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Sample records for dioxide trace gases

  1. Atmospheric Trace Gases from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, models, etc. and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication, Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. The collections under the CDIAC heading of Atmospheric Trace Gases include: Atmospheric Carbon Dioxide, Atmospheric Methane, Atmospheric Carbon Monoxide, Atmospheric Hydrogen, Isotopes in Greenhouse Gases, Radionuclides, Aerosols, and Other Trace Gases.

  2. Carbon dioxide Information Analysis Center and World Data Center: A for Atmospheric trace gases. Annual progress report, FY 1994

    SciTech Connect

    Burtis, M.D.; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.R.; Stoss, F.W.

    1995-03-01

    This report summarizes the activities and accomplishments made by the Carbon Dioxide Information Analysis Center and World Data Center-A for Atmospheric Trace Gases during the fiscal year 1994. Topics discussed in this report include; organization and staff, user services, systems, communications, Collaborative efforts with China, networking, ocean data and activities of the World Data Center-A.

  3. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases, Fiscal Year 2002 Annual Report

    SciTech Connect

    Cushman, R.M.

    2003-08-28

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including atmospheric concentrations and atmospheric emissions of carbon dioxide (CO{sub 2}) and other radiatively active gases; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

  4. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2000 Annual Report

    SciTech Connect

    Cushman, R.M.

    2001-11-15

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

  5. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: FY 1993 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W. |

    1994-01-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provide technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC (including World Data Center-A for Atmospheric Trace Gases) during the period October 1, 1992, to September 30, 1993. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of NDPS, CMPS, technical reports, newsletters, fact sheets, specialty publications, and reprints are provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also presented.

  6. Emission rates of sulfur dioxide, trace gases and metals from Mount Erebus, Antartica

    SciTech Connect

    Kyle, P.R.; Meeker, K. ); Finnegan, D. )

    1990-11-01

    SO{sub 2} emission rates have been measured annually since 1983 at Mount Erebus, Antarctica by correlation spectrometer (COSPEC V). Following a 4 month period of sustained strombolian activity in late 1984, SO{sub 2} emissions declined from 230 Mg/day in 1983 to 25 Mg/day and then slowly increased from 16 Mg/day in 1985 to 51 Mg/day in 1987. Nine sets of filter packs containing partcle and {sup 7}LiOH treated filters were collected in the plume in 1986 and analyzed by neutron activation. Using the COSPEC data and measured element/S ratios on the filters, emission rates have been determined for trace gases and metals. The authors infer HCl and HF emissions in 1983 to be about 1200 and 500 Mg/day, respectively. Mt Erebus has therefore been an important source of halogens to the Anarctic atmosphere and could be responsible for excess Cl found in Central Antarctica snow.

  7. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2001 Annual Report

    SciTech Connect

    Cushman, R.M.

    2002-10-15

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels. CDIAC is located within the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. CDIAC is co-located with ESD researchers investigating global-change topics, such as the global carbon cycle and the effects of carbon dioxide on climate and vegetation. CDIAC staff are also connected with current ORNL research on related topics, such as renewable energy and supercomputing technologies. CDIAC is supported by the Environmental Sciences Division (Jerry Elwood, Director) of DOE's Office of Biological and Environmental Research. CDIAC represents DOE in the multi-agency Global Change Data and Information System (GCDIS). Wanda Ferrell is DOE's Program Manager with overall responsibility for CDIAC. Roger Dahlman is responsible for CDIAC's AmeriFlux tasks, and Anna Palmisano for CDIAC's Ocean Data tasks. CDIAC is made up of three groups: Data

  8. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 1999 Annual Report

    SciTech Connect

    Cushman, R.M.

    2000-03-31

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global-change data and information analysis center of the Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has--since its inception in 1982--enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea level. CDIAC is located within the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. CDIAC is co-located with ESD researchers investigating global-change topics, such as the global carbon cycle and the effects of carbon dioxide on vegetation. CDIAC staff are also connected with current ORNL research on related topics, such as renewable energy and supercomputing technologies. CDIAC is supported by the Environmental Sciences Division (Jerry Elwood, Acting Director) of DOE's Office of Biological and Environmental Research. CDIAC's FY 1999 budget was 2.2M dollars. CDIAC represents the DOE in the multi-agency Global Change Data and Information System. Bobbi Parra, and Wanda Ferrell on an interim basis, is DOE's Program Manager with responsibility for CDIAC. CDIAC comprises three groups, Global Change Data, Computer Systems, and Information

  9. An improved back-flush-to-vent gas chromatographic method for determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia.

    PubMed

    Trubyanov, Maxim M; Mochalov, Georgy M; Vorotyntsev, Ilya V; Vorotyntsev, Andrey V; Suvorov, Sergey S; Smirnov, Konstantin Y; Vorotyntsev, Vladimir M

    2016-05-20

    A novel method for rapid, quantitative determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia by dual-channel two-dimensional GC-PDHID is presented. An improved matrix back-flush-to-vent approach combining back-flush column switching technique with auxiliary NaHSO4 ammonia trap is described. The NaHSO4 trap prevents traces of ammonia from entering the analytical column and is shown not to affect the impurity content of the sample. The approach allows shortening the analysis time and increasing the amount of measurements without extensive maintenance of the GC-system. The performance of the configuration has been evaluated utilizing ammonia- and helium-based calibration standards. The method has been applied for the analysis of 99.9999+% ammonia purified by high-pressure distillation at the production site.

  10. An improved back-flush-to-vent gas chromatographic method for determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia.

    PubMed

    Trubyanov, Maxim M; Mochalov, Georgy M; Vorotyntsev, Ilya V; Vorotyntsev, Andrey V; Suvorov, Sergey S; Smirnov, Konstantin Y; Vorotyntsev, Vladimir M

    2016-05-20

    A novel method for rapid, quantitative determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia by dual-channel two-dimensional GC-PDHID is presented. An improved matrix back-flush-to-vent approach combining back-flush column switching technique with auxiliary NaHSO4 ammonia trap is described. The NaHSO4 trap prevents traces of ammonia from entering the analytical column and is shown not to affect the impurity content of the sample. The approach allows shortening the analysis time and increasing the amount of measurements without extensive maintenance of the GC-system. The performance of the configuration has been evaluated utilizing ammonia- and helium-based calibration standards. The method has been applied for the analysis of 99.9999+% ammonia purified by high-pressure distillation at the production site. PMID:27083259

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

    ERIC Educational Resources Information Center

    Aubrecht, Gordon J., II

    1988-01-01

    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)

  12. Tropospheric trace gases

    NASA Technical Reports Server (NTRS)

    Gammon, R.; Wofsy, S. C.; Cicerone, R. J.; Delany, A. C.; Harriss, R. T.; Khalil, M. A. K.; Logan, J. A.; Midgley, P.; Prather, M.

    1985-01-01

    Trace gas concentrations in the atmosphere reflect in part the overall metabolism of the biosphere, and in part the broad range of human activities such as agriculture, production of industrial chemicals, and combustion of fossil fuels and biomass. There is compelling evidence that the composition of the atmosphere is now changing. Observed trends in trace gas levels are reviewed and implications for the chemistry of the atmosphere are discussed. Throughout the discussion, particular emphasis is given to those species which are now increasing in the atmosphere.

  13. Robust IR Remote Sensing Technique of the Total Column of Trace Gases Including Carbon Dioxide and Methane

    NASA Technical Reports Server (NTRS)

    Georgieva, E. M.; Heaps, W. S.

    2011-01-01

    Progress on the development of a differential radiometer based upon the Fabry-Perot interferometer (FPI) for methane (CH4) and carbon dioxide (C02) detection in the atmosphere is presented. Methane measurements are becoming increasingly important as a component of NASA's programs to understand the global carbon cycle and quantifY the threat of global warming. Methane is the third most important greenhouse gas in the Earth's radiation budget (after water vapor and carbon dioxide) and the second most important anthropogenic contributor to global warming. The importance of global warming and air quality to society caused the National Research Council to recommend that NASA develop the following missions [1]: ASCENDS (Active Sensing of C02 Emissions over Nights, Days, and Seasons), GEOCAPE (Geostationary Coastal and Air Pollution Events), and GACM (Global Atmosphere Composition Mission). Though methane measurements are not specifically called out in these missions, ongoing environmental changes have raised the importance of understanding the methane budget. In the decadal survey is stated that "to close the carbon budget, we would also address methane, but the required technology is not obvious at this time. If appropriate and cost-effective methane technology becomes available, we strongly recommend adding a methane capability". In its 2007 report the International Panel on Climate Change identified methane as a key uncertainty in our understanding saying that the causes of recent changes in the growth rate of atmospheric CH4 are not well understood. What we do know is that methane arises from a number of natural sources including wet lands and the oceans plus man made sources from agriculture, as well as coal and petroleum production and distribution. It has recently been pointed out that large amount of methane are frozen in the permafrost of Canada and Siberia. There is a fear that melting of this permafrost driven by global warming may release large amounts of

  14. Carbon Dioxide Information Analysis Center and World Data Center - A for atmospheric trace gases. Fiscal year 1996, annual report

    SciTech Connect

    Cushman, R.M.; Boden, T.A.; Jones, S.B.

    1997-02-01

    Fiscal year 1996 was especially productive for the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL). This report describes publications and statistical data from the CDIAC.

  15. Method for detecting trace impurities in gases

    DOEpatents

    Freund, Samuel M.; Maier, II, William B.; Holland, Redus F.; Beattie, Willard H.

    1981-01-01

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (.about.2 ppm) present in commercial Xe and ppm levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  16. Method for detecting trace impurities in gases

    DOEpatents

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  17. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: Fiscal year 1995 annual report

    SciTech Connect

    Burtis, M.D.; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.; Stoss, F.W.

    1996-01-01

    Fiscal year 1995 was both a very productive year for the Carbon Dioxide Information Analysis Center and a year of significant change. This document presents information about the most notable accomplishments made during the year. Topics include: high-lights; statistics; future plans; publications, presentations, and awards; and change in organization and staff.

  18. Carbon Dioxide Analysis Center and World Data Center-A for Atmospheric Trace Gases fiscal year 1997 annual report

    SciTech Connect

    Burtis, M.D.; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Kaiser, D.P.; Nelson, T.R.

    1998-03-01

    Fiscal year (FY) 1997 was another exciting and productive one for the Carbon Dioxide Information Analysis Center (CDIAC) at the Oak Ridge National Laboratory. During FY 1997, CDIAC launched the Quality Systems Science Center for the North American Research Strategy for Tropospheric Ozone (NARSTO). The purpose of NARSTO--a US-Canada-Mexico initiative of government agencies, industry, and the academic research community--is to improve the understanding of the formation and transport of tropospheric ozone.

  19. Fiscal Year 1998 Annual Report, Carbon Dioxide Information Analysis Center, World Data Center -- A for Atmospheric Trace Gases

    SciTech Connect

    Cushman, R.M.; Boden, T.A.; Hook, L.A.; Jones, S.B.; Kaiser, D.P.; Nelson, T.R.

    1999-03-01

    Once again, the most recent fiscal year was a productive one for the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL), as well as a year for change. The FY 1998 in Review section in this report summarizes quite a few new and updated data and information products, and the ''What's Coming in FY 1999'' section describes our plans for this new fiscal year. During FY 1998, CDIAC began a data-management system for AmeriFlux, a long-term study of carbon fluxes between the terrestrial biosphere of the Western Hemisphere and the atmosphere. The specific objectives of AmeriFlux are to establish an infrastructure for guiding, collecting, synthesizing, and disseminating long-term measurements of CO{sub 2}, water, and energy exchange from a variety of ecosystems; collect critical new information to help define the current global CO{sub 2} budget; enable improved predictions of future concentrations of atmospheric CO{sub 2}; and enhance understanding of carbon fluxes. Net Ecosystem Production (NEP), and carbon sequestration in the terrestrial biosphere. The data-management system, available from CDIAC'S AmeriFlux home page (http://cdiac.esd.ornl.gov/programs/ameriflux/ ) is intended to provide consistent, quality-assured, and documented data across all AmeriFlux sites in the US, Canada, Costa Rica, and Brazil. It is being developed by Antoinette Brenkert and Tom Boden, with assistance from Susan Holladay (who joined CDIAC specifically to support the AmeriFlux data-management effort).

  20. Greenhouse Trace Gases in Deadwood

    NASA Astrophysics Data System (ADS)

    Covey, Kristofer; Bueno de Mesquita, Cliff; Oberle, Brad; Maynard, Dan; Bettigole, Charles; Crowther, Thomas; Duguid, Marlyse; Steven, Blaire; Zanne, Amy; Lapin, Marc; Ashton, Mark; Oliver, Chad; Lee, Xuhui; Bradford, Mark

    2016-04-01

    Deadwood, long recognized as playing an important role in carbon cycling in forest ecosystems, is more recently drawing attention for its potential role in the cycling of other greenhouse trace gases. We report data from four independent studies measuring internal gas concentrations in deadwood in in three Quercus dominated upland forest systems in the Northeastern and Central United States. Mean methane concentrations in deadwood were 23 times atmospheric levels, indicating a lower bound, mean radial wood surface area flux of ~6 x 10-4 μmol CH4 m-2 s-1. Site, decay class, diameter, and species were all highly significant predictors of methane abundance in deadwood, and log diameter and decay stage interacted as important controls limiting methane concentrations in the smallest and most decayed logs. Nitrous oxide concentrations were negatively correlated with methane and on average ~25% lower than ambient, indicating net consumption of nitrous oxide. These data suggest nonstructural carbohydrates fuel archaeal methanogens and confirm the potential for widespread in situ methanogenesis in both living and deadwood. Applying this understanding to estimate methane emissions from microbial activity in living trees implies a potential global flux of 65.6±12.0 Tg CH4 yr-1, more than 20 times greater than currently considered.

  1. Climate change and trace gases.

    PubMed

    Hansen, James; Sato, Makiko; Kharecha, Pushker; Russell, Gary; Lea, David W; Siddall, Mark

    2007-07-15

    Palaeoclimate data show that the Earth's climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the 'albedo flip' property of ice/water, provides a powerful trigger mechanism. A climate forcing that 'flips' the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration and a burst of added global warming. Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate change that could run out of our control, with great dangers for humans and other creatures. Carbon dioxide (CO2) is the largest human-made climate forcing, but other trace constituents are also important. Only intense simultaneous efforts to slow CO2 emissions and reduce non-CO2 forcings can keep climate within or near the range of the past million years. The most important of the non-CO2 forcings is methane (CH4), as it causes the second largest human-made GHG climate forcing and is the principal cause of increased tropospheric ozone (O3), which is the third largest GHG forcing. Nitrous oxide (N2O) should also be a focus of climate mitigation efforts. Black carbon ('black soot') has a high global warming potential (approx. 2000, 500 and 200 for 20, 100 and 500 years, respectively) and deserves greater attention. Some forcings are especially effective at high latitudes, so concerted efforts to reduce their emissions could preserve Arctic ice, while also having major benefits for human health, agricultural productivity and the global environment.

  2. Removing Sulphur Dioxide From Stack Gases

    ERIC Educational Resources Information Center

    Slack, A. V.

    1973-01-01

    Process types, process concepts, claims and counterclaims, cost factors, and the level of developed technology for sulfur dioxide control in stack gases are focused upon and evaluated. Wet and dry processes as well as recovery and throwaway processes are compared. (BL)

  3. Measurement of Selected Organic Trace Gases During TRACE-P

    NASA Technical Reports Server (NTRS)

    Atlas, Elliot

    2004-01-01

    Major goals of the TRACE-P mission were: 1) to investigate the chemical composition of radiatively important gases, aerosols, and their precursors in the Asian outflow over the western Pacific, and 2) to describe and understand the chemical evolution of the Asian outflow as it is transported and mixed into the global troposphere. The research performed as part of this proposal addressed these major goals with a study of the organic chemical composition of gases in the TRACE-P region. This work was a close collaboration with the Blake/Rowland research group at UC-Irvine, and they have provided a separate report for their funded effort.

  4. Preliminary simulations of planned experiments to study the impact of trace gases on the capacity of the Weyburn-Midale field to store carbon dioxide

    SciTech Connect

    Carroll, S; Hao, Y

    2009-11-13

    The CO{sub 2} stream injecting into the Weyburn-Midale field can be generally classified as a reducing stream with residual H{sub 2}S and low-molecular weight hydrocarbons. The composition of the CO{sub 2} gas stream from the Dakota Gasification Company is reported to be 95% CO{sub 2}, 4% hydrocarbons, and 1% H{sub 2}S by volume (Huxley 2006). In addition to the H{sub 2}S introduced at the injection wells, significant concentrations of H{sub 2}S are thought to have been produced in-situ by sulfate reducing bacteria from previous water floods for enhanced oil production. Produced gas compositions range in H{sub 2}S concentrations from 1 to 6 volume percent. The produced gas, including the trace impurities, is re-injected into the field. Although there is no evidence for inorganic reduction of SO{sub 4}{sup 2-} to H{sub 2}S at the Weyburn-Midale field, Sitchler and Kazuba (2009) suggest that SO{sub 4}{sup 2-} can be inorganically reduced to elemental sulfur in highly reducing environments based on a natural analog study of the Madison Formation in Wyoming. They propose that elevated concentrations of CO{sub 2} dissolve anhydrite to produce the sulfate that is then reduced. Oxidizing CO{sub 2} streams with residual O{sub 2} and SO{sub 2} typical of streams captured from oxyfuel and post combustion processes are not presently an issue at the Weyburn-Midale field. However it is possible that the oxidizing CO{sub 2} streams may be injected in the future in carbonate reservoirs similar to the Weyburn-Midale field. To date there are few modeling and experimental studies that have explored the impact of impurity gases in CO{sub 2} streams targeted for geologic storage (Gale 2009). Jacquemet et al (2009) reviewed select geochemical modeling studies that explored the impact of SO{sub 2} and H{sub 2}S impurities in the waste streams (Gunter et al., 2000, Knauss et al., 2005, Xu et al., 2007). These studies collectively show that SO{sub 2} significantly reduces the pH when

  5. Biogenic and anthropogenic trace gases in the atmosphere

    NASA Technical Reports Server (NTRS)

    Brasseur, G. P.; Prinn, R. G.

    1992-01-01

    This paper illustrates the importance of biogenic and anthropogenic trace gases for the global environment and for the climate system. The paper briefly reviews the currently available estimates of sources and strengths of the biogenic and anthropogenic gases on the global scale. One of the major concerns for the global environment is the rapid increase in the concentration of long-lived trace gases such as CO2, CH4, N2O and the chlorofluorocarbons. The trend in the carbon dioxide concentration, as a result of fossil-fuel burning, is of the order of 0.4 percent per year, and this trend is related to the CO2 uptake by the ocean and by terrestrial ecosystems, which are likely to be modified if the planet warms up in the forthcoming decades. The concentrations of methane and nitrous oxide are increasing by 0.9 and 0.25 percent per year, respectively. In the case of the most widely used chlorofluorocarbons, trends as large as 10 percent per year or more are being measured.

  6. Carbon Dioxide Information Analysis Center and World Data Center-A for atomspheric trace gases: Catalog of data bases and reports

    SciTech Connect

    Burtis, M.D.

    1995-04-01

    This document provides information about the many reports and other materials made available by the US Department of Energy`s Global Change Research Program (GCRP). Section A provides information about the activities, scope, and direction of the GCRP; Sections B,C, D, and E contain information about research that has been sponsered by GCRP; Sections F and G contains information about the numeric data packages and computer model pa kages the have been compiled by the GCRP; Section H describes reports about research dealing with the responses of vegetation to carbon dioxide; and Section I conatins reports from various workshops, symposia, and reviews.

  7. Somatic and genetic effects of the increase of carbon dioxide and other trace gases in the atmosphere through changes of radon and thoron exhalation rates and other factors

    NASA Astrophysics Data System (ADS)

    Okamoto, Kazuto

    Somatic and genetic effects of the increase of greenhouse gases are investigated. The exhalation rates of radon and thoron are affected by the climate change through the temperature rise itself, melting of snow and ice and the change of soil moisture, and the lung cancer rate is affected by these changes. On the other hand the greenhouse warming of the troposphere leads to cooling of the stratosphere, which protects the O 3 layer and reduces skin cancer. In the genetic side the temperature rise is harmful for sperm. The Rn increase leads to an increase of chromosome aberrations. Crude estimates of these effects show that the soil moisture effect is probably the largest, but the O 3 protection effect may also be significant.

  8. EVALUATION OF SIGNIFICANT ANTHROPOGENIC SOURCES OF RADIATIVELY IMPORTANT TRACE GASES

    EPA Science Inventory

    The report is an initial evaluation of significant anthropogenic sources of radiatively important trace gases. missions of greenhouse gases from human activities--including fossil fuel combustion, industrial/agricultural activities, and transportation--contribute to the increasin...

  9. Source compositions of trace gases released during African savanna fires

    NASA Astrophysics Data System (ADS)

    Cofer, Wesley R.; Levine, Joel S.; Winstead, Edward L.; Cahoon, Donald R.; Sebacher, Daniel I.; Pinto, Joseph P.; Stocks, Brian J.

    1996-10-01

    Measurements of biomass burn-produced trace gases were made using low-altitude helicopter penetrations of smoke plumes above burning African savanna during the Southern African Fire-Atmosphere Research Initiative (SAFARI-92). Smoke from two large prescribed fires conducted in the Kruger National Park, South Africa, on September 18 and 24, 1992, was sampled at altitudes ranging from 20 to 100 m above ground level during flaming and smoldering phases of combustion. Carbon dioxide (CO2) normalized emission ratios (dX/dCO2 (vol/vol), where X denotes a trace gas) for carbon monoxide (CO), hydrogen (H2), methane (CH4), total nonmethane hydrocarbons (TNMHC), and nitrous oxide (N2O) were determined. The emission ratios were used in conjunction with fuel consumption estimates to calculate emission factors (grams of product per gram of fuel) for these gases. Emission factors for CO2, CO, CH4, and N2O of 1.61, 0.055, 0.003, and 1.6 × 10-4 g/g fuel, respectively, were determined. The fires advanced rapidly through the savanna (primarily grass) fuels with minimal amounts of smoldering combustion. The relatively low emission ratios determined for these fires indicated excellent combustion efficiency. About 93% of the carbon released into the atmosphere as a result of these fires was in the form of CO2.

  10. Wet precipitation scavenging of soluble atmospheric trace gases due to chemical absorption in inhomogeneous atmosphere

    NASA Astrophysics Data System (ADS)

    Elperin, Tov; Fominykh, Andrew; Krasovitov, Boris

    2016-04-01

    We analyze the effects of irreversible chemical reactions of the first and higher orders and aqueous-phase dissociation reactions on the rate of trace gas scavenging by rain in the atmosphere with non-uniform concentration and temperature. We employ an one-dimensional model of precipitation scavenging of chemically active soluble gaseous pollutants that is valid for small gradients of temperature and concentration in the atmosphere. It is demonstrated that transient altitudinal distribution of concentration under the influence of rain is determined by the partial hyperbolic differential equation of the first order. Scavenging coefficients are calculated for wet removal of chlorine, nitrogen dioxide and sulfur dioxide for the exponential and linear initial altitudinal distributions of trace gases concentration in the atmosphere and linear and uniform altitudinal temperature distributions. Theoretical predictions of the dependence of the magnitude of the scavenging coefficient on rain intensity for sulfur dioxide are in a good agreement with the available atmospheric measurements.

  11. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use...

  12. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use...

  13. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use...

  14. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use...

  15. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use...

  16. Greenhouse effect of trace gases, 1970-1980

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  17. Analysis of atmospheric spectra for trace gases

    NASA Technical Reports Server (NTRS)

    Rinsland, Curtis P.; Seals, Robert K., Jr.; Smith, Mary Ann H.; Goldman, Aaron; Murcray, David G.; Murcray, Frank J.

    1990-01-01

    The objective is the comprehensive analysis of high resolution atmospheric spectra recorded in the middle-infrared region to obtain simultaneous measurements of coupled parameters (gas concentrations of key trace constituents, total column amounts, pressure, and temperature) in the stratosphere and upper troposphere. Solar absorption spectra recorded at 0.002 and 0.02 cm exp -1 resolutions with the University of Denver group's balloon-borne, aircraft borne, and ground-based interferometers and 0.005 to 0.01 cm exp -1 resolution solar spectra from Kitt Peak are used in the analyses.

  18. Soil and litter exchange of reactive trace gases

    EPA Science Inventory

    The soil and litter play an important role in the exchange of trace gases between terrestrial ecosystems and the atmosphere. - The exchange of ammonia between vegetation and the atmosphere is highly influenced by soil and litter emissions especially in managed ecosystems (grassla...

  19. 1988 Pilot Institute on Global Change on trace gases and the biosphere

    SciTech Connect

    Eddy, J.A.; Moore, B. III

    1998-07-01

    This proposal seeks multi-agency funding to conduct an international, multidisciplinary 1988 Pilot Institute on Global Change to take place from August 7 through 21, 1988, on the topic: Trace Gases and the Biosphere. The institute, to be held in Snowmass, Colorado, is envisioned as a pilot version of a continuing series of institutes on Global Change (IGC). This proposal seeks support for the 1988 pilot institute only. The concept and structure for the continuing series, and the definition of the 1988 pilot institute, were developed at an intensive and multidisciplinary Summer Institute Planning Meeting in Boulder, Colorado, on August 24--25, 1987. The theme for the 1988 PIGC, Trace Gases and the Biosphere, will focus a concerted, high-level multidisciplinary effort on a scientific problem central to the Global Change Program. Dramatic year-to-year increases in the global concentrations of radiatively-active trace gases such as methane and carbon dioxide are now well documented. The predicted climatic effects of these changes lend special urgency to efforts to study the biospheric sources and sinks of these gases and to clarify their interactions and role in the geosphere-biosphere system.

