu Iwasaka; Guangyu Shi; Daizhou Zhang; Dmitri Trochkine; Maromu Yamada; Yoon-Suk Kim; Bin Chen; Tetsuji Nagatani; Takeshi Miyazawa; Masahiro Nagatani; Hiroshi Nakata

2005-01-01

298

Experimental observation of a traveling plasma grating formed by two crossing filaments in gases  

SciTech Connect

The spatial motion and effective duration of a traveling plasma grating formed by two interfering femtosecond laser filaments in gases is characterized by its Doppler effect imparted on a probe pulse. The shift velocity determined experimentally agrees with the theoretical calculations.

Durand, Magali [Laboratoire d'Optique Appliquee, ENSTA ParisTech-Ecole Polytechnique-CNRS, 91761 Palaiseau (France); ONERA, Chemin de la Huniere, 91761 Palaiseau (France); Liu Yi; Forestier, Benjamin; Houard, Aurelien; Mysyrowicz, Andre [Laboratoire d'Optique Appliquee, ENSTA ParisTech-Ecole Polytechnique-CNRS, 91761 Palaiseau (France)

2011-03-21

299

An Ongoing Observational Study of Greenhouse Gas Emissions in the Greater Boston Area  

NASA Astrophysics Data System (ADS)

Observations of greenhouse gas (GHG) concentrations and their relationship to atmospheric conditions in major cities are an important component of current efforts to understand the effects of urbanization on anthropogenic sources of GHGs. One-minute CO2 mixing ratio measurements in the city of Cambridge, MA have been determined from air samples collected from an intake mounted at on the roof of MIT's Green building (99.0 m) since July 3, 2012. Atmospheric CO2 concentrations are governed by a diurnal cycle with July hourly average mixing ratios ranging from a minimum of 390.22 ± 9.22 ppm at 4:00PM to a maximum of 412.89 ± 16.78 ppm at 6:00AM. Occasional plume events, with mixing ratios exceeding 500 ppm, are seen in preliminary records especially in the morning hours (6:00AM-12:00PM). Small CO2 detectors also have been deployed at other locations on MIT's campus to determine CO2 mixing ratios to within 30 ppm at different elevations. These detectors provide a cost effective way to determine the spatial extent of plume events. To assess overall levels of GHGs in the Boston area, corresponding CO and N2O concentrations, obtained with a continuous wave, quantum cascade tunable infrared laser absorption spectrometer are used to determine source signatures during plume events. The potential exists to establish a baseline diurnal signal in the CO and N2O records similar to that of CO2 in the ongoing measurements. Further analyses will look to determine the existence and extent of an urban GHG dome over the city of Boston. Some unique source signatures are identified on the basis of their characteristic N2O-CO-CO2 ratios; this information will be used to evaluate the location of significant anthropogenic sources of GHGs in conjunction with wind direction and traffic flow data. Preliminary N2O/CO2 ratios, averaged over six hour periods, fall between (7.31 ± 0.31)*10-4 in the morning (6:00AM-12:00PM) and (8.34 ± 0.13)*10-4 in the evening (6:00PM - 12:00AM) are slightly higher than Jimenez et al.'s mixed traffic ratio ((12.8±0.3)*10-5 ) and Farmulari et al.'s urban emission ratio ((2.5)*10-4) from Edinburgh, Scotland. In further analysis, CO/CO2 and N2O/CO ratios will also be considered. While diurnal cycles in GHG levels are largely attributed to changes in temperature and planetary boundary layer (PBL) height, the geographical variation and significance of high frequency plume events will be evaluated in the context of the urban CO2 budget.

Merrifield, A.; Prinn, R. G.; Ono, S.

2012-12-01

300

Greenhouse Effect in a Greenhouse  

NSDL National Science Digital Library

Build your own miniature "greenhouse" out of a plastic container and plastic wrap, and fill it with different things such as dirt and sand to observe the effect this has on temperature. Monitor the temperature using temperature probes and digitally plot the data on the graphs provided in the activity.

2012-07-19

301

Comparison of the observed and calculated clear sky greenhouse effect - Implications for climate studies  

NASA Technical Reports Server (NTRS)

The clear sky greenhouse effect is defined in terms of the outgoing longwave clear sky flux at the top of the atmosphere. Recently, interest in the magnitude of the clear sky greenhouse effect has increased due to the archiving of the clear sky flux quantity through the Earth Radiation Budget Experiment (ERBE). The present study investigates to what degree of accuracy this flux can be analyzed by using independent atmospheric and surface data in conjunction with a detailed longwave radiation model. The conclusion from this comparison is that for most regions over oceans the analyzed fluxes agree to within the accuracy of the ERBE-retrieved fluxes (+/- 5 W/sq m). However, in regions where deep convective activity occurs, the ERBE fluxes are significantly higher (10-15 W/sq m) than the calculated fluxes. This bias can arise from either cloud contamination problems or variability in water vapor amount. It is argued that the use of analyzed fluxes may provide a more consistent clear sky flux data set for general circulation modeling validation. Climate implications from the analyzed fluxes are explored. Finally, results for obtaining longwave surface fluxes over the oceans are presented.

Kiehl, J. T.; Briegleb, B. P.

1992-01-01

302

Greenhouse gas emissions of biofuels, Improving Life Cycle Assessments by taking into  

E-print Network

Greenhouse gas emissions of biofuels, Improving Life Cycle Assessments by taking into account local.......................................................................................................................................................14 Chapter 1 Biofuels, greenhouse gases and climate change 1 Introduction

Paris-Sud XI, Université de

303

Greenhouse effect of NO X  

Microsoft Academic Search

Through various processes the nitrogen oxides (NOX) interact with trace gases in the troposphere and stratosphere which do absorb in the spectral range relevant to the greenhouse\\u000a effect (infrared wavelengths). The net effect is an enhancement of the greenhouse effect. The catalytic role of NOX in the production of tropospheric ozone provides the most prominent contribution. The global waming potential

Gerhard Lammel; Hartmut Grafll

1995-01-01

304

What is the Greenhouse Effect?  

NSDL National Science Digital Library

As part of this activity, students will read and discuss information on the greenhouse effect and list important points about global warming. Tables are provided to show the most important greenhouse gases and how much their concentrations have increased since the pre-industrial era.

Rosenberg, David

305

Greenhouse gas emissions from a managed grassland  

Microsoft Academic Search

Managed grasslands contribute to global warming by the exchange of the greenhouse gases carbon dioxide, nitrous oxide and methane. To reduce uncertainties of the global warming potential of European grasslands and to assess potential mitigation options, an integrated approach quantifying fluxes from all three gases is needed. Greenhouse gas emissions from a grassland site in the SE of Scotland were

S. K. Jones; R. M. Rees; U. M. Skiba; B. C. Ball

2005-01-01

306

GreenHouse Gas Online  

NSDL National Science Digital Library

GreenHouse Gas Online catalogues greenhouse gas related articles published in over 100 peer-reviewed journals from around the world. Only journal articles with freely available abstracts are included. The latest general news and journal articles can be found listed by title, while links to archived material is available by topic. Pages devoted to background information on the various greenhouse gases, current scientific understanding and the potential for control of emissions are also available.

2002-08-01

307

Greenhouse Gas Molecules  

NSDL National Science Digital Library

This resource consists of an interactive table with a comprehensive list of 29 Greenhouse Gases, their molecular structures, a chart showing a time series of their atmospheric concentrations (at several sampling sites), their global warming potential (GWP) and their atmospheric lifetimes. References are given to the data sets that range from the mid-1990s to 2008.

George Lisensky

308

Influence of orography on variability of a non-CO2 greenhouse gases concentrations measured at Kasprowy Wierch station, Tatra, Poland  

NASA Astrophysics Data System (ADS)

Kasprowy Wierch is a mountain peak in north-western Tatra mountain ridge, where meteorological station was settled in year 1936. As the station is situated in the convergence area of three large valleys it suffers from breeze wind and from frequent katabatic winds as well. Unfortunately vertical constituent of wind is not measured at the station. Prevailing wind direction pattern in this part of Europe is western circulation. However 75-years record consistently indicate south as the predominant direction of wind at Kasprowy Wierch. Two of the valleys coming toward this mountain peak are forcing the transport of air exactly from that direction. Since 1994 trace gas analysis is performed at the station. In year 1996 automated gas chromatograph was installed at the station and data are collected till nowadays. "In situ" concentrations of CH4, N2O and SF6 are measured every 16 minutes. Since 2010 also H2 and CO are observed at the station. Especially carbon monoxide concentration may be used as a proxy for determination of cases when local emission contaminates the air coming to the station. Usually location of the station in high mountain assures large distance from sources of the observed gases. Some tracers connected with human activity like carbon monoxide or sulphur hexafluoride may indicate proximity of anthropogenic sources of N2O and CH4, which might substantially change the composition of air surrounding the station. Valley breezes occur frequently in each mountain area. It has a large influence on air composition meas-ured at the mountain stations. It can be clearly noticed in CH4 and N2O records and at much smaller rate in SF6 concentration as well. Diurnal cycle of methane and nitrous oxide concentrations reflects substantial change of its value usually shortly after the sunrise. During the summer season a valley breeze transports to the station an air enriched in CH4 and N2O from the peat lands located along the foothill of Tatra mountains. Additionally ni-trous oxide is emitted from arable lands representing almost half of the terrain bordering with Tatra. In case of Kasprowy Wierch methane enhancement may reach even 150ppb usually in July and August. Average diurnal amplitude remains at 30ppb. Variations of nitrous oxide concentration remains is usually characterized by amplitude of 3ppb. Sulphur hexafluoride amplitude remains usually below 1.5ppt. In winter, mean diurnal amplitude of methane abundance recorded at Kasprowy Wierch decrease to 10ppb as most of the terrain including peat lands is shielded by a deep snow cover. N2O reproduces also decreased variations in opposition to SF6 which tend to represent much stronger fluctuation with impaired diurnal frequency. Global circulation models doesn't take to account valley breeze wind. This is one of the reasons why model results of trace gas concentration for mountainous sites are incoherent with measurements. The research leading to these results has received funding from the European Community's Seventh Frame-work Programs (FP7/2007-2013) under grant agreement n° 244122 (GHG-Europe) and n° 284274 (InGOS).

Necki, J.; Chmura, L.; Zimnoch, M.

2012-04-01

309

POSTING: Technician 5 Heat and Greenhouse gas Exchange The Centre for Earth Observation Science (CEOS) within the Faculty of Environment,  

E-print Network

POSTING: Technician 5 ­ Heat and Greenhouse gas Exchange technician in support of multidisciplinary research on heat and greenhouse gas exchange within marine and estuarine environments of the Arctic and sub

310

The earth's radiation budget and its relation to atmospheric hydrology. I - Observations of the clear sky greenhouse effect. II - Observations of cloud effects  

NASA Technical Reports Server (NTRS)

The clear-sky components of the earth's radiation budget (ERB), the relationship of these components to the sea surface temperature (SST), and microwave-derived water-vapor amount are analyzed in an observational study along with the relationship between the cloudy-sky components of ERB and space/time coincident observations of SST, microwave-derived cloud liquid water, and cloud cover. The purpose of the study is to use these observations for establishing an understanding of the couplings between radiation and the atmosphere that are important to understanding climate feedback. A strategy for studying the greenhouse effect of earth by analyzing the emitted clear-sky longwave flux over the ocean is proposed. It is concluded that the largest observed influence of clouds on ERB is more consistent with macrophysical properties of clouds as opposed to microphysical properties. The analysis for clouds and the greenhouse effect of clouds is compared quantitatively with the clear sky results. Land-ocean differences and tropical-midlatitude differences are shown and explained in terms of the cloud macrostructure.

Stephens, Graeme L.; Greenwald, Thomas J.

1991-01-01

311

The Greenhouse Effect and Built Environment Education.  

ERIC Educational Resources Information Center

The greenhouse effect has always existed. Without the greenhouse effect, Earth could well have the oven-like environment of Venus or the deep-freeze environment of Mars. There is some debate about how much the Earth's surface temperature will rise given a certain amount of increase in the amount of greenhouse gases such as carbon dioxide, nitrous…

Greenall Gough, Annette; Gough, Noel

312

Indices for comparing greenhouse gas emissions: integrating science and economics  

Microsoft Academic Search

Abatement of greenhouse gases is a key element of possible policy responses to global warming. Comprehensive abatement strategies view the greenhouse abatement issue as one involving multiple gases and not CO2 alone. These strategies require the formulation of greenhouse gas indices that will allow for an evaluation of the trade offs involved. This paper uses an optimal control methodology to

Milind Kandlikar

1996-01-01

313

Photoacoustic measurement of internal quantum efficiency and observation of the exciton effect in GaSe with photoacoustic phase spectra.  