  20. The removal of sulfur dioxide from flue gases

    PubMed Central

    Kettner, Helmut

    1965-01-01

    The growth of industrialization makes it imperative to reduce the amounts of sulfur dioxide emitted into the atmosphere. This article describes various processes for cleaning flue gases, and gives details of new methods being investigated. Wet scrubbing with water, though widely practised, has many disadvantages. Scrubbing with zinc oxide, feasible in zinc works, is more satisfactory. Dry methods use a solid absorbent; they have the advantage of a high emission temperature. Other methods are based on the addition to the fuel or the flue gases of substances such as activated metal oxides, which react with the sulfur to form compounds less harmful than sulfur dioxide. Also being investigated are a two-stage combustion system, in which the sulfur dioxide is removed in the first stage, and the injection of activated powdered dolomite into burning fuel; the resulting sulfates being removed by electrostatic precipitation. A wet catalysis process has recently been developed. Most of the cleaning processes are not yet technically mature, but first results show good efficiency and relatively low cost. PMID:14315714

  1. Atmospheric trace gases monitoring by UV-vis spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Xie, Pinhua; Li, Ang; Wu, Fengcheng; Qin, Min; Hu, Rezhi; Xu, Jin; Si, Fuqi; Liu, Jianguo; Liu, Wenqing

    2016-04-01

    Due to rapidly economic development, air pollution has become an important issue in China. Phenomena such as regional haze in winter and high O3 concentration in summer are strongly related to increasing trace species. For better understanding the air pollution formation, it is necessary to know spatial and temporal distribution of trace species in the atmosphere. UV-vis spectroscopic techniques are of great advantages for trace species monitoring to meet several requirements, e.g. versatility, high sensitivity, good temporal resolution and field applicability. We have studied and developed various trace gases monitoring techniques and instruments based on UV-vis spectroscopic technique for in-situ measurements and remote sensing, e.g. LP-DOAS, IBBCEAS, CRDS, MAX-DOAS and mobile DOAS for NO2, SO2, HCHO, HONO, NO3, and N2O5 etc. The principle, instrumentation and inversion algorithm are presented. As typical applications of these techniques, investigation of the evolution of HONO and NO3 radicals over Beijing area, measurements of regional pollution in NCP and YRD are discussed in the aspects of HONO and nocturnal NO3 radical characteristics, trace gases (NO2, SO2 etc.) temporal and spatial distribution, pollution transport pathway, emission sources.

  2. Greenhouse effect of chlorofluorocarbons and other trace gases

    NASA Astrophysics Data System (ADS)

    Hansen, James; Lacis, Andrew; Prather, Michael

    1989-11-01

    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.

  3. Greenhouse effect of chlorofluorocarbons and other trace gases

    NASA Technical Reports Server (NTRS)

    Hansen, James; Lacis, Andrew; Prather, Michael

    1989-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  5. Responses of trace gases to hydrologic pulses in desert floodplains

    NASA Astrophysics Data System (ADS)

    Harms, Tamara K.; Grimm, Nancy B.

    2012-03-01

    Pulsed hydrologic inputs interact with antecedent moisture conditions to shape biogeochemical dynamics in many ecosystems, but the outcomes of these interactions remain difficult to predict. Hydrologic pulses may influence biogeochemical activity through several mechanisms: by providing water as a resource, providing limiting nutrients or substrates that fuel particular biogeochemical pathways, or determining redox conditions. Antecedent moisture conditions may modify the relative importance of each of these potential mechanisms, by influencing accumulation of labile carbon and nutrients, the severity of water limitation to biological processes, and longer-term effects on abiotic conditions, including redox. We experimentally applied hydrologic pulses of different sizes (1-cm and 20-cm events) to soils of desert floodplains and assessed responses of trace gases (CO2, CH4, NO, and N2O) in dry and monsoon seasons to test these mechanisms. Size of the hydrologic pulse strongly interacted with antecedent soil-moisture conditions to determine emissions of some trace gases. Following dry antecedent conditions, water addition stimulated emissions of CO2, CH4, and NO, but not N2O, and larger experimental pulses resulted in larger fluxes. In the monsoon season, responses to water addition were muted and size of the hydrologic pulse had no effect, except for CH4emission, which increased in response to the 20-cm event. Seasonal contrasts indicated that antecedent moisture conditions constrain the effects of hydrologic pulses on biogeochemical processes, whereas contrasts among responses of different trace gases demonstrated that mechanisms controlling emissions of particular gases are water limitation (CO2), in situ production of nitrogen substrates (NO), or redox conditions (CH4). Strong and predictable interactive effects of water inputs and antecedent conditions indicate that extended droughts may cause elevated emissions of gaseous C and NO following the return of

  6. Patterns of trace gases near sources of global pollution

    SciTech Connect

    Khalil, M.A.K.; Rasmussen, R.A. )

    1990-08-01

    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.

  7. Analysis of Process Gases and Trace Contaminants in Membrane-Aerated Gaseous Effluent Streams.

    NASA Technical Reports Server (NTRS)

    Coutts, Janelle L.; Lunn, Griffin Michael; Meyer, Caitlin E.

    2015-01-01

    In membrane-aerated biofilm reactors (MABRs), hollow fibers are used to supply oxygen to the biofilms and bulk fluid. A pressure and concentration gradient between the inner volume of the fibers and the reactor reservoir drives oxygen mass transport across the fibers toward the bulk solution, providing the fiber-adhered biofilm with oxygen. Conversely, bacterial metabolic gases from the bulk liquid, as well as from the biofilm, move opposite to the flow of oxygen, entering the hollow fiber and out of the reactor. Metabolic gases are excellent indicators of biofilm vitality, and can aid in microbial identification. Certain gases can be indicative of system perturbations and control anomalies, or potentially unwanted biological processes occurring within the reactor. In confined environments, such as those found during spaceflight, it is important to understand what compounds are being stripped from the reactor and potentially released into the crew cabin to determine the appropriateness or the requirement for additional mitigation factors. Reactor effluent gas analysis focused on samples provided from Kennedy Space Center's sub-scale MABRs, as well as Johnson Space Center's full-scale MABRs, using infrared spectroscopy and gas chromatography techniques. Process gases, such as carbon dioxide, oxygen, nitrogen, nitrogen dioxide, and nitrous oxide, were quantified to monitor reactor operations. Solid Phase Microextraction (SPME) GC-MS analysis was used to identify trace volatile compounds. Compounds of interest were subsequently quantified. Reactor supply air was examined to establish target compound baseline concentrations. Concentration levels were compared to average ISS concentration values and/or Spacecraft Maximum Allowable Concentration (SMAC) levels where appropriate. Based on a review of to-date results, current trace contaminant control systems (TCCS) currently on board the ISS should be able to handle the added load from bioreactor systems without the need

  8. The effects of biomass burning on the concentration of trace gases in the atmosphere

    NASA Technical Reports Server (NTRS)

    Donaldson, Leon M.

    1988-01-01

    Over the past several years, there has been considerable interest concerning the global effects of biomass burning on concentrations of trace gases in the atmosphere. The paucity of reported studies and investigations into the effects of the Greenhouse Gases such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), up until about a decade ago, would suggest that the topic was not then one of universal concern. Efforts are now being made to understand the biogenic, anthropogenic and photochemical sources of atmospheric trace gases. Biomass burning which includes the burning of forests for clearing, the burning of vegetative stubble after harvesting, and lightning and human-induced wildfires is but one consideration under the general paradigm of atmospheric perturbations. A team of researchers from the Langley Research Center, along with the Canadian Forest Ministry, Ontario, Canada collaborated in an experiment in a deforestration effort through a prescribed burn. Through a specially designed experimental modeling and instrumentation, a substantial pre-burn data set was collected. The primary focus of the pre-burn experimental activities was the emission of nitrous oxide (N2O) gas from selected sites.

  9. Epiphytic cryptogams as a source of bioaerosols and trace gases

    NASA Astrophysics Data System (ADS)

    Ruckteschler, Nina; Hrabe de Angelis, Isabella; Zartman, Charles E.; Araùjo, Alessandro; Pöschl, Ulrich; Manzi, Antonio O.; Andreae, Meinrat O.; Pöhlker, Christopher; Weber, Bettina

    2016-04-01

    Cryptogamic covers comprise (cyano-)bacteria, algae, lichens, bryophytes, fungi, and archaea in varying proportions. These organisms do not form flowers, but reproduce by spores or cell cleavage with these reproductive units being dispersed via the atmosphere. As so-called poikilohydric organisms they are unable to regulate their water content, and their physiological activity pattern mainly follows the external water conditions. We hypothesize, that both spore dispersal and the release of trace gases are governed by the moisture patterns of these organisms and thus they could have a greater impact on the atmosphere than previously thought. In order to test this hypothesis, we initiated experiments at the study site Amazonian Tall Tower Observatory (ATTO) in September 2014. We installed microclimate sensors in epiphytic cryptogams at four different heights of a tree to monitor the activity patterns of these organisms. Self-developed moisture probes are used to analyze the water status of the organisms accompanied by light and temperature sensors. The continuously logged data are linked to ongoing measurements of trace gases and particulate bioaerosols to analyze these for the relevance of cryptogams. Here, we are particularly interested in diurnal cycles of coarse mode particles and the atmospheric abundance of fine potassium-rich particles from a currently unknown biogenic source. Based upon the results of this field study we also investigate the bioaerosol and trace gas release patterns of cryptogamic covers under controlled conditions. With this combined approach of field and laboratory experiments we aim to disclose the role of cryptogamic covers in bioaerosol and trace gas release patterns in the Amazonian rainforest.

  10. Climate-active Trace Gases from ACE Satellite Observations

    NASA Astrophysics Data System (ADS)

    Bernath, P. F.; Brown, A.; Harrison, J.; Chipperfield, M.; Boone, C.; Wilson, C.; Walker, K. A.

    2011-12-01

    ACE (also known as SCISAT) is making a comprehensive set of simultaneous measurements of more than 30 trace gases, thin clouds, aerosols and temperature by solar occultation from a satellite in low earth orbit. A high inclination (74 degrees) low earth orbit (650 km) gives ACE coverage of tropical, mid-latitudes and polar regions. A high-resolution (0.02 cm-1) infrared Fourier Transform Spectrometer (FTS) operating from 2 to 13 microns (750-4400 cm-1) is measuring the vertical distribution of trace gases, and the meteorological variables of temperature and pressure. Launched by NASA in August 2003 for a nominal two-year mission, ACE performance remains excellent after 8 years in orbit. Volume mixing ratio (VMR) profiles of sixteen halogenated trace gases are routinely retrieved from ACE-FTS atmospheric spectra: CCl4, CF4, CCl3F (CFC-11), CCl2F2 (CFC-12), C2Cl3F3 (CFC-113), CH3Cl, ClONO2, COF2, COCl2, COClF, CHF2Cl (HCFC-22), CH3CCl2F (HCFC-141b), CH3CClF2 (HCFC-142b), HCl, HF and SF6. ACE also provides VMR profiles for CH4, N2O and OCS; HCFC-23 (CHF3) is a recent research product. ACE-FTS measurements were compared to surface measurements made by the AGAGE network and output from the SLIMCAT three-dimensional (3-D) chemical transport model, which is constrained by similar surface data. ACE-FTS measurements of CFCs (and HCl) show declining trends which agree with both AGAGE and SLIMCAT values. The concentrations of HCFCs are increasing with ACE-FTS, SLIMCAT and AGAGE all showing positive trends. These results illustrate the success of the Montreal Protocol in reducing ozone depleting substances. The replacement of CFCs with HCFCs has led to an increase in the VMR of HF in the stratosphere. As chlorine containing compounds continue to be phased out and replaced by fluorine-containing molecules, it is likely that total atmospheric fluorine will continue increasing in the near future. These species are all powerful greenhouse gases. ACE provides near global VMR

  11. Measurements of Trace Gases Using a Tunable Diode Laser

    NASA Technical Reports Server (NTRS)

    Jost, Hans-Juerg

    2005-01-01

    This report is the final report for "Measurements of Trace Gases Using a Tunable Diode Laser." The tasks outlined in the proposal are listed below with a brief comment. The publications and the conference presentations are listed. Finally, the important publications are attached. The Cooperative Agreement made possible a research effort to produce high- precision and high-accuracy in-situ measurements of carbon monoxide, methane and nitrous oxide on the WB-57 during the CRYSTAL-FACE and pre-AVE field campaigns and to analyze these measurements. These measurements of CO and CH4 were of utmost importance to studies of the radiative effects of clouds. Some important results of the CRYSTAL-FACE program were contained in two scientific papers (attached). This Cooperative Agreement allowed the participation of the Argus instrument in the program and the analysis of the data.

  12. Atmospheric trace gases and global climate - A seasonal model study

    NASA Technical Reports Server (NTRS)

    Wang, Wei-Chyung; Molnar, Gyula; Ko, Malcolm K. W.; Goldenberg, Steven; Sze, Nien Dak

    1990-01-01

    Atmospheric models with seasonal cycles are used to study the possible near-future changes in latitudinal and vertical distributions of atmospheric ozone and temperature caused by increases of trace gases. It is found that increases of CFCs, CH4, and N2O may add to the surface warming from increased CO2. Calculations based on projected trends of CO2, N2O, CH4, and CFCs show that the annual mean and global mean surface temperature could warm by as much as 2.5 C by the year 2050, with larger warming at high latitudes. The results suggest that the warming in the lower stratosphere and upper troposphere is much larger than that at the surface, especially during the summer season.

  13. Climate-chemical interactions and greenhouse effects of trace gases

    NASA Technical Reports Server (NTRS)

    Shi, Guang-Yu; Fan, Xiao-Biao

    1994-01-01

    A completely coupled one-dimensional radiative-convective (RC) and photochemical-diffusion (PC) model has been developed recently and used to study the climate-chemical interactions. The importance of radiative-chemical interactions within the troposphere and stratosphere has been examined in some detail. We find that increases of radiatively and/or chemically active trace gases such as CO2, CH4 and N2O have both the direct effects and the indirect effects on climate change by changing the atmospheric O3 profile through their interaction with chemical processes in the atmosphere. It is also found that the climatic effect of ozone depends strongly on its vertical distribution throughout the troposphere and stratosphere, as well on its column amount in the atmosphere.

  14. Sensitivity of RF-driven Plasma Filaments to Trace Gases

    NASA Astrophysics Data System (ADS)

    Burin, M. J.; Czarnocki, C. J.; Czarnocki, K.; Zweben, S. J.; Zwicker, A.

    2011-10-01

    Filamentary structures have been observed in many types of plasma discharges in both natural (e.g. lightning) and industrial systems (e.g. dielectric barrier discharges). Recent progress has been made in characterizing these structures, though various aspects of their essential physics remain unclear. A common example of this phenomenon can be found within a toy plasma globe (or plasma ball), wherein a primarily neon gas mixture near atmospheric pressure clearly and aesthetically displays filamentation. Recent work has provided the first characterization of these plasma globe filaments [Campanell et al., Physics of Plasmas 2010], where it was noticed that discharges of pure gases tend not to produce filaments. We have extended this initial work to investigate in greater detail the dependence of trace gases on filamentation within a primarily Neon discharge. Our preliminary results using a custom globe apparatus will be presented, along with some discussion of voltage dependencies. Newly supported by the NSF/DOE Partnership in Basic Plasma Science and Engineering.

  15. MAX-DOAS measurements of atmospheric trace gases in Ny-Ålesund

    NASA Astrophysics Data System (ADS)

    Wittrock, F.; Oetjen, H.; Richter, A.; Fietkau, S.; Medeke, T.; Rozanov, A.; Burrows, J. P.

    2003-12-01

    A new approach to derive tropospheric concentrations of some atmospheric trace gases from ground-based UV/vis measurements is described. The instrument, referred to as the MAX-DOAS, is based on the well-known UV/vis instruments, which use the sunlight scattered in the zenith sky as the light source and the method of Differential Optical Absorption Spectroscopy (DOAS) to derive column amounts of absorbers like ozone and nitrogen dioxide. Substantial enhancements have been applied to this standard setup to use different lines of sight near to the horizon as additional light sources (MAX - multi axis). Results from measurements at Ny-Ålesund (79° N, 12° E) are presented and interpreted with the full-spherical radiation transport model SCIATRAN. In particular, measurements of the oxygen dimer O4 which has a known column and vertical distribution in the atmosphere are used to evaluate the sensitivity of the retrieval to parameters such as multiple scattering, solar azimuth, surface albedo and refraction in the atmosphere and also to validate the radiative transport model. As a first application, measurements of NO2 emissions from a ship lying in Ny-Ålesund harbour are presented. The results of this study demonstrate the feasibility of long term UV/vis multi axis measurement that can be used to derive not only column amounts of different trace gases but also some information on the vertical location of these absorbers.

  16. Quantum cascade laser open-path system for remote sensing of trace gases in Beijing, China

    NASA Astrophysics Data System (ADS)

    Michel, Anna P. M.; Liu, Peter Q.; Yeung, June K.; Corrigan, Paul; Baeck, Mary Lynn; Wang, Zifa; Day, Timothy; Smith, James A.

    2010-11-01

    Exploiting several key characteristics of quantum cascade (QC) lasers, including wide tunability and room-temperature operation, the Quantum Cascade Laser Open-Path System (QCLOPS) was designed for the detection of a range of trace gases and for field deployment in urban environments. Tunability over a wavelength range from 9.3 to 9.8 μm potentially provides the capability for monitoring ozone, ammonia, and carbon dioxide, a suite of trace gases important for air quality and regional climate applications in urban environments. The 2008 Olympic Games in Beijing, China drew attention to air quality problems in urban environments. Prior to and during the Olympic games, regional air quality modifications through factory shutdowns, car restrictions, and construction halts in Beijing and its surrounding areas created a unique test bed for new sensor technologies such as the QCLOPS sensor. We report the design of this novel, open-path air quality sensor and the results of both laboratory tests and field trials during the 2008 Olympic Games in Beijing, China.

  17. Volatile organic trace gases emitted from North American wildfires

    NASA Astrophysics Data System (ADS)

    Friedli, H. R.; Atlas, E.; Stroud, V. R.; Giovanni, L.; Campos, T.; Radke, L. F.

    2001-06-01

    Trace gases from wildfires and prescribed burns were collected from the National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) C-130 aircraft at fire locations in temperate forests (Montana, Colorado) and sage scrub (California). Comprehensive compositions for hydrocarbons, partially oxidized hydrocarbons (POHC), halocarbons, alkyl nitrates, and some sulfur compounds were determined in 99 samples. All of these trace gas emission groups correlated linearly with CO emissions. Fires in temperate forests emitted ˜28% more nonmethane hydrocarbons (NMHC) and 120% more POHC than the California fire and the molecular weight range of the emitted hydrocarbons was higher. The POHC contribution relative to NMHC emissions is significant: 26 and 38% for California and temperate forests, respectively. Since the observed POHCs (mostly ketones, aldehydes, and furans) typically react faster than many NMHC and undergo cascades of photochemical degradations, they should be included in calculations of the effect that fires have on the local and global oxidative capacity of the atmosphere. The composition of the hydrocarbons and POHCs in the plumes varied with combustion efficiency, displaying a distinct pattern, which reflected fire chemistry. Interfire differences were evident among fires in temperate forests. The dominant halocarbon emissions from all fires were methyl halides. The emission ratio was always largest for methyl chloride and was dependent on vegetation and fire location. C1-C5 alkyl nitrates were found in all fire emissions and showed little dependence on the location of the fire. The major organic sulfur compound measured was carbonyl sulfide. Minor amounts of dimethyl sulfide and dimethyl disulfide were observed. Budget estimates for emissions from fires in temperate forests were made based on the measured emission ratios and published carbon monoxide estimates.

  18. Remote sensing of atmospheric trace gases by diode laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Jianguo; Kan, Ruifeng; He, Yabai; He, Ying; Zhang, Yujun; Xie, Pinhua; liu, Wenqing

    2016-04-01

    Gaseous ammonia is the most abundant alkaline trace gas in the atmosphere. In order to study its role in acid deposition and aerosol formation, as well as its influence on the regional air quality and atmospheric visibility, several instruments has been developed based on TDLAS (Tunable Diode Laser Absorption Spectroscopy) techniques. In this paper, a long open path TDLAS system and a continuous-wave CRDS (Cavity-Ring down Spectroscopy) system are presented. The long open path system has been developed for NH3 in-situ monitoring by combining wavelength modulation with harmonic detection techniques to obtain the necessary detection sensitivity. The prototype instrument has been used to monitor atmospheric NH3 concentration at an urban site near Beijing National Stadium during Beijing Olympics in 2008, and recently used to measure the fluxes of NH3 from farm fields by flux-gradient method. The detection limit for ammonia is proved approximately 3ppb for a total path length of 456m. The continuous-wave, rapidly swept CRDS system has been developed for localized atmospheric sensing of trace gases at remote sites. Passive open-path optical sensor units could be coupled by optical fiber over distances of >1 km to a single transmitter/receiver console incorporating a photodetector and a swept-frequency diode laser tuned to molecule-specific near-infrared wavelengths. A noise-limited minimum detectable mixing ratio of ~11 ppbv is attained for ammonia at atmospheric pressure. The developed instruments are deployable in agricultural, industrial, and natural atmospheric environments.

  19. Trace gases in the atmosphere over Russian cities

    NASA Astrophysics Data System (ADS)

    Elansky, Nikolai F.; Lavrova, Olga V.; Skorokhod, Andrey I.; Belikov, Igor B.

    2016-10-01

    Multiyear observational data (obtained at the mobile railroad laboratory in the course of the 1995-2010 TROICA experiments) on the composition and state of the atmosphere were used to study the features of both spatial and temporal variations in the contents of trace gases in the surface air layer over Russian cities. The obtained characteristics of urban air noticeably differ from those obtained at stationary stations. The emission fluxes of NOx, CO, and CH4 and their integral emissions from large cities have been estimated on the basis of observational data obtained at the mobile laboratory. The values of these emission fluxes reflect the state of urban infrastructure. The integral urban emissions of CO depend on the city size and vary from 50 Gg yr-1 for Yaroslavl to 130 Gg yr-1 for Yekaterinburg. For most cities, they agree with the EDGAR v4.2 data within the limits of experimental error. The agreement is worse for the emissions of NOx. The EDGAR v4.2 data on the emissions of CH4 seem to be overestimated.

  20. Microwave limb sounder. [measuring trace gases in the upper atmosphere

    NASA Technical Reports Server (NTRS)

    Gustincic, J. J. (Inventor)

    1981-01-01

    Trace gases in the upper atmosphere can be measured by comparing spectral noise content of limb soundings with the spectral noise content of cold space. An offset Cassegrain antenna system and tiltable input mirror alternately look out at the limb and up at cold space at an elevation angle of about 22. The mirror can also be tilted to look at a black body calibration target. Reflection from the mirror is directed into a radiometer whose head functions as a diplexer to combine the input radiation and a local ocillator (klystron) beam. The radiometer head is comprised of a Fabry-Perot resonator consisting of two Fabry-Perot cavities spaced a number of half wavelengths apart. Incoming radiation received on one side is reflected and rotated 90 deg in polarization by the resonator so that it will be reflected by an input grid into a mixer, while the klystron beam received on the other side is also reflected and rotated 90 deg, but not without passing some energy to be reflected by the input grid into the mixer.

  1. Biogenic trace gases in the atmosphere of Mars

    NASA Astrophysics Data System (ADS)

    Jahangeer, Muffarah

    Trace gases are known to exert a tremendous influence on planetary atmospheres. By understanding spatial and temporal trace gas behavioral patterns vast amounts of information about the celestial body can be deduced, from current conditions to past history to future evolution. The discovery of episodic methane plumes on Mars argues the presence of ethane, regardless of origin, biogenic or abiogenic, even though it has yet to be detected there. The Earth's methane is produced both by serpentinization as well as by Archaean methanogens. Methane is a potent greenhouse gas and large methane excursions on Earth have been linked with dramatic shifts in its climate, as with the Permian-Triassic extinction event. Atmospheric ethane while present on Earth at about 0.5 ppbv, results primarily from the photochemical action on methane gas. Ultraviolet photons of wavelengths shorter than 160 nm dissociate methane to a methyl radical and one hydrogen atom. When two methyl radicals recombine, the result is ethane: CH4+hv→CH3• +•H CH3•+•CH3+M→C2H6+M A small fraction of terrestrial ethane is also produced by methanogens and ethanogens. Ethane is a constituent of the atmospheres of all four outer solar system planetary bodies as well as of some moons and comets but has not yet been explored or studied in Mars. Possible mechanisms that control the synthesis, occurrence and lifetime of ethane in the atmosphere of Mars are examined in this study along with the Martian trace gas profile using a 1-D photochemical model of its atmosphere. Upper limits of the flux of ethane used are based on our understanding of the Earth's atmospheric component of ethane and vertical patterns of lifetime, mixing ratio and kinetic reaction rates probed from the regolith to 240km. Ethane molecules are heavier and exhibit "creep" and pooling on the ground, allowing it to linger at the regolith. Ethane also benefits from shielding by methane molecules, allowing some ethane to persist at higher

  2. Titan's temporal evolution in stratospheric trace gases near the poles

    NASA Astrophysics Data System (ADS)

    Coustenis, Athena; Jennings, Donald E.; Achterberg, Richard K.; Bampasidis, Georgios; Lavvas, Panayiotis; Nixon, Conor A.; Teanby, Nicholas A.; Anderson, Carrie M.; Cottini, Valeria; Flasar, F. Michael

    2016-05-01

    We analyze spectra acquired by the Cassini/Composite Infrared Spectrometer (CIRS) at high resolution from October 2010 until September 2014 in nadir mode. Up until mid 2012, Titan's Northern atmosphere exhibited the enriched chemical content found since the Voyager days (November 1980), with a peak around the Northern Spring Equinox (NSE) in 2009. Since then, we have observed the appearance at Titan's south pole of several trace species for the first time, such as HC3N and C6H6, observed only at high northern latitudes before equinox. We investigate here latitudes poleward of 50°S and 50°N from 2010 (after the Southern Autumnal Equinox) until 2014. For some of the most abundant and longest-lived hydrocarbons (C2H2, C2H6 and C3H8) and CO2, the evolution in the past 4 years at a given latitude is not very significant within error bars especially until mid-2013. In more recent dates, these molecules show a trend for increase in the south. This trend is dramatically more pronounced for the other trace species, especially in 2013-2014, and at 70°S relative to 50°S. These two regions then demonstrate that they are subject to different dynamical processes in and out of the polar vortex region. For most species, we find higher abundances at 50°N compared to 50°S, with the exception of C3H8, CO2, C6H6 and HC3N, which arrive at similar mixing ratios after mid-2013. While the 70°N data show generally no change with a trend rather to a small decrease for most species within 2014, the 70°S results indicate a strong enhancement in trace stratospheric gases after 2012. The 663 cm-1 HC3N and the C6H6 674 cm-1 emission bands appeared in late 2011/early 2012 in the south polar regions and have since then exhibited a dramatic increase in their abundances. At 70°S HC3N, HCN and C6H6 have increased by 3 orders of magnitude over the past 3-4 years while other molecules, including C2H4, C3H4 and C4H2, have increased less sharply (by 1-2 orders of magnitude). This is a strong

  3. Miniaturized Gas Correlation Radiometer for the Detection of Trace Gases in the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Melroy, H.; Wilson, E. L.; Georgieva, E.

    2012-12-01

    We present a miniaturized and simplified version of a gas correlation radiometer (GCR) capable of simultaneously mapping multiple trace gases and identifying active regions on the Mars surface. Gas correlation radiometry (GCR) has been shown to be a sensitive and versatile method for detecting trace gases in Earth's atmosphere. Reduction of the size and mass of the GCR was achieved by implementing compact, light-weight 1 mm inner diameter hollow-core optical fibers (hollow waveguides) as the gas correlation cells. In a comparison with an Earth orbiting CO2 GCR instrument, exchanging the 10 m multipass cells with hollow waveguide gas correlation cells of equivalent pathlength reduces the mass from ~150 kg to ~0.5 kg, and reduces the volume from 1.9 m x 1.3 m x 0.86 m to a small bundle of fiber coils approximately 1 meter in diameter by 0.05 m in height (mass and volume reductions of >99%). A unique feature of this instrument is its stackable module design, with a single module for each trace gas. Each of the modules is self-contained, and fundamentally identical; differing by the bandpass filter wavelength range and gas mixtures inside the hollow-waveguide absorption cells. The current configuration contains four stacked modules for simultaneous measurements of methane (CH4), formaldehyde (H2CO), water vapor (H2O), and deuterated water vapor (HDO) but could easily be expanded to include measurements of additional species of interest including nitrous oxide (N2O), hydrogen sulfide (H2S), methanol (CH3OH), and sulfur dioxide (SO2), as well as carbon dioxide (CO2) for a simultaneous measure of mass balance. Preliminary results indicate that a 1 ppb detection limit is possible for both formaldehyde and methane with one second of averaging. Using non-optimized components, we have demonstrated an instrument sensitivity equivalent to ~30 ppb for formaldehyde, and ~500 ppb for methane. We expect custom bandpass filters and 6 m long waveguides to significantly improve these

  4. Miniaturized Gas Correlation Radiometer for the Detection of Trace Gases in the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Melroy, Hilary R.; Wilson, Emily L.; Georgieva, Elena

    2012-01-01

    We present a miniaturized and simplified version of a gas correlation radiometer (GCR) capable of simultaneously mapping multiple trace gases and identifying active regions on the Mars surface. Gas correlation radiometry (GCR) has been shown to be a sensitive and versatile method for detecting trace gases in Earth's atmosphere. Reduction of the size and mass of the GCR was achieved by implementing compact, light-weight 1 mm inner diameter hollow-core optical fibers (hollow waveguides) as the gas correlation cells. In a comparison with an Earth orbiting CO2 GCR instrument, exchanging the 10 m multipass cells with hollow waveguide gas correlation cells of equivalent path length reduces the mass from approximately 150 kg to approximately 0.5 kg, and reduces the volume from 1.9 m x 1.3 m x 0.86 m to a small bundle of fiber coils approximately 1 meter in diameter by 0.05 m in height (mass and volume reductions of greater than 99%). A unique feature of this instrument is its stackable module design, with a single module for each trace gas. Each of the modules is self-contained, and fundamentally identical; differing by the bandpass filter wavelength range and gas mixtures inside the hollow-waveguide absorption cells. The current configuration contains four stacked modules for simultaneous measurements of methane (CH4), formaldehyde (H2CO), water vapor (H2O), and deuterated water vapor (HDO) but could easily be expanded to include measurements of additional species of interest including nitrous oxide (N2O), hydrogen sulfide (H2S), methanol (CH3OH), and sulfur dioxide (SO2), as well as carbon dioxide (CO2) for a simultaneous measure of mass balance. Preliminary results indicate that a 1 ppb detection limit is possible for both formaldehyde and methane with one second of averaging. Using non-optimized components, we have demonstrated an instrument sensitivity equivalent to approximately 30 ppb for formaldehyde, and approximately 500 ppb for methane. We expect custom

  5. Trace Gases and Aerosols Simulated Over the Indian Domain: Evaluation of the Model Wrf-Chem

    NASA Astrophysics Data System (ADS)

    Michael, M.; Yadav, A.; Tripathi, S. N.; Venkataraman, C.; Kanawade, V. P.

    2012-12-01

    As the anthropogenic emissions from the Asian countries contribute substantially to the global aerosol loading, the study of the distribution of trace gases and aerosols over this region has received increasing attention in recent years. In the present work, the aerosol properties over the Indian domain during the pre-monsoon season has been addressed. The "online" meteorological and chemical transport Weather Research and Forecasting-Chemistry (WRF-Chem) model has been implemented over Indian subcontinent for three consecutive summers in 2008, 2009 and 2010.The initial and boundary conditions are obtained from NCAR reanalysis data. The global emission inventories (REanalysis of the TROpospheric chemical composition (RETRO) and Emissions Database for Global Atmospheric Research (EDGAR)) have been used and are projected for the period of study using the method provided in Ohara et al. (2007). The emission rates of sulfur dioxide, black carbon, organic carbon and PM2.5 available in the global inventory are replaced with the high resolution emission inventory developed over India for the present study. The model simulates meteorological parameters, trace gases and particulate matter. Simulated mixing ratios of trace gases (Ozone, carbon monoxide, nitrogen oxides, and SO2) are compared with ground based as well as satellite observations over India with specific focus on Indo-Gangetic Plain. Simulated aerosol optical depth are in good agreement with those observed by Aerosol Robotic Network (AERONET). The vertical profiles of extinction coefficient have been compared with the Micro Pulse Lidar Network (MPLnet) data. The simulated mass concentration of BC shows very good agreement with those observed at a few ground stations. The vertical profiles of BC have also been compared with aircraft observations carried out during summer of 2008 and 2009, resulting in good agreement. This study shows that WRF-Chem model captures many important features of the observations and

  6. Pilot Institute on Global Change on Trace Gases and the Biosphere, 1988

    NASA Technical Reports Server (NTRS)

    Eddy, J. A.; Moore, B.

    1998-01-01

    Table of Contents: Summary; Background; General Framework for a Series of Institutes on Global Change; The 1988 Pilot Institute on Global Changes: Trace Gases and the Biosphere; Budget; List of Acronyms; and Attachments.

  7. Emission of climate-relevant trace gases and succession of microbial communities during open-windrow composting

    SciTech Connect

    Hellmann, B.; Zelles, L.; Palojaervi, A.; Bai, Q.

    1997-03-01

    Municipal solid-waste composting is a process of increasing importance, based primarily on augmentation of microbial activity. The composting of organic matter leads not only to a reduction in waste but a sensible recycling of residuals to their origin. Carbon dioxide derived from plant matter degradation does not contribute to global warming. However, emitted nitrous oxide and methane molecules contribute to the enhancement of the greenhouse effect. This study determined a wide variety of microbial properties during the composting processes at a whole windrow level and quantified the emission rates of the climate relevant trace gases, carbon dioxide, nitrous oxide and methane during the course of maturation of a compost row. 47 refs., 6 figs., 1 tab.

  8. Optical parametric oscillators in lidar sounding of trace atmospheric gases in the mid infrared region

    NASA Astrophysics Data System (ADS)

    Romanovskii, O. A.; Sadovnikov, S. A.; Kharchenko, O. V.; Shumskii, V. K.; Yakovlev, S. V.

    2015-12-01

    Applicability of a KTA crystal-based laser system with optical parametric generation to lidar sounding of the atmosphere in the spectral range 3-4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases is based on differential absorption (DIAL) technique and differential optical absorption spectroscopy (DOAS). The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases.

  9. MIRAGE: Model Description and Evaluation of Aerosols and Trace Gases

    SciTech Connect

    Easter, Richard C.; Ghan, Steven J.; Zhang, Yang; Saylor, Rick D.; Chapman, Elaine G.; Laulainen, Nels S.; Abdul-Razzak, Hayder; Leung, Lai-Yung R.; Bian, Xindi; Zaveri, Rahul A.

    2004-10-27

    The MIRAGE (Model for Integrated Research on Atmospheric Global Exchanges) modeling system, designed to study the impacts of anthropogenic aerosols on the global environment, is described. MIRAGE consists of a chemical transport model coupled on line with a global climate model. The chemical transport model simulates trace gases, aerosol number, and aerosol chemical component mass [sulfate, MSA, organic matter, black carbon (BC), sea salt, mineral dust] for four aerosol modes (Aitken, accumulation, coarse sea salt, coarse mineral dust) using the modal aerosol dynamics approach. Cloud-phase and interstitial aerosol are predicted separately. The climate model, based on the CCM2, has physically-based treatments of aerosol direct and indirect forcing. Stratiform cloud water and droplet number are simulated using a bulk microphysics parameterization that includes aerosol activation. Aerosol and trace gas species simulated by MIRAGE are presented and evaluated using surface and aircraft measurements. Surface-level SO2 in N. American and European source regions is higher than observed. SO2 above the boundary layer is in better agreement with observations, and surface-level SO2 at marine locations is somewhat lower than observed. Comparison with other models suggests insufficient SO2 dry deposition; increasing the deposition velocity improves simulated SO2. Surface-level sulfate in N. American and European source regions is in good agreement with observations, although the seasonal cycle in Europe is stronger than observed. Surface-level sulfate at high-latitude and marine locations, and sulfate above the boundary layer, are higher than observed. This is attributed primarily to insufficient wet removal; increasing the wet removal improves simulated sulfate at remote locations and aloft. Because of the high sulfate bias, radiative forcing estimates for anthropogenic sulfur in Ghan et al. [2001c] are probably too high. Surface-level DMS is {approx}40% higher than observed

  10. Distribution and Sources of Trace Gases and Aerosols in the Asian Summer Monsoon Anticyclone - Aircraft Observations and Model Simulations

    NASA Astrophysics Data System (ADS)

    Schlager, H.; Klausner, T.; Aufmhoff, H.; Baumann, R.; Gottschaldt, K. D.

    2015-12-01

    We report aircraft observations of trace gases and aerosols from recent field campaigns in the Asian summer monsoon anticyclone. Measurements were performed with the DLR Falcon and HALO aircraft at altitudes up to 15 km across the boundary of the anticyclone over the Arabian Sea during June, July and September conditions. Sharp gradients in chemical tracer mixing ratios were observed at the boundary of the anticyclone. In particular, sulfur dioxide and aerosols were enhanced inside the anticyclone. Ozone and carbon monoxide were enhanced or reduced in the anticyclone depending on the degree of in-mixing of air from the stratosphere inferred from observations of the stratospheric tracer hydrochloric acid. Backward trajectory analysis, tracer dispersion calculations, and simulations with the chemistry-climate model EMAC, nudged to the meteorological conditions of the measurements, were used to investigate the origin and transport of trace gases in and in the vicinity of the anticyclone. A chemistry-aerosol box model was used to simulate the formation of sulfate aerosol from sulfur dioxide inside the anticyclone uplifted by deep convection over northern India and in the Gulf of Bengal.

  11. Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes

    USGS Publications Warehouse

    Gerlach, Terrence

    1990-01-01

    Volcanic degassing of carbon dioxide plays an important role in keeping the atmosphere-ocean portion of the carbon geochemical cycle in balance. The atmosphere-ocean carbon deficit requires replenishment of 6??1012 mol CO2/yr, and places an upper limit on the output of carbon dioxide from volcanoes. The CO2 output of the global mid-oceanic ridge system is ca. 0.7??1012 mol/yr, thus supplying only a fraction of the amount needed to balance the carbon deficit. The carbon dioxide flux from subaerial volcanoes is poorly known, but it appears to be at least as large as the mid-oceanic ridge flux. Much (perhaps most) of the CO2 emitted from volcanoes is degassed noneruptively. This mode of degassing may lead to impacts on the environment and biosphere that are fundamentally different in character from those envisioned in published scenarios, which are based on the assumption that CO2 degassing occurs predominantly by eruptive processes. Although the flux of carbon dioxide from volcanoes is poorly constrained at present, it is clearly two orders of magnitude lower than the anthropogenic output of CO2.

  12. Trace anesthetic gases during xenon arc photocoagulation for retinoblastoma.

    PubMed

    Rosenberg, A M; Abramson, D H; Sussman, D; Servodidio, C; Turner, L

    1989-10-01

    In pediatric ocular examinations, administration of continuous-flow anesthetic gases containing nitrous oxide, halothane, and oxygen enables the physician to do safe, controlled, reproducible examinations. We did a study in which the levels of waste anesthetic gases were measured during xenon arc photocoagulation procedures used for retinoblastoma. Waste nitrous oxide and halothane gases measured during these procedures significantly exceeded the levels recommended by the National Institute of Safety and Health. These high levels are of particular importance because of the physician's proximity to the patient during the procedure. The high levels of waste gases may have immediate deleterious effects on the physician's functioning capacity and may also pose long-term health hazards for the physician and operating room personnel. PMID:2589745

  13. A search for biogenic trace gases in the atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Mckay, Christopher P.

    1989-01-01

    The detection of certain trace gases in the atmosphere of Mars may serve as a possible indicator of microbial life on the surface of Mars. Candidate biogenic gases include methane CH4, ammonia NH3, nitrous oxide N2O, and several reduced sulfur species. Chemical thermodynamic equilibrium and photochemical calculations preclude the presence of these gases in any measurable concentrations in the atmosphere of Mars in the absence of biogenic production. A search for these gases utilizing either high resolution (spectral and spatial) spectroscopy from a Mars orbiter, such as the Observer, and or in situ measurements from a Mars lander or rover, is proposed.

  14. Trace gases in the atmosphere of Mars - An indicator of microbial life

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Rinsland, Curtis P.; Boston, Penelope J.; Cofer, Wesley R., III; Chameides, William L.

    1989-01-01

    The detection of certain trace gases in the atmosphere of Mars would indicate the presence of microbial life on the surface. Candidate biogenic gases include CH4, NH3, N2O, and several reduced sulfur species. Chemical thermodynamic equilibrium and photochemical calculations preclude the presence of these gases in any measurable concentrations in the atmosphere of Mars in the absence of biogenic production. A search for these gases utilizing either high-resolution (spectral and spatial) spectroscopy from a Mars orbiter, such as the Mars Observer orbiter, and/or in situ measurements from a Mars lander or rover is proposed.

  15. Trace water determination in gases by infrared spectroscopy

    SciTech Connect

    Stallard, B.R.; Espinoza, L.H.; Niemczyk, T.M.

    1995-05-01

    Water determination in semiconductor process gases is desirable in order to extend the life of gas delivery systems and improve wafer yields. The authors review their work in applying Fourier transform infrared spectroscopy to this problem, where a 10 ppb detection limit has been demonstrated for water in N{sub 2}, HCl, and HBr. The potential for optical determination of other contaminants in these gases is discussed. Also, alternative optical spectroscopic approaches are briefly described. Finally, they discuss methods for dealing with interference arising from water in the instrument beam path, yet outside the sample cell.

  16. First-principles energetics of rare gases incorporation into uranium dioxide

    NASA Astrophysics Data System (ADS)

    Ao, Bingyun; Lu, Haiyan

    2016-04-01

    First-principles density functional theory-generalized gradient approximation methods have been used to calculate the energetics (incorporation energy, formation energy and binding energy) of rare gases (He, Ne, Ar, Kr and Xe) at the three incorporation sites (octahedral interstitial, uranium and oxygen vacancies) of uranium dioxide. The Hubbard parameter U and van der Waals corrections have been used to describe the strongly correlated electronic behavior of uranium 5f electrons and the weak interactions of rare gases, respectively. The results indicate that the energetics of rare gases depend significantly on the incorporation sites and on the atomic properties such as atomic radius. All rare gases considered here are energetically unfavorable at the three incorporation sites. However, rare gases exhibit significant binding ability to both U and O vacancies. The main trends of relative stability of rare gases generally reflect a size effect: the rare gases become more unstable with increasing atomic number. Electronic structures of these systems containing rare gases also exhibit general trends in their relative stability and charge-transfer character.

  17. Devices and methods to detect and quantify trace gases

    DOEpatents

    Allendorf, Mark D.; Robinson, Alex

    2016-05-03

    Sensing devices based on a surface acoustic wave ("SAW") device coated with an absorbent crystalline or amorphous layer for detecting at least one chemical analyte in a gaseous carrier. Methods for detecting the presence of a chemical analyte in a gaseous carrier using such devices are also disclosed. The sensing devices and methods for their use may be configured for sensing chemical analytes selected from the group consisting of water vapor, carbon dioxide, methanol, ethanol, carbon monoxide, nitric oxide, nitrous oxide, organic amines, organic compounds containing NO.sub.2 groups, halogenated hydrocarbons, acetone, hexane, toluene, isopropanol, alcohols, alkanes, alkenes, benzene, functionalized aromatics, ammonia (NH.sub.3), phosgene (COCl.sub.2), sulfur mustard, nerve agents, sulfur dioxide, tetrahydrofuran (THF) and methyltertbutyl ether (MTBE) and combinations thereof.

  18. Application of Derivative Spectrometry to the Analysis of Trace Gases

    NASA Technical Reports Server (NTRS)

    Hager, Robert N.

    1971-01-01

    A derivative spectrometer is sensitive to changes in spectral intensity over narrow wavelength internal. Specifically, a second derivative spectrometer senses the curvature of the incident spectral intensity, providing an output voltage signal proportional to the second derivative of intensity with respect to wavelength. When such an instrument is combined with multi-pass White cell, a unique trace gas analyzer results. The analyzer, operating within the middle ultraviolet spectral region, provides a highly amplified derivative spectrum of any molecular narrow band absorption which is used for trace gas identification. The intensity of any peak within a spectrum is proportional to the trace gas concentration. Such an analyzer, utilizing a 20 meter pathlength White cell, is presently being used to automatically monitor ambient air for SO2, NO, NO2, and O3 with minimum detectable concentration limits in the part per billion range.

  19. Method of recovering elemental sulfur from reactive gases containing sulfur dioxide and hydrogen sulfide

    SciTech Connect

    Thomsen, A.

    1981-12-01

    Reactive gases containing sulfur dioxide and hydrogen sulfide, e.g. reaction gases of the claus process, are passed through a catalyst stage having an inlet side and an outlet side for the gas mixture to produce elemental sulfur and water. According to the invention the gases are cooled between the inlet and discharge sides by heat-exchanger means to a temperature not less than the activation temperature for the reaction and preferably not less than the temperature at which the gases are initially introduced into the catalyst body. The heat exchanger means can be provided in gaps between catalyst beds and/or within the catalyst beds of the body of catalyst.

  20. Development of 2-D-MAX-DOAS and retrievals of trace gases and aerosols optical properties

    NASA Astrophysics Data System (ADS)

    Ortega, Ivan

    Air pollution is a major problem worldwide that adversely a_ects human health, impacts ecosystems and climate. In the atmosphere, there are hundreds of important compounds participating in complex atmospheric reactions linked to air quality and climate. Aerosols are relevant because they modify the radiation balance, a_ect clouds, and thus Earth albedo. The amount of aerosol is often characterized by the vertical integral through the entire height of the atmosphere of the logarithm fraction of incident light that is extinguished called Aerosol Optical Depth (AOD). The AOD at 550 nm (AOD550) over land is 0.19 (multi annual global mean), and that over oceans is 0.13. About 43 % of the Earth surface shows AOD550 smaller than 0.1. There is a need for measurement techniques that are optimized to measure aerosol optical properties under low AOD conditions, sample spatial scales that resemble satellite ground-pixels and atmospheric models, and help integrate remote sensing and in-situ observations to obtain optical closure on the effects of aerosols and trace gases in our changing environment. In this work, I present the recent development of the University of Colorado two dimensional (2-D) Multi-AXis Differential Optical Absorption Spectroscopy (2-D-MAX-DOAS) instrument to measure the azimuth and altitude distribution of trace gases and aerosol optical properties simultaneously with a single instrument. The instrument measures solar scattered light from any direction in the sky, including direct sun light in the hyperspectral domain. In Chapter 2, I describe the capabilities of 2-D measurements in the context of retrievals of azimuth distributions of nitrogen dioxide (NO2), formaldehyde (HCHO), and glyoxal (CHOCHO), which are precursors for tropospheric O3 and aerosols. The measurements were carried out during the Multi-Axis DOAS Comparison campaign for Aerosols and Trace gases (MAD-CAT) campaign in Mainz, Germany and show the ability to bridge spatial scales to

  1. Greenhouse effects due to man-made perturbations of trace gases

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    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.

  2. ENSO effects on stratospheric trace gases: How do we capture reality?

    NASA Astrophysics Data System (ADS)

    Braesicke, Peter; Kirner, Oliver; Versick, Stefan; Joeckel, Patrick; Stiler, Gabriele

    2016-04-01

    The El Niño/Southern Oscillation (ENSO) phenomenon is an important pacemaker for interannual variability in the Earth's atmosphere. ENSO impacts on trace gases have been observed and modelled for the stratosphere and the troposphere. However, unambiguous attribution is often difficult due to the limited length of homogenous observational records and thus long-term (decadal) trends are sometimes difficult to detect. Generally ENSO impacts in low latitudes are easier to detect, because the response emerges close (temporally and spatially) to the forcing. Moving from low to high latitudes it becomes increasingly difficult to isolate ENSO driven variability, due to time-lags involved and many other modes of variability playing a role as well. Here, we use a nudged version of the EMAC chemistry-climate model to evaluate ENSO impacts on trace gases over the last 35 years (a so-called Ref-C1SD integration) and contrast the nudged model with its free running counterpart. We use water vapour and ozone observations from the MIPAS instrument on ENVISAT from 2002 to 2012 to test the model performance. Using lagged correlations for the longer model time-series we trace the ENSO signal from the tropical lower troposphere to the polar lower and middle stratosphere and provide a framework for simple attribution of the ENSO signal in trace gases. This concise characterisation of the ENSO impact on trace gases aids improved trend detection in temporally limited time series.

  3. MAX-DOAS measurements of atmospheric trace gases in Ny-Ålesund - Radiative transfer studies and their application

    NASA Astrophysics Data System (ADS)

    Wittrock, F.; Oetjen, H.; Richter, A.; Fietkau, S.; Medeke, T.; Rozanov, A.; Burrows, J. P.

    2004-06-01

    A new approach to derive tropospheric concentrations of some atmospheric trace gases from ground-based UV/vis measurements is described. The instrument, referred to as the MAX-DOAS, is based on the well-known UV/vis instruments, which use the sunlight scattered in the zenith sky as the light source and the method of Differential Optical Absorption Spectroscopy (DOAS) to derive column amounts of absorbers like ozone and nitrogen dioxide. Substantial enhancements have been applied to this standard setup to use different lines of sight near to the horizon as additional light sources (MAX - multi axis). Results from measurements at Ny-Ålesund (79° N, 12° E) are presented and interpreted with the full-spherical radiative transfer model SCIATRAN. In particular, measurements of the oxygen dimer O4 which has a known column and vertical distribution in the atmosphere are used to evaluate the sensitivity of the retrieval to parameters such as multiple scattering, solar azimuth, surface albedo and refraction in the atmosphere and also to validate the radiative transfer model. As a first application, measurements of NO2 emissions from a ship lying in Ny-Ålesund harbour are presented. The results of this study demonstrate the feasibility of long term UV/vis multi axis measurement that can be used to derive not only column amounts of different trace gases but also some information on the vertical location of these absorbers.

  4. Efficient atmospheric cleansing of oxidized organic trace gases by vegetation.

    PubMed

    Karl, T; Harley, P; Emmons, L; Thornton, B; Guenther, A; Basu, C; Turnipseed, A; Jardine, K

    2010-11-01

    The biosphere is the major source and sink of nonmethane volatile organic compounds (VOCs) in the atmosphere. Gas-phase chemical reactions initiate the removal of these compounds from the atmosphere, which ultimately proceeds via deposition at the surface or direct oxidation to carbon monoxide or carbon dioxide. We performed ecosystem-scale flux measurements that show that the removal of oxygenated VOC via dry deposition is substantially larger than is currently assumed for deciduous ecosystems. Laboratory experiments indicate efficient enzymatic conversion and potential up-regulation of various stress-related genes, leading to enhanced uptake rates as a response to ozone and methyl vinyl ketone exposure or mechanical wounding. A revised scheme for the uptake of oxygenated VOCs, incorporated into a global chemistry-transport model, predicts appreciable regional changes in annual dry deposition fluxes.

  5. Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

    1991-01-01

    Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

  6. Measurement of stratospheric trace gases by millimeter-wave spectroscopy for an annual cycle at the South Pole

    SciTech Connect

    De Zafra, R.L.; Trimble, C.; Reeves, M.

    1994-12-31

    Chemistry and transport processes in the south polar stratosphere have been intensively studied since discovery of the seasonal {open_quotes}ozone hole{close_quotes} appearing over Antarctica. Nevertheless, large gaps still exist in our knowledge of the dynamical and chemical behavior of the polar winter vortex. This behavior is responsible for much of the prior processing of air, and the processing makes possible the formation of a springtime ozone hole. The work described here was intended to fill some of these gaps by frequently monitoring the behavior of several trace gases over as much of a full year cycle as possible, from a central position within the annually forming winter vortex region. The species covered (not all for the full duration of the observations) were ozone, nitrogen dioxide, nitrous oxide, nitric acid, and chlorine monoxide. An upper limit for hydrogen peroxide was also determined by an unsuccessful attempt to detect it. 7 refs.

  7. Titan's temporal evolution in stratospheric trace gases near the poles

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Jennings, D.; Achterberg, R.; Bampasidis, G.; Lavvas, P.; Nixon, C.; Teanby numeration="7">Teanby, N.; Anderson, C.; Cottini, V.; Flasar, F. M.

    2015-10-01

    We analyze spectra acquired by the Cassini/Composite Infrared Spectrometer (CIRS) at high resolution from October 2010 until September 2014 in nadir mode. Up until mid 2012, Titan's Northern atmosphere exhibited the enriched chemical content found since the Voyager days (November 1980), with a peak around the Northern Spring Equinox (NSE) in 2009. Since then, we have observed the appearance at Titan's south pole of several trace species for the first time, such as HC3N and C6H6, observed only at high northern latitudes before equinox. We investigate here latitudes poleward of 50°S and 50°N from 2010 (after the Southern Autumnal Equinox : SAE) until 2014.