PubMed

We studied the room temperature photoacoustic spectra of GaSe single crystals in the vicinity of the energy gap. Exciton formation was observed in both amplitude and phase spectra. The thermal source that arises in the illuminated sample because of optical absorption without free-carrier generation was incorporated in the heat diffusion equation in order to extend the theoretical approach of photoacoustic signal generation. We calculated the optical absorption coefficient, which shows the exciton formation, and the electron-hole generation quantum efficiency eta(G) using an extended model from the phase and amplitude photoacoustic spectra, respectively. PMID:18250722

Ristovski, Z D; Dramí?anin, M D

1997-01-20

314

Development of inexpensive continuous emission monitors for feedback control of combustion devices that minimize greenhouse gases, toxic emissions, and ozone damaging products  

SciTech Connect

This is the final report of a three-year, Laboratory Directed Research and Development project at the Los Alamos National Laboratory. Combustion is the major cause of poor urban air quality, of depletion of the ozone layer, and a major source of the greenhouse gas, carbon dioxide. Careful control of combustor conditions is important for minimizing the effects of combustion on the environment. The authors have developed sensitive, inexpensive continuous emission monitors that will assist in direct feedback of turbine power systems and provide assurance to the public and the operators of the facilities that their facility emissions lie within the accepted bounds. These include a robust solid-state Fourier transform spectrometer for rapid gas analysis, based on the use of ferroelectric liquid crystal technology, and an infrared helium-neon probe for real time measurement of combustor air-to-fuel ratios.

Funk, D.J.; Moore, D.S. [Los Alamos National Lab., NM (US); Mongia, R.K.; Tomita, E.; Hsu, F.K.; Talbot, L.; Dibble, R.W. [Univ. of California, Berkeley, CA (US); Lovett, J. [Pratt and Whitney (US); Yamazaki, Akira [Tsukuba Univ. (Japan)

1998-11-01

315

2013 Update of NOAA's Annual Greenhouse Gas Index  

NASA Astrophysics Data System (ADS)

Indexes are becoming increasingly important in communicating messages about climate change to a diverse public. Indexes exist for a number of climate-related phenomena including heat, precipitation, and extreme events. These help communicate complex phenomena to the public and, at times, policy makers, to aid in understanding or making decisions. Several years ago, NOAA introduced a unique index for expressing the influence of human-emitted, long-lived greenhouse gases in the atmosphere (DJ Hofmann et al., Tellus, 2006, S8B 614-619). Essentially a condensation and normalization of radiative forcing from long-lived gases, the NOAA Annual Greenhouse Gas Index (AGGI) was designed to enhance the connection between scientists and society by providing a standard that could be easily understood and followed. The index each year is calculated from high quality, long-term observations by NOAA's Global Monitoring Division, which includes real-time measurements extending over the past five decades, as well as published ice core record that go back to 1750. The AGGI is normalized to 1.00 in 1990, the Kyoto Climate Protocol baseline year. At the end of 2011, the AGGI was 1.30, indicating that global radiative forcing by long-lived greenhouse gases had increased 30% since 1990. During the 1980s CO2 accounted for about 50-60% of the annual increase in radiative forcing by long-lived greenhouse gases, whereas, since 2000, it has accounted for 85-90% of this increase each year. After nearly a decade of virtually level concentrations in the atmosphere, methane (CH4) increased measurably over the past 2-3 years, as did its contribution to radiative forcing. In addition to presenting the AGGI for 2012, increases in radiative forcing will be evaluated and discussed with respect to the contributions from CO2, CH4, nitrous oxide (N2O), chlorofluorocarbons (CFCs), and other emerging greenhouse gases.

Butler, James H.; Montzka, Stephen A.; Dlugokencky, Edward J.; Elkins, James W.; Masari, Kenneth A.; Schnell, Russell C.; Tans, Pieter P.

2013-04-01

316

Greenhouse effect of NOX.  

PubMed

Through various processes the nitrogen oxides (NOX) interact with trace gases in the troposphere and stratosphere which do absorb in the spectral range relevant to the greenhouse effect (infrared wavelengths). The net effect is an enhancement of the greenhouse effect. The catalytic role of NOX in the production of tropospheric ozone provides the most prominent contribution. The global waming potential is estimated as GWP (NOX = 30 - 33 and 7 - 10 for the respective time horizons of 20 and 100 years, and is thereby comparable to that of methane. NOX emissions in rural areas of anthropogenically influenced regions, or those in the vicinity of the txopopause caused by air traffic, cause the greenhouse effectivity to be substantially more intense. We estimate an additional 5-23 % for Germany's contribution to the anthropogenic greenhouse effect as a result of the indirect greenhouse effects stemming from NOX. Furthermore, a small and still inaccurately defined amount of the deposited NOX which has primarily been converted into nitrates is again released from the soil into the atmosphere in the form of the long-lived greenhouse gas nitrous oxide (N2O). Thus, anthropogenically induced NOX emissions contribute to enhanced greenhouse effect and to stratospheric ozone depletion in the time scale of more than a century. PMID:24234471

Lammel, G; Graßl, H

1995-07-01

317

Model Greenhouses  

NSDL National Science Digital Library

Students learn about the advantages and disadvantages of the greenhouse effect. They construct their own miniature greenhouses and explore how their designs take advantage of heat transfer processes to create controlled environments. They record and graph measurements, comparing the greenhouse indoor and outdoor temperatures over time. Students are also introduced to global issues such as greenhouse gas emissions and their relationship to global warming.

2014-09-18

318

Wednesday, January 30, 2013 Infrared Trapping the "Greenhouse Effect"  

E-print Network

Wednesday, January 30, 2013 Infrared Trapping ­ the "Greenhouse Effect" Goals ­ to look is the same as a 1.8 degree F change. #12;Last time - Greenhouse effect demo Selective absorption. Greenhouse Constituents in Earth's atmosphere #12;Atmospheric Composition The Greenhouse Gases #12;How molecules interact

Toohey, Darin W.

319

Greenhouse gas emissions related to Dutch food consumption  

Microsoft Academic Search

The consumption of food products involves emissions of greenhouse gases. Emissions occur in the various stages of the life cycle of food products. In this paper we discuss the greenhouse gas emissions, CO2, CH4, and N2O, related to Dutch household food consumption. Combinations of greenhouse gas intensities (per Dfl) with annual household expenditures results in the greenhouse gas emissions from

Klaas Jan Kramer; Henri C. Moll; Sanderine Nonhebel; Harry C. Wilting

1999-01-01

320

Direct measurements of chemical composition of shock-induced gases from calcite: an intense global warming after the Chicxulub impact due to the indirect greenhouse effect of carbon monoxide  

NASA Astrophysics Data System (ADS)

Shock-induced devolatilization in hypervelocity impacts has been considered to play important roles in the atmospheric evolution and mass extinctions in Earth's history. Although the chemical composition of shock-induced gas species from carbonate rocks has been considered as a key to understand the environmental change after the Chicxulub impact, it has not been investigated extensively before. Here, we conduct direct measurements of the chemical composition (CO/CO 2) of shock-induced gas species from calcite (CaCO 3) using both a laser gun system and an isotopic labeling technique. The CO/CO 2 ratio of the shock-induced gas species from calcite is measured to be 2.02 ± 0.41, suggesting that gaseous CO has been dominant in the shock-induced gases in the Chicxulub impact. In order to evaluate the environmental effects of the injection of CO gas, we investigated the post-impact atmospheric chemistry by incorporating our experimental results into a tropospheric photochemical model. The results suggest that an intense (2-5 °C) global warming would have lasted for several years after a Chicxulub-size impact mainly due to the greenhouse effect of tropospheric O 3, which is produced via photochemical reactions associated with CO gas. Such an intense global warming could have damaged the biosphere in the mass extinction at the Cretaceous-Paleogene (K-P) boundary.

Kawaragi, Ko; Sekine, Yasuhito; Kadono, Toshihiko; Sugita, Seiji; Ohno, Sohsuke; Ishibashi, Ko; Kurosawa, Kosuke; Matsui, Takafumi; Ikeda, Susumu

2009-05-01

321

Simple model of photo acoustic system for greenhouse effect  

E-print Network

The simple theoretical basis for photo acoustic (PA) system for studying infrared absorption properties of greenhouse gases is constructed. The amplitude of sound observed in PA depends on the modulation frequency of light pulse. Its dependence can be explained by our simple model. According to this model, sound signal has higher harmonics. The theory and experiment are compared in third and fifth harmonics by spectrum analysis. The theory has the analogy with electric circuits. This analogy helps students for understanding the PA system.

Fukuhara, Akiko; Ogawa, Naohisa

2010-01-01

322

40 CFR 600.108-08 - Analytical gases.  

Code of Federal Regulations, 2013 CFR

... false Analytical gases. 600.108-08...POLICY FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES ...Carbon-Related Exhaust Emission Test Procedures § 600.108-08 Analytical gases. The...

2013-07-01

323

40 CFR 600.108-08 - Analytical gases.  

Code of Federal Regulations, 2012 CFR

... false Analytical gases. 600.108-08...POLICY FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES ...Carbon-Related Exhaust Emission Test Procedures § 600.108-08 Analytical gases. The...

2012-07-01

324

Observed dependence of the water vapor and clear-sky greenhouse effect on sea surface temperature: Comparison with climate warming experiments  

Microsoft Academic Search

This study presents a comparison of the water vapor and clear-sky greenhouse effect dependence on sea surface temperature for climate variations of different types. Firstly, coincident satellite observations and meteorological analyses are used to examine seasonal and interannual variations and to evaluate the performance of a general circulation model. Then, this model is used to compare the results inferred from

Sandrine Bony; H. Le Treut; J. P. Duvel

1995-01-01

325

Observed dependence of the water vapor and clear-sky greenhouse effect on sea surface temperature: comparison with climate warming experiments  

Microsoft Academic Search

This study presents a comparison of the water vapor and clear-sky greenhouse effect dependence on sea surface temperature for climate variations of different types. Firstly, coincident satellite observations and meteorological analyses are used to examine seasonal and interannual variations and to evaluate the performance of a general circulation model. Then, this model is used to compare the results inferred from

Sandrine Bony; Jean-Philippe Duvel; Hervé Trent

1995-01-01

326

Analysis of air quality with numerical simulation (CMAQ), and observations of trace gases  

NASA Astrophysics Data System (ADS)

Ozone, a secondary pollutant, is a strong oxidant that can pose a risk to human health. It is formed from a complex set of photochemical reactions involving nitrogen oxides (NOx) and volatile organic compounds (VOCs). Ambient measurements and air quality modeling of ozone and its precursors are important tools for support of regulatory decisions, and analyzing atmospheric chemical and physical processes. I worked on three methods to improve our understanding of photochemical ozone production in the Eastern U.S.: a new detector for NO2, a numerical experiment to test the sensitivity to the timing to emissions, and comparison of modeled and observed vertical profiles of CO and ozone. A small, commercially available cavity ring-down spectroscopy (CRDS) NO2 detector suitable for surface and aircraft monitoring was modified and characterized. The CRDS detector was run in parallel to an ozone chemiluminescence device with photolytic conversion of NO2 to NO. The two instruments measured ambient air in suburban Maryland. A linear least-squares fit to a direct comparison of the data resulted in a slope of 0.960+/-0.002 and R of 0.995, showing agreement between two measurement techniques within experimental uncertainty. The sensitivity of the Community Multiscale Air Quality (CMAQ) model to the temporal variation of four emissions sectors was investigated to understand the effect of emissions' daily variability on modeled ozone. Decreasing the variability of mobile source emissions changed the 8-hour maximum ozone concentration by +/-7 parts per billion by volume (ppbv). Increasing the variability of point source emissions affected ozone concentrations by +/-6 ppbv, but only in areas close to the source. CO is an ideal tracer for analyzing pollutant transport in AQMs because the atmospheric lifetime is longer than the timescale of boundary layer mixing. CO can be used as a tracer if model performance of CO is well understood. An evaluation of CO model performance in CMAQ was carried out using aircraft observations taken for the Regional Atmospheric Measurement, Modeling and Prediction Program (RAMMPP) in the summer of 2002. Comparison of modeled and observed CO total columns were generally in agreement within 5-10%. There is little evidence that the CO emissions inventory is grossly overestimated. CMAQ predicts the same vertical profile shape for all of the observations, i.e. CO is well mixed throughout the boundary layer. However, the majority of observations have poorly mixed air below 500 m, and well mixed air above. CMAQ appears to be transporting CO away from the surface more quickly than what is observed. Turbulent mixing in the model is represented with K-theory. A minimum Kz that scales with fractional urban land use is imposed in order to account for subgrid scale obstacles in urban areas and the urban heat island effect. Micrometeorological observations suggest that the minimum Kz is somewhat high. A sensitivity case where the minimum K z was reduced from 0.5 m2/s to 0.1 m2/s was carried out. Model performance of surface ozone observations at night increased significantly. The model better captures the observed ozone minimum with slower mixing, and increases ozone concentrations in the residual layer. Model performance of CO and ozone morning vertical profiles improves, but the effect is not large enough to bring the model and measurements into agreement. Comparison of modeled CO and O3 vertical profiles shows that turbulent mixing (as represented by eddy diffusivity) appears to be too fast, while convective mixing may be too slow.

Castellanos, Patricia

327

Observations of tropospheric trace gases and meteorology in rural Virginia using an unattended monitoring system: Hurricane Hugo (1989), a case study  

Microsoft Academic Search

Tropospheric trace gases such as ozone and reactive nitrogen compounds exert a strong influence on global climate, but observations of these species are limited by the necessity of having a trained observer on site to monitor instruments. A technique using modern communications technology has been developed to transport and review data collected at a remote site. The site was equipped

Bruce G. Doddridge; Russell R. Dickerson; Joshua Z. Holland; James N. Cooper; R. Glenn Wardell; Olga Poulida; James G. Watkins

1991-01-01

328

Observation of low-field Fano-Feshbach resonances in ultracold gases of dysprosium  

E-print Network

We report the observation of resonance-like loss in the trap population of ultracold dysprosium as a function of magnetic field, which we attribute to anisotropy-induced Fano-Feshbach resonances arising from Dy's large magnetic dipole moment and nonzero electronic orbital angular momentum. We recorded these resonances for four different isotopes, three bosonic and one fermionic, over a field range of 0-6 G and show that the number of resonances changes significantly as a function of temperature, even in the nK regime. Most of the observed resonances are of very narrow width. The fermionic isotope, unlike its bosonic counterparts, possesses nonzero nuclear spin and exhibits a much higher density of resonances.