  8. Atmospheric trace gases: trends and distributions over the last decade.

    PubMed

    Rasmussen, R A; Khalil, M A

    1986-06-27

    Concentrations of the halocrbons CCl(3)F (F-11), CCl(2)F(2) (F-12), CCl(4), and CH(3)CCl(3), methane (CH(4)), and nitrous oxide (N(2)O) over the decade between 1975 and 1985 are reported, based on measurements taken every January at the South Pole and in the Pacific Northwest. The concentrations of F-11, F-12, and CH(3)CCl(3) in both hemispheres are now more than twice their concentrations 10 years ago. However, the annual rates of increase of F-11, F-12, and CH(3)CC1(3) are now considerably slower than earlier in the decade, reflecting in part the effects of a ban on their nonessential uses. Continued increases in these trace gas concentrations may warm the earth and deplete the stratospheric ozone layer, which may cause widespread climatic changes and affect global habitability.

  9. Interannual variability of trace gases in the subtropical winter stratosphere

    SciTech Connect

    Gray, L.J.; Russell, J.M. III

    1999-04-01

    Measurements of water vapor and methane from the Halogen Occultation Experiment instrument on board the Upper Atmosphere Research Satellite are used to study the interannual variability of trace gas distributions in the atmosphere. Particular attention is paid to the mechanisms influencing trace gas distributions in the subtropics. The study highlights the quasi-biennial oscillation (QBO) dependence of subtropical tracer distributions more clearly than in previous studies. There is a strong correlation between the equatorial wind QBO and the slope of the tracer isolines in the Northern Hemisphere subtropics, with steeper subtropical isoline slopes in the easterly phase compared with the westerly phase. This is particularly so in the lower stratosphere. Two possible mechanisms for the QBO signal in subtropical isoline slopes are identified: advection by the mean circulation and isentropic mixing. A comparison between the QBO signal in the slope of the tracer isolines and the isentropic tracer gradients is proposed as a method of determining which process is dominant. The authors suggest that the behavior of these two data diagnostics provides a stringent constraint on computer models of the atmosphere. On the basis of these diagnostics three height regions of the subtropical atmosphere are identified. (1) Below 450--500 K isentropic mixing associated with tropospheric disturbances penetrating the lower stratosphere is dominant. (2) In the region 500--750 K the data suggest that advection by the mean meridional circulation is important and that the role of isentropic mixing by eddies is relatively small. (3) Above 750 K isentropic mixing becomes increasingly important with height, and both advection and mixing are influential in determining the subtropical tracer distributions.

  10. Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

    PubMed Central

    Cadena-Pereda, Raúl O.; Rivera-Muñoz, Eric M.; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J.; Anaya-Rivera, Ely K.

    2012-01-01

    Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0–100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible. PMID:23112626

  11. Effects of traces of molecular gases (hydrogen, nitrogen) in glow discharges in noble gases

    NASA Astrophysics Data System (ADS)

    Steers, E. B. M.; Smid, P.; Hoffmann, V.

    2008-07-01

    The "Grimm" type of low pressure glow discharge source, introduced some forty years ago, has proved to be a versatile analytical source. A flat sample is used as the cathode and placed about 0.2mm away from the end of a hollow tubular anode leading to an obstructed discharge. When the source was first developed, it was used for the direct analysis of solid metallic samples by optical emission spectroscopy (OES), normally with argon as the plasma gas; it was soon found that, using suitable electrical parameters, the cathode material was sputtered uniformly from a circular crater of diameter equal to that of the tubular anode, so that the technique could be used for compositional depth profile analysis (CDPA). Over the years the capability and applications of the technique have steadily increased. The use of rf powered discharges now permits the analysis of non-conducting layers and samples; improved instrumental design now allows CDPA of ever thinner layers (e.g. resolution of layers 5 nm thick in multilayer stacks is possible). For the original bulk material application, pre-sputtering could be used to remove any surface contamination but for CDPA, analysis must start immediately the discharge is ignited, so that any surface contamination can introduce molecular gases into the plasma gas and have significant analytical consequences, especially for very thin layers; in addition, many types of samples now analysed contain molecular gases as components (either as occluded gas, or e.g. as a nitride or oxide), and this gas enters the discharge when the sample is sputtered. It is therefore important to investigate the effect of such foreign gases on the discharge, in particular on the spectral intensities and hence the analytical results. The presentation will concentrate mainly on the effect of hydrogen in argon discharges, in the concentration range 0-2 % v/v but other gas mixtures (e.g. Ar/N_2, Ne/H_2) will be considered for comparison. In general, the introduction of

  12. Tracing changes in ecosystem function under elevated carbon dioxide conditions.

    SciTech Connect

    Pataki, D. E.; Ellsworth, D. S.; Evans, R. D.; Gonzalez-Meler, M.; King, J.; Leavitt, S. W.; Lin, G.; Matamala, R.; Pendall, E.; Siegwolf, R.; Van Kessel, C.; Ehleringer, J. F.; Environmental Research; Univ. of Utah; Univ. of Michigan; Washington State Univ.; Univ. of Illinois at Chicago; Michigan Technological Univ.; Univ. of Arizona; Columbia Univ.; Univ. of Wyoming; Paul Scherrer Inst.; Univ. of California, Davis

    2003-09-01

    Responses of ecosystems to elevated levels of atmospheric carbon dioxide (CO{sub 2}) remain a critical uncertainty in global change research. Two key unknown factors are the fate of carbon newly incorporated by photosynthesis into various pools within the ecosystem and the extent to which elevated CO{sub 2} is transferred to and sequestered in pools with long turnover times. The CO{sub 2} used for enrichment in many experiments incorporates a dual isotopic tracer, in the sense that ratios of both the stable carbon-13 ({sup 13}C) and the radioactive carbon-14 ({sup 14}C) isotopes with respect to carbon-12 are different from the corresponding ratios in atmospheric CO{sub 2}. Here we review techniques for using {sup 13}C and {sup 14}C abundances to follow the fate of newly fixed carbon and to further our understanding of the turnover times of ecosystem carbon pools. We also discuss the application of nitrogen, oxygen, and hydrogen isotope analyses for tracing changes in the linkages between carbon, nitrogen, and water cycles under conditions of elevated CO{sub 2}.

  13. Observations of halogenated trace gases in Taiwan and Malaysia

    NASA Astrophysics Data System (ADS)

    Gooch, Lauren J.; Laube, Johannes C.; Sturges, William T.; Oram, David E.; Wang, Jia-Lin; Ou-Yang, Cheng-Feng; Lin, Neng-Huei; Mead, Iq; Rigby, Matt; White, Emily

    2015-04-01

    There are a large variety of halocarbons present in the atmosphere that significantly impact on stratospheric ozone depletion and/or global warming. Though the use of some of these compounds has been phased out and replaced under global control measures, relatively long atmospheric lifetimes, imperfect substitutes and incomplete reductions in usage mean that global concentrations of halocarbons still require regular monitoring. This is especially true for the rapidly developing East Asian region, where high emissions have been repeatedly reported in recent years. We here present results from an air sampling activity in Taiwan and Malaysia during the spring months of 2013 and 2014. A large range of halocarbons, including a number of novel gases, were investigated via high sensitivity gas chromatography mass spectrometry (GC-MS). We find periods of relatively clean air as well as episodes that appear to be impacted by urban and/or industrial emissions and examine correlations between individual species. Observed mixing ratios are compared in context with both global background data and other regional studies. Enhancements in the abundances of many halocarbons are detected with examples including the Halons 1211 and 1202 as well as the very long-lived perfluorocarbons c-C4F8, C5F12 and C7F16. We also show and evaluate unusually high mixing ratios of other globally growing halocarbons such as sulphur hexafluoride (SF6), HCFC-133a (CF3CH2Cl), and CFC-113a (CF3CCl3). Finally, we use NAME analysis to produce back-trajectories in order to assess possible regional emission sources.

  14. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    DOEpatents

    Wijmans, Johannes G.; Merkel, Timothy C; Baker, Richard W.

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  15. A measurement system for the atmospheric trace gases CH4 and CO

    NASA Technical Reports Server (NTRS)

    Condon, E. P.

    1977-01-01

    A system for measuring ambient clean air levels of the atmospheric trace gases methane and carbon monoxide is described. The analytical method consists of a gas chromatographic technique that incorporates sample preconcentration with catalytic conversion of CO to CH4 and subsequent flame ionization detection of these gases. The system has sufficient sensitivity and repeatability to make the precise measurements required to establish concentration profiles for CO and CH4 in the planetary boundary layer. A discussion of the bottle sampling program being conducted to obtain the samples for the concentration profiles is also presented.

  16. Long-Term Changes of Tropospheric Trace Gases over Pakistan Derived From Multiple Satellite Instruments

    NASA Astrophysics Data System (ADS)

    Zeb, Naila; Fahim Khokhar, Muhammad; Murtaza, Rabbia; Noreen, Asma; Khalid, Tameem

    2016-07-01

    Air pollution is the expected key environmental issue of Pakistan in coming years due to its ongoing rapid economic growth and this trend suggests only worst air quality over time. In 2014, World bank reported the Pakistan's urban air quality among the most severe in the world and intimated the government to make improvement in air quality as a priority policy agenda. In addition it is recommended to strengthen the institutional and technical capacity of organizations responsible for air quality management. Therefore, the study is designed to put efforts in highlighting air quality issues. The study will provide first database for tropospheric trace gases over Pakistan. The study aims to analyse tropospheric concentrations of CO, TOC, NO2 and HCHO over Pakistan using multisensory data from January 2005 to January 2014. Spatio-temporal and seasonal variability of tropospheric trace gases is observed over the decade to explore long term trend. Hotspots are identified to see variation of species with latitude and to highlight possible sources of trace gases over the Pakistan. High concentrations of trace gases are mainly observed over the Punjab region, which may be attributed to its metropolitan importance. It is the major agricultural, industrialized and urbanized (nearly 60% of the Pakistan's population) sector of the country. Overall significant decreasing trend of CO is identified by MOPITT with relative change of 12.4%. Tropospheric ozone column (TOC) showed insignificant increasing trend with temporal increase of 10.4% whereas NO2 exhibited a significant temporal increase of about 28%. For formaldehyde (HCHO), an increase of about 3.8% is calculated for SCIAMACHY data. Well defined seasonal cycles for these trace gases are observed over the whole study period. CO concentrations showed peak in winter months (November/December/January/February) and dip in the months of Summer/Monsoon (June/July/August). In spite of CO, TCO increases gradually in March and peaks

  17. Climate-chemical interactions and effects of changing atmospheric trace gases

    SciTech Connect

    Ramanathan, V.; Callis, L.; Cess, R.; Hansen, J.; Isaksen, I.; Kuhn, W.; Lacis, A.; Luther, F.; Mahlman, J.; Reck, R.; and others

    1987-08-01

    The problem concerning the greenhouse effects of human activities has broadened in scope from the CO2-climate problem to the trace gas-climate problem. The climate effects of non-CO2 trace gases are strongly governed by interactions between chemistry, radiation, and dynamics. We discuss in detail the nature of the trace gas radiative heating and describe the importance of radiative-chemical interactions within the troposphere and the stratosphere. We make an assessment of the trace gas effects on troposphere-stratosphere temperature trends for the period covering the preindustrial era to the present and for the next several decades. Non-CO2 greenhouse gases in the atmosphere are now adding to the greenhouse effect by an amount comparable to the effect of CO2. The rate of decadal increase of the total greenhouse forcing is now 3--6 times greater than the mean rate for the period 1850--1960. Time-dependent calculations with a simplified one-dimensional diffusive ocean model suggest that a surface warming about 0.4--0.8 K should have occurred during 1850 to 1980. For the various trace gas scenarios considered in this study, the equilibrium surface warming for the period 1980 to 2030 ranges from 0.8 to 4.1 K. This wide range in the projected warming is due to the range in the assumed scenario as well as due to the threefold uncertainty in the sensitivity of climate models.

  18. Development of Optical Parametric Amplifier for Lidar Measurements of Trace Gases on Earth and Mars

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Riris, Haris; Li, Steve; Wu, Stewart; Kawa, Stephen R.; Krainak, Michael; Abshire, James

    2011-01-01

    Trace gases in planetary atmospheres offer important clues as to the origins of the planet's hydrology, geology. atmosphere. and potential for biology. Wc report on the development effort of a nanosecond-pulsed optical parametric amplifier (OPA) for remote trace gas measurements for Mars and Earth. The OP A output light is single frequency with high spectral purity and is widely tunable both at 1600 nm and 3300 nm with an optical-optical conversion efficiency of approximately 40%. We demonstrated open-path atmospheric measurements ofCH4 (3291 nm and 1651 nm). CO2 (1573 nm), H20 (1652 nm) with this laser source.

  19. Co-laser photoacoustic spectroscopy of gases and vapours for trace gas analysis

    NASA Astrophysics Data System (ADS)

    Bernegger, S.; Sigrist, M. W.

    This comprehensive study reviews the sensitive and selective detection of trace gases by laser photoacoustic spectroscopy. A computer controlled CO-laser photoacoustic system is presented. The wavelength range between 5.0 and 6.5 μm is of great interest because it coincides with specific absorption bands of various gases and vapours of environmental concern. However, since water-vapour, which is present in most samples, absorbs rather strongly in this wavelength region, its contribution to the total absorption has to be determined with high accuracy. For this purpose, we developed a dual-beam setup with sample- and reference cell. The novel design of these resonant photoacoustic cells is based on a new matrix formalism with distributed acoustic impedances and sources. Our photoacoustic system is calibrated with certified gas mixtures and vapours. In total, the absorption cross sections of 18 gases and vapours have been derived for all CO-laser lines. In addition to the absorption, the relaxation time of vibrationally excited nitric oxide (NO) could be deduced by measuring the phase shift of the photoacoustic signal for a sample of nitrogen containing traces of NO and water-vapour. The main application concerns the detection of multiple components in gas mixtures, particularly in exhaust gases. The high sensitivity achieved permits the detection of trace gases at ppbv concentrations. The problem of interfering absorptions occurring for multicomponent mixtures is studied in detail. We discuss measurements and results on exhausts of various vehicles. The photoacoustic spectra of the exhaust samples are analyzed on the basis of the calibration spectra with the aid of an iterative mathematical procedure. The individual concentrations of 12 of the most important components including nitric oxide, olefines, aromatic hydrocarbons and aldehydes could be derived. In particular, the selective detection of the different isomers of xylene is emphasized.

  20. High sensitivity detection of trace gases at atmospheric pressure using tunable diode lasers

    NASA Technical Reports Server (NTRS)

    Reid, J.; Sinclair, R. L.; Grant, W. B.; Menzies, R. T.

    1985-01-01

    A detailed study of the detection of trace gases at atmospheric pressure using tunable diode lasers is described. The influence of multipass cells, retroreflectors and topographical targets is examined. The minimum detectable infrared absorption ranges from 0.1 percent for a pathlength of 1.2 km to 0.01 percent over short pathlengths. The factors which limit this sensitivity are discussed, and the techniques are illustrated by monitoring atmospehric CO2 and CH4.

  1. Effects of systematic errors on the mixing ratios of trace gases obtained from occulation spectra

    NASA Technical Reports Server (NTRS)

    Shaffer, W. A.; Shaw, J. H.; Farmer, C. B.

    1983-01-01

    The influence of systematic errors in the parameters of the models describing the geometry and the atmosphere on the profiles of trace gases retrieved from simulated solar occultation spectra, collected at satellite altitudes, is investigated. Because of smearing effects and other uncertainties, it may be preferable to calibrate the spectra internally by measuring absorption lines of an atmospheric gas such as CO2 whose vertical distribution is assumed rather than to relay on externally supplied information.

  2. Distributions and Correlations of Organic Trace Gases in the Western Pacific Atmosphere

    NASA Astrophysics Data System (ADS)

    Donets, V.; Atlas, E. L.; Schauffler, S.; Navarro, M. A.; Lueb, R.; Campos, T. L.; Weinheimer, A. J.; Montzka, D.; Kaser, L.; Pan, L.; Salawitch, R. J.; Zhu, X.; Pope, L.

    2014-12-01

    The chemistry of the Tropical Western Pacific atmosphere was studied during three coordinated research missions (CONTRAST, ATTREX, CAST) during Winter, 2014. The purpose of the studies was to examine the chemical emissions of reactive gases from the marine surface, to diagnose transport characteristics of this region, and to better understand the controls of the chemical composition and reactive gas budgets of the tropical atmosphere, including the Tropical Transition Layer (TTL) and lower tropical stratosphere. As part of these studies a wide range of trace gases were measured, including various halo- and hydrocarbons, organic nitrates, methyl halides and solvents. In this presentation we will discuss results from whole air samples that were collected from NASA Global Hawk and NSF/NCAR Gulfstream-V aircrafts during ATTREX and CONTRAST, respectively. Samples were collected at altitudes from near 0.5 km to 18 km, and included latitudes from 40°N to 20°S in the Western Pacific. Combined measurements from two aircrafts produced over 1200 samples, which were subsequently analyzed in the field by means of gas chromatography combined with mass selective, flame ionization and electron capture detectors. The observed distributions of trace gases reflected the combined effects of marine emissions and convective mixing, long range transport, and slow ascent in the TTL. We will show our preliminary results featuring vertical and horizontal distributions of selected hydrocarbon and organic halogen trace species and correlations among these species that were observed during the campaigns.

  3. Measuring OH Reaction Rate Constants and Estimating the Atmospheric Lifetimes of Trace Gases.

    NASA Astrophysics Data System (ADS)

    Orkin, Vladimir; Kurylo, Michael

    2015-04-01

    Reactions with hydroxyl radicals and photolysis are the main processes dictating a compound's residence time in the atmosphere for a majority of trace gases. In case of very short-lived halocarbons their reaction with OH dictates both the atmospheric lifetime and active halogen release. Therefore, the accuracy of OH kinetic data is of primary importance for the comprehensive modeling of a compound's impact on the atmosphere, such as in ozone depletion (i.e., the Ozone Depletion Potential, ODP) and climate change (i.e., the Global Warming Potential, GWP), each of which are dependent on the atmospheric lifetime of the compound. We have demonstrated the ability to conduct very high accuracy determinations of OH reaction rate constants over the temperature range of atmospheric interest, thereby decreasing the uncertainty of kinetic data to 2-3%. The atmospheric lifetime of a well-mixed compound due to its reaction with tropospheric hydroxyl radicals can be estimated by using a simple scaling procedure that is based on the results of field observations of methyl chloroform concentrations and detailed modeling of the OH distribution in the atmosphere. The currently available modeling results of the atmospheric fate of various trace gases allow for an improved understanding of the ability and accuracy of simplified semi-empirical estimations of atmospheric lifetimes. These aspects will be illustrated in this presentation for a variety of atmospheric trace gases.

  4. Measuring OH Reaction Rate Constants and Estimating the Atmospheric Lifetimes of Trace Gases.

    NASA Astrophysics Data System (ADS)

    Orkin, V. L.; Kurylo, M. J., III

    2014-12-01

    Reactions with hydroxyl radicals and photolysis are the main processes dictating a compound's residence time in the atmosphere for a majority of trace gases. In case of very short-lived halocarbons their reaction with OH dictates both the atmospheric lifetime and active halogen release. Therefore, the accuracy of OH kinetic data is of primary importance for the comprehensive modeling of a compound's impact on the atmosphere, such as in ozone depletion (i.e., the Ozone Depletion Potential, ODP) and climate change (i.e., the Global Warming Potential, GWP), each of which are dependent on the atmospheric lifetime of the compound. We have demonstrated the ability to conduct very high accuracy determinations of OH reaction rate constants over the temperature range of atmospheric interest, thereby decreasing the uncertainty of kinetic data to 2-3%. The atmospheric lifetime of a tropospherically well-mixed compound due to its reaction with tropospheric hydroxyl radicals can be estimated by using a simple scaling procedure that is based on the results of field observations of methyl chloroform concentrations and detailed modeling of the OH distribution in the atmosphere. The currently available modeling results of the atmospheric fate of various trace gases allow for an improved understanding of the ability and accuracy of simplified semi-empirical estimations of atmospheric lifetimes. These aspects will be illustrated in this presentation for a variety of atmospheric trace gases.

  5. Mid-Infrared OPO for High Resolution Measurements of Trace Gases in the Mars Atmosphere

    NASA Technical Reports Server (NTRS)

    Yu, Anthony W.; Numata,Kenji; Riris, haris; Abshire, James B.; Allan, Graham; Sun, Xiaoli; Krainak, Michael A.

    2008-01-01

    The Martian atmosphere is composed primarily (>95%) of CO2 and N2 gas, with CO, O2, CH4, and inert gases such as argon comprising most of the remainder. It is surprisingly dynamic with various processes driving changes in the distribution of CO2, dust, haze, clouds and water vapor on global scales in the meteorology of Mars atmosphere [I]. The trace gases and isotopic ratios in the atmosphere offer important but subtle clues as to the origins of the planet's atmosphere, hydrology, geology, and potential for biology. In the search for life on Mars, an important process is the ability of bacteria to metabolize inorganic substrates (H2, CO2 and rock) to derive energy and produce methane as a by-product of anaerobic metabolism. Trace gases have been measured in the Mars atmosphere from Earth, Mars orbit, and from the Mars surface. The concentration of water vapor and various carbon-based trace gases are observed in variable concentrations. Within the past decade multiple groups have reported detection of CH4, with concentrations in the 10's of ppb, using spectroscopic observations from Earth [2]. Passive spectrometers in the mid-infrared (MIR) are restricted to the sunlit side of the planet, generally in the mid latitudes, and have limited spectral and spatial resolution. To accurately map the global distribution and to locate areas of possibly higher concentrations of these gases such as plumes or vents requires an instrument with high sensitivity and fine spatial resolution that also has global coverage and can measure during both day and night. Our development goal is a new MIR lidar capable of measuring, on global scales, with sensitivity, resolution and precision needed to characterize the trace gases and isotopic ratios of the Martian atmosphere. An optical parametric oscillator operating in the MIR is well suited for this instrument. The sufficient wavelength tuning range of the OPO can extend the measurements to other organic molecules, CO2, atmospheric water

  6. Climate-chemical interactions and effects of changing atmospheric trace gases

    NASA Astrophysics Data System (ADS)

    Ramanathan, V.; Callis, L.; Cess, R.; Hansen, J.; Isaksen, I.

    1987-08-01

    The paper considers trace gas-climate effects including the greenhouse effect of polyatomic trace gases, the nature of the radiative-chemical interactions, and radiative-dynamical interactions in the stratosphere, and the role of these effects in governing stratospheric climate change. Special consideration is given to recent developments in the investigations of the role of oceans in governing the transient climate responses, and a time-dependent estimate of the potential trace gas warming from the preindustrial era to the early 21st century. The importance of interacting modeling and observational efforts is emphasized. One of the problems remaining on the observational front is the lack of certainty in current estimates of the rate of growth of CO, O3, and NOx; the primary challenge is the design of a strategy that will minimize the sampling errors.

  7. Climate-chemical interactions and effects of changing atmospheric trace gases

    NASA Technical Reports Server (NTRS)

    Ramanathan, V.; Callis, L.; Cess, R.; Hansen, J.; Isaksen, I.

    1987-01-01

    The paper considers trace gas-climate effects including the greenhouse effect of polyatomic trace gases, the nature of the radiative-chemical interactions, and radiative-dynamical interactions in the stratosphere, and the role of these effects in governing stratospheric climate change. Special consideration is given to recent developments in the investigations of the role of oceans in governing the transient climate responses, and a time-dependent estimate of the potential trace gas warming from the preindustrial era to the early 21st century. The importance of interacting modeling and observational efforts is emphasized. One of the problems remaining on the observational front is the lack of certainty in current estimates of the rate of growth of CO, O3, and NOx; the primary challenge is the design of a strategy that will minimize the sampling errors.

  8. Trends in source gases

    NASA Technical Reports Server (NTRS)

    Ehhalt, D. H.; Fraser, P. J.; Albritton, D.; Cicerone, R. J.; Khalil, M. A. K.; Legrand, M.; Makide, Y.; Rowland, F. S.; Steele, L. P.; Zander, R.

    1989-01-01

    Source gases are defined as those gases that, by their breakdown, introduce into the stratosphere halogen, hydrogen, and nitrogen compounds that are important in stratospheric ozone destruction. Given here is an update of the existing concentration time series for chlorocarbons, nitrous oxide, and methane. Also reviewed is information on halogen containing species and the use of these data for establishing trends. Also reviewed is evidence on trends in trace gases that influence tropospheric chemistry and thus the tropospheric lifetimes of source gases, such as carbon dioxide, carbon monoxide, or nitrogen oxides. Much of the information is given in tabular form.

  9. Discrepancy between Measured Serum Total Carbon Dioxide Content and Bicarbonate Concentration Calculated from Arterial Blood Gases

    PubMed Central

    Kim, Youngho; Massie, Larry; Murata, Glen H

    2015-01-01

    Large differences between the concentrations of serum total carbon dioxide (TCO2) and blood gas bicarbonate (HCO3-) were observed in two consecutive simultaneously drawn sets of samples of serum and arterial blood gases in a patient who presented with severe carbon dioxide retention and profound acidemia. These differences could not be explained by the effect of the high partial pressure of carbon dioxide on TCO2, by variations in the dissociation constant of the carbonic acid/bicarbonate system or by faults caused by the algorithms of the blood gas apparatus that calculate HCO3-. A recalculation using the Henderson-Hasselbach equation revealed arterial blood gas HCO3- values close to the corresponding serum TCO2 values and clarified the diagnosis of the acid-base disorder, which had been placed in doubt by the large differences between the reported TCO2 and HCO3- values. Human error in the calculation of HCO3- was identified as the source of these differences. Recalculation of blood gas HCO3- should be the first step in identifying the source of large differences between serum TCO2 and blood gas HCO3-. PMID:26824002

  10. Spatial and temporal variability in the ratio of trace gases emitted from biomass burning

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G. R.

    2010-10-01

    Fires are a major source of trace gases and aerosols to the atmosphere. Quantitative knowledge on biomass burned is improving, most importantly due to new burned area datasets. The partitioning of biomass burned into emitted trace gases and aerosols, however, has received relatively little attention. To convert estimates of biomass burned to trace gas and aerosol emissions, most studies have used emission ratios (or emission factors (EFs)) based on the arithmetic mean of field measurement outcomes, stratified by biome. However, EFs vary substantially in time and space, even within a single biome. In addition, it is unknown whether the measurement locations provide a representative sample for the various biomes. Here we used the available body of EF literature in combination with satellite-derived information on vegetation characteristics and climatic conditions to better understand the spatio-temporal variability in EFs. While focusing on CO, CH4, and CO2, our findings are also applicable to other trace gases and aerosols. We explored relations between EFs and different satellite datasets thought to drive part of the variability in EFs (tree cover density, vegetation greenness, temperature, precipitation, and the length of the dry season). Although reasonable correlations were found for specific case studies, correlations based on the full suite of available measurements were less satisfying (rmax=0.62). This may be partly due to uncertainties in the driver datasets, differences in measurement techniques, assumptions on the ratio between flaming and smoldering combustion, and incomplete information on the location and timing of measurements. We derived new mean EFs, using the relative importance of each measurement location with regard to the amount of biomass burned. These weighted averages were within 18% of the arithmetic mean. We argue that from a global modeling perspective, future measurement campaigns could be more beneficial if measurements are made over

  11. Spatial and temporal variability in the ratio of trace gases emitted from biomass burning

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G.