Kristian Baumann; Nathaniel Q. Burdick; Mingwu Lu; Benjamin L. Lev

2013-12-22

329

Observation of low-field Fano-Feshbach resonances in ultracold gases of dysprosium  

E-print Network

We report the observation of resonance-like loss in the trap population of ultracold dysprosium as a function of magnetic field, which we attribute to anisotropy-induced Fano-Feshbach resonances arising from Dy's large magnetic dipole moment and nonzero electronic orbital angular momentum. We recorded these resonances for four different isotopes, three bosonic and one fermionic, over a field range of 0-6 G and show that the number of resonances changes significantly as a function of temperature, even in the nK regime. Most of the observed resonances are of very narrow width. The fermionic isotope, unlike its bosonic counterparts, possesses nonzero nuclear spin and exhibits a much higher density of resonances.

Baumann, Kristian; Lu, Mingwu; Lev, Benjamin L

2013-01-01

330

The Berkeley Atmospheric CO2 Observation Network (BEACON): Measuring Greenhouse Gases and Criteria Pollutants within the Urban Dome  

NASA Astrophysics Data System (ADS)

Efforts to curb greenhouse gas emissions, while global in their impacts, often focus on local and regional scales for execution and are dependent on the actions of communities and individuals. Evaluating the effectiveness of local policies requires observations with much higher spatial resolution than are currently available---kilometer scale. The Berkeley Atmospheric CO2 Observation Network (BEACON):, launched at the end of 2011, aims to provide measurements of urban-scale concentrations of CO2, temperature, pressure, relative humidity, O3, CO, and NO2 with sufficient spatial and temporal resolution to characterize the sources of CO2 within cities. Our initial deployment in Oakland, California uses ~40 sensor packages at a roughly 2 km spacing throughout the city. We will present an initial analysis of the vertical gradients and other spatial patterns observed to date.

Teige, V. E.; Weichsel, K.; Hooker, A.; Wooldridge, P. J.; Cohen, R. C.

2012-12-01

331

The use of guide to the expression of uncertainty in measurement for uncertainty management in National Greenhouse Gas Inventories  

Microsoft Academic Search

Research basis for annual greenhouse gases (GHG) emissions assessment is national and branch statistics data. Quality and confidence of greenhouse gases inventory through assessment methodologies, preparation procedures and processing of data is confirm. Request at National Greenhouse Gases Inventory which contain assessment and analyses uncertainty elements on Intergovernmental Panel on Climate Change-GPG 2000 and IPCC 2006 are determine. Main approaches

O. Velychko; T. Gordiyenko

2009-01-01

332

Gas-water-rock interactions in Frio Formation following CO2 injection: Implications for the storage of greenhouse gases in sedimentary basins  

USGS Publications Warehouse

To investigate the potential for the geologic storage of CO2 in saline sedimentary aquifers, 1600 t of CO2 were injected at 1500 m depth into a 24-m-thick sandstone section of the Frio Formation, a regional brine and oil reservoir in the U.S. Gulf Coast. Fluid samples obtained from the injection and observation wells before CO2 injection showed a Na-Ca-Cl-type brine with 93,000 mg/L total dissolved solids (TDS) at near saturation with CH4 at reservoir conditions. Following CO2 breakthrough, samples showed sharp drops in pH (6.5-5.7), pronounced increases in alkalinity (100-3000 mg/L as HCO3) and Fe (30-1100 mg/L), and significant shifts in the isotopic compositions of H2O, dissolved inorganic carbon (DIC), and CH4. Geochemical modeling indicates that brine pH would have dropped lower but for the buffering by dissolution of carbonate and iron oxyhydroxides. This rapid dissolution of carbonate and other minerals could ultimately create pathways in the rock seals or well cements for CO2 and brine leakage. Dissolution of minerals, especially iron oxyhydroxides, could mobilize toxic trace metals and, where residual oil or suitable organics are present, the injected CO2 could also mobilize toxic organic compounds. Environmental impacts could be major if large brine volumes with mobilized toxic metals and organics migrated into potable groundwater. The ??18O values for brine and CO2 samples indicate that supercritical CO2 comprises ???50% of pore-fluid volume ???6 mo after the end of injection. Postinjection sampling, coupled with geochemical modeling, indicates that the brine gradually will return to its preinjection composition. ?? 2006 Geological Society of America.

Kharaka, Y.K.; Cole, D.R.; Hovorka, S.D.; Gunter, W.D.; Knauss, K.G.; Freifeld, B.M.

2006-01-01

333

Gas-water-rock interactions in Frio Formation following CO2 injection: Implications for the storage of greenhouse gases in sedimentary basins  

NASA Astrophysics Data System (ADS)

To investigate the potential for the geologic storage of CO2 in saline sedimentary aquifers, 1600 t of CO2 were injected at 1500 m depth into a 24-m-thick sandstone section of the Frio Formation, a regional brine and oil reservoir in the U.S. Gulf Coast. Fluid samples obtained from the injection and observation wells before CO2 injection showed a Na-Ca-Cl type brine with 93,000 mg/L total dissolved solids (TDS) at near saturation with CH4 at reservoir conditions. Following CO2 breakthrough, samples showed sharp drops in pH (6.5 5.7), pronounced increases in alkalinity (100 3000 mg/L as HCO3) and Fe (30 1100 mg/L), and significant shifts in the isotopic compositions of H2O, dissolved inorganic carbon (DIC), and CH4. Geochemical modeling indicates that brine pH would have dropped lower but for the buffering by dissolution of carbonate and iron oxyhydroxides. This rapid dissolution of carbonate and other minerals could ultimately create pathways in the rock seals or well cements for CO2 and brine leakage. Dissolution of minerals, especially iron oxyhydroxides, could mobilize toxic trace metals and, where residual oil or suitable organics are present, the injected CO2 could also mobilize toxic organic compounds. Environmental impacts could be major if large brine volumes with mobilized toxic metals and organics migrated into potable groundwater. The ?18O values for brine and CO2 samples indicate that supercritical CO2 comprises ˜50% of pore-fluid volume ˜6 mo after the end of injection. Postinjection sampling, coupled with geochemical modeling, indicates that the brine gradually will return to its preinjection composition.

Kharaka, Y. K.; Cole, D. R.; Hovorka, S. D.; Gunter, W. D.; Knauss, K. G.; Freifeld, B. M.

2006-07-01

334

What we learn from updates of NOAA's Annual Greenhouse Gas Index (AGGI)  

NASA Astrophysics Data System (ADS)

Several years ago, NOAA introduced a unique index for expressing the influence of human-emitted, long-lived greenhouse gases in the atmosphere (D.J. Hofmann et al., Tellus, 2006, S8B, 614-619). Being a condensation and normalization of radiative forcing from long-lived gases, the NOAA Annual Greenhouse Gas Index (AGGI) was designed to enhance the connection between scientists and society by providing a standard that could be easily understood and followed. The index each year is calculated from high quality, long-term observations by NOAA's Global Monitoring Division, which includes real-time measurements extending over the past five decades, as well as published ice core records that go back to 1750. The AGGI is radiative forcing from these long-lived gases, normalized to 1.00 in 1990, the Kyoto Climate Protocol baseline year. For 2012, the AGGI was 1.32, indicating that global radiative forcing by long-lived greenhouse gases had increased 32% since 1990. During the 1980s CO2 accounted for about 50-60% of the annual increase in radiative forcing (and the AGGI) by long-lived greenhouse gases, whereas, since 2000, it has accounted for 80-90% of this increase each year. After nearly a decade of virtually level concentrations in the atmosphere, methane (CH4) has increased measurably over the past 6 years, as did its contribution to radiative forcing (and the AGGI). This year, in addition to updating the AGGI for 2013, increases in radiative forcing will be evaluated and discussed with respect to time-dependent changes in the contributions from CO2, CH4, nitrous oxide (N2O), chlorofluorocarbons (CFCs), and other emerging greenhouse gases.

Butler, James H.; Montzka, Stephen A.; Dlugokencky, Edward; Elkins, James W.; Masarie, Kenneth; Schnell, Russell C.; Tans, Pieter; Dutton, Geoff; Miller, Ben R.

2014-05-01

335

Integrated Energy and Greenhouse Gas Management System  

E-print Network

an integrated Energy and Greenhouse Gas Management System that allows companies to reduce energy and carbon intensity at the same time all the while bolstering bottom line performance. Reducing energy use and greenhouse gases is not an option but a necessity...

Spates, C. N.

2010-01-01

336

Recent trends of inorganic chlorine and halogenated source gases above the Jungfraujoch and Kitt Peak stations derived from high-resolution FTIR solar observations  

NASA Astrophysics Data System (ADS)

The longest series of Fourier Transform Infrared (FTIR) high spectral resolution solar absorption observations are available from the Jungfraujoch and Kitt Peak stations, located at 46.5°N and 30.9°N, respectively. State-of-the-art interferometers are operated at these sites within the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, visit http://www.ndacc.org). These instruments allow to record spectra on a regular basis, under clear-sky conditions, using a suite of optical filters which altogether cover the 2 to 16 micron spectral range. Numerous absorption features characterized in the HITRAN compilations (e.g. Rothman et al., 2008) are encompassed in this mid-infrared region. Their analyses with either the SFIT-1 or SFIT-2 algorithm allow retrieving total columns of the target gases. Moreover, information on their distribution with altitude can generally be derived when using SFIT-2 which implements the Optimal Estimation Method of Rodgers (1990). Among the two dozen gases of atmospheric interest accessible to the ground-based FTIR technique, we have selected here a suite of long-lived halogenated species: HCl, ClONO2, CCl2F2, CCl3F, CHClF2, CCl4 and SF6. Time series available from the two sites will be presented, compared and critically discussed. In particular, changes in the abundances of theses gases since the peak in inorganic chlorine (Cly, which occurred in 1996-1997) and their intra-annual variability will be characterized with a statistical tool using bootstrap resampling (Gardiner et al., 2008). Trends and their associated uncertainties will be reported and put into perspective with the phase-out regulations of the production of ozone depleting substances adopted and implemented by the Montreal Protocol, its Amendments and Adjustments. For instance, the trends affecting the reservoir species HCl, ClONO2, and their summation which is a good proxy of the total inorganic chlorine, have been calculated using all available daily mean measurements from January 1996 onwards. The following values were obtained for Jungfraujoch, when using 1996 as the reference year: -0.90±0.10%/yr for HCl, -0.92±0.26 %/yr for ClONO2, and -0.96±0.14 %/yr for Cly; in all cases, the uncertainties define the 95% confidence interval around the trend values. For Kitt Peak (covering 1977-2009 but with far fewer measurements than from Jungfraujoch), the corresponding trends are: -0.55±0.34 %/yr for HCl, -1.27±0.84 %/yr for ClONO2 and -0.61±0.51 %/yr for Cly, they are statistically consistent with the Jungfraujoch rates of decrease. Further trend data will be presented at the EGU General Assembly while supplementary information on Jungfraujoch results will be available from communications at the same meeting by Duchatelet et al. (2010), Lejeune et al (2010) and Rinsland et al (2010). Comparisons with model data are also foreseen. Acknowledgments The University of Liège contribution to present work has primarily been supported by the AGACC and SECPEA projects funded by the Belgian Federal Science Policy Office (BELSPO), Brussels. We further acknowledge the support of the GEOMon European project. Work at the NASA Langley Research Center was supported by NASA's Upper Atmospheric Chemistry and Modeling Program (ACMAP). References Duchatelet et al., Updating hydrogen fluoride (HF) FTIR time series above Jungfraujoch: comparison of two retrieval algorithms and impact of line shape models, this issue, 2010. Gardiner, T., A. Forbes, M. De Mazière et al., Trend analysis of greenhouse gases over Europe measured by a network of ground-based remote FTIR instruments, Atmos. Chem. Phys., 8, 6719-6727, 2008. Lejeune et al., Optimized approach to retrieve information on the Tropospheric and Stratospheric Carbonyl Sulfide (OCS) vertical distributions above Jungfraujoch from high-resolution FTIR solar spectra, this issue, 2010. Rinsland et al., Long-term trend of carbon tetrachloride (CCl4) from ground-based high-resolution infrared solar spectra recorded at the Jungfraujoch, this issue, 2010. Rodgers, C.D., Char

Mahieu, Emmanuel; Rinsland, Curtis P.; Gardiner, Tom; Zander, Rodolphe; Demoulin, Philippe; Chipperfield, Martyn P.; Ruhnke, Roland; Chiou, Linda S.; de Mazière, Martine

2010-05-01

337

NOBLE GASES  

EPA Science Inventory

The Noble Gases symposium, on which this report is based, provided comprehensive coverage of the noble gases. The coverage included, but was not limited to, the properties, biokinetics, bioeffects, production and release to the environment, detection techniques, standards, and ap...

338

Manure Gases  

MedlinePLUS

... of manure. The gases of most concern are ammonia and hydrogen sulfide. Other gases of concern include ... in low areas of manure storage or accumulation. Ammonia, which is lighter than air, is found above ...

339

Fallow Contributions to Greenhouse Gas Flux in Dryland Cropping Systems: Observations from a GRACEnet Site in Central North Dakota  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fallow is often used in dryland cropping systems to mitigate production risks by increasing storage of soil water. Increased soil water and a lack of vegetation cover during fallow, however, may contribute to greater greenhouse gas emissions. An investigation was conducted to quantify the effects ...

340

Improving material management to reduce greenhouse gas emissions  

Microsoft Academic Search

Climate change due to greenhouse gas emissions caused by human actions is probably one of the major global environmental problems that we face today.\\u000aIn order to reduce the risk of climate change and the potential effects thereof,\\u000athe emission of greenhouse gases like carbon dioxide (CO2) and methane\\u000a(CH4 ) should be reduced.\\u000aMuch greenhouse gases are emitted due

Marko Peter Hekkert

2000-01-01

341

Greenhouse-gas emissions from soils increased by earthworms  

NASA Astrophysics Data System (ADS)

Earthworms play an essential part in determining the greenhouse-gas balance of soils worldwide, and their influence is expected to grow over the next decades. They are thought to stimulate carbon sequestration in soil aggregates, but also to increase emissions of the main greenhouse gases carbon dioxide and nitrous oxide. Hence, it remains highly controversial whether earthworms predominantly affect soils to act as a net source or sink of greenhouse gases. Here, we provide a quantitative review of the overall effect of earthworms on the soil greenhouse-gas balance. Our results suggest that although earthworms are largely beneficial to soil fertility, they increase net soil greenhouse-gas emissions.

Lubbers, Ingrid M.; van Groenigen, Kees Jan; Fonte, Steven J.; Six, Johan; Brussaard, Lijbert; van Groenigen, Jan Willem

2013-03-01

342

1. Introduction The atmospheric greenhouse effect is the basic mechanism  

E-print Network

1. Introduction The atmospheric greenhouse effect is the basic mechanism whereby absorbed solar radiation is converted by longwave (LW) opacity of atmospheric greenhouse gases (GHGs) and clouds system of the Earth is endowed with a moderately strong greenhouse effect that is characterized by non

343

Greenhouse gas emissions related to Dutch food consumption  

Microsoft Academic Search

The consumption of food products involves emissions of greenhouse gases. Emissions occur in the various stages of the life cycle of food products. In this paper we discuss the greenhouse gas emissions, CO 2 ,C H 4 , and N 2 O, related to Dutch household food consumption. Combinations of greenhouse gas intensities (per D#) with annual household expenditures results

Klaas Jan Kramer; Henri C. Moll; Sanderine Nonhebel; Harry C. Wilting

1995-01-01

344

Costs of reducing greenhouse gas emissions in the USA and Canada  

Microsoft Academic Search

A number of possible policy responses can be adopted in order to address the prospect of increasing greenhouse gases in the earth's atmosphere. These include mitigation measures, that reduce greenhouse gas emissions or enhance the processes that remove greenhouse gases from the atmosphere, adaptation measures that reduce the consequences or damages from climate change, and information measures, including scientific research

W David Montgomery

1996-01-01

345

Overview of global greenhouse effects  

SciTech Connect

This report reviews the factors that influence the evolution of climate and climate change. Recent studies have confirmed that CO{sub 2}, O{sub 3}, N{sub 2}O, CH{sub 4}, and chlorofluorocarbos are increasing in abundance in the atmosphere and can alter the radiation balance by means of the so-called greenhouse effect. The greenhouse effect is as well-accepted phenomenon, but the prediction of its consequences is much less certain. Attempts to detect a human-caused temperature change are still inconclusive. This report presents a discussion of the scientific basis for the greenhouse effect, its relationship to the abundances of greenhouse gases, and the evidence confirming the increases in the abundances. The basis for climate modeling is presented together with an example of the model outputs from one of the most sophisticated modeling efforts. Uncertainties in the present understanding of climate are outlined.

Reck, R.A.

1993-09-01

346

Greenhouse Effect  

NSDL National Science Digital Library

This activity is a greenhouse-effect-in-a-bottle experiment. The lesson includes readings from NEED.org and an inquiry lab measuring the effect of carbon dioxide and temperature change in an enclosed environment.

Connecticut Energy Education

347

Composition and Trends of Short-Lived Trace Gases in the UT/LS over Europe Observed by the CARIBIC Aircraft  

NASA Astrophysics Data System (ADS)

The CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) involves the monthly deployment of an instrument container equipped to make atmospheric measurements from aboard a commercial airliner, and has operated since 2005 from aboard a Lufthansa Airbus 340-600 . Measurements from the container include in-situ trace gas and aerosol analyses and the collection of aerosol and whole air samples for post-flight laboratory analysis. Measurements made from the sampling flasks include greenhouse gas (GHG), halocarbon and nonmethane hydrocarbon (NMHC) analysis. CARIBIC flights originate in Frankfurt, Germany with routes to India, East Asia, South America, North America and Africa, and typical aircraft cruising altitudes of 10-12km allow for the monitoring of the upper troposphere/lower stratosphere (UT/LS) along these routes. Data collected during the aircraft’s departure from and return to Frankfurt provide a 4 year time series of near-monthly measurements of the composition of the UT/LS above Europe. Here we present a discussion of the composition of short-lived trace gases in the whole air samples collected above Europe during CARIBIC flights. Over 150 air samples were collected between May 2005 and July 2009, or about 4 samples per month. Of the whole air samples collected, about 45% showed influence by stratospheric air (i.e. very low values of GHG, NMHC and halocarbons, elevated O3, high potential vorticity). The remaining samples were representative of the upper troposphere; back trajectories for these samples indicate that a little over half were collected in air masses that had been in the boundary layer within the previous 8 days. The predominant source regions for these samples were the Gulf of Mexico and continental North America. Owing to their wide range of chemical lifetimes and the varying composition of emissions, short-lived trace gases transported to the UT/LS can be useful indicators of source region, photochemical processing and transport timescales of an air mass. Seasonal and longer-term trends in trace gases and trace gas composition are discussed, as well as composition of air masses having different origins. Additionally, we apply relationships between the different species, particularly the NMHC, to gain a qualitative understanding of photochemical processes occurring during transport from the boundary layer to the upper troposphere over Europe.

Baker, A. K.; Brenninkmeijer, C. A.; Oram, D. E.; O'Sullivan, D. A.; Slemr, F.; Schuck, T. J.

2009-12-01

348

Urban greenhouse gas mole fraction in-situ measurements: Results from the Indianapolis Flux Experiment (INFLUX)  

NASA Astrophysics Data System (ADS)

The Indianapolis Flux Experiment (INFLUX) was designed to develop and evaluate methods for the measurement and modeling of greenhouse gas fluxes from urban environments. Determination of greenhouse gas fluxes and uncertainty bounds is essential for the evaluation of the effectiveness of mitigation strategies. The current INFLUX observation network includes twelve in-situ tower-based, continuous measurements of CO2, CO, and CH4, flask sampling of 14CO2 and other trace gases, and periodic aircraft sampling of greenhouse gases and meteorological conditions. Eddy covariance and radiative flux are measured at four of the tower sites, and a scanning Doppler lidar was installed in April 2013; both are used to quantify key boundary layer meteorological properties and evaluate model performance. Additionally, a total carbon column observing network (TCCON) column remote sensing station was deployed August - December 2012. The data from the towers, TCCON, and aircraft measurements are being used in an inverse-modeling approach to yield estimates of the urban area flux at 1 km2 resolution. Very high space/time resolution estimates of fossil fuel carbon emissions (Hestia project) offer state-of-the-art "bottom up" emissions estimates for the city and its surroundings. Here we present an overview of the progress from INFLUX, with a focus on tower-based results. With this high density of urban tower-based greenhouse gas measurements, we will quantify horizontal and vertical spatial patterns in atmospheric mole fractions of CO2, CO, and CH4 in Indianapolis. The consistency of the observed horizontal gradients with that expected based on differences in land-cover contributions according to footprint analysis will be evaluated. The ability to correctly model transport and mixing in the atmospheric boundary layer, responsible for carrying greenhouse gases from their source to the point of measurement, is essential. Thus we investigate differences between the modeled and observed sensible heat flux, latent heat flux, air temperature, and wind speed.

Miles, Natasha; Lauvaux, Thomas; Davis, Kenneth; Richardson, Scott; Sarmiento, Daniel; Sweeney, Colm; Karion, Anna; Hardesty, Robert Michael; Turnbull, Jocelyn; Iraci, Laura; Gurney, Kevin; Razlivanov, Igor; Obiminda Cambaliza, Maria; Shepson, Paul; Whetstone, James

2014-05-01

349

CD Greenhouse  

NSDL National Science Digital Library

In this activity, learners plant seeds and watch them sprout and grow inside a CD case. This is a creative way to introduce learners to the process of germination as well as plant anatomy and elements of habitat. Learners will be surprised that they can construct a functioning greenhouse inside a simple CD case.

Workshop, Watsonville E.

2011-01-01

350

The Greenhouse Effect Does Exist!  

Microsoft Academic Search

In particular, without the greenhouse effect, essential features of the atmospheric temperature profile as a function of height cannot be described, i.e., the existence of the tropopause above which we see an almost isothermal temperature curve, whereas beneath it the temperature curve is nearly adiabatic. The relationship between the greenhouse effect and observed temperature curve is explained and the paper

Jochen Ebel

2009-01-01

351

Report urges greenhouse action now  

SciTech Connect

A recent report that is a product of a process initiated and monitored by three major international organizations, the United Nations Environmental Program, the World Meteorological Organization, and the International Council of Scientific Unions, brings the greenhouse effect into the public eye. The report estimates rates of temperature increase of the earth due to CO/sub 2/ plus the other greenhouse gases. Estimates of the greenhouse effect arising from unrestrained gas emissions and a highly sensitive climate or strong global restraint of emissions and a low climate sensitivity range from 0.8 to 0.06/sup 0/C per decade. Long term policies that the report recommends should be reexamined are increased efficiency in the consumption of energy and a shift toward alternative energy to reduce CO/sub 2/ emissions and reforestation to remove CO/sub 2/ from the atmosphere.

Kerr, R.A.

1988-07-01

352

Observation-based assessment of stratospheric fractional release, lifetimes, and Ozone Depletion Potentials of ten important source gases  

NASA Astrophysics Data System (ADS)

Estimates of the recovery time of stratospheric ozone heavily rely on the exact knowledge of the processes that lead to the decomposition of the relevant halogenated source gases. Crucial parameters in this context are Fractional Release Factors (FRFs) as well as stratospheric lifetimes and Ozone Depletion Potentials (ODPs). We here present data from the analysis of air samples collected between 2009 and 2011 on board research aircraft flying in the mid- and high latitudinal stratosphere and infer the above-mentioned parameters for ten major source gases:CFCl3 (CFC-11), CF2Cl2 (CFC-12), CF2ClCFCl2(CFC-113), CCl4 (carbon tetrachloride),CH3CCl3 (methyl chloroform), CHF2Cl (HCFC-22), CH3CFCl2 (HCFC-141b), CH3CF2Cl (HCFC-142b), CF2ClBr (H-1211), and CF3Br (H-1301). The inferred correlations of their FRFs with mean ages of air reveal less decomposition as compared to previous studies for most compounds. When using the calculated set of FRFs to infer equivalent stratospheric chlorine we find a reduction of more than 20% as compared to the values inferred in the most recent Scientific Assessment of Ozone Depletion by the World Meteorological Organisation (WMO, 2011). We also note that FRFs and their correlations with mean age are not generally time-independent as often assumed. The stratospheric lifetimes were calculated relative to that of CFC-11. Within our uncertainties the inferred ratios between lifetimes agree with those between stratospheric lifetimes from recent WMO reports except for CFC-11, CFC-12 and CH3CCl3. Finally we calculate lower ODPs than WMO for six out of ten compounds with changes most pronounced for the three HCFCs. Collectively these newly calculated values may have important implications for the severity and recovery time of stratospheric ozone loss.

Laube, J. C.; Keil, A.; Bönisch, H.; Engel, A.; Röckmann, T.; Volk, C. M.; Sturges, W. T.

2012-10-01

353

Observation-based assessment of stratospheric fractional release, lifetimes, and ozone depletion potentials of ten important source gases  

NASA Astrophysics Data System (ADS)

Estimates of the recovery time of stratospheric ozone heavily rely on the exact knowledge of the processes that lead to the decomposition of the relevant halogenated source gases. Crucial parameters in this context are fractional release factors (FRFs) as well as stratospheric lifetimes and ozone depletion potentials (ODPs). We here present data from the analysis of air samples collected between 2009 and 2011 on board research aircraft flying in the mid- and high-latitude stratosphere and infer the above-mentioned parameters for ten major source gases: CFCl3 (CFC-11), CF2Cl2 (CFC-12), CF2ClCFCl2 (CFC-113), CCl4 (carbon tetrachloride), CH3CCl3 (methyl chloroform), CHF2Cl (HCFC-22), CH3CFCl2 (HCFC-141b), CH3CF2Cl (HCFC-142b), CF2ClBr (H-1211), and CF3Br (H-1301). The inferred correlations of their FRFs with mean ages of air reveal less decomposition as compared to previous studies for most compounds. When using the calculated set of FRFs to infer equivalent stratospheric chlorine, we find a reduction of more than 20% as compared to the values inferred in the most recent Scientific Assessment of Ozone Depletion by the World Meteorological Organisation (WMO, 2011). We also note that FRFs and their correlations with mean age are not generally time-independent as often assumed. The stratospheric lifetimes were calculated relative to that of CFC-11. Within our uncertainties the ratios between stratospheric lifetimes inferred here agree with the values in recent WMO reports except for CFC-11, CFC-12 and CH3CCl3. Finally, we calculate lower ODPs than recommended by WMO for six out of ten compounds, with changes most pronounced for the three HCFCs. Collectively these newly calculated values may have important implications for the severity and recovery time of stratospheric ozone loss.