    2010-12-01

    Fires are a major source of trace gases and aerosols to the atmosphere. The amount of biomass burned is becoming better known, most importantly due to improved burned area datasets. The partitioning of biomass burned into emitted trace gases and aerosols, however, has received relatively little attention. To convert estimates of biomass burned to trace gas and aerosol emissions, most studies have used emission ratios (or emission factors [EFs]) based on the arithmetic mean of field measurement outcomes, stratified by biome. However, EFs vary substantially in time and space, even within a single biome, and in addition it is unknown whether the measurement locations provide a representative sample for the various biomes. Here we used the available body of EF literature in combination with satellite-derived information on vegetation characteristics and climatic conditions to better understand the spatio-temporal variability in EFs. While focusing on CO, CH4, and CO2, our findings are also applicable to other trace gases and aerosols. We explored relations between EFs and different satellite datasets thought to drive part of the variability in EFs (tree cover density, vegetation greenness, temperature, precipitation, and the length of the dry season). Although reasonable correlations were found for specific case studies, correlations based on the full suite of available measurements were less satisfying (r-max=0.62). This may be partly due to uncertainties in the driver datasets, differences in measurement techniques, assumptions on the ratio between flaming and smoldering combustion, and incomplete information on the location and timing of measurement. We derived new mean EFs, using the relative importance of each measurement location. These weighted averages were within 18% of the arithmetic mean. We argue that from a global modeling perspective, future measurement campaigns could be more beneficial if measurements are made over the full fire season, or alternatively

  12. Long-lived atmospheric trace gases measurements in flask samples from three stations in India

    NASA Astrophysics Data System (ADS)

    Lin, X.; Indira, N. K.; Ramonet, M.; Delmotte, M.; Ciais, P.; Bhatt, B. C.; Reddy, M. V.; Angchuk, D.; Balakrishnan, S.; Jorphail, S.; Dorjai, T.; Mahey, T. T.; Patnaik, S.; Begum, M.; Brenninkmeijer, C.; Durairaj, S.; Kirubagaran, R.; Schmidt, M.; Swathi, P. S.; Vinithkumar, N. V.; Yver Kwok, C.; Gaur, V. K.

    2015-09-01

    With the rapid growth in population and economic development, emissions of greenhouse gases (GHGs) from the Indian subcontinent have sharply increased during recent decades. However, evaluation of regional fluxes of GHGs and characterization of their spatial and temporal variations by atmospheric inversions remain uncertain due to a sparse regional atmospheric observation network. As a result of an Indo-French collaboration, three new atmospheric stations were established in India at Hanle (HLE), Pondicherry (PON) and Port Blair (PBL), with the objective of monitoring the atmospheric concentrations of GHGs and other trace gases. Here we present the results of the measurements of CO2, CH4, N2O, SF6, CO, and H2 from regular flask sampling at these three stations over the period 2007-2011. For each species, annual means, seasonal cycles and gradients between stations were calculated and related to variations in natural GHG fluxes, anthropogenic emissions, and monsoon circulations. Covariances between species at the synoptic scale were analyzed to investigate the likely source(s) of emissions. The flask measurements of various trace gases at the three stations have the potential to constrain the inversions of fluxes over southern and northeastern India. However, this network of ground stations needs further extension to other parts of India to better constrain the GHG budgets at regional and continental scales.

  13. Five-year flask measurements of long-lived trace gases in India

    NASA Astrophysics Data System (ADS)

    Lin, X.; Indira, N. K.; Ramonet, M.; Delmotte, M.; Ciais, P.; Bhatt, B. C.; Reddy, M. V.; Angchuk, D.; Balakrishnan, S.; Jorphail, S.; Dorjai, T.; Mahey, T. T.; Patnaik, S.; Begum, M.; Brenninkmeijer, C.; Durairaj, S.; Kirubagaran, R.; Schmidt, M.; Swathi, P. S.; Vinithkumar, N. V.; Yver Kwok, C.; Gaur, V. K.

    2015-03-01

    With the rapid growth in population and economic development, emissions of greenhouse gases (GHGs) from the Indian subcontinent have sharply increased during recent decades. However, evaluation of regional fluxes of GHGs and characterization of their spatial and temporal variations by atmospheric inversions remain uncertain due to a sparse regional atmospheric observation network. As a result of Indo-French collaboration, three new atmospheric stations were established in India at Hanle (HLE), Pondicherry (PON) and Port Blair (PBL), with the objective of monitoring the atmospheric concentrations of GHGs and other trace gases. Here we present the results of five-year measurements (2007-2011) of CO2, CH4, N2O, SF6, CO, and H2 from regular flask sampling at these three stations. For each species, annual means, seasonal cycles and gradients between stations were calculated and related to variations in the natural GHG fluxes, anthropogenic emissions, and the monsoon circulations. Covariances between species at the synoptic scale were analyzed to investigate the dominant source(s) of emissions. The flask measurements of various trace gases at the three stations show potential to constrain the inversions of fluxes over Southern and Northeastern India. However, this network of ground stations needs further extension to other parts of India to allow a better understanding of, and constraints on the GHG budgets at regional and continental scales.

  14. Trace water vapor determination in nitrogen and corrosive gases using infrared spectroscopy

    SciTech Connect

    Espinoza, L.H.; Niemczyk, T.M.; Stallard, B.R.; Garcia, M.J.

    1997-06-01

    The generation of particles in gas handling systems as a result of corrosion is a major concern in the microelectronics industry. The corrosion can be caused by the presence of trace quantities of water in corrosive gases such as HCl or HBr. FTIR spectroscopy has been shown to be a method that can be made compatible with corrosive gases and is capable of detecting low ppb levels of water vapor. In this report, the application of FTIR spectroscopy combined with classical least squares multivariate calibration to detect trace H{sub 2}O in N{sub 2}, HCl and HBr is discussed. Chapter 2 discusses the gas handling system and instrumentation required to handle corrosive gases. A method of generating a background spectrum useful to the measurements discussed in this report, as well as in other application areas such as gas phase environmental monitoring, is discussed in Chapter 3. Experimental results obtained with the first system are presented in Chapter 4. Those results made it possible to optimize the design options for the construction of a dedicate system for low ppb water vapor determination. These designs options are discussed in Chapter 5. An FTIR prototype accessory was built. In addition, a commercially available evacuable FTIR system was obtained for evaluation. Test results obtained with both systems are discussed in Chapter 6. Experiments dealing with the interaction between H{sub 2}O-HCl and potential improvements to the detection system are discussed in Chapter 7.

  15. Horizonal and Vertical Spatial Patterns of Radon and Other Soil-gases Across the El Pilar Fault Trace at Guaraphiche, Edo. Surce (Venezuela)

    NASA Astrophysics Data System (ADS)

    LaBrecque, J. J.

    2002-05-01

    Soil-gases (radon, thoron, carbon dioxide and hydrogen) were measured at 63-cm depths along a transect perpendicular to the rupture (fault trace) from the 1997 Caricao earthquake (Mw=6.9) at Guarapiche, state of Sucre (Venezuela). The transect was about 40 meters long with ten sampling points with the spacings was smaller near the rupture. The shapes of the horizontal spatial patterns for radon (Rn-222), thoron (Rn-220) and total radon (Rn-222+Rn-220) were similar; the gas concentrations increased from both ends of the transect toward the rupture where a dip (valley) occurred. Both carbon dioxide and hydrogen gases showed anomalous values at the same sampling points. Twin peaks (anomalies) had been previously reported and suggested that they were due to blockage in the rupture. We have also determined soil-gases from 25-cm to 155-cm depths near the rupture and at the ends of the transect. The results showed that the soil-gas concentrations were not only higher in the upper levels (less than 65-cm) near the fault trace but were similar or greater than the lower levels. Thus, producing the twin peaks when soil-gas sampling was performed at the 65-cm depth. When the sampling was performed at only 45-cm depth the dip over the rupture was much less and the patterns looked more like a broad doublet peak. In conclusion, one can clearly see that not only positive soil-gas anomalies can occur over a fault trace but also negative ones too. 1) This work was partially funded by a research contract from the Venezuelan National Science Foundation (CONICIT Proyecto S1-95000448). 2) Mailing Address: Centro de Quimica, 8424 NW 56th Street, Suite 00204,Miami, Fl 33166 (USA). E-mail jjlabrec@ivic.ve FAX: +58-212-504-1214

  16. Tracing a past thermal event by using atmospheric noble gases dissolved in deep Michigan Basin brines

    NASA Astrophysics Data System (ADS)

    Ma, L.; Castro, M. C.; Hall, C. M.

    2008-12-01

    Atmospheric noble gases (e.g., 22Ne, 36Ar, 84Kr, 130Xe) are introduced into the subsurface by recharge water in solubility equilibrium with the atmosphere (Air Saturated Water - ASW). Because noble gases are chemically inert and stable in nature, they are only sensitive to subsurface physical processes. More specifically, depletion of this component in sedimentary systems commonly suggests loss to an oil or natural gas phase in the subsurface, which is originally free of atmospheric noble gases. This has been traditionally used to identify and quantify subsurface oil, gas, and water phase interactions. Alternatively, depletion of atmospheric noble gases due to subsurface boiling and steam phase separation has also been previously recorded in tectonically active areas (hydrothermal systems). Such depletion is thus indicative of the occurrence of a thermal event and can be used to trace the thermal history of stable tectonic regions. Here, we present noble gas concentrations of 38 deep brines (~0.5-3.6km) from the Michigan Basin. The atmospheric noble gas component shows a strong depletion pattern with respect to air saturated water. Depletion of lighter gases (22Ne and 36Ar) is stronger compared to the heavier ones (84Kr and 130Xe). To understand the mechanisms responsible for this overall atmospheric noble gas depletion, phase interaction models were tested. We show that this atmospheric noble gas depletion pattern is best explained by a model involving subsurface boiling and steam separation, and thus, consistent with the occurrence of a past thermal event of mantle origin as previously indicated by both high 4He/heat flux ratios and the presence of primordial mantle He and Ne signatures in the basin. Such a conceptual model is also consistent with the presence of past elevated temperatures in the Michigan Basin (e.g., ~80- 260°C) at shallow depths as suggested by previous thermal studies in the basin. We suggest that recent reactivation of the ancient mid

  17. An investigation of the sub-grid variability of trace gases and aerosols for global climate modeling

    SciTech Connect

    Qian, Yun; Gustafson, William I.; Fast, Jerome D.

    2010-07-29

    One fundamental property and limitation of grid based models is their inability to identify spatial details smaller than the grid cell size. While decades of work have gone into developing sub-grid treatments for clouds and land surface processes in climate models, the quantitative understanding of sub-grid processes and variability for aerosols and their precursors is much poorer. In this study, WRF-Chem is used to simulate the trace gases and aerosols over central Mexico during the 2006 MILAGRO field campaign, with multiple spatial resolutions and emission/terrain scenarios. Our analysis focuses on quantifying the sub-grid variability (SGV) of trace gases and aerosols within a typical global climate model grid cell, i.e. 75x75 km2. Our results suggest that a simulation with 3-km horizontal grid spacing adequately reproduces the overall transport and mixing of trace gases and aerosols downwind of Mexico City, while 75-km horizontal grid spacing is insufficient to represent local emission and terrain-induced flows along the mountain ridge, subsequently affecting the transport and mixing of plumes from nearby sources. Therefore, the coarse model grid cell average may not correctly represent aerosol properties measured over polluted areas. Probability density functions (PDFs) for trace gases and aerosols show that secondary trace gases and aerosols, such as O3, sulfate, ammonium, and nitrate, are more likely to have a relatively uniform probability distribution (i.e. smaller SGV) over a narrow range of concentration values. Mostly inert and long-lived trace gases and aerosols, such as CO and BC, are more likely to have broad and skewed distributions (i.e. larger SGV) over polluted regions. Over remote areas, all trace gases and aerosols are more uniformly distributed compared to polluted areas. Both CO and O3 SGV vertical profiles are nearly constant within the PBL during daytime, indicating that trace gases are very efficiently transported and mixed vertically by

  18. An overview of current issues in the uptake of atmospheric trace gases by aerosols and clouds

    NASA Astrophysics Data System (ADS)

    Kolb, C. E.; Cox, R. A.; Abbatt, J. P. D.; Ammann, M.; Davis, E. J.; Donaldson, D. J.; Garrett, B. C.; George, C.; Griffiths, P. T.; Hanson, D. R.; Kulmala, M.; McFiggans, G.; Pöschl, U.; Riipinen, I.; Rossi, M. J.; Rudich, Y.; Wagner, P. E.; Winkler, P. M.; Worsnop, D. R.; O'Dowd, C. D.

    2010-11-01

    A workshop was held in the framework of the ACCENT (Atmospheric Composition Change - a European Network) Joint Research Programme on "Aerosols" and the Programme on "Access to Laboratory Data". The aim of the workshop was to hold "Gordon Conference" type discussion covering accommodation and reactive uptake of water vapour and trace pollutant gases on condensed phase atmospheric materials. The scope was to review and define the current state of knowledge of accommodation coefficients for water vapour on water droplet and ice surfaces, and uptake of trace gas species on a variety of different surfaces characteristic of the atmospheric condensed phase particulate matter and cloud droplets. Twenty-six scientists participated in this meeting through presentations, discussions and the development of a consensus review. In this review we present an analysis of the state of knowledge on the thermal and mass accommodation coefficient for water vapour on aqueous droplets and ice and a survey of current state-of the-art of reactive uptake of trace gases on a range of liquid and solid atmospheric droplets and particles. The review recommends consistent definitions of the various parameters that are needed for quantitative representation of the range of gas/condensed surface kinetic processes important for the atmosphere and identifies topics that require additional research.

  19. The temporal and spatial variability of halogenated trace gases in the upper troposphere.

    NASA Astrophysics Data System (ADS)

    Oram, D.; O'Sullivan, D.; Brenninkmeijer, C.; van Velthoven, P.; Sturges, W.

    2007-12-01

    Halogenated trace gases play an important role in stratospheric and tropospheric chemistry, particularly affecting ozone concentrations. In addition they have direct and indirect effects on radiative forcing, and impact on tropospheric reactivity. Data from the CARIBIC project (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrumented Container) have been used in conjunction with back-trajectory analysis to further our understanding of the chemical composition, inter-hemispheric distribution and source regions of halogenated compounds in the upper troposphere and lower stratosphere. Whole air samples collected within CARIBIC, have been analyzed using gas chromatography mass spectrometry for around 35 halocarbons and related trace gases, among them many potent greenhouse gases and species important for ozone depletion. The large spatial and temporal coverage of the CARIBIC project has enabled new work to be done investigating recent inter-annual trends in the CFCs, halons, and other anthropogenic halocarbons, as well as identifying clear inter-hemispheric and seasonal variability for a number of species, such as methylene chloride, HCFCs, methyl chloride, methyl bromide, methyl iodide and several reactive short lived bromo and chloro carbons. In this paper results from the CARIBIC flights to China and the Philippines will be highlighted, to discuss anthropogenic emissions of ozone depleting and greenhouse gases, from Asia and Africa. Data from flights to South America will also be presented. As production and consumption of many of these substances are being phased out in Europe and North America, emissions from Asia, Africa and also South America are becoming increasingly more important. Emissions from these regions are also of interest, as the most significant sources are often collocated with regions of convection in the tropics and sub-tropics. Thus enabling a greater proportion of the substances emitted to reach the stratosphere, where

  20. Ozone and other trace gases in the Arctic and Antarctic regions: Three-dimensional model simulations

    SciTech Connect

    Granier, C.; Brasseur, G. )

    1991-02-20

    A three-dimensional mechanistic model of the middle atmosphere with calculated dynamics and chemistry is used to study the behavior of chemically active trace gases at high latitudes in winter and spring, and to simulate the formation of an ozone hole in Antarctica. The dynamics of both hemispheres is simulated by applying at the lower boundary of the model (8.5 km) a wavelike perturbation representing qualitatively a climatological tropospheric forcing. The chemical heterogeneous processes converting chlorine reservoirs into active chlorine in cold air masses are parameterized. The model simulates the behavior of nitrogen oxides, nitric acid, water vapor, methane, hydrogen radicals, chlorine compounds, and ozone. It reproduces important features observed during different Antarctic and Arctic observation campaigns. The ozone hole in the southern hemisphere can only be simulated when the heterogeneous polar chemistry is taken into account. The springtime ozone depletion over Antarctica calculated in the model is thus mostly the result of chemical removal although the dynamics is responsible for the low temperature that triggers the large ozone loss rates. Unresolved questions are related to the strength of the vertical exchanges inside the vortex, the preconditioning of trace gases before and during the winter season, the behavior of the different trace gases as the vortex breaks down (dilution effects), accurate determination of the ozone sink inside the vortex, and a better quantitative estimation of the role of polar stratospheric clouds. Despite elevated concentrations of active chlorine at high latitudes in the northern hemisphere in late winter, no ozone hole is produced by the model, even with chlorine levels as high as 6 ppbv. This conclusion could, however, be modified for very stable and cold winters with delayed final warming.

  1. Monitoring shipping emissions with MAX-DOAS measurements of reactive trace gases

    NASA Astrophysics Data System (ADS)

    Wittrock, Folkard; Peters, Enno; Seyler, André; Kattner, Lisa; Mathieu-Üffing, Barbara; Burrows, John P.; Chirkov, Maksym; Meier, Andreas C.; Richter, Andreas; Schönhardt, Anja; Schmolke, Stefan; Theobald, Norbert

    2014-05-01

    Air pollution from ships contributes to overall air quality problems and it has direct health effects on the population in particular in coastal regions, and in harbor cities. In order to reduce the emissions the International Maritime Organisation (IMO) have tightened the regulations for air pollution. E.g. Sulfur Emission Control Areas (SECA) have been introduced where the sulfur content of marine fuel is limited. However, up to now there is no regular monitoring system available to verify that ships are complying with the new regulations. Furthermore measurements of reactive trace gases in marine environments are in general sparse. The project MeSMarT (Measurements of shipping emissions in the marine troposphere, www.mesmart.de) has been established as a cooperation between the University of Bremen and the German Bundesamt für Seeschifffahrt und Hydrographie (Federal Maritime and Hydrographic Agency) with support of the Helmholtz Research Centre Geesthacht to estimate the influence of ship emissions on the chemistry of the atmospheric boundary layer and to establish a monitoring system for main shipping routes. Here we present MAX-DOAS observations of NO2 and SO2 carried out during ship campaigns in the North and Baltic Sea and from two permanent sites close to the Elbe river (Wedel, Germany) and on the island Neuwerk close to the mouths of Elbe and Weser river. Mixing ratios of both trace gases have been retrieved using different approaches (pure geometric and taking into account the radiative transfer) and compared to in situ and air borne observations (see Kattner et al., Monitoring shipping emissions with in-situ measurements of trace gases, and Meier et al., Airborne measurements of NO2 shipping emissions using imaging DOAS) observations. Furthermore simple approaches have been used to calculate emission factors of NOx and SO2 for single ships.

  2. Quantum cascade laser based sensor for in situ and real time atmospheric trace gases (CO and N2O) measurements

    NASA Astrophysics Data System (ADS)

    Li, Jingsong; Parchatka, Uwe; Fischer, Horst

    2013-04-01

    In addition to the primary greenhouse gases carbon dioxide (CO2) and methane (CH4), several other atmospheric trace gases are radiatively active, and thereby can also contribute to a greenhouse warming of the lower atmosphere directly or indirectly. Nitrous oxide (N2O) is a greenhouse gas with a global warming potential about 200-300 times that of CO2. Carbon monoxide (CO) is not considered a direct greenhouse gas, mostly because it does not absorb terrestrial thermal IR energy strongly enough. However, CO plays an important role in the oxidative chemistry of Earth's atmosphere, since it is a key trace gas for controlling the budget and distribution of the hydroxyl (OH) radical, which exerts a controlling influence on the gas phase chemistry of many atmospheric species [1]. Therefore, there is a critical need to identify sources and sinks of N2O and CO in order to better understand their impact on global climate change [2]. We present a fast, compact, and precise sensor based-on a novel thermoelectrically (TE) cooled quantum cascade laser (QCL) operating at near-room temperature in CW (continuous-wave) mode for simultaneous detection of atmospheric N2O and CO. The technique is based on atmospheric absorption of these trace species in the mid-infrared region near 4.56 µm, using a single QC laser source and two TE-cooled infrared detectors. Wavelength modulation spectroscopy with second harmonic detection technique in conjunction with a compact multi-pass absorption cell has been employed to demonstrate highly sensitive and precise measurements. CO and N2O at ambient concentration levels are detected simultaneously with a high temporal response (< 1s). Preliminary results (Laboratory investigation and field application) of the sensor's performance will be presented. This completely TE-cooled system shows the capability of long-term, unattended and continuous operation at room temperature without complicated cryogenic cooling [3]. [1] J. A. Logan, M. J. Prather, S. C

  3. Method and apparatus for detecting and measuring trace impurities in flowing gases

    DOEpatents

    Taylor, Gene W.; Dowdy, Edward J.

    1979-01-01

    Trace impurities in flowing gases may be detected and measured by a dynamic atomic molecular emission spectrograph utilizing as its energy source the energy transfer reactions of metastable species, atomic or molecular, with the impurities in the flowing gas. An electronically metastable species which maintains a stable afterglow is formed and mixed with the flowing gas in a region downstream from and separate from the region in which the metastable species is formed. Impurity levels are determined quantitatively by the measurement of line and/or band intensity as a function of concentration employing emission spectroscopic techniques.

  4. Acetone in the upper troposphere and lower stratosphere: Impact on trace gases and aerosols

    NASA Astrophysics Data System (ADS)

    Arnold, F.; Bürger, V.; Droste-Fanke, B.; Grimm, F.; Krieger, A.; Schneider, J.; Stilp, T.

    Upper tropospheric and lower stratospheric acetone measurements have been performed in summer and winter 1994 through 1996 at latitudes between 30°N and 75°N using ion-molecule reaction mass spectrometry. We observed very high acetone volume mixing ratios of up to 3000 pptv (parts per trillion by volume) in extended air masses and in summer when acetone destruction by photodissociation is fast. This indicates efficient transport of acetone and photochemical acetone precursors to the upper troposphere and efficient upper tropospheric formation of acetone products, especially HOx radicals and PAN. Our data indicate large HOx production from acetone which has important implications for other trace gases and aerosols.

  5. Seasonal variation of the temporal variance of long-lived trace gases measured during MAP

    NASA Technical Reports Server (NTRS)

    Roeth, E. P.; Schmidt, U.

    1989-01-01

    A series of balloon observations of long lived trace gases was performed in the midlatitude stratosphere during MAP. The temporal variance of the local mixing ratios of CH4, N2O, CFCl3, and CF2Cl2 indicates a substantial annual variability. The concept of the equivalent displacement height (EDH), introduced by Ehhalt et al., is used to investigate some features of transport activity in the lower stratosphere. It appears that most of the temporal variance originates from strong transport effects during the periods of the spring and autumn turn-around of the stratospheric circulation. The dynamical process was found to be considerably reduced during October.

  6. Neural detection of gases--carbon dioxide, oxygen--in vertebrates and invertebrates.

    PubMed

    Luo, Minmin; Sun, Liming; Hu, Ji

    2009-08-01

    Carbon dioxide (CO(2)) and oxygen (O(2)) are important cues that can signal the presence of food, predators, and environmental stress. Here we will review recent studies on the mechanisms of how the olfactory system detects these two molecules. In both vertebrates and invertebrates, the two molecules are detected by subsets of specialized olfactory neurons. In addition, the signal transduction cascades for sensing these two gases appear to be different from those for sensing typical odorants. CO(2) and O(2) signals can evoke stereotypical innate behaviors such as attraction and avoidance in many animal species. Future studies on the neural pathways underlying CO(2) and O(2) sensing may shed light on the circuit mechanisms of these behaviors.

  7. Foliage plants for indoor removal of the primary combustion gases carbon monoxide and nitrogen dioxide

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.; Mesick, H. H.

    1985-01-01

    Foliage plants were evaluated for their ability to sorb carbon monoxide and nitrogen dioxide, the two primary gases produced during the combustion of fossil fuels and tobacco. The spider plant (Chlorophytum elatum var. vittatum) could sorb 2.86 micrograms CO/sq cm leaf surface in a 6 h photoperiod. The golden pothos (Scindapsus aureus) sorbed 0.98 micrograms CO/sq cm leaf surface in the same time period. In a system with the spider plant, greater than or equal to 99 percent of an initial concentration of 47 ppm NO2 could be removed in 6 h from a void volume of approximately 0.35 cu m. One spider plant potted in a 3.8 liter container can sorb 3300 micrograms CO and effect the removal of 8500 micrograms NO2/hour, recognizing the fact that a significant fraction of NO2 at high concentrations will be lost by surface sorption, dissolving in moisture, etc.

  8. Light emitting diode cavity enhanced differential optical absorption spectroscopy (LED-CE-DOAS): a novel technique for monitoring atmospheric trace gases

    NASA Astrophysics Data System (ADS)

    Thalman, Ryan M.; Volkamer, Rainer M.

    2009-08-01

    The combination of Cavity Enhanced Absorption Spectroscopy (CEAS) with broad-band light sources (e.g. Light- Emitting Diodes, LEDs) lends itself to the application of cavity enhanced DOAS (CE-DOAS) to perform sensitive and selective point measurements of multiple trace gases with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e., does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0). We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420-490nm) to measure nitrogen dioxide (NO2), glyoxal (CHOCHO), iodine monoxide (IO), water (H2O) and oxygen dimers (O4). Aerosol extinction is retrieved at two wavelengths by means of observing water and O4 and measuring pressure, temperature and relative humidity independently. The instrument components are presented, and the approach to measure aerosol extinction is demonstrated by means of a set of experiments where laboratory generated monodisperse aerosols are added to the cavity. The aerosol extinction cross section agrees well with Mie calculations, demonstrating that our setup enables measurements of the above gases in open cavity mode.