Laube, J. C.; Keil, A.; Bönisch, H.; Engel, A.; Röckmann, T.; Volk, C. M.; Sturges, W. T.

2013-03-01

354

Study of the Effects on Student Knowledge and Perceptions of Activities Related to Submetering the 6th Grade Wing of a Middle School, to Displaying the Carbon Footprint, and to Efforts to Reduce Energy Consumption and Greenhouse Gases  

ERIC Educational Resources Information Center

The purpose of the study was to determine the effects upon student knowledge and perceptions regarding greenhouse gas emissions as a result of an intervention relying upon the submetering the 6th grade wing of a Middle School, displaying the information regarding electrical consumption and carbon footprint, and reducing the electrical consumption…

Peck, Rick

2009-01-01

355

40 CFR 1036.108 - Greenhouse gas emission standards.  

Code of Federal Regulations, 2012 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride. This section describes the applicable CO2 , N2 O, and CH4 standards for engines. Except as...

2012-07-01

356

40 CFR 1036.108 - Greenhouse gas emission standards.  

Code of Federal Regulations, 2013 CFR

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride. This section describes the applicable CO2 , N2 O, and CH4 standards for engines. Except as...

2013-07-01

357

40 CFR 1036.108 - Greenhouse gas emission standards.  

...group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride. This section describes the applicable CO2 , N2 O, and CH4 standards for engines. Except as...

2014-07-01

358

Comparing the effects of greenhouse gas emissions on global warming  

E-print Network

Policies dealing with global warming require a measure of the effects of the emissions of greenhouse gases that create different magnitudes of instantaneous radiative forcing and have different lifetimes. The Global Warming ...

Eckaus, Richard S.

1990-01-01

359

Energy Efficiency and Emerging Markets for Greenhouse Gas Trading  

E-print Network

an important economic input into the generation of electricity in the United States. The commoditization of the Greenhouse Gases will likely develop in a similar fashion but on a global scale, becoming another economic input into electricity generation...

Ferguson, M.

360

What is a Greenhouse?  

NSDL National Science Digital Library

This activity is designed to familiarize students with how a greenhouse retains heat by building simple models. As a result of this activity, students will come to understand that greenhouses are useful because they both allow sunlight to enter and prevent heat from escaping. The transparent covering of the greenhouse allows visible light to enter unhindered, where it warms the interior as it is absorbed by the material within. The student guide has an overall description of the activity, a list of materials, the procedure, and observations and questions. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

361

Assessing the uncertainty associated with national greenhouse gas emission inventories  

Microsoft Academic Search

The uncertainty associated with the Austrian Greenhouse Gas emission inventory has been determined for the gases CO2, CH4 and N2O and for the overall greenhouse potential. Expert interviews were conducted to obtain uncertainties in inventory input data. Based on these interviews, error distributions were developed and combined using Monte-Carlo analysis. Results for all sources and gases combined indicate an overall

Wilfried Winiwarter; Kristin Rypdal

2001-01-01

362

Greenhouse Gas Emissions from Hydroelectric Reservoirs in Tropical Regions  

Microsoft Academic Search

This paper discusses emissions by power-dams in the tropics. Greenhouse gas emissions from tropical power-dams are produced underwater through biomass decomposition by bacteria. The gases produced in these dams are mainly nitrogen, carbon dioxide and methane. A methodology was established for measuring greenhouse gases emitted by various power-dams in Brazil. Experimental measurements of gas emissions by dams were made to

Luiz Pinguelli Rosa; Marco Aurelio dos Santos; Bohdan Matvienko; Ednaldo Oliveira dos Santos; Elizabeth Sikar

2004-01-01

363

Atmospheric gases  

NSDL National Science Digital Library

Which gases make up the atmosphere? This activity page, part of an interactive laboratory series for grades 8-12, introduces students to the gaseous components of the atmosphere. Students explore the main gases of the atmosphere using a pop-up pie chart. Descriptions of the gases and their percentages in the atmosphere are provided. Students read about water vapor in the atmosphere, and an animation shows a simplified process of precipitation. A pop-up window explains the effects of dust on the atmosphere, and a photograph shows how large amounts of dust in the atmosphere create the reds and oranges displayed in sunsets. Finally, ozone is introduced to students as a necessary component of human life on Earth. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

364

40 CFR 600.108-08 - Analytical gases.  

...CONTINUED) ENERGY POLICY FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy and Carbon-Related Exhaust Emission... The analytical gases for all fuel economy testing must meet the criteria...

2014-07-01

365

Middle-School Understanding of the Greenhouse Effect using a NetLogo Computer Model  

NASA Astrophysics Data System (ADS)

We investigated the effectiveness of a freely available agent based, modeling program as a learning tool for seventh and eighth grade students to explore the greenhouse effect without added curriculum. The investigation was conducted at two Maine middle-schools with 136 seventh-grade students and 11 eighth-grade students in eight classes. Students were given a pre-test that consisted of a concept map, a free-response question, and multiple-choice questions about how the greenhouse effect influences the Earth's temperature. The computer model simulates the greenhouse effect and allows students to manipulate atmospheric and surface conditions to observe the effects on the Earth’s temperature. Students explored the Greenhouse Effect model for approximately twenty minutes with only two focus questions for guidance. After the exploration period, students were given a post-test that was identical to the pre-test. Parametric post-test analysis of the assessments indicated middle-school students gained in their understanding about how the greenhouse effect influences the Earth's temperature after exploring the computer model for approximately twenty minutes. The magnitude of the changes in pre- and post-test concept map and free-response scores were small (average free-response post-test score of 7.0) compared to an expert's score (48), indicating that students understood only a few of the system relationships. While students gained in their understanding about the greenhouse effect, there was evidence that students held onto their misconceptions that (1) carbon dioxide in the atmosphere deteriorates the ozone layer, (2) the greenhouse effect is a result of humans burning fossil fuels, and (3) infrared and visible light have similar behaviors with greenhouse gases. We recommend using the Greenhouse Effect computer model with guided inquiry to focus students’ investigations on the system relationships in the model.

Schultz, L.; Koons, P. O.; Schauffler, M.

2009-12-01

366

GREENHOUSE GAS ANALYSIS OF SOLAR-THERMAL ELECTRICITY GENERATION  

Microsoft Academic Search

Solar-thermal electricity generation contributes to climate change because it incurs the emission of greenhouse gases during the provision of services and the production of materials needed for the construction and operation of solar power plants. These greenhouse gas costs (GGC) can be determined using either material inventories in physical units or monetary cost breakdowns. Solar-only plants employing parabolic troughs, central

M. LENZEN

1999-01-01

367

Greenhouse Effect Detection Experiment (GEDEX). Selected data sets  

NASA Technical Reports Server (NTRS)

This CD-ROM contains selected data sets compiled by the participants of the Greenhouse Effect Detection Experiment (GEDEX) workshop on atmospheric temperature. The data sets include surface, upper air, and/or satellite-derived measurements of temperature, solar irradiance, clouds, greenhouse gases, fluxes, albedo, aerosols, ozone, and water vapor, along with Southern Oscillation Indices and Quasi-Biennial Oscillation statistics.

Olsen, Lola M.; Warnock, Archibald, III

1992-01-01

368

Soil organic matter: Distribution, genesis, and management to reduce greenhouse gas emissions  

Microsoft Academic Search

In this paper we describe the accumulation of soil organic matter (SOM) during pedogenesis and the processes that can lead to the emission of greenhouse gases (CO2, CH4, N2O) to the atmosphere via SOM decomposition and denitrification. We discuss the role of management on SOM accumulation and loss, and the potential for controlling emission or comsumption of greenhouse gases by

Mark G. Johnson; Elissa R. Levine; Jeffrey S. Kern

1995-01-01

369

Spatial distributions, sources and sinks of methyl iodide, methyl chloride, methyl bromide, carbonyl sulfide, and other trace gases from observations over North America during INTEX-NA  

NASA Astrophysics Data System (ADS)

Whole air sampling aboard the NASA DC-8 in summer 2004 as part of the Intercontinental Chemical Transport Experiment (INTEX-NA) provided an excellent opportunity to obtain a picture of the spatial distribution of trace gases over the North American continent. Our nearly 3,000 measurements of a wide range of trace gases are a crucial component in the investigation of the influence of anthropogenic and biogenic sources, fires, photochemical and biogenic sinks, long range transport and convection on the northern hemisphere troposphere. Here we highlight just a few interesting features of the trace gas distributions observed during INTEX-NA, including the large contrasts between the character of marine and continental boundary layer air masses. We also saw surprisingly high methyl iodide levels over the continent, which we attribute to strong marine influence during several INTEX-NA flights. However, we do not rule out a small terrestrial source for methyl iodide. The effect of vegetative draw-down was evident in the vertical distribution of carbonyl sulfide during INTEX-NA. Methyl chloride levels were also diminished over the same regions. Methyl bromide "hot spots" over certain agricultural regions of the US suggest continued use of this gas as a soil fumigant.

Blake, N. J.; Blake, D. R.; Baker, A.; Beyersdorf, A.; Doezema, L.; Meinardi, S.; Novak, B.; Barletta, B.; Midyett, J.; Kamboures, M.; Fuelberg, H. E.; Vay, S. A.; Rowland, F. S.

2005-12-01

370

Greenhouse gas sources in the southern San Joaquin Valley of California derived from Positive Matrix Factorization of CalNex 2010 observations  

NASA Astrophysics Data System (ADS)

Quantifying the contributions of methane (CH4) and nitrous oxide (N2O) emission from sources in the southern San Joaquin valley is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law (California Global Warming Solutions Act 2006) implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The "bottom-up" emission factors for CH4 and N2O have large uncertainties and there is a lack of adequate "top-down" measurements to characterize emission rates from sources. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agriculture and industry intensive region with large concentration of dairies, refineries and active oil fields which are known CH4 sources while agricultural soil management and vehicular combustion are known sources of N2O. In summer of 2010, GHG sources in the southern San Joaquin valley were investigated as part of the CalNex (California at the Nexus of Air Quality and Climate Change) campaign. Measurements of GHG gases (CO2, CH4, and N2O) and the combustion tracer CO were performed at the Bakersfield super-site over a period of six weeks using fast response lasers based on cavity enhanced absorption spectroscopy (LGR Inc. CA). Coincident measurements of hundreds of volatile organic compounds (VOCs) served as anthropogenic and biogenic tracers of the GHG sources at local and regional levels. We present the results of Positive Matrix Factorization (PMF) analysis applied to the GHGs, CO, and 60 VOCs to define dominant source emission profiles. Seven source factors were identified and used to attribute the contribution of regional sources to enhancements above the background. Dairy operations were found to be the largest CH4 source in the region with approximately 80% of the regional emissions attributed to the 'dairy' factor. Factors dominated by 'vehicular combustion' and 'evaporative emissions' had negligible contributions to regional CH4 or N2O emissions. We identified an 'agricultural emissions' factor as the dominant regional source of N2O. Emission Factors of GHG enhancements with respect to specific source tracers are derived from the PMF analysis and compared to emission factors from prior source-specific and regional field studies (e.g. Shaw et al., 2007; Bon et al., 2006; CABERNET 2011) to gain a better understanding of GHG source contributions in the southern San Joaquin valley.

Guha, A.; Gentner, D. R.; Weber, R.; Baer, D. S.; Gardner, A.; Provencal, R. A.; Goldstein, A. H.

2012-12-01

371

Automotive Emissions and the Greenhouse Effect  

NSDL National Science Digital Library

In this activity about global climate change, learners will conduct an experiment and collect data to compare the amount of carbon dioxide (CO2) in four different sources of gases. Learners will then determine the CO2 contribution from automobiles and brainstorm ways they can reduce their carbon footprint. This lesson guide includes background information about the greenhouse effect and handouts for learners.

Texas, Railroad C.

2007-01-01

372

SIMULATION IN COMPLEX LEARNING DOMAIN: GREENHOUSE EFFECT  

Microsoft Academic Search

The greenhouse effect is one of the most complex topics in the Finnish national core curriculum, and understanding of it requires knowledge of many science concepts like radiation as well as the role of atmosphere, clouds and gases. Research has indicated that students' misconceptions or alternative conceptions are a formidable challenge in the enactment of instruction for students' understanding of

J. KUKKONEN; S. KÄRKKÄINEN; T. KEINONEN; P. VESALA; A. HURRI

373

Policy Analysis of the Greenhouse Effect (PAGE)  

EPA Science Inventory

PAGE09 is a spreadsheet probabilistic model written in Microsoft Office Excel. The model calculates regional and global impacts of climate change, and social costs of different greenhouse gases. It also calculates the costs of abatement and adaptation. It is an Integrated Assessm...