  9. Detectability of trace gases in the Martian atmosphere using gas correlation filter radiometry

    NASA Astrophysics Data System (ADS)

    Sinclair, J.; Irwin, P. G. J.; Wilson, E.; Calcutt, S.

    2015-10-01

    We present the results of radiative transfer simulations of a gas correlation filter radiometer (GCFR) in the detection of trace species in the Martian atmosphere. We investigated two scenarios: 1) nadir and/or limb sounding from a Mars orbiter in the thermal infrared, 2) solar occultation measurements in the near-infrared from the Martian surface. In both scenarios, a GCFR would allow detection of trace gases at a lower concentration than that detectable by a conventional filter radiometer. In nadir/limb sounding, we find that CH4, SO2, N2O, C2H2 and CH3OH are detectable at concentrations lower than previously-derived upper limits. From solar occultation measurements, we find that CH4, SO2, C2H2, C2H6 are detectable at concentrations lower than previously-derived upper limits but only in low dust conditions.

  10. Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania

    NASA Astrophysics Data System (ADS)

    Lawson, S. J.; Keywood, M. D.; Galbally, I. E.; Gras, J. L.; Cainey, J. M.; Cope, M. E.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Bentley, S. T.; Meyer, C. P.; Ristovski, Z.; Goldstein, A. H.

    2015-12-01

    (ΔO3 / ΔCO 0.001-0.074). A short-lived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2-4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meteorological events on BB emission ratios. Emission factors (EFs) were derived for a range of trace gases, some never before reported for Australian fires, (including hydrogen, phenol and toluene) using the carbon mass balance method. This provides a unique set of EFs for Australian coastal heathland fires. Methyl halide EFs were higher than EFs reported from other studies in Australia and the Northern Hemisphere which is likely due to high halogen content in vegetation on Robbins Island. This work demonstrates the substantial impact that BB plumes can have on the composition of marine air, and the significant changes that can occur as the plume interacts with terrestrial, aged urban and marine emission sources.

  11. Joseph Black, carbon dioxide, latent heat, and the beginnings of the discovery of the respiratory gases.

    PubMed

    West, John B

    2014-06-15

    The discovery of carbon dioxide by Joseph Black (1728-1799) marked a new era of research on the respiratory gases. His initial interest was in alkalis such as limewater that were thought to be useful in the treatment of renal stone. When he studied magnesium carbonate, he found that when this was heated or exposed to acid, a gas was evolved that he called "fixed air" because it had been combined with a solid material. He showed that the new gas extinguished a flame, that it could not support life, and that it was present in gas exhaled from the lung. Within a few years of his discovery, hydrogen, nitrogen, and oxygen were also isolated. Thus arguably Black's work started the avalanche of research on the respiratory gases carried out by Priestley, Scheele, Lavoisier, and Cavendish. Black then turned his attention to heat and he was the first person to describe latent heat, that is the heat added or lost when a liquid changes its state, for example when water changes to ice or steam. Latent heat is a key concept in thermal physiology because of the heat lost when sweat evaporates. Black was a friend of the young James Watt (1736-1819) who was responsible for the development of early steam engines. Watt was puzzled why so much cooling was necessary to condense steam into water, and Black realized that the answer was the latent heat. The resulting improvements in steam engines ushered in the Industrial Revolution.

  12. Joseph Black, carbon dioxide, latent heat, and the beginnings of the discovery of the respiratory gases.

    PubMed

    West, John B

    2014-06-15

    The discovery of carbon dioxide by Joseph Black (1728-1799) marked a new era of research on the respiratory gases. His initial interest was in alkalis such as limewater that were thought to be useful in the treatment of renal stone. When he studied magnesium carbonate, he found that when this was heated or exposed to acid, a gas was evolved that he called "fixed air" because it had been combined with a solid material. He showed that the new gas extinguished a flame, that it could not support life, and that it was present in gas exhaled from the lung. Within a few years of his discovery, hydrogen, nitrogen, and oxygen were also isolated. Thus arguably Black's work started the avalanche of research on the respiratory gases carried out by Priestley, Scheele, Lavoisier, and Cavendish. Black then turned his attention to heat and he was the first person to describe latent heat, that is the heat added or lost when a liquid changes its state, for example when water changes to ice or steam. Latent heat is a key concept in thermal physiology because of the heat lost when sweat evaporates. Black was a friend of the young James Watt (1736-1819) who was responsible for the development of early steam engines. Watt was puzzled why so much cooling was necessary to condense steam into water, and Black realized that the answer was the latent heat. The resulting improvements in steam engines ushered in the Industrial Revolution. PMID:24682452

  13. Cavity Attenuation Phase Shift Detection of Trace Atmospheric Species: Nitrogen Dioxide

    NASA Astrophysics Data System (ADS)

    Freedman, A.; Herndon, S. C.; Kebabian, P. L.; Wood, E. C.

    2007-12-01

    We present details of an apparatus capable of measuring optical extinction (i.e., scattering and/or absorption) which employs one variant of cavity enhanced detection, specifically cavity attenuated phase shift spectroscopy (CAPS). It uses a near confocal arrangement of two high reflectivity (R~0.9999) mirrors in tandem with an enclosed cell 26 cm in length, a light emitting diode (LED) and a vacuum photodiode detector. Square wave modulated light from the LED passes through the sample cell and is detected as a distorted waveform which is characterized by a phase shift with respect to the initial modulation. The amount of that phase shift is a function of fixed instrument properties - cell length, mirror reflectivity, and modulation frequency - and of the presence of a scatterer or absorber (air, particles, trace gases, etc.) within the cell. The monitor is enclosed within a standard rack-mounted instrumentation box, weighs 10 kg and uses 70 W of electrical power including a vacuum pump. The instrument has demonstrated a detection limit of 0.02 Mm-1 (1σ) in ten seconds integration time and a baseline drift of less than ± 0.1 Mm-1 over a 24 hour period. We also present an intercomparison of measurements of ambient nitrogen dioxide concentrations using this sensor, a quantum cascade laser-based infrared absorption spectrometer and a standard hot metal/chemiluminescence-based NOx analyzer. Measurements using the quantum cascade-laser and CAPS monitor agree well within the inter- calibration error. The chemiluminescence analyzer data falls outside the expected error band, a fact that is ascribed to the presence of known chemical interferences for the chemiluminescence-based analyzer.

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

    SciTech Connect

    Kao, C.Y.J.; Morz, E. ); Tie, X. )

    1991-11-01

    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.

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

    SciTech Connect

    Kao, C.Y.J.; Morz, E.; Tie, X.

    1991-11-01

    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.

  16. Assessment of a 2016 Mission Concept: The Search for Trace Gases in the Atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Zurek, Richard W.; Chicarro, Augustin; Allen, Mark A.; Bertauz, Jean-Loup; Clancy, R. Todd; Daerden, Frank; Formisano, Vittorio; Garvin, James B.; neukum, Gerhard; Smith, Michael D.

    2011-01-01

    The reported detection of methane in the atmosphere of Mars as well as its potentially large seasonal spatial variations challenge our understanding of both the sources and sinks of atmospheric trace gases. The presence of methane suggests ongoing exchange between the subsurface and the atmosphere of potentially biogenic trace gases, while the spatial and temporal variations cannot be accounted for with current knowledge of martian photochemistry. A Joint Instrument Definition Team (JIDT) was asked to assess concepts for a mission that might follow up on these discoveries within the framework of a series of joint missions being considered by ESA and NASA for possible future exploration of Mars. The following is based on the report of the JIDT to the space agencies (Zurek et al., 2009); a synopsis of the report was presented at the Workshop on Mars Methane held in Frascati, Italy, in November 2009. To summarize, the JIDT believed that a scientifically exciting and credible mission could be conducted within the evolving capabilities of the science/telecommunications orbiter being considered by ESA and NASA for possible launch in the 2016 opportunity for Mars.

  17. Airborne Measurements of Trace Gases and Aerosols in Northern China: EAST-AIRE IOP 2005

    NASA Astrophysics Data System (ADS)

    Li, C.; Dickerson, R. R.; Li, Z.; Stehr, J. W.; Chen, H.; Marufu, L. T.

    2005-12-01

    To characterize the emission, transport and removal of pollutants and aerosols emitted from East Asia, a US-China joint field campaign was conducted from February to April in China under the EAST-AIRE project. Surface and airborne measurements of trace gases and aerosols were made at different locations in northern China. In early April, eight research flights were conducted around Shenyang, an industrialized city with a population of about 6 million, 600 km northeast of Beijing. Parameters measured include SO2, CO, O3, aerosol size distribution, aerosol scattering and absorption coefficients. During 4 of the 8 flights, the research aircraft made spirals over two suburban locations (~50 km south and north of the downtown area of Shenyang) to determine the detailed vertical distribution of trace gases and aerosols. Various weather patterns were encountered, allowing an examination of the roles of atmospheric circulation in transporting local pollutants to much larger areas. For example, the flights made ahead of the cold front showed fairly high concentrations of pollutants above the planetary boundary layer, probably lifted by the upward motion associated with the approaching cold fronts. On the other hand, much lower pollutant levels were found for the flights made behind the cold front. Also observed in one cold-sector flight is a level (~3000 m) with enhanced aerosol scattering but almost undetectable SO2. Back trajectory analysis using NOAA-HYSPLIT model suggests possible dust transport from source regions.

  18. Arctic haze: Patterns and relationships to regional signatures of trace gases

    NASA Astrophysics Data System (ADS)

    Khalil, M. A. K.; Rasmussen, R. A.

    1993-03-01

    We took measurements of up to 30 gases in Arctic haze and in clean Arctic air. These data were obtained from some 500 flask samples taken on three expeditions of the Arctic Gas and Aerosol Sampling Program (AGASP 1, 2, and 3) during the spring of 1983, 1986, and 1989. Concentrations of many gases are significantly higher in the haze layers compared to outside the haze. To look for the possible origins of the haze, we used cluster analysis to derive regional signatures of trace gases at ground-based sites in middle and high northern latitudes. Comparison of the regional signatures with concentrations observed in Arctic haze suggest that there are no significant contributions from North America but possible influences from Russia and eastern Europe. These conclusions complement results derived from the analysis of the Arctic aerosol chemistry. It is possible, however, that Arctic haze originates from the military, industrial, and mining activities within the Arctic circle, particularly from the Russian Koala peninsula.

  19. Halocarbons and other trace heteroatomic organic compounds in volcanic gases from Vulcano (Aeolian Islands, Italy)

    NASA Astrophysics Data System (ADS)

    Schwandner, Florian M.; Seward, Terry M.; Giże, Andrew P.; Hall, Keith; Dietrich, Volker J.

    2013-01-01

    Adsorbent-trapped volcanic gases, sublimates and condensates from active vents of the La Fossa crater on the island of Vulcano (Aeolian Islands, Italy) as well as ambient and industrial air were quantitatively analyzed by Short-Path Thermal Desorption-Solid Phase Microextraction-Cryotrapping-Gas Chromatography/Mass Spectrometry (SPTD-SPME-CF-GC-MS). Among the over 200 detected and quantified compounds are alkanes, alkenes, arenes, phenols, aldehydes, carboxylic acids, esters, ketones, nitriles, PAHs and their halogenated, methylated and sulfonated derivatives, as well as various heterocyclic compounds including thiophenes and furans. Most compounds are found at concentrations well above laboratory, ambient air, adsorbent and field blank levels. For some analytes (e.g., CFC-11, CH2Cl2, CH3Br), concentrations are up to several orders of magnitude greater than even mid-latitudinal industrial urban air maxima. Air or laboratory contamination is negligible or absent on the basis of noble gas measurements and their isotopic ratios. The organic compounds are interpreted as the product of abiogenic gas-phase radical reactions. On the basis of isomer abundances, n-alkane distributions and substitution patterns the compounds are thought to have formed by high-temperature (e.g., 900 °C) alkyl free radical reactions and halide electrophilic substitution on arenes, alkanes and alkenes. The apparent abiogenic organic chemistry of volcanic gases may give insights into metal transport processes during the formation and alteration of hydrothermal ore deposits, into the natural volcanic source strength of ozone-depleting atmospheric trace gases (i.e., halocarbons), into possibly sensitive trace gas redox pairs as potential early indicators of subsurface changes on volcanoes in the state of imminent unrest, and into the possible hydrothermal origin of early life on Earth, as indicated by the presence of simple amino acids, nitriles, and alkanoic acids.

  20. Spatial and temporal variability in the ratio of trace gases emitted from biomass burning

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G. R.

    2011-04-01

    Fires are a major source of trace gases and aerosols to the atmosphere. The amount of biomass burned is becoming better known, most importantly due to improved burned area datasets and a better representation of fuel consumption. The spatial and temporal variability in the partitioning of biomass burned into emitted trace gases and aerosols, however, has received relatively little attention. To convert estimates of biomass burned to trace gas and aerosol emissions, most studies have used emission ratios (or emission factors (EFs)) based on the arithmetic mean of field measurement outcomes, stratified by biome. However, EFs vary substantially in time and space, even within a single biome. In addition, it is unknown whether the available field measurement locations provide a representative sample for the various biomes. Here we used the available body of EF literature in combination with satellite-derived information on vegetation characteristics and climatic conditions to better understand the spatio-temporal variability in EFs. While focusing on CO, CH4, and CO2, our findings are also applicable to other trace gases and aerosols. We explored relations between EFs and different measurements of environmental variables that may correlate with part of the variability in EFs (tree cover density, vegetation greenness, temperature, precipitation, and the length of the dry season). Although reasonable correlations were found for specific case studies, correlations based on the full suite of available measurements were lower and explained about 33%, 38%, 19%, and 34% of the variability for respectively CO, CH4, CO2, and the Modified Combustion Efficiency (MCE). This may be partly due to uncertainties in the environmental variables, differences in measurement techniques for EFs, assumptions on the ratio between flaming and smoldering combustion, and incomplete information on the location and timing of EF measurements. We derived new mean EFs, using the relative importance of

  1. Emissions of Trace Gases and Particles from Two Ships in the Southern Atlantic Ocean

    NASA Technical Reports Server (NTRS)

    Sinha, Parikhit; Hobbs, Peter V.; Yokelson, Robert J.; Christian, Ted J.; Kirchstetter, Thomas W.; Bruintjes, Roelof

    2003-01-01

    Measurements were made of the emissions of particles and gases from two diesel-powered ships in the southern Atlantic Ocean off the coast of Namibia. The measurements are used to derive emission factors from ships of three species not reported previously, namely, black carbon, accumulation-mode particles, and cloud condensation nuclei (CCN), as well as for carbon dioxide, carbon monoxide (CO), methane (CH4), non-methane hydrocarbons, sulfur dioxide (SO2), nitrogen oxides (NOx), and condensation nuclei. The effects of fuel grade and engine power on ship emissions are discussed. The emission factors are combined with fuel usage data to obtain estimates of global annual emissions of various particles and gases from ocean-going ships. Global emissions of black carbon, accumulation- mode particles, and CCN from ocean-going ships are estimated to be 19-26 Gg yr(sup -1), (4.4-6.1) x 10(exp 26) particles yr(sup -1), and (1.0-1.5) x l0(exp 26) particles yr(sup -1), respectively. Black carbon emissions from ocean-going ships are approximately 0.2% of total anthropogenic emissions. Emissions of NOx and SO2 from ocean-going ships are approximately 10-14% and approximately 3-4%, respectively, of the total emissions of these species from the burning of fossil fuels, and approximately 40% and approximately 70%, respectively, of the total emissions of these species from the burning of biomass. Global annual emissions of CO and CH4 from ocean-going ships are approximately 2% and approximately 2-5%, respectively, of natural oceanic emissions of these species.

  2. The production of trace gases by photochemistry and lightning in the early atmosphere

    NASA Technical Reports Server (NTRS)

    Levine, J. S.; Tennille, G. M.; Towe, K. M.; Khanna, R. K.

    1986-01-01

    Recent atmospheric calculation suggest that the prebiological atmosphere was most probably composed of nitrogen, carbon dioxide, and water vapor, resulting from volatile outgassing, as opposed to the older view of a strongly reducing early atmosphere composed of methane, ammonia, and hydrogen. Photochemical calculations indicate that methane would have been readily destroyed via reaction with the hydroxyl radical produced from water vapor and that ammonia would have been readily lost via photolysis and rainout. The rapid loss of methane and ammonia, coupled with the absence of a significant source of these gases, suggest that atmospheric methane and ammonia were very short lived, if they were present at all. An early atmosphere of N2, CO2, and H2O is stable and leads to the chemical production of a number of atmospheric species of biological significance, including oxygen, ozone, carbon monoxide, formaldehyde, and hydrogen cyanide. Using a photochemical model of the early atmosphere, the chemical productionof these species over a wide range of atmospheric parameters were investigated. These calculations indicate that early atmospheric levels of O3 were significantly below the levels needed to provide UV shielding. The fate of volcanically emitted sulfur species, e.g., sulfur dioxide and hydrogen sulfide, was investigated in the early atmosphere to assess their UV shielding properties. The photochemical calculations show that these species were of insufficient levels, due in part to their short photochemical lifetimes, to provide UV shielding.

  3. Environmental factors controlling transient and seasonal changes of trace gases within shallow vadose zone

    NASA Astrophysics Data System (ADS)

    Pla, Concepcion; Galiana-Merino, Juan Jose; Cuezva, Soledad; Fernandez-Cortes, Angel; Garcia-Anton, Elena; Cuevas, Jaime; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio; Benavente, David

    2014-05-01

    Shallow vadose environments below soil, mainly caves, show significant seasonal and even daily variations in gas composition of ground air, which involves the exchange of large amounts of gases, e.g. greenhouse gases (GHGs) as CO2 or CH4, with the lower troposphere. To understand better the role of caves as a sink or depot of GHGs, geochemical tracing of air (atmosphere, soil and ground air) was performed at Rull cave (southeast Spain) by monitoring CH4, CO2 and the stable carbon isotopic delta13C[CO2] using cavity ring-down spectroscopy (CRDS). A comprehensive microclimatic monitoring of exterior and cave atmosphere was simultaneously conducted to GHGs-tracking, including factors as temperature, barometric pressure, relative humidity and concentration of CO2 and 222Rn. The analysis of the measured data allows understanding outgassing and isolation processes taking place in the karst cavity. Annual patterns of gases behaviour can be distinguished, depending on the prevailing relationship between outer atmosphere, indoor atmosphere and soil system. Cave air temperature fluctuates around 15.7 ºC and relative humidity remains higher than 96% the whole annual cycle. The mean concentration of 222Rn is 1584 Bq m-3 while CO2 remains 1921 ppm. When external temperature is higher of indoor temperature (April-October), the highest levels of both trace gases are reached, while levels drop to its lowest values in the coldest months. Preliminary results obtained show an annual variation in concentration of CO2 inside the cave between 3300 ppm and 900 ppm, whereas corresponding isotopic signal delta13CO2 varies between -24‰ and -21‰. The results have been studied by Keeling model that approximates the isotopic signal of the source contribution in a resulting air mix. The values registered inside the cave were represented joined to results for exterior air (average values round 410 ppm of CO2 and -9 ‰ for delta13C). Value obtained is -27‰ pointing to a high influence of

  4. Spatial Variability of Trace Gases During DISCOVER-AQ: Planning for Geostationary Observations of Atmospheric Composition

    NASA Technical Reports Server (NTRS)

    Follette-Cook, Melanie B.; Pickering, K.; Crawford, J.; Appel, W.; Diskin, G.; Fried, A.; Loughner, C.; Pfister, G.; Weinheimer, A.

    2015-01-01

    Results from an in-depth analysis of trace gas variability in MD indicated that the variability in this region was large enough to be observable by a TEMPO-like instrument. The variability observed in MD is relatively similar to the other three campaigns with a few exceptions: CO variability in CA was much higher than in the other regions; HCHO variability in CA and CO was much lower; MD showed the lowest variability in NO2All model simulations do a reasonable job simulating O3 variability. For CO, the CACO simulations largely under over estimate the variability in the observations. The variability in HCHO is underestimated for every campaign. NO2 variability is slightly overestimated in MD, more so in CO. The TX simulation underestimates the variability in each trace gas. This is most likely due to missing emissions sources (C. Loughner, manuscript in preparation).Future Work: Where reasonable, we will use these model outputs to further explore the resolvability from space of these key trace gases using analyses of tropospheric column amounts relative to satellite precision requirements, similar to Follette-Cook et al. (2015).

  5. Understanding the contribution of non-carbon dioxide gases in deep mitigation scenarios

    SciTech Connect

    Gernaat, David; Calvin, Katherine V.; Lucas, Paul; Luderer, Gunnar; Otto, Sander; Rao, Shilpa; Strefler, Jessica; Van Vuuren, Detlef

    2015-07-01

    The combined 2010 emissions of methane (CH4), nitrous oxide (N2O) and the fluorinated gasses (F-gas) account for about 20-30% of total emissions and about 30% of radiative forcing. At the moment, most studies looking at reaching ambitious climate targets project the emission of carbon dioxide (CO2) to be reduced to zero (or less) by the end of the century. As for non-CO2 gases, the mitigation potential seem to be more constrained, we find that by the end of the century in the current deep mitigation scenarios non-CO2 emissions could form the lion’s share of remaining greenhouse gas emissions. In order to support effective climate policy strategies, in this paper we provide a more in-depth look at the role of non-CO2¬ emission sources (CH4, N2O and F-gases) in achieving deep mitigation targets (radiative forcing target of 2.8 W/m2 in 2100). Specifically, we look at the sectorial mitigation potential and the remaining non-CO2 emissions. By including a set of different models, we provide some insights into the associated uncertainty. Most of the remaining methane emissions in 2100 in the climate mitigation scenario come from the livestock sector. Strong reductions are seen in the energy supply sector across all models. For N2O, less reduction potential is seen compared to methane and the sectoral differences are larger between the models. The paper shows that the assumptions on remaining non-CO2 emissions are critical for the feasibility of reaching ambitious climate targets and the associated costs.

  6. CARBONGASES: Retrieval and Analysis of Carbon Dioxide and Methane Greenhouse Gases from SCIAMACHY on Envisat

    NASA Astrophysics Data System (ADS)

    Schneising, O.; Buchwitz, M.; Reuter, M.; Bovensmann, H.; Burrows, J. P.

    2010-12-01

    Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases contributing to global climate change. Despite their importance our knowledge about their variable natural and anthropogenic sources and sinks has significant gaps. Satellite observations can add important global scale information on greenhouse gas sources and sinks provided the data are accurate and precise enough and are sensitive to the lowest atmospheric layers where the variability due to regional greenhouse gas sources and sinks are largest. SCIAMACHY onboard ENVISAT was the first and is now besides TANSO onboard GOSAT the only satellite instrument which covers important absorption bands of both gases in the near-infrared/shortwave- infrared (NIR/SWIR) spectral region. In nadir mode SCIAMACHY observes reflected and backscattered solar radiation. The daytime measurements are therefore very sensitive to near-surface greenhouse gas concentration changes except in case of significant cloud cover. The atmospheric greenhouse gas information is extracted from the SCIAMACHY spectra using the Weighting Function Modified Differential Optical Absorption Spectroscopy (WFM-DOAS or WFMD) algorithm developed at the Institute of Environmental Physics (IUP) of the University of Bremen, Germany. In the framework of the CARBONGASES project, which is part of the Changing Earth Science Network, the afore existing data set focussing on the first three full years of the ENVISAT mission (2003-2005) is improved and extended up to end of 2009 constituting seven years of greenhouse gas information derived from European Earth observation data and closing the gap to GOSAT. The status of this retrieval activity and first results are presented.

  7. Column amounts of trace gases from ground based FTIR measurements in the late north polar winters 1990 and 1991

    NASA Technical Reports Server (NTRS)

    Adrian, Gabriele; Blumenstock, Thomas; Fischer, Herbert; Frank, Eckard; Gerhardt, Lothar; Gulde, Thomas; Maucher, Guido; Oelhaf, Hermann; Thomas, Peter; Trieschmann, Olaf

    1994-01-01

    Two FTIR spectrometers were employed in the late winters 1990 and 1991 in Esrange, North Sweden, and in Ny Aalesund, Spitsbergen to detect zenith column amounts of several trace gases. Time series of column amounts of the trace gases O3, N2O, CH4, HNO3, NO2, CHl, and HF have been derived from the measured spectra. Additionally, some information on the vertical distribution of HCl could be obtained by analyzing the spectral line shapes. The results are interpreted in terms of dynamical and chemical processes.

  8. Eddy correlation fluxes of trace gases using a tandem mass spectrometer

    NASA Astrophysics Data System (ADS)

    Shaw, William J.; Spicer, Chester W.; Kenny, Donald V.

    This paper describes a field evaluation of a tandem mass spectrometer (TAGA) for use in measuring turbulence fluxes of trace gases. Measurements were made over a two-day period in a fallow farm field west of Columbus, OH. The results show that for weakly adsorbing species such as acetone, the effective time constant for the TAGA is <0.1 s, and the device can be used for eddy correlation flux measurements with little need for corrections. The effective time constant is longer for adsorbing species, such as ammonia, but spectral corrections can permit flux estimates for these species as well. This paper presents the first reported measurements of fluxes of acetone, formic acid, and ammonia using the eddy correlation technique.

  9. Measurements of Long-Lived Trace Gases from Commercial Aircraft Platforms: Development of Instrumentation

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The upper troposphere (6-12 km altitude) is a poorly understood and highly vulnerable region of the atmosphere. It is important because many trace species, including ozone, have their greatest impact as greenhouse (infrared-absorbing) gases in this region. The addition of relatively small amounts of anthropogenic chemicals, such as nitrogen oxides, can have a dramatic effect on the abundance of ozone. Some of these pollutants are deposited directly, e.g., by aircraft, while others are transported in. The primary goal of this project was to measure several chemical compounds in the upper troposphere that will help us to understand how air is to transported to that part of the atmosphere; that is, does it come down from the stratosphere, does it rise from the surface via convection, and so on. To obtain adequate sampling to accomplish this goal, we proposed to make measurements from revenue aircraft during normal flight operations.

  10. Mixing ratios of trace gases in the austral polar atmosphere during August and September of 1987

    NASA Technical Reports Server (NTRS)

    Vedder, James F.; Heidt, Leroy E.; Pollock, Walter H.; Henry, Bruce E.; Lueb, Richard A.