374

Global and Regional Greenhouse Gas Emissions Scenarios  

Microsoft Academic Search

This article presents a set of 30 greenhouse gas (GHG) emissions scenarios developed by six modeling teams. The scenarios describe trajectories up to 2100 by four world regions. Today the distribution of both income and GHG emissions is very unbalanced between various world regions. Furthermore, the relative importance of individual gases and sources of emission differ from region to region.

Tom Kram; Tsuneyuki Morita; Keywan Riahi; R. Alexander Roehrl; Sascha Van Rooijen; Alexei Sankovski; Bert De Vries

2000-01-01

375

Cluster mechanism of the anti-greenhouse effect  

Microsoft Academic Search

The Earth’s atmosphere is a complex dynamic system, which protects the biosphere. One of the significant factors impacting Earth’s radiation balance is the greenhouse effect. Its enhancement is not only due to an increase in solar activity but also due to an increase in the content of gases with pronounced radiation properties in the atmosphere. Water vapor and atmospheric gases,

V. N. Chukanov; A. E. Galashev

2008-01-01

376

How might global warming and the greenhouse effect impact rangelands?  

Microsoft Academic Search

he earth has a history of almost continuous climatic change. The presence of carbon dioxide and other greenhouse gases are ex- tremely important to the maintenance of the earth's temperature. However, increases in the quantities of these gases—especialy carbon dioxide due to human activities—is raising con- cern about climatic change and global warming.

Khair J. El-Shatnawi; Taoufik Ksiksi

377

CLIMATICALLY-ACTIVE GASES IN THE EASTERN BOUNDARY UPWELLING AND OXYGEN MINIMUM ZONE (OMZ) SYSTEMS  

E-print Network

to the greenhouse gases (hereafter GHG). From in-situ ocean measurements, the uncertainty of the net global ocean-atmosphere and the atmosphere [1, 2], notably with respect to the greenhouse gases (here- after GHG). Invasion or outgasing) contribute very significantly to the gas exchange between the ocean and the atmosphere, notably with respect

Garbe, Christoph S.

378

Greenhouse Light and Temperature  

NSDL National Science Digital Library

Make your own miniature greenhouse and measure the light levels at different "times of day"--modeled by changing the angle of a lamp on the greenhouse--using a light sensor. Next, investigate the temperature in your greenhouse with and without a cover. Learn how a greenhouse works and how you can regulate the temperature in your model greenhouse.

2012-07-19

379

Noble Gases  

NASA Astrophysics Data System (ADS)

The noble gases are the group of elements - helium, neon, argon, krypton, xenon - in the rightmost column of the periodic table of the elements, those which have "filled" outermost shells of electrons (two for helium, eight for the others). This configuration of electrons results in a neutral atom that has relatively low electron affinity and relatively high ionization energy. In consequence, in most natural circumstances these elements do not form chemical compounds, whence they are called "noble." Similarly, much more so than other elements in most circumstances, they partition strongly into a gas phase (as monatomic gas), so that they are called the "noble gases" (also, "inert gases"). (It should be noted, of course, that there is a sixth noble gas, radon, but all isotopes of radon are radioactive, with maximum half-life a few days, so that radon occurs in nature only because of recent production in the U-Th decay chains. The factors that govern the distribution of radon isotopes are thus quite different from those for the five gases cited. There are interesting stories about radon, but they are very different from those about the first five noble gases, and are thus outside the scope of this chapter.)In the nuclear fires in which the elements are forged, the creation and destruction of a given nuclear species depends on its nuclear properties, not on whether it will have a filled outermost shell when things cool off and nuclei begin to gather electrons. The numerology of nuclear physics is different from that of chemistry, so that in the cosmos at large there is nothing systematically special about the abundances of the noble gases as compared to other elements. We live in a very nonrepresentative part of the cosmos, however. As is discussed elsewhere in this volume, the outstanding generalization about the geo-/cosmochemistry of the terrestrial planets is that at some point thermodynamic conditions dictated phase separation of solids from gases, and that the Earth and the rest of the inner solar were made by collecting the solids, to the rather efficient exclusion of the gases. In this grand separation the noble gases, because they are noble, were partitioned strongly into the gas phase. The resultant generalization is that the noble gases are very scarce in the materials of the inner solar system, whence their common synonym "rare gases."This scarcity is probably the most important single feature to remember about noble-gas cosmochemistry. As illustration of the absolute quantities, for example, a meteorite that contains xenon at a concentration of order 10 -10 cm3STP g -1 (4×10-15 mol g-1) would be considered relatively rich in xenon. Yet this is only 0.6 ppt (part per trillion, fractional abundance 10-12) by mass. In most circumstances, an element would be considered efficiently excluded from some sample if its abundance, relative to cosmic proportions to some convenient reference element, were depleted by "several" orders of magnitude. But a noble gas would be considered to be present in quite high concentration if it were depleted by only four or five orders of magnitude (in the example above, 10-10 cm3STP g-1 of xenon corresponds to depletion by seven orders of magnitude), and one not uncommonly encounters noble-gas depletion of more than 10 orders of magnitude.The second most important feature to note about noble-gas cosmochemistry is that while a good deal of the attention given to noble gases really is about chemistry, traditionally a good deal of attention is also devoted to nuclear phenomena, much more so than for most other elements. This feature is a corollary of the first feature noted above, namely scarcity. A variety of nuclear transmutation processes - decay of natural radionuclides and energetic particle reactions - lead to the production of new nuclei that are often new elements. Most commonly, the quantity of new nuclei originating in nuclear transmutation is very small compared to the quantity already present in the sample in question,

Podosek, F. A.

2003-12-01

380

What do near-term observations tell us about long-term developments in greenhouse gas emissions?  

SciTech Connect

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term developments in the global energy system and land-use patterns and the associated emissions. The phenomena that determine these longterm developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years). Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales. In this letter, we discuss some of differences between the factors that operate on in the short and long term and use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments. Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends. The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce them.

Van Vuuren, Detlef; Edmonds, James A.; Smith, Steven J.; Calvin, Katherine V.; Karas, Joseph F.; Kainuma, M.; Nakicenovic, Nebojsa; Riahi, Keywan; van Ruijven, Bas; Swart, Robert; Thomson, Allison M.

2010-10-26

381

Direct electrical observation of plasma wave-related effects in GaN-based two-dimensional electron gases  

NASA Astrophysics Data System (ADS)

In this work, signatures of plasma waves in GaN-based high electron mobility transistors were observed by direct electrical measurement at room temperature. Periodic grating-gate device structures were fabricated and characterized by on-wafer G-band (140-220 GHz) s-parameter measurements as a function of gate bias voltage and device geometry. A physics-based equivalent circuit model was used to assist in interpreting the measured s-parameters. The kinetic inductance extracted from the measurement data matches well with theoretical predictions, consistent with direct observation of plasma wave-related effects in GaN-channel devices at room temperature. This observation of electrically significant room-temperature plasma-wave effects in GaN-channel devices may have implications for future millimeter-wave and THz device concepts and designs.

Zhao, Y.; Chen, W.; Li, W.; Zhu, M.; Yue, Y.; Song, B.; Encomendero, J.; Sensale-Rodriguez, B.; Xing, H.; Fay, P.

2014-10-01

382

Methods for exploring management options to reduce greenhouse gas emissions from tropical grazing systems  

Microsoft Academic Search

Increasing atmospheric concentrations of ‘greenhouse gases’ are expected to result in global climatic changes over the next decades. Means of evaluating and reducing greenhouse gas emissions are being sought. In this study an existing simulation model of a tropical savanna woodland grazing system was adapted to account for greenhouse gas emissions. This approach may be able to be used in

S. Mark Howden; David H. White; Greg M. Mckeon; Joe C. Scanlan; John O. Carter

1994-01-01

383

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation  

E-print Network

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation Bruce A. Mc Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation Today society faces important in an effort to reduce net emissions of greenhouse gases. While agriculture is a small emitter of the most

McCarl, Bruce A.

384

An integrated model for the assessment of the greenhouse effect: The Dutch approach  

Microsoft Academic Search

This paper describes a simulation policy model of the combined greenhouse effects of trace gases. With this model, the Integrated Model for the Assessment of the Greenhouse Effect (IMAGE) scenarios for the future impact of the greenhouse effect can be made, based on different assumptions for technological and socio-economic developments. The contribution of each trace gas can be estimated separately.

Jan Rotmans; HANS DE BOOIS; Robert J. Swart

1990-01-01

385

What Is the Greenhouse Effect?  

NSDL National Science Digital Library

In this introductory textbook chapter, students learn that life on Earth would not be possible without the atmosphere and its greenhouse effect. The history of research on the role of greenhouse gases in the atmosphere is presented, and the concept of contemporary climate change and global warming are introduced. This is the first chapter in the unit, Climate Change, which addresses the question of how human activities are changing Earth's climate. The resource includes a textbook chapter, integrated hands-on and inquiry activities, links to current news articles, and a suite of pre and post unit assessments. A teacher's guide supports classroom use. The resource is part of Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

386

Observations of tropospheric trace gases and meteorology in rural Virginia using an unattended monitoring system: Hurricane Hugo (1989), A case study  

NASA Astrophysics Data System (ADS)

Tropospheric trace gases such as ozone and reactive nitrogen compounds exert a strong influence on global climate, but observations of these species are limited by the necessity of having a trained observer on site to monitor instruments. A technique using modern communications technology has been developed to transport and review data collected at a remote site. The site was equipped with a PAM II station and satellite data link so that raw, real-time data and equipment status were available for inspection readily on a workstation at the University of Maryland campus through a combination of wide and local area networks. CO, NO, NOy, O3, UV radiative flux, and meteorological parameters were measured in rural Virginia for a full year. The cleanest air observed over the year was associated with the passage of Hurricane Hugo over the mid-Atlantic region on September 22, 1989. Hourly average data for concentrations of CO, NOy, and O3 observed during this particular case study were as low as 90 ppbv, 570 pptv, and 11 ppbv, respectively. Within this period, daytime NO was highly variable, ranging between the detection limit of the instrument, ˜ 20 pptv, and 2.4 ppbv. These concentrations are well below the hourly concentration average at this site for these species during September 1989. Equivalent potential temperature, ?e, in conjunction with the trace gas concentrations and geostrophic back-trajectories, illustrates how this hurricane influenced air parcel history; observed concentrations of CO and NOy increased with the time the air parcel spent over land. Observations at this site were consistent with current hurricane models based on mean soundings and aircraft flights. Hurricanes over land also appear to redistribute air vertically throughout the troposphere, creating the potential for substantial post-storm tropospheric column O3 increase.

Doddridge, Bruce G.; Dickerson, Russell R.; Holland, Joshua Z.; Cooper, James N.; Wardell, R. Glenn; Poulida, Olga; Watkins, James G.

1991-05-01

387

Sulfuric acid vapor and other cloud-related gases in the Venus atmosphere - Abundances inferred from observed radio opacity  

NASA Technical Reports Server (NTRS)

It is suggested that the absorbing characteristics of sulfuric acid vapor appear to reconcile what had been thought to be an inconsistency among measurements and deductions regarding the constituents of the Venus atmosphere and radio occultation, radar reflection, and radio emission measurements of its opacity. Laboratory measurements of sulfuric acid, sulfur dioxide, water vapor, and carbon dioxide are used to model relative contributions to opacity as a function of height in a way that is consistent with observations of the constituents and absorbing properties of the atmosphere. It is concluded that sulfuric acid vapor is likely to be the principal microwave absorber in the 30-50 km altitude range of the middle atmosphere of Venus.

Steffes, P. G.; Eshleman, V. R.

1982-01-01

388

Meridional Distribution Feature of Minor Constituents as Observed by IMG Sensor Aboard ADEOS Satellite  

NASA Astrophysics Data System (ADS)

Interferometric Monitor for Greenhouse gases (IMG) sensor aboard the Advanced Earth Observing Satellite (ADEOS) is a Fourier Transform type infrared spectrometer (FT-IR) which was developed aiming to measure the greenhouse gases in the atmosphere, particularly in the troposphere. It was operated for about 7 months from November 1996 up to the end of the life time of the ADEOS on June 1997, and measured over 138000 terrestrial thermal emission spectra which are available for the retrieval analysis. A cloud detection and correction method based on the analysis of the initially retrieved temperature profiles were presented. Using the cloud correction method, meridional distribution of temperature and minor constituents were preliminarily ana yzed

Imasu, R.; Ogawa, T.; Shimoda, H.

389

Airborne Observations of NO, NOy, Particles, and Other Trace Gases Over the Antarctic Continent During ANTCI 2003  

NASA Astrophysics Data System (ADS)

The Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) field studies in 1998 and 2000 generated several surprising atmospheric-chemistry findings. Based on observations at South Pole's (SP) Atmospheric Research Observatory, very little gas phase sulfur was measured during these studies, but unexpectedly high levels of NO were recorded (e.g., 650 pptv). Although it has now been convincingly demonstrated that the source of this NO is its emission from the snowpack due to the photolysis of nitrate ions, major unanswered questions persist. Among the more significant of these has been the issue of "the spatial extent of this phenomenon". Do these highly elevated levels of NO at SP occur only in the immediate region surrounding SP? If not, how far out do they range over the 1000+ km wide Antarctic plateau? Equally important is the question: what does the altitudinal profile of NO look like over the plateau, and does the presence of elevated NO lead to the formation of an OH oxidizing canopy over this region? There also remain the pivotal issues of identifying the primary source of nitrogen to the plateau as well as determining the major pathways by which this reactive nitrogen is lost from near surface snow (~ 1m). During the Antarctic Tropospheric Chemistry Investigation (ANTCI), an airborne platform was added to extend the sampling already taking place at SP. The Twin Otter aircraft provided the opportunity to examine several of the issues raised above requiring three-dimensional sampling. Over the time period of 27 November to 6 December 2003, a total of 10 data collection flights were flown. Major species sampled were NO, NOy and CN particles. The NO and NOy were measured using a chemiluminescence instrument equipped with a Molybdenum converter, and particles were measured using a standard CN counter. More limited observations were made of DMS, CHBr3, CH3I, CH3ONO2, and other low molecular weight NMHC's using evacuated canisters in conjunction with grab-sampling. Details concerning the results from these flights will be presented.

Davis, D. D.; Blake, D. R.; Weber, R. J.; Buhr, M.

2004-12-01

390

Greenhouses and their humanizing synergies  

NASA Astrophysics Data System (ADS)

Greenhouses in space will require advanced technical systems of automatic watering, soil-less cultivation, artificial lighting, and computerized observation of plants. Functions discussed for plants in space habitats include physical/health requirements and human psychology, social cohesion, as well as the complex sensorial benefits of plants for humans. The authors consider the role of plants in long-term space missions historically since 1971 (Salyut 1) and propose a set of priorities to be considered within the design requirements for greenhouses and constructed environments given a range of benefits associated with plant-human relationships. They cite recent research into the use of greenhouses in extreme environments to reveal the relative importance of greenhouses for people living in isolated locations. Additionally, they put forward hypotheses about where greenhouses might factor into several strata of human health. In a recent design-in-use study of astronauts' experiences in space habitats discussed in Architecture for Astronauts (Springer Press 2011) it was found that besides the basic advantages for life support there are clearly additional "side benefits" for habitability and physical wellbeing, and thus long-term mission success. The authors have composed several key theses regarding the need to promote plant-human relationships in space, including areas where synergy and symbiosis occur. They cite new comprehensive research into the early US Space Program to reveal where programmatic requirements could be added to space architecture to increase the less quantifiable benefits to astronauts of art, recreation, and poetic engagement with their existential condition of estrangement from the planet. Specifically in terms of the technological requirements, the authors propose the integration of a new greenhouse subsystem component into space greenhouses—the Mobile Plant Cultivation Subsystem—a portable, personal greenhouse that can be integrated functionally into future greenhouse constructions in space.

Haeuplik-Meusburger, Sandra; Paterson, Carrie; Schubert, Daniel; Zabel, Paul

2014-03-01

391

Gases: Characteristics and Properties  

NSDL National Science Digital Library

The first site related to ideal gas, called Ideal and Real Gas Laws, is maintained by Liina Ladon of Townsen University (1). Visitors can read about the properties of ideal gases, what the ideal gas law is, how to use it, and much more. The next site, titled Gas Laws, (2) is offered by the Ohio State University Department of Chemistry. This interactive site contains Shockwave movies of animations and audio files that describe what a gas is, the Ideal Gas Law equation, mixtures of gases, and problems using the ideal gas law. The University of Oregon site, Virtual Laboratory, teaches about the ideal gas law on the Welcome to the Pressure Chamber page (3). Those who enjoy online interaction will enjoy being able to control the action of a piston in a pressure chamber to see how the gases inside react. The fourth site includes another fun multimedia activity related to ideal gases provided by the Department of Physics and Astronomy at Western Washington University. The Air Filled Balloon in Liquid Nitrogen (4) movie shows an actual experiment of the effects on a balloon that's covered with liquid nitrogen. The page contains some additional information on the science behind the observations. The next site, called Ideal Gas Equations (5) is an online calculator that's part of Kean University's Department of Geology and Meteorology Web site. Users can calculate the pressure, volume, or temperature of a gas by inputting known variables into the various forms. Several methods and variations of calculating the values are provided as well as brief instructions. The next page from North Carolina State University's Basic Concepts in Environmental Science Web site is called Characteristics of Gases (6). Part of a larger learning module, the lesson plans objective is to use the ideal gas law to determine gas volumes at different absolute temperatures and absolute pressures. Everything needed to conduct the activity is provided including links to a volume calculator and practice problems. The seventh site is another animation that illustrates how gases react, called Molecular Model for an Ideal Gas (7). By changing the number of molecules in the chamber, their velocity, and the pressure and width of the container, users get to see how the molecules react to the conditions. The last site, Gases and Their Properties, is maintained by the Electronic Teaching Assistance Program(8). Students learn about the history of gas science, how gas laws describe ideal gases, what Dalton's Law and Graham's Law are, and much more.

Brieske, Joel A.

392

PHYSICAL REVIEW E 87, 012807 (2013) Isothermal absorption of soluble gases by atmospheric nanoaerosols  

E-print Network

, counteracting the warming effect of greenhouse gases [3]. Scavenging of atmospheric gaseous pollutants by cloudPHYSICAL REVIEW E 87, 012807 (2013) Isothermal absorption of soluble gases by atmospheric absorption of atmospheric trace soluble gases by a single droplet whose size is comparable to the molecular

Elperin, Tov

393

Greenhouse gas mitigation options for Washington State  

SciTech Connect

President Clinton, in 1993, established a goal for the United States to return emissions of greenhouse gases to 1990 levels by the year 2000. One effort established to help meet this goal was a three part Environmental Protection Agency state grant program. Washington State completed part one of this program with the release of the 1990 greenhouse gas emissions inventory and 2010 projected inventory. This document completes part two by detailing alternative greenhouse gas mitigation options. In part three of the program EPA, working in partnership with the States, may help fund innovative greenhouse gas reduction strategies. The greenhouse gas control options analyzed in this report have a wide range of greenhouse gas reductions, costs, and implementation requirements. In order to select and implement a prudent mix of control strategies, policy makers need to have some notion of the potential change in climate, the consequences of that change and the uncertainties contained therein. By understanding the risks of climate change, policy makers can better balance the use of scarce public resources for concerns that are immediate and present against those that affect future generations. Therefore, prior to analyzing alternative greenhouse gas control measures, this report briefly describes the phenomenon and uncertainties of global climate change, and then projects the likely consequences for Washington state.

Garcia, N.

1996-04-01

394

Gardening with Greenhouses  

ERIC Educational Resources Information Center

Greenhouses come in all shapes, sizes, and price ranges: from simple hand-built plastic-covered frames to dazzling geodesic domes. Some child care centers install greenhouses as a part of their outdoor garden space. Other centers have incorporated a greenhouse into the building itself. Greenhouses provide a great opportunity for children to grow…

Keeler, Rusty

2010-01-01

395

Observations of 1,1-difluoroethane (HFC152a) at AGAGE and SOGE monitoring stations in 1994-2004 and derived global and regional emission estimates  

Microsoft Academic Search

Ground-based in situ measurements of 1,1-difluoroethane (HFC-152a, CH3CHF2) which is regulated under the Kyoto Protocol are reported under the auspices of the AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System of Observation of halogenated Greenhouse gases in Europe) programs. Observations of HFC-152a at five locations (four European and one Australian) over a 10 year period were recorded. The annual

B. R. Greally; A. J. Manning; S. Reimann; A. McCulloch; J. Huang; B. L. Dunse; P. G. Simmonds; R. G. Prinn; P. J. Fraser; D. M. Cunnold; S. O'Doherty; L. W. Porter; K. Stemmler; M. K. Vollmer; C. R. Lunder; N. Schmidbauer; O. Hermansen; J. Arduini; P. K. Salameh; P. B. Krummel; R. H. J. Wang; D. Folini; R. F. Weiss; M. Maione; G. Nickless; F. Stordal; R. G. Derwent

2007-01-01

396

Global and regional emissions of HFC125 (CHF2CF3) from in situ and air archive atmospheric observations at AGAGE and SOGE observatories  

Microsoft Academic Search

High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and System for Observation of halogenated Greenhouse gases in Europe (SOGE) networks for the period 1998 to 2008, combined with archive flask measurements dating back to 1978, have been used to capture the rapid growth of HFC-125 (CHF2CF3) in the atmosphere. HFC-125 is the fifth most abundant HFC,

S. O'Doherty; D. M. Cunnold; B. R. Miller; J. Mühle; A. McCulloch; P. G. Simmonds; A. J. Manning; S. Reimann; M. K. Vollmer; B. R. Greally; R. G. Prinn; P. J. Fraser; L. P. Steele; P. B. Krummel; B. L. Dunse; L. W. Porter; C. R. Lunder; N. Schmidbauer; O. Hermansen; P. K. Salameh; C. M. Harth; R. H. J. Wang; R. F. Weiss

2009-01-01

397

Patterns of trace gases near sources of global pollution  

SciTech Connect

Many trace gases are increasing in the earth's armosphere and may couase global environmental changes in the future. Consequently there has been growing interest in the cycles of the long-lived gases that are likely to contribute the most to global change. At present there are four such gases: methane (CH{sub 4}), nitrous oxide (N{sub 2}0), trichlorofluoromethane (CCl{sub 3}F,F-11), and dichlorodifluoromethane (CCl{sub 2}F{sub 2},F-12). Methane and N{sub 2}O are involved mostly in adding to the greenhouse effect with some role in the stratospheric ozone cycle, and the two main fluorocarbons (F-11 and F-12) are involved in the depletion of the ozone layer with some role in global warming. This paper is about the patterns of these trace gases near regions of global scale pollution. Our purpose is to provide a synthesis of observations from diverse environments and ecosystems of the world and to provide readers with intuitive connections between sources and concentrations. We will consider four types of regions: rice fields in CHina that are a major source of methane, urban areas of the United States and China that are sources of fluorocarbons and other gases, rivers and surrounding wetlands, specifically the Yangtze in China and the Amazon in Brazil, and finally the environment of Boola Boola National Forest in Australia populated by many speices of termites that are a source of methane to the atmosphere. Eventually these patterns can be translated into estimeates of fluxes from the various sources of global pollution.

Khalil, M.A.K.; Rasmussen, R.A. (Oregon Graduate Inst., Beaverton (USA))

1990-08-01

398

Supercontinuum generation in gases  

Microsoft Academic Search

Supercontinua extending from the ultraviolet to the infrared are observed from high-pressure (1-40 atm) Ar, Kr, Xe, H2, or CO2 illuminated with 2-psec or 70-fsec, 0.6-micron pulses with an energy of less than about 500 micro J. The blue spectral component is shown to display a nearly universal behavior for all gases and pulse durations. Although the maximum intensity of

P. B. Corkum; Claude Rolland; T. Srinivasan-Rao

1986-01-01

399

Arctic stratospheric winter warming forced by observed SSTs Yongyun Hu1  

E-print Network

is caused by the green- house effect due to increasing greenhouse gases [Inter- governmental Panel, in contrast to cooling trends in late winter months mainly due to ozone depletion. To examine whether observed [Hu et al., 2005], in contrast to the cooling trends which are mainly caused by ozone depletion

Hu, Yongyun

400

Ten years of continuous observations of stratospheric ozone depleting gases at Monte Cimone (Italy)--comments on the effectiveness of the Montreal Protocol from a regional perspective.  

PubMed

Halogenated gases potentially harmful to the stratospheric ozone layer are monitored worldwide in order to assess compliance with the Montreal Protocol requiring a phase out of these compounds on a global scale. We present the results of long term (2002-2011) continuous observation conducted at the Mt. Cimone GAW Global Station located on the highest peak of the Italian Northern Apennines, at the border of two important regions: the Po Valley (and the Alps) to the North and the Mediterranean Basin to the South. Bi-hourly air samples of CFC-12, CFC-11, CFC-114, CFC-115, H-1211, H-1301, methyl chloroform, carbon tetrachloride, HCFC-22, HCFC-142b, HCFC-124 and methyl bromide are collected and analysed using a gas chromatograph-mass spectrometer, providing multi annual time series. In order to appreciate the effectiveness of the Montreal Protocol from a regional perspective, trends and annual growth rates of halogenated species have been calculated after identification of their baseline values. A comparison with results from other international observation programmes is also presented. Our data show that the peak in the atmospheric mixing ratios of four chlorofluorocarbons, two halons and two chlorocarbons has been reached and all these species now show a negative atmospheric trend. Pollution episodes are still occurring for species like halon-1211, methyl chloroform and carbon tetrachloride, indicating fresh emissions from the site domain which could be ascribed both to fugitive un-reported uses of the compounds and/or emissions from banks. For the hydrofluorocarbons changes in the baseline are affected by emissions from fast developing Countries in East Asia. Fresh emissions from the site domain are clearly declining. Methyl bromide, for which the Mediterranean area is an important source region, shows, in a generally decreasing trend, an emission pattern that is not consistent with the phase-out schedule of this compound, with a renewed increase in the last two years of pollution episodes. PMID:23333511

Maione, M; Giostra, U; Arduini, J; Furlani, F; Graziosi, F; Lo Vullo, E; Bonasoni, P

2013-02-15

401

The NOAA Annual Greenhouse Gas Index - 2012 Update  

NASA Astrophysics Data System (ADS)

For the past several decades, the U.S. National Oceanic and Atmospheric Administration (NOAA) has monitored all of the long-lived atmospheric greenhouse gases. These global measurements have provided input to databases, analyses, and various relevant products, including national and international climate assessments. To make these data more useful and available, NOAA several years ago released its Annual Greenhouse Gas Index (AGGI), http://www.esrl.noaa.gov/gmd/aggi. This index, based on the climate forcing properties of long-lived greenhouse gases, was designed to enhance the connection between scientists and society by providing a normalized standard that can be easily understood and followed. The long-lived gases capture most of the radiative forcing, and uncertainty in their measurement is very small. This allows us to provide a robust measure and assessment of the long-term, radiative influence of these gases. Continuous greenhouse gas measurements are made at baseline climate observatories (Pt. Barrow, Alaska; Mauna Loa, Hawaii; American Samoa; and the South Pole) and weekly flask air samples are collected through a global network of over 60 sites, including an international cooperative program for carbon dioxide and other greenhouse gases. The gas samples are analyzed at NOAA's Earth System Research Laboratory (NOAA/ESRL) in Boulder, Colorado, using WMO standard reference gases prepared by NOAA/ESRL. The AGGI is normalized to 1.00 in 1990, the Kyoto Climate Protocol baseline year. In 2010, the AGGI was 1.29, indicating that global radiative forcing by long-lived greenhouse gases had increased 29% since 1990. During the 1980s CO2 accounted for about 50-60% of the annual increase in radiative forcing by long-lived greenhouse gases, whereas, since 2000, it has accounted for 85-90% of this increase each year. After nearly a decade of virtually level concentrations in the atmosphere, methane (CH4) increased measurably over the past 2-3 years, as did its contribution to radiative forcing. In this presentation, preliminary values for 2011 will be evaluated and discussed with respect to the contributions from CO2, CH4,nitrous oxide (N2O), chlorofluorocarbons (CFCs), and other emerging greenhouse gases.