    1988-01-01

    Mixing ratios are presented for a number of long-lived trace gases in the austral polar atmosphere during August and September of 1987. The recent discovery of a 12-year trend of increasing depletion of ozone over the Antarctic Continent in the spring of each year led to numerous theoretical interpretations and several scientific expeditions to the region. The results herein were obtained as part of a major effort involving penetration of the region of ozone depletion by NASA's multi-instrumented aircraft. One of the 14 instruments on the high-altitude ER-2 aircraft collected pressurized air samples between latitudes of 53 degrees and 72 degrees south at pressure altitudes up to 21 km in a series of 12 flights from Punta Arenas, Chile, over the Palmer Peninsula. The sampling system, located in the nose section of ER-2, has an inlet tube in the free airstream, a metal-bellows air pump, and 14 specially treated 1.6 l stainless-steel canisters for containing the pressurized air at 350 kPa. A typical flight profile consisted of a southbound path on the 428 K potential temperature surface, a descent to a pressure altitude of 13.7 km, a climb to the 460 K surface, and return on this surface. Mixing ratios for the trace gases were obtained from gas chromatographic analyses of the pressurized air samples. Of the species measured, the mixing ratios for CH4, CO, N2O, CF2 Cl2, CFCl3, CH3, CCl3, CCl4, and C2F3Cl3 are reported here.

  11. Characteristics of Fine Particles in an Urban Atmosphere—Relationships with Meteorological Parameters and Trace Gases

    PubMed Central

    Zhang, Tianhao; Zhu, Zhongmin; Gong, Wei; Xiang, Hao; Fang, Ruimin

    2016-01-01

    Atmospheric fine particles (diameter < 1 μm) attract a growing global health concern and have increased in urban areas that have a strong link to nucleation, traffic emissions, and industrial emissions. To reveal the characteristics of fine particles in an industrial city of a developing country, two-year measurements of particle number size distribution (15.1 nm–661 nm), meteorological parameters, and trace gases were made in the city of Wuhan located in central China from June 2012 to May 2014. The annual average particle number concentrations in the nucleation mode (15.1 nm–30 nm), Aitken mode (30 nm–100 nm), and accumulation mode (100 nm–661 nm) reached 4923 cm−3, 12193 cm−3 and 4801 cm−3, respectively. Based on Pearson coefficients between particle number concentrations and meteorological parameters, precipitation and temperature both had significantly negative relationships with particle number concentrations, whereas atmospheric pressure was positively correlated with the particle number concentrations. The diurnal variation of number concentration in nucleation mode particles correlated closely with photochemical processes in all four seasons. At the same time, distinct growth of particles from nucleation mode to Aitken mode was only found in spring, summer, and autumn. The two peaks of Aitken mode and accumulation mode particles in morning and evening corresponded obviously to traffic exhaust emissions peaks. A phenomenon of “repeated, short-lived” nucleation events have been created to explain the durability of high particle concentrations, which was instigated by exogenous pollutants, during winter in a case analysis of Wuhan. Measurements of hourly trace gases and segmental meteorological factors were applied as proxies for complex chemical reactions and dense industrial activities. The results of this study offer reasonable estimations of particle impacts and provide references for emissions control strategies in industrial cities of

  12. Characteristics of Fine Particles in an Urban Atmosphere-Relationships with Meteorological Parameters and Trace Gases.

    PubMed

    Zhang, Tianhao; Zhu, Zhongmin; Gong, Wei; Xiang, Hao; Fang, Ruimin

    2016-01-01

    Atmospheric fine particles (diameter < 1 μm) attract a growing global health concern and have increased in urban areas that have a strong link to nucleation, traffic emissions, and industrial emissions. To reveal the characteristics of fine particles in an industrial city of a developing country, two-year measurements of particle number size distribution (15.1 nm-661 nm), meteorological parameters, and trace gases were made in the city of Wuhan located in central China from June 2012 to May 2014. The annual average particle number concentrations in the nucleation mode (15.1 nm-30 nm), Aitken mode (30 nm-100 nm), and accumulation mode (100 nm-661 nm) reached 4923 cm(-3), 12193 cm(-3) and 4801 cm(-3), respectively. Based on Pearson coefficients between particle number concentrations and meteorological parameters, precipitation and temperature both had significantly negative relationships with particle number concentrations, whereas atmospheric pressure was positively correlated with the particle number concentrations. The diurnal variation of number concentration in nucleation mode particles correlated closely with photochemical processes in all four seasons. At the same time, distinct growth of particles from nucleation mode to Aitken mode was only found in spring, summer, and autumn. The two peaks of Aitken mode and accumulation mode particles in morning and evening corresponded obviously to traffic exhaust emissions peaks. A phenomenon of "repeated, short-lived" nucleation events have been created to explain the durability of high particle concentrations, which was instigated by exogenous pollutants, during winter in a case analysis of Wuhan. Measurements of hourly trace gases and segmental meteorological factors were applied as proxies for complex chemical reactions and dense industrial activities. The results of this study offer reasonable estimations of particle impacts and provide references for emissions control strategies in industrial cities of developing

  13. Increasing CO2 Coupled with Other Anthropogenic Perturbations: Effects on Ozone and Other Trace Gases

    NASA Technical Reports Server (NTRS)

    Rosenfield, J. E.; Douglass, A. R.

    1999-01-01

    The GSFC 2D interactive chemistry-radiation-dynamics model has been used to study the effects on stratospheric trace gases of past and future CO2 increases coupled with changes in CFC'S, methane, and nitrous oxide. Previous simulations with the GSFC model showed that the stratospheric cooling calculated to result from doubling atmospheric CO2 would lead, in the absence of a growth of other anthropogenic gases, to a decrease in upper stratospheric NO(y) of roughly 15%. This work has been extended to simulate changes in stratospheric chemistry and dynamics occurring between the years 1960 and 2050. The simulations have been carried out with and without changes in CO2. In the low latitude upper stratosphere ozone is predicted to be 10% greater in 2050 than in 1990 when increased CO2 is included, compared with an increase of only 2% without the inclusion of CO2. In the low latitude lower stratosphere, ozone is predicted to decrease by about 1% between 1990 and 2050 when CO2 changes are taken into account, in contrast to an approximate 3% increase when they are not. The simulated behavior of water vapor is another example of the coupled responses. Between 1990 and 2050 low latitude water vapor is predicted to increase by 4% and 2% in the upper and lower stratosphere, respectively, without the inclusion of CO2 increases. with the inclusion of CO2 changes, the water vapor increases are predicted to be roughly 12% and 8%, for the upper and lower stratosphere, respectively.

  14. Atmospheric variability and emissions of halogenated trace gases near New York City

    NASA Astrophysics Data System (ADS)

    Santella, Nicholas; Ho, David T.; Schlosser, Peter; Gottlieb, Elaine; Munger, William J.; Elkins, James W.; Dutton, Geoffrey S.

    2012-02-01

    Elevated mixing ratios of chlorofluorocarbons (CFC-11 and CFC-12), and sulfur hexafluoride (SF 6) have been observed at Lamont-Doherty Earth Observatory (LDEO), located approximately 25 km north of New York City (NYC). Emissions and transport of these gases are of interest because of their global warming potential, the role of CFCs in depletion of stratospheric ozone and information they provide on the transport of atmospheric pollutants. Comparison of trace gas time series with meteorological data indicates that both NYC and the region to the southwest (New Jersey and the Philadelphia -Washington DC area) are significant sources of CFCs, and confirms that NYC is an unusually large source of SF 6. From 1996 to 2005 the elevation of CFC-12 mixing ratio above that of the remote (well mixed) atmosphere has decreased on average by 5.2 ± 0.6 ppt y -1, whereas that of CFC-11 has not changed significantly (0.0 ± 2.0 ppt y -1). From 1998 to 2006, the elevation of SF 6 mixing ratios above that of the remote atmosphere declined by 0.4 ± 0.1 ppt y -1. Time series of the same gases measured at Harvard Forest, 205 km northeast of LDEO, demonstrate transport of air masses with elevated levels of these gases from their source region to central Massachusetts. Emissions in the local area around LDEO were quantified through analysis of diurnal cycles. Local CFC-12 emissions decreased ca. 95% between 1996 and 2005 while CFC-11 emission decreased ca. 51% during the same period. Local SF 6 emissions decreased by 47% between 1998 and 2005.

  15. PHOTOENHANCED DEPOSITION OF TRACE GASES AT THE INTERFACE OF ORGANIC SURFACES

    NASA Astrophysics Data System (ADS)

    George, C.; Barbara, D.; Jammoul, A.; Favez, O.; Rosenoern, T.

    2009-12-01

    Atmospheric aerosol particles have been found to contain moderate to high fractions by mass of organic compounds. These may be biogenic or anthropogenic in origin, depending on the location and history of the individual particle. The recent and growing awareness of this has spurred a significant effort in understanding how organic compounds on particle surfaces influence water condensation there; how this changes as the particle becomes “processed” (i.e. oxidized) in the atmosphere, and how these processes influence the gas phase composition in volumes containing such particles. Most of these studies evaluated the uptakes or the deposition of some trace gases at the organic interface under dark conditions. However, very few investigations focus on the effect of solar irradiation on atmospheric heterogeneous chemistry, although recent findings confirm the presence of UV-A/Visible light absorbing material in airborne particles and environmental surfaces which can allow photo-induced (or photosensitized) processes. The present work demonstrates the photo-enhanced uptake of NO2 and O3 on various organic surfaces as various aromatic compounds used as proxy of biogenic and anthropogenic emissions (PAHs, phenolic compounds) and humic acid coatings and submicron particles. The results suggest that photo-induced uptake can be important under atmospheric conditions with respect irradiance, humidity, temperature and gas trace mixing ratio.

  16. Airborne multi-axis DOAS measurements of atmospheric trace gases on CARIBIC long-distance flights

    NASA Astrophysics Data System (ADS)

    Dix, B.; Brenninkmeijer, C. A. M.; Frieß, U.; Wagner, T.; Platt, U.

    2009-11-01

    A DOAS (Differential Optical Absorption Spectroscopy) instrument was implemented and operated onboard a long-distance passenger aircraft within the framework of the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container). The instrument was designed to keep weight, size and power consumption low and to comply with civil aviation regulations. It records spectra of scattered light from three viewing directions (nadir, 10° above and below horizon) using a miniaturized telescope system. The telescopes are integrated in the main pylon of the inlet system which is mounted at the belly of the aircraft. Fibre bundles transmit light from the telescopes to spectrograph-detector units inside the DOAS container instrument. The latter is part of the removable CARIBIC instrument container, which is installed monthly on the aircraft for a series of measurement flights. During 30 flight operations within three years, measurements of HCHO, HONO, NO2, BrO, O3 and the oxygen dimer O4 were conducted. All of these trace gases except BrO could be analysed with a 30 s time resolution. HONO was detected for the first time in a deep convective cloud over central Asia, while BrO, NO2 and O3 could be observed in tropopause fold regions. Biomass burning signatures over South America could be seen and measurements during ascent and descent provided information on boundary layer trace gas profiles (e.g. NO2 or HCHO).

  17. Airborne multi-axis DOAS measurements of atmospheric trace gases on CARIBIC long-distance flights

    NASA Astrophysics Data System (ADS)

    Dix, B.; Brenninkmeijer, C. A. M.; Frieß, U.; Wagner, T.; Platt, U.

    2009-02-01

    A DOAS (Differential Optical Absorption Spectroscopy) instrument was implemented and operated onboard a long-distance passenger aircraft within the framework of the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container). The instrument was designed to keep weight, size and power consumption low and to comply with civil aviation regulations. It records spectra of scattered light from three viewing directions (nadir, 10° above and below horizon) using a miniaturized telescope system. The telescopes are integrated in the main pylon of the inlet system which is mounted at the belly of the aircraft. Fibre bundles transmit light from the telescopes to spectrograph-detector units inside the DOAS container instrument. The latter is part of the removable CARIBIC instrument container, which is installed monthly on the aircraft for a series of measurement flights. During 30 flight operations within three years, measurements of HCHO, HONO, NO2, BrO, O3 and the oxygen dimer O4 were conducted. All of these trace gases except BrO could be analysed with a 30 s time resolution. HONO was detected for the first time in a deep convective cloud over central Asia. BrO, NO2 and O3 could be observed in tropopause fold regions, biomass burning signatures over South America could be seen and measurements during ascent and descent provided information on boundary layer trace gas profiles (e.g. NO2 or HCHO).

  18. Validation of Global Climatologies of Trace Gases Using NASA Global Tropospheric Experiment (GTE) Data

    NASA Technical Reports Server (NTRS)

    Courchaine, Brian; Venable, Jessica C.

    1995-01-01

    Methane is an important trace gas because it is a greenhouse gas that affects the oxidative capacity of the atmosphere. It is produced from biological and anthropogenic sources, and is increasing globally at a rate of approximately 0.6% per year [Climate Change 1992, IPCC]. By using National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) ground station data, a global climatology of methane values was produced. Unfortunately, because the NOAA/CMDL ground stations are so sparse, the global climatology is low resolution. In order to compensate for this low resolution data, it was compared to in-situ flight data obtained from the NASA Global Tropospheric Experiment (GTE). The smoothed ground station data correlated well with the flight data. Thus, for the first time it is shown that the smoothing process used to make global contours of methane using the ground stations is a plausible way to approximate global atmospheric concentrations of the gas. These verified climatologies can be used for testing large-scale models of chemical production, destruction, and transport. This project develops the groundwork for further research in building global climatologies from sparse ground station data and studying the transport and distribution of trace gases.

  19. Exomars orbiter science and data-relay mission / looking for trace gases on Mars

    NASA Astrophysics Data System (ADS)

    Fratacci, Olivier

    EXOMARS Orbiter Module: looking for trace gas on Mars and providing data relay support for future Mars Surface assets O.Fratacci, M.Mesrine, H.Renault, Thales Alenia Space France B.Musetti, M.Montagna, Thales Alenia Space Italy M.Kesselmann, M.Barczewski OHB P.Mitschdoerfer, D.Dellantonio Euro-pean Space Agency / ESTEC The European Space Agency (ESA) in a joint cooperation with NASA, will launch in 2016 the EXOMARS spacecraft composite to develop European landing technologies and provide a science orbiter with data-relay capability around Mars until end 2022. The spacecraft composite is composed of the Orbitr Module (OM), provided by TAS-France, an entry descent and landing demonstrator module (EDM) provided by TAS-Italy, and a set of six scientific payloads to be selected by the JPL during 2010. Recent observations of the planet Mars have indicated detection of methane as well as temporal, perhaps spatial variability in the detected signal while current photochemical models cannot explain the presence of methane in the atmosphere of Mars nor its reported rapid variations in space and time. The triple scientific objectives that drive the selection of these six instruments for the Exomars 2016 mission is to detect trace gases in Mars atmosphere, to characterise their spatial and temporal variation and to explore the source of the key trace gases (e.g. methane) on the surface. The launch is scheduled in January 2016 from Kennedy Space Center (KSC) using an ATLAS V 421 launcher with a total launch mass of 4.4 tons. After release of the EDM on Mars, the OM will perform the Mars Orbit Insertion manoeuvre and then reduce its elliptic orbit by implementing the first European Aerobraking around Mars for about 6 to 9 months, to finally end on a circular 400x400km orbit with an altitude in the range of 350km to 420km. From this orbit, a science phase will follow lasting 2 years in which the Mars atmosphere and surface is continuously observed. Science instruments composed of

  20. Differential Radiometers Using Fabry-Perot Interferometric Technique for Remote Sensing Determination of Various Atmospheric Trace Gases

    NASA Technical Reports Server (NTRS)

    Georgieva, E. M.; Heaps, W. S.; Wilson, E. L.

    2007-01-01

    New type of remote sensing instrument based upon the Fabry-Perot inte rferometric technique has been developed at NASA's Goddard Space Flight Center. Fabry-Perot interferometry (FPI) is a well known, powerful spectroscopic technique and one of its many applications is to be use d to measure greenhouse gases and also some harmful species in the at mosphere. With this technique, absorption of particular species is me asured and related to its concentration. A solid Fabry-Perot etalon is used as a frequency filter to restrict the measurement to particular absorption bands of the gas of interest. With adjusting the thicknes s of the etalon that separation (in frequency) of the transmitted fri nges can be made equal to the almost constant separation of the gas a bsorption lines. By adjusting the temperature of the etalon, which changes the index of refi-action of its material, the transmission fring es can be brought into nearly exact correspondence with absorption li nes of the particular species. With this alignment between absorption lines and fringes, changes in the amount of a species in the atmosph ere strongly affect the amount of light transmitted by the etalon and can be related to gas concentration. The instrument that we have dev eloped detects the absorption of various atmospheric trace gases in d irect or reflected sunlight. Our instrument employing Fabry-Perot interferometer makes use of two features to achieve high sensitivity. The first is high spectral resolution enabling one to match the width of an atmospheric absorption feature by the instrumental band pass. The second is high optical throughput enabled by using multiple spectral lines simultaneously. For any species that one wishes to measure, thi s first feature is available while the use of multiple spectral features can be employed only for species with suitable spectra and freedom from interfering species in the same wavelength region. We have deve loped an instrument for use as ground based

  1. Theoretical computation of trace gases retrieval random error from measurements of high spectral resolution infrared sounder

    NASA Technical Reports Server (NTRS)

    Huang, Hung-Lung; Smith, William L.; Woolf, Harold M.; Theriault, J. M.

    1991-01-01

    The purpose of this paper is to demonstrate the trace gas profiling capabilities of future passive high spectral resolution (1 cm(exp -1) or better) infrared (600 to 2700 cm(exp -1)) satellite tropospheric sounders. These sounders, such as the grating spectrometer, Atmospheric InfRared Sounders (AIRS) (Chahine et al., 1990) and the interferometer, GOES High Resolution Interferometer Sounder (GHIS), (Smith et al., 1991) can provide these unique infrared spectra which enable us to conduct this analysis. In this calculation only the total random retrieval error component is presented. The systematic error components contributed by the forward and inverse model error are not considered (subject of further studies). The total random errors, which are composed of null space error (vertical resolution component error) and measurement error (instrument noise component error), are computed by assuming one wavenumber spectral resolution with wavenumber span from 1100 cm(exp -1) to 2300 cm(exp -1) (the band 600 cm(exp -1) to 1100 cm(exp -1) is not used since there is no major absorption of our three gases here) and measurement noise of 0.25 degree at reference temperature of 260 degree K. Temperature, water vapor, ozone and mixing ratio profiles of nitrous oxide, carbon monoxide and methane are taken from 1976 US Standard Atmosphere conditions (a FASCODE model). Covariance matrices of the gases are 'subjectively' generated by assuming 50 percent standard deviation of gaussian perturbation with respect to their US Standard model profiles. Minimum information and maximum likelihood retrieval solutions are used.

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

    NASA Astrophysics Data System (ADS)

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

    2004-10-01

    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 (CH3ONO2), methyl iodide (CH3I) and bromoform (CHBr3). 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 (τ≈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 CH3ONO2 and CHBr3, 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 CH3ONO2 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, CH3ONO2 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.

  3. Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO).

    PubMed Central

    Conrad, R

    1996-01-01

    Production and consumption processes in soils contribute to the global cycles of many trace gases (CH4, CO, OCS, H2, N2O, and NO) that are relevant for atmospheric chemistry and climate. Soil microbial processes contribute substantially to the budgets of atmospheric trace gases. The flux of trace gases between soil and atmosphere is usually the result of simultaneously operating production and consumption processes in soil: The relevant processes are not yet proven with absolute certainty, but the following are likely for trace gas consumption: H2 oxidation by abiontic soil enzymes; CO cooxidation by the ammonium monooxygenase of nitrifying bacteria; CH4 oxidation by unknown methanotrophic bacteria that utilize CH4 for growth; OCS hydrolysis by bacteria containing carbonic anhydrase; N2O reduction to N2 by denitrifying bacteria; NO consumption by either reduction to N2O in denitrifiers or oxidation to nitrate in heterotrophic bacteria. Wetland soils, in contrast to upland soils are generally anoxic and thus support the production of trace gases (H2, CO, CH4, N2O, and NO) by anaerobic bacteria such as fermenters, methanogens, acetogens, sulfate reducers, and denitrifiers. Methane is the dominant gaseous product of anaerobic degradation of organic matter and is released into the atmosphere, whereas the other trace gases are only intermediates, which are mostly cycled within the anoxic habitat. A significant percentage of the produced methane is oxidized by methanotrophic bacteria at anoxic-oxic interfaces such as the soil surface and the root surface of aquatic plants that serve as conduits for O2 transport into and CH4 transport out of the wetland soils. The dominant production processes in upland soils are different from those in wetland soils and include H2 production by biological N2 fixation, CO production by chemical decomposition of soil organic matter, and NO and N2O production by nitrification and denitrification. The processes responsible for CH4 production

  4. Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO).

    PubMed

    Conrad, R

    1996-12-01

    Production and consumption processes in soils contribute to the global cycles of many trace gases (CH4, CO, OCS, H2, N2O, and NO) that are relevant for atmospheric chemistry and climate. Soil microbial processes contribute substantially to the budgets of atmospheric trace gases. The flux of trace gases between soil and atmosphere is usually the result of simultaneously operating production and consumption processes in soil: The relevant processes are not yet proven with absolute certainty, but the following are likely for trace gas consumption: H2 oxidation by abiontic soil enzymes; CO cooxidation by the ammonium monooxygenase of nitrifying bacteria; CH4 oxidation by unknown methanotrophic bacteria that utilize CH4 for growth; OCS hydrolysis by bacteria containing carbonic anhydrase; N2O reduction to N2 by denitrifying bacteria; NO consumption by either reduction to N2O in denitrifiers or oxidation to nitrate in heterotrophic bacteria. Wetland soils, in contrast to upland soils are generally anoxic and thus support the production of trace gases (H2, CO, CH4, N2O, and NO) by anaerobic bacteria such as fermenters, methanogens, acetogens, sulfate reducers, and denitrifiers. Methane is the dominant gaseous product of anaerobic degradation of organic matter and is released into the atmosphere, whereas the other trace gases are only intermediates, which are mostly cycled within the anoxic habitat. A significant percentage of the produced methane is oxidized by methanotrophic bacteria at anoxic-oxic interfaces such as the soil surface and the root surface of aquatic plants that serve as conduits for O2 transport into and CH4 transport out of the wetland soils. The dominant production processes in upland soils are different from those in wetland soils and include H2 production by biological N2 fixation, CO production by chemical decomposition of soil organic matter, and NO and N2O production by nitrification and denitrification. The processes responsible for CH4 production

  5. Global satellite analysis of the relation between aerosols and short-lived trace gases

    NASA Astrophysics Data System (ADS)

    Veefkind, J. P.; Boersma, K. F.; Wang, J.; Kurosu, T. P.; Krotkov, N.; Chance, K.; Levelt, P. F.

    2011-02-01

    The spatial and temporal correlations between concurrent satellite observations of aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) and tropospheric columns of nitrogen dioxide (NO2), sulfur dioxide (SO2), and formaldehyde (HCHO) from the Ozone Monitoring Instrument (OMI) are used to infer information on the global composition of aerosol particles. When averaging the satellite data over large regions and longer time periods, we find significant correlation between MODIS AOT and OMI trace gas columns for various regions in the world. This shows that these enhanced aerosol and trace gas concentrations originate from common sources, such as fossil fuel combustion, biomass burning, and organic compounds released from the biosphere. This leads us to propose that satellite-inferred AOT to NO2 ratios for regions with comparable photochemical regimes can be used as indicators for the relative regional pollution control of combustion processes. Indeed, satellites observe low AOT to NO2 ratios over the eastern United States and western Europe, and high AOT to NO2 ratios over comparably industrialized regions in eastern Europe and China. Emission databases and OMI SO2 observations over these regions suggest a much stronger sulfur contribution to aerosol formation than over the well-regulated areas of the eastern United States and western Europe. Furthermore, satellite observations show AOT to NO2 ratios are a factor 100 higher over biomass burning regions than over industrialized areas, reflecting the unregulated burning practices with strong primary particle emissions in the tropics compared to the heavily controlled combustion processes in the industrialized Northern Hemisphere. Simulations with a global chemistry transport model (GEOS-Chem) capture most of these variations, although on regional scales significant differences are found. Wintertime aerosol concentrations show strongest correlations with NO2 throughout most of the

  6. Emissions of formaldehyde, acetic acid, methanol, and other trace gases from biomass fires in North Carolina measured by airborne Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yokelson, R. J.; Goode, J. G.; Ward, D. E.; Susott, R. A.; Babbitt, R. E.; Wade, D. D.; Bertschi, I.; Griffith, D. W. T.; Hao, W. M.

    1999-12-01

    Biomass burning is an important source of many trace gases in the global troposphere. We have constructed an airborne trace gas measurement system consisting of a Fourier transform infrared spectrometer (FTIR) coupled to a "flow-through" multipass cell (AFTIR) and installed it on a U.S. Department of Agriculture Forest Service King Air B-90. The first measurements with the new system were conducted in North Carolina during April 1997 on large, isolated biomass fire plumes. Simultaneous measurements included Global Positioning System (GPS); airborne sonde; particle light scattering, CO, and CO2; and integrated filter and canister samples. AFTIR spectra acquired within a few kilometers of the fires yielded excess mixing ratios for 10 of the most common trace gases in the smoke: water, carbon dioxide, carbon monoxide, methane, formaldehyde, acetic acid, formic acid, methanol, ethylene, and ammonia. Emission ratios to carbon monoxide for formaldehyde, acetic acid, and methanol were each 2.5±1%. This is in excellent agreement with (and confirms the relevance of) our results from laboratory fires. However, these ratios are significantly higher than the emission ratios reported for these compounds in some previous studies of "fresh" smoke. We present a simple photochemical model calculation that suggests that oxygenated organic compounds should be included in the assessment of ozone formation in smoke plumes. Our measured emission factors indicate that biomass fires could account for a significant portion of the oxygenated organic compounds and HOx present in the tropical troposphere during the dry season. Our fire measurements, along with recent measurements of oxygenated biogenic emissions and oxygenated organic compounds in the free troposphere, indicate that these rarely measured compounds play a major, but poorly understood, role in the HOx, NOx, and O3 chemistry of the troposphere.

  7. Sensitivity of net thermal flux to the abundance of trace gases in the lower atmosphere of Venus

    NASA Astrophysics Data System (ADS)

    Lee, Yeon Joo; Sagawa, Hideo; Haus, Rainer; Stefani, Stefania; Imamura, Takeshi; Titov, Dmitrij V.; Piccioni, Giuseppe

    2016-09-01

    We calculated the net thermal flux in the atmosphere of Venus from the surface to 100 km altitude. Our atmospheric model was carefully constructed especially for altitudes below the clouds (<48 km), using recent CO2 absorption data. It includes updated collision-induced absorptions in the <250 cm-1, 1200-1500 cm-1, and 2650-3130 cm-1 wave number ranges. We studied sensitivity of the net thermal flux below the clouds on the abundances of trace gases that were varied within the range reported by observations. Our results reveal a considerable effect of trace gases on radiative budget. We successfully simulate net thermal flux profiles measured in situ by the Night and North probes of Pioneer Venus using 20-50 ppmv H2O, suggesting that the high H2O abundance of 200 ppmv derived in the earlier analysis is not required. Our sensitivity study shows that the trace gases SO2, H2O, and OCS are effective thermal agents, while CO and HCl influences are rather weak. We suggest that the influence of the former three gases should be taken into account to estimate the net radiative energy in the deep atmosphere.

  8. Study on the kinetic characteristics of trace harmful gases for a two-person-30-day integrated CELSS test.

    PubMed

    Guo, Shuangsheng; Ai, Weidang; Fei, Jinxue; Xu, Guoxin; Zeng, Gu; Shen, Yunze

    2015-05-01

    A two-person-30-day controlled ecological life support system (CELSS) integrated test was carried out, and more than 30 kinds of trace harmful gases including formaldehyde, benzene, and ammonia were measured and analyzed dynamically. The results showed that the kinds and quantities of the trace harmful gases presented a continuously fluctuating state during the experimental period, but none of them exceed the spacecraft maximum allowable concentration (SMAC). The results of the Pre-Test (with two persons without plants for 3 days) and the Test (with two persons and four kinds of plants for 30 days) showed that there are some notable differences for the compositions of the trace harmful gases; the volatile organic compounds (VOCs) such as toluene, hexane, and acetamide were searched out in the Pre-Test, but were not found in the Test. Moreover, the concentrations of the trace harmful gases such as acetic benzene, formaldehyde, and ammonia decreased greatly in the Test more than those in the Pre-Test, which means that the plants can purify these gases efficiently. In addition, the VOCs such as carbon monoxide, cyclopentane, and dichloroethylene were checked out in the Test but none in the Pre-Test, which indicates that these materials might be from the crew's metabolites or those devices in the platform. Additionally, the ethylene released specially by plants accumulated in the later period and its concentration reached nearly ten times of 0.05 mg m(-3) (maximum allowed concentration for plant growth, which must have promoted the later withering of plants). We hoped that the work can play a referring function for controlling VOCs effectively so that future more CELSS integrating tests can be implemented smoothly with more crew, longer period, and higher closure. PMID:25483969

  9. Study on the kinetic characteristics of trace harmful gases for a two-person-30-day integrated CELSS test.

    PubMed

    Guo, Shuangsheng; Ai, Weidang; Fei, Jinxue; Xu, Guoxin; Zeng, Gu; Shen, Yunze

    2015-05-01

    A two-person-30-day controlled ecological life support system (CELSS) integrated test was carried out, and more than 30 kinds of trace harmful gases including formaldehyde, benzene, and ammonia were measured and analyzed dynamically. The results showed that the kinds and quantities of the trace harmful gases presented a continuously fluctuating state during the experimental period, but none of them exceed the spacecraft maximum allowable concentration (SMAC). The results of the Pre-Test (with two persons without plants for 3 days) and the Test (with two persons and four kinds of plants for 30 days) showed that there are some notable differences for the compositions of the trace harmful gases; the volatile organic compounds (VOCs) such as toluene, hexane, and acetamide were searched out in the Pre-Test, but were not found in the Test. Moreover, the concentrations of the trace harmful gases such as acetic benzene, formaldehyde, and ammonia decreased greatly in the Test more than those in the Pre-Test, which means that the plants can purify these gases efficiently. In addition, the VOCs such as carbon monoxide, cyclopentane, and dichloroethylene were checked out in the Test but none in the Pre-Test, which indicates that these materials might be from the crew's metabolites or those devices in the platform. Additionally, the ethylene released specially by plants accumulated in the later period and its concentration reached nearly ten times of 0.05 mg m(-3) (maximum allowed concentration for plant growth, which must have promoted the later withering of plants). We hoped that the work can play a referring function for controlling VOCs effectively so that future more CELSS integrating tests can be implemented smoothly with more crew, longer period, and higher closure.

  10. A sensitivity study for far infrared balloon-borne limb emission sounding of stratospheric trace gases

    NASA Astrophysics Data System (ADS)

    Xu, J.; Schreier, F.; Vogt, P.; Doicu, A.; Trautmann, T.

    2013-05-01

    This paper presents a sensitivity study performed for trace gases retrieval from synthetic observations by TELIS (TErahertz and submillimeter LImb Sounder) which is a stratospheric balloon-borne cryogenic heterodyne spectrometer. Issues pertaining to hydroxyl radical (OH) retrieval from the far infrared measurements by the 1.8 THz channel are addressed. The study is conducted by a retrieval code PILS (Profile Inversion for Limb Sounding) developed to solve the nonlinear inverse problems arising in the analysis of infrared/microwave limb sounding measurements. PILS combines a line-by-line forward model with automatic differentiation for computing Jacobians and employs regularized nonlinear least squares inversion. We examine the application of direct and iterative regularization methods and evaluate the performance of single- and multi-profile retrievals. Sensitivities to expected errors in calibration procedure, instrumental knowledge and atmospheric profiles have been analyzed. Nonlinearity effect, inaccurate sideband ratio, and pointing error turned out to be the dominant error sources. Furthermore, the capability of multi-channel simultaneous retrieval from the far infrared and submillimeter data has been investigated. The errors and averaging kernels infer that the quality of the obtained hydrogen chloride (HCl) can be improved by significantly better exploitation of information from the observations.

  11. Recent developments in high altitude aircraft sampling - Mount St. Helens and stratospheric trace gases

    NASA Astrophysics Data System (ADS)

    Leifer, R.; Sommers, K. G.; Guggenheim, S. F.; Fisenne, I.

    1981-02-01

    An ultra-clean, low volume gas sampling system (CLASS), flown aboard a high altitude aircraft (WB-57F), and providing information on stratospheric trace gases is presented. Attention is given to the instrument design and the electronic control design. Since remote operation is mandatory on the WB-57F, a servo pressure transducer, electrical pressure switch for automatic shutdown, and a mechanical safety relief valve were installed on the sampling manifold, indicated on the CLASS flow chart. The electronic control system consists of hermetically sealed solid state timers, relays, and a stepping switch, for controlling the compressor pump and solenoid valves. In designing the automatic control system, vibration, shock, acceleration, extreme low temperature, and aircraft safety were important considerations. CLASS was tested on three separate occasions, and tables of analytical data from these flights are presented. Readiness capability was demonstrated when the Mount St. Helens eruption plume of May 18, 1980, was intercepted, and it was concluded that no large injection of Rn-222 entered the stratosphere or troposphere from the eruption.

  12. Lidar remote sensing of tropospheric pollutants and trace gases - Programs of NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Browell, E. V.

    1978-01-01

    NASA Langley Research Center is engaged in a number of in-house and contracted programs to develop, evaluate, and apply lidar techniques to remote measurements of pollutant gases, trace molecules, and aerosols. The differential absorption lidar (DIAL) research programs include the development and evaluation of a UV DIAL system for remote measurements of SO2 and O3 concentrations and aerosol dispersion in urban and power-plant stack plumes, a near-IR DIAL system for vertical measurements of water vapor concentrations, and a high-power tunable IR DIAL system which will measure the concentration of gas species that have absorption features in the 1.4- to 4.4-micron wavelength range. The lidar programs which deal with aerosol measurements include the evaluation of a mobile ruby lidar system for use in plume dispersion model verification and the development of a high-spectral-resolution lidar system for measurement of aerosol extinction and backscattering coefficients. System characteristics and measurement sensitivities are discussed, and comparisons are made between simulations and experimental results.

  13. Emission of methane and other trace gases from the Amazon Varzea

    NASA Technical Reports Server (NTRS)

    Richey, Jeffrey E.; Devol, Allan H.

    1986-01-01

    Researchers measured the distributions and fluxes of methane and other trace gases from the various Amazon floodplain environments. These were determined during both a large scale, quasi-synoptic survey along a 2000 km reach of the Amazon river and an intensive local study (by J. Melack, R. Harriss et al.) covering a six-week period. The environments studied included the major rivers, connecting channels (paranas), floating macrophyte beds, flooded forests, open lakes and recently wetted soils. The results are summarized. Measured rates of methane emission averaged about 300 mg m-2 d-1, but with considerable variance, and were comparable to or higher than previously reported emissions from similar temperature zone environments. In general, areas covered by floating macrophytes showed the highest emissions. Individual hotspots had among the highest rates ever observed, over 10 g m-2 d-1. The high methane emissions appear to result because about 50% of the organic matter fixed on the floodplain (either terrestrial or aquatic) that is oxidized in the water is decomposed anaerobically via methanogensis. Measured fluxes of methane to the atmosphere appear to be significantly correlated with surface water dissolved methane concentrations.

  14. Long Range Transport of Aerosols and Trace Gases from China: The Role of Dry Convection.

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.; Levy, R.; Li, C.; Li, Z.; Lackson, M. T.; Jeffrey, S.

    2006-05-01

    Substantial concentrations of trace gases and aerosols are lofted and carried from Asia over the Pacific producing an inter-hemispheric impact on atmospheric chemistry and climate. The meteorological mechanism leading to this large-scale transport of dust and pollutants remains a major uncertainty in quantifying the global effects of emissions from the developing world. Models and downwind measurements have identified isentropic advection associated with wave cyclones (warm conveyor belt, WCB,circulation) as an important mechanism. We present data from a case study conducted s part of EAST-AIRE in April 2005 in which upstream convection, rather that WCB lofting appears to dominate. Observations from instrumented aircraft flights (O3, CO, SO2, and aerosol optical properties), back trajectories, and satellite images of clouds (GOES) and aerosols (MODIS) are analyzed. These show that dry (non-precipitating) convection ahead of cold fronts can be an important mechanism for converting local air pollution problems into regional or global atmospheric chemistry problems. Climatological spring (MAM) precipitation over NE China is low, about 90 mm compared to 290 mm over the NE US. Cloud cover, however, is similar with cumulus clouds reported about 7% of the time over NE China and about 9% of the time over the NE US suggesting that this is not an isolated event. Evaluation of models' convective schemes and further observations near the source regions are called for.

  15. Cyclic process for the removal of sulfur dioxide and the recovery of sulfur from gases

    SciTech Connect

    Lo, C.L.

    1991-11-19

    This patent describes a process for the removal of sulfur dioxide from a gas containing sulfur dioxide. It comprises contacting a gas containing sulfur dioxide with an aqueous solution comprising water, ferric chloride and a salt selected from the group consisting of barium chloride and calcium chloride to form ferrous chloride, hydrochloric acid and a precipitate selected from the group consisting of barium sulfate and calcium sulfate; and treating the aqueous solution with an oxidizing agent to convert ferrous chloride to ferric chloride.

  16. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    PubMed Central

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-01-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials. PMID:24964404

  17. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture.

    PubMed

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-06-25

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 4(4) square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials.

  18. In situ measurements and modeling of reactive trace gases in a small biomass burning plume

    NASA Astrophysics Data System (ADS)

    Müller, Markus; Anderson, Bruce E.; Beyersdorf, Andreas J.; Crawford, James H.; Diskin, Glenn S.; Eichler, Philipp; Fried, Alan; Keutsch, Frank N.; Mikoviny, Tomas; Thornhill, Kenneth L.; Walega, James G.; Weinheimer, Andrew J.; Yang, Melissa; Yokelson, Robert J.; Wisthaler, Armin

    2016-03-01

    An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin to derive emission factors and followed ˜ 13.6 km downwind to observe chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecedented spatiotemporal resolution (10 m spatial/0.1 s temporal). Quantitative emission data are reported for CO2, CO, NO, NO2, HONO, NH3, and 16 NMOGs (formaldehyde, methanol, acetonitrile, propene, acetaldehyde, formic acid, acetone plus its isomer propanal, acetic acid plus its isomer glycolaldehyde, furan, isoprene plus isomeric pentadienes and cyclopentene, methyl vinyl ketone plus its isomers crotonaldehyde and methacrolein, methylglyoxal, hydroxy acetone plus its isomers methyl acetate and propionic acid, benzene, 2,3-butanedione, and 2-furfural) with molar emission ratios relative to CO larger than 1 ppbV ppmV-1. Formaldehyde, acetaldehyde, 2-furfural, and methanol dominated NMOG emissions. No NMOGs with more than 10 carbon atoms were observed at mixing ratios larger than 50 pptV ppmV-1 CO. Downwind plume chemistry was investigated using the observations and a 0-D photochemical box model simulation. The model was run on a nearly explicit chemical mechanism (MCM v3.3) and initialized with measured emission data. Ozone formation during the first hour of atmospheric aging was well captured by the model, with carbonyls (formaldehyde, acetaldehyde, 2,3-butanedione, methylglyoxal, 2-furfural) in addition to CO and CH4 being the main drivers of peroxy radical chemistry. The model also accurately reproduced the sequestration of NOx into peroxyacetyl nitrate (PAN) and the OH-initiated degradation of furan and 2-furfural at an average OH concentration of 7.45 ± 1.07 × 106 cm-3 in the

  19. In situ measurements and modeling of reactive trace gases in a small biomass burning plume

    NASA Astrophysics Data System (ADS)

    Müller, M.; Anderson, B.; Beyersdorf, A.; Crawford, J. H.; Diskin, G.; Eichler, P.; Fried, A.; Keutsch, F. N.; Mikoviny, T.; Thornhill, K. L.; Walega, J. G.; Weinheimer, A. J.; Yang, M.; Yokelson, R.; Wisthaler, A.

    2015-11-01

    An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin for deriving emission factors and followed ~ 13.6 km downwind for observing chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecedented spatio-temporal resolution (10 m/0.1 s). Quantitative emission data are reported for CO2, CO, NO, NO2, HONO, NH3 and 16 NMOGs (formaldehyde, methanol, acetonitrile, propene, acetaldehyde, formic acid, acetone plus its isomer propanal, acetic acid plus its isomer glycolaldehyde, furan, isoprene plus isomeric pentadienes and cyclopentene, methyl vinyl ketone plus its isomers crotonaldehyde and methacrolein, methylglyoxal, hydroxy acetone plus its isomers methyl acetate and propionic acid, benzene, 2,3-butandione and 2-furfural) with molar emission ratios relative to CO larger than 1 ppbV ppmV-1. Formaldehyde, acetaldehyde, 2-furfural and methanol dominated NMOG emissions. No NMOGs with more than 10 carbon atoms were observed at mixing ratios larger than 50 ppbV ppmV-1 CO emitted. Downwind plume chemistry was investigated using the observations and a 0-D photochemical box model simulation. The model was run on a near-explicit chemical mechanism (MCM v3.3) and initialized with measured emission data. Ozone formation during the first hour of atmospheric aging was well captured by the model, with carbonyls (formaldehyde, acetaldehyde, 2,3-butanedione, methylglyoxal, 2-furfural) in addition to CO and CH4 being the main drivers of peroxy radical chemistry. The model also accurately reproduced the sequestration of NOx into PAN and the OH-initiated degradation of furan and 2-furfural at an average OH concentration of 7.45 ± 1.07 × 106 cm-3 in the plume. Formaldehyde, acetone

  20. Resistively-Heated Microlith-based Adsorber for Carbon Dioxide and Trace Contaminant Removal

    NASA Technical Reports Server (NTRS)

    Roychoudhury, S.; Walsh, D.; Perry, J.

    2005-01-01

    An integrated sorber-based Trace Contaminant Control System (TCCS) and Carbon Dioxide Removal Assembly (CDRA) prototype was designed, fabricated and tested. It corresponds to a 7-person load. Performance over several adsorption/regeneration cycles was examined. Vacuum regenerations at effective time/temperature conditions, and estimated power requirements were experimentally verified for the combined CO2/trace contaminant removal prototype. The current paper details the design and performance of this prototype during initial testing at CO2 and trace contaminant concentrations in the existing CDRA, downstream of the drier. Additional long-term performance characterization is planned at NASA. Potential system design options permitting associated weight, volume savings and logistic benefits, especially as relevant for long-duration space flight, are reviewed. The technology consisted of a sorption bed with sorbent- coated metal meshes, trademarked and patented as Microlith by Precision Combustion, Inc. (PCI). By contrast the current CO2 removal system on the International Space Station employs pellet beds. Preliminary bench scale performance data (without direct resistive heating) for simultaneous CO2 and trace contaminant removal was reviewed in SAE 2004-01-2442. In the prototype, the meshes were directly electrically heated for rapid response and accurate temperature control. This allowed regeneration via resistive heating with the potential for shorter regeneration times, reduced power requirement, and net energy savings vs. conventional systems. A novel flow arrangement, for removing both CO2 and trace contaminants within the same bed, was demonstrated. Thus, the need for a separate trace contaminant unit was eliminated resulting in an opportunity for significant weight savings. Unlike the current disposable charcoal bed, zeolites for trace contaminant removal are amenable to periodic regeneration.

  1. Trace gases generated in closed plant cultivation systems and their effects on plant growth.

    PubMed

    Tani, A; Kiyota, M; Aiga, I

    1995-12-01

    Interactions between plants and trace gases, especially ethylene, were investigated from two different viewpoints; ethylene is toxic for plant growth, whereas the ethylene release rate of plants can be utilized as a plant growth indicator. When lettuce plants and shiitake mushroom mycelium were cultivated in closed chambers, ethylene concentration increased with time. Ethylene was released both from lettuce plant and from shiitake mushroom mycelium. Dioctyl phthalate (DOP) and Dibutyl phthalate (DBP) were detected, and these concentrations reached 3.7 ngL-1 for DOP and 2.4 ngL-1 for DBP 4 days after closing. Organic solvents such as xylene and toluene and organic siloxane were detected with GCMS. Visible injury was observed in lettuce plants cultivated in the chambers and it seemed to result from trace contaminants such as DOP, DBP, organic solvents, dimethylsiloxane polymer, and ethylene. In order to obtain basic data of ethylene evolution from plants, ethylene concentration in a closed chamber in which the plants were cultivated under a controlled environment (25 degrees C air temperature, 60-70% relative humidity, 250-300 micromoles m-2 s-1 photosynthetic photon flux density (PPFD)) was measured. Lettuce (Lactuca sativa L. cv. Okayama) released ethylene more than Brassica rapa var. pervidis, Brassica campestris var. communis, and Brassica campestris var. narinosa. Ethylene release rate of intact lettuce plant was highly correlated with plant growth parameters such as dry weight, leaf area and photosynthetic rate. Ethylene release rates of intact lettuce plant were affected by cultivation conditions such as ambient CO2 concentration, light intensity and light/dark period. Increase in ambient ethylene level influenced lettuce growth even at the concentration of 0.1 microliter L-1. The level of ethylene inhibited leaf expansion and slightly accelerated chlorophyll degradation. It did not affect photosynthesis and transpiration, and also little affected dry matter

  2. Trace gases generated in closed plant cultivation systems and their effects on plant growth.

    PubMed

    Tani, A; Kiyota, M; Aiga, I

    1995-12-01

    Interactions between plants and trace gases, especially ethylene, were investigated from two different viewpoints; ethylene is toxic for plant growth, whereas the ethylene release rate of plants can be utilized as a plant growth indicator. When lettuce plants and shiitake mushroom mycelium were cultivated in closed chambers, ethylene concentration increased with time. Ethylene was released both from lettuce plant and from shiitake mushroom mycelium. Dioctyl phthalate (DOP) and Dibutyl phthalate (DBP) were detected, and these concentrations reached 3.7 ngL-1 for DOP and 2.4 ngL-1 for DBP 4 days after closing. Organic solvents such as xylene and toluene and organic siloxane were detected with GCMS. Visible injury was observed in lettuce plants cultivated in the chambers and it seemed to result from trace contaminants such as DOP, DBP, organic solvents, dimethylsiloxane polymer, and ethylene. In order to obtain basic data of ethylene evolution from plants, ethylene concentration in a closed chamber in which the plants were cultivated under a controlled environment (25 degrees C air temperature, 60-70% relative humidity, 250-300 micromoles m-2 s-1 photosynthetic photon flux density (PPFD)) was measured. Lettuce (Lactuca sativa L. cv. Okayama) released ethylene more than Brassica rapa var. pervidis, Brassica campestris var. communis, and Brassica campestris var. narinosa. Ethylene release rate of intact lettuce plant was highly correlated with plant growth parameters such as dry weight, leaf area and photosynthetic rate. Ethylene release rates of intact lettuce plant were affected by cultivation conditions such as ambient CO2 concentration, light intensity and light/dark period. Increase in ambient ethylene level influenced lettuce growth even at the concentration of 0.1 microliter L-1. The level of ethylene inhibited leaf expansion and slightly accelerated chlorophyll degradation. It did not affect photosynthesis and transpiration, and also little affected dry matter

  3. Development of an Amine-based System for Combined Carbon Dioxide, Humidity, and Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Nalette, Tim; Reiss, Julie; Filburn, Tom; Seery, Thomas; Smith, Fred; Perry, Jay

    2005-01-01

    A number of amine-based carbon dioxide (CO2) removal systems have been developed for atmosphere revitalization in closed loop life support systems. Most recently, Hamilton Sundstrand developed an amine-based sorbent, designated SA9T, possessing approximately 2-fold greater capacity compared to previous formulations. This new formulation has demonstrated applicability for controlling CO2 levels within vehicles and habitats as well as during extravehicular activity (EVA). System volume is competitive with existing technologies. Further enhancements in system performance can be realized by incorporating humidity and trace contaminant control functions within an amine-based atmosphere revitalization system. A 3-year effort to develop prototype hardware capable of removing CO2, H2O, and trace contaminants from a cabin atmosphere has been initiated. Progress pertaining to defining system requirements and identifying alternative amine formulations and substrates is presented.

  4. Transport of trace gases into the Tropical Tropopause Layer: the CAST experiment

    NASA Astrophysics Data System (ADS)

    Harris, N. R.

    2013-12-01

    The transport of trace gases from the lower troposphere into and through the Tropical Tropopause Layer is of fundamental importance in determining the chemical composition of the stratosphere. This occurs in convection which is particularly strong in the West Pacific in Boreal winter. A joint aircraft experiment will take place which involves the NERC CAST (Coordinated Airborne Studies in the Tropics), the NASA ATTREX (Airborne Tropical TRopopause EXperiment) and the NSF/NCAR CONTRAST Convective Transport of Active Species in the Tropics) projects. These will be supplemented by ground-based and sonde measurements made at Palau in CAST and in Biak in the Japanese SOWER experiment. One aim of the combined experiment is to measure the chemical composition of both the inflow and the outflow of the convection. The use of tracers with different lifetimes, including a range of short-lived halocarbons and hydrocarbons, should reveal a great deal about the mass fluxes of air from the lower troposphere to different altitudes in the TTL. This presentation describes the studies examining the composition and structure of the TTL, the plans for the aircraft and ground-based measurements, and the analyses to be used for interpretation. Examples of similar analyses based on the ATTREX measurements made in the East Pacific in February 2013 will be presented. These show the variability in the amount of air transported from the lower troposphere into the TTL calculated by the UK Met Office's NAME dispersion model as well as that model's ability to reproduce tracer distributions in the TTL.

  5. Emissions of methane, nitrous oxide, and other trace gases from rice fields in China

    NASA Astrophysics Data System (ADS)

    Khalil, M. A. K.; Rasmussen, R. A.; Shearer, M. J.; Chen, Zong-Liang; Yao, Heng; Yang, Jun

    1998-10-01

    We measured the emissions of methane, nitrous oxide, and other environmentally important trace gases from rice fields in China. The experiments were conducted near Beijing, representing temperate latitude rice agriculture, and at Guangzhou, representing tropical and subtropical agriculture. These studies complement our intensive research at Tu Zu in China (subtropical) and the work near Bogor, Indonesia, representing tropical rice agriculture. The experiments described here span 5 years between 1992 and 1996. The seasonally averaged methane emissions from Beijing were about 9 (5-16) mg m-2 h-1. Emissions from the first crop of the year at Guangzhou were about 5 (2-8) mg m-2 h-1 and about 30 (18-54) mg m-2 h-1 from the second crop. Measurements of nitrous oxide fluxes from the same rice fields show that emissions are confined to events that consist of high fluxes decaying to zero within a few days. Some of the events appear to be triggered by fertilizer applications. It is apparent that rice fields using nitrogen-based fertilizers are a source of N2O, but a robust estimate of whole season average emission rate is still not possible. The composite of all the N2O fluxes we observed gives a geometric mean of about 70 μg m-2 h-1. These rates are high enough to suggest that the rice fields could be a globally important source of N2O. As the agricultural practices change from use of organic fertilizers to nitrogen-based fertilizers, the role of N2O emissions from rice fields may become more important in its global budget. We also observed that chloroform and carbon monoxide were emitted from all fields studied. The flux of CO is not large enough to be important on the global scale, but the emissions of chloroform may be.

  6. Metagenomic evidence for metabolism of trace atmospheric gases by high-elevation desert Actinobacteria

    PubMed Central

    Lynch, Ryan C.; Darcy, John L.; Kane, Nolan C.; Nemergut, Diana R.; Schmidt, Steve K.

    2014-01-01

    Previous surveys of very dry Atacama Desert mineral soils have consistently revealed sparse communities of non-photosynthetic microbes. The functional nature of these microorganisms remains debatable given the harshness of the environment and low levels of biomass and diversity. The aim of this study was to gain an understanding of the phylogenetic community structure and metabolic potential of a low-diversity mineral soil metagenome that was collected from a high-elevation Atacama Desert volcano debris field. We pooled DNA extractions from over 15 g of volcanic material, and using whole genome shotgun sequencing, observed only 75–78 total 16S rRNA gene OTUs3%. The phylogenetic structure of this community is significantly under dispersed, with actinobacterial lineages making up 97.9–98.6% of the 16S rRNA genes, suggesting a high degree of environmental selection. Due to this low diversity and uneven community composition, we assembled and analyzed the metabolic pathways of the most abundant genome, a Pseudonocardia sp. (56–72% of total 16S genes). Our assembly and binning efforts yielded almost 4.9 Mb of Pseudonocardia sp. contigs, which accounts for an estimated 99.3% of its non-repetitive genomic content. This genome contains a limited array of carbohydrate catabolic pathways, but encodes for CO2 fixation via the Calvin cycle. The genome also encodes complete pathways for the catabolism of various trace gases (H2, CO and several organic C1 compounds) and the assimilation of ammonia and nitrate. We compared genomic content among related Pseudonocardia spp. and estimated rates of non-synonymous and synonymous nucleic acid substitutions between protein coding homologs