Butler, J. H.; Montzka, S. A.; Conway, T. J.; Dlugokencky, E. J.; Elkins, J. W.; Masari, K. A.; Schnell, R. C.; Tans, P. P.

2012-04-01

402

Separation of polar gases from nonpolar gases  

Microsoft Academic Search

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol

S. Kulprathipanja; S. S. Kulkarni

1986-01-01

403

Greenhouse effect and the global climate. (Latest citations from the Aerospace database). Published Search  

SciTech Connect

The bibliography contains citations concerning terrestrial climatic changes known as the greenhouse effect. The greenhouse effect is an accumulation of carbon dioxide and other gases that retain solar-induced heat, thereby increasing the average global temperature. Modeling studies, measurements of atmospheric gases, pollutants and temperatures, studies of climatic records for occurrence of similar changes (paleoclimatology), prediction of environmental changes due to the greenhouse effect, government energy policy as a result of possible climate change, and the contributions of manmade and natural pollutants to the greenhouse effect are among the topics discussed. (Contains a minimum of 52 citations and includes a subject term index and title list.)

Not Available

1993-09-01

404

Climate model simulation of anthropogenic influence on greenhouse-induced climate change (early agriculture to modern): the role of ocean feedbacks  

Microsoft Academic Search

We present further steps in our analysis of the early anthropogenic hypothesis (Ruddiman, Clim Change 61:261–293, 2003) that increased levels of greenhouse gases in the current interglacial, compared to lower levels in previous interglacials,\\u000a were initiated by early agricultural activities, and that these increases caused a warming of climate long before the industrial\\u000a era (?1750). These steps include updating observations

John E. Kutzbach; W. F. Ruddiman; S. J. Vavrus; G. Philippon

2010-01-01

405

Climate Change: Methane and Other Greenhouse Gas  

NSDL National Science Digital Library

This new site from the Environmental Protection Agency (EPA) "addresses methane's contribution to global warming; trends in emission of methane, nitrous oxide, and fully fluorinated compounds; and economic analyses related to stabilization of these greenhouse gases." The site offers several information-rich sections (Topics in Brief, Reports, Questions & Answers) and descriptive links to further resources (Voluntary Programs, Resources, Calendar). The information provided here is user-friendly without sacrificing detail, making this a worthwhile stop on the Internet.

406

PUBLISHED ONLINE: 15 NOVEMBER 2009 | DOI: 10.1038/NGEO692 Nitrogen-enhanced greenhouse warming on  

E-print Network

that more N2 in the atmosphere would have increased the warming effect of existing greenhouse gases, if the early Earth was less cloudy) or a means of amplifying the greenhouse effect. Higher atmospheric pressure greenhouse effect or a lower planetary albedo. Here we use a radiative­convective climate model to show

Matthews, Adrian

407

A study of regional-scale variability of in situ and model-generated tropospheric trace gases: Insights into observational requirements for a satellite in geostationary orbit  

NASA Astrophysics Data System (ADS)

We examine the results from a regional-scale chemical-transport model with 4-km resolution to determine the spatial variability of trace gases on this scale. Model-derived variability statistics are generated using 1st-order structure functions and then compared with in situ trace gas measurements from a series of aircraft campaigns. The variability of the observations and the model-derived concentrations are found to be in reasonable agreement for O 3 and CO, but the model underestimates the observed variability of NO 2. Variability statistics are then calculated for model-derived tropospheric column integrals. These integrals are calculated for 0-10 km (representative of the entire tropospheric column), 0-2 km (representative of the planetary boundary layer, PBL) and 2-10 km (representative of the free troposphere, FT). For each of the species examined, the variability of the tropospheric column is generally controlled by the variability in the lowest 2 km. The degree of control for each trace gas, however, is different. Whereas NO 2 is completely dominated by PBL processes, CO variability in the FT contributes appreciably to the variability of the entire tropospheric column, suggesting that two independent pieces of information for CO would be most helpful for describing the variability of the entire tropospheric column. Likewise, the variability of an independent free tropospheric measurement of O 3 would provide additional insight into the observed variability of the entire column, but the amount of additional information provided by a separate FT measurement is not as beneficial to what was found for CO. We provide additional analyses to quantify relationships that can be used to better understand the model-derived structure functions and their dependence on grid size and time of day. Lastly we present a practical example of how this information may be used for guidance in the development of science requirements for future satellite instruments since measurements from these instruments must be able to resolve smaller scale gradients to be used successfully for air quality applications.

Fishman, Jack; Silverman, Morgan L.; Crawford, James H.; Creilson, John K.

2011-09-01

408

The ice-core record - Climate sensitivity and future greenhouse warming  

NASA Technical Reports Server (NTRS)

The prediction of future greenhouse-gas-warming depends critically on the sensitivity of earth's climate to increasing atmospheric concentrations of these gases. Data from cores drilled in polar ice sheets show a remarkable correlation between past glacial-interglacial temperature changes and the inferred atmospheric concentration of gases such as carbon dioxide and methane. These and other palaeoclimate data are used to assess the role of greenhouse gases in explaining past global climate change, and the validity of models predicting the effect of increasing concentrations of such gases in the atmosphere.

Lorius, C.; Raynaud, D.; Jouzel, J.; Hansen, J.; Le Treut, H.

1990-01-01

409

NASA's mission to planet Earth: Earth observing system  

NASA Technical Reports Server (NTRS)

The topics covered include the following: global climate change; radiation, clouds, and atmospheric water; the ocean; the troposphere - greenhouse gases; land cover and the water cycle; polar ice sheets and sea level; the stratosphere - ozone chemistry; volcanoes; the Earth Observing System (EOS) - how NASA will support studies of global climate change?; research and assessment - EOS Science Investigations; EOS Data and Information System (EOSDIS); EOS observations - instruments and spacecraft; a national international effort; and understanding the Earth System.

1993-01-01

410

Benefits of dealing with uncertainty in greenhouse gas inventories: introduction  

Microsoft Academic Search

\\u000a The assessment of greenhouse gases emitted to and removed from the atmosphere is high on the international political and scientific\\u000a agendas. Growing international concern and cooperation regarding the climate change problem have increased the need for policy-oriented\\u000a solutions to the issue of uncertainty in, and related to, inventories of greenhouse gas (GHG) emissions. The approaches to\\u000a addressing uncertainty discussed in

Matthias Jonas; Gregg Marland; Wilfried Winiwarter; Thomas White; Zbigniew Nahorski; Rostyslav Bun; Sten Nilsson

411

Benefits of dealing with uncertainty in greenhouse gas inventories: introduction  

Microsoft Academic Search

The assessment of greenhouse gases emitted to and removed from the atmosphere is high on the international political and scientific\\u000a agendas. Growing international concern and cooperation regarding the climate change problem have increased the need for policy-oriented\\u000a solutions to the issue of uncertainty in, and related to, inventories of greenhouse gas (GHG) emissions. The approaches to\\u000a addressing uncertainty discussed in

Matthias Jonas; Gregg Marland; Wilfried Winiwarter; Thomas White; Zbigniew Nahorski; Rostyslav Bun; Sten Nilsson

2010-01-01

412

Large Greenhouse Gas Emissions from a Temperate Peatland Pasture  

Microsoft Academic Search

Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH4 emissions reduced in favor of greater CO2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on\\u000a N2O or global warming potential. We report greenhouse gas fluxes (CH4, CO2, N2O) from a drained peatland in the

Yit Arn Teh; Whendee L. Silver; Oliver Sonnentag; Matteo Detto; Maggi Kelly; Dennis D. Baldocchi

2011-01-01

413

The Dynamic Greenhouse Challenge  

ERIC Educational Resources Information Center

Greenhouses are marvelous devices, allowing one to enjoy the flower spectacle of summer all year round. At night, greenhouses use supplemental heat to keep the fragile plants warm. Over the last 30 years, greenhouse technology has undergone many changes, with the structures being automated and monitored and low-cost plastic structures emerging as…

Roman, Harry T.

2010-01-01

414

Build a Solar Greenhouse.  

ERIC Educational Resources Information Center

Attached solar greenhouses are relatively inexpensive and easy to build; they can provide additional heat to homes all winter as well as fresh vegetables and flowers. This bulletin: (1) describes the characteristics of a solar greenhouse; (2) provides a checklist of five items to consider before building a solar greenhouse; (3) describes the four…

Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

415

Satellite observations of the water vapor greenhouse effect and column longwave cooling rates: Relative roles of the continuum and vibration-rotation to pure rotation bands  

Microsoft Academic Search

The Clouds and the Earth's Radiant Energy System (CERES) instrument on board the Tropical Rainfall Measuring Mission (TRMM) satellite provides, for the first time, a large-scale (40 S to 40 N) data set for the atmospheric greenhouse effect and the column-averaged longwave (LW) radiative cooling rates in the broadband (5-100 microns) and the window (8-12 microns) regions. We demonstrate here

Anand K. Inamdar; V. Ramanathan; Norman G. Loeb

2004-01-01

416

Satellite observations of the water vapor greenhouse effect and column longwave cooling rates: Relative roles of the continuum and vibration-rotation to pure rotation bands  

Microsoft Academic Search

The Clouds and the Earth's Radiant Energy System (CERES) instrument on board the Tropical Rainfall Measuring Mission (TRMM) satellite provides, for the first time, a large-scale (40 S to 40 N) data set for the atmospheric greenhouse effect and the column-averaged longwave (LW) radiative cooling rates in the broadband (5–100 microns) and the window (8–12 microns) regions. We demonstrate here

Anand K. Inamdar; V. Ramanathan; Norman G. Loeb

2004-01-01

417

The Greenhouse Effect Does Exist!  

E-print Network

In particular, without the greenhouse effect, essential features of the atmospheric temperature profile as a function of height cannot be described, i.e., the existence of the tropopause above which we see an almost isothermal temperature curve, whereas beneath it the temperature curve is nearly adiabatic. The relationship between the greenhouse effect and observed temperature curve is explained and the paper by Gerlich and Tscheuschner [arXiv:0707.1161] critically analyzed. Gerlich and Tscheuschner called for this discussion in their paper.

Ebel, Jochen

2009-01-01

418

Estimating the benefits of greenhouse gas emission reduction from agricultural policy reform  

SciTech Connect

Land use and agricultural activities contribute directly to the increased concentrations of atmospheric greenhouse gases. Economic support in industrialized countries generally increases agriculture's contribution to global greenhouse gas concentrations through fluxes associated with land use change and other sources. Changes in economic support offers opportunities to reduce net emissions, through this so far has gone unaccounted. Estimates are presented here of emissions of methane from livestock in the UK and show that, in monetary terms, when compared to the costs of reducing support, greenhouse gases are a significant factor. As signatory parties to the Climate Change Convection are required to stabilize emissions of all greenhouse gases, options for reduction of emissions of methane and other trace gases from the agricultural sector should form part of these strategies.

Adger, W.N. (Univ. of East Anglia, Norwich (United Kingdom). Centre for Social and Economic Research on the Global Environment); Moran, D.C. (Univ. College, London (United Kingdom). Centre for Social and Economic Research on the Global Environment)

1993-09-01

419

Modeling & learning from the design recommendations for California's Greenhouse Gas Cap-and-Trade System  

E-print Network

Climate Change has become a Major issue beginning with our generation. Governments the world over are now recognizing that industry cannot continue to pollute in a business-as-usual manner. Emitting Greenhouse gases has a ...

Fernandes, Chester, S.M. Massachusetts Institute of Technology

2008-01-01

420

GLOBAL ANTROPOGENIC NON-CO2 GREENHOUSE GAS EMISSIONS: 1990-2020  

EPA Science Inventory

This report will synthesize available data on emissions of non-CO2 greenhouse gases by gas, source category, and country or region. Historic emissions data, as well as projected emission levels will be provided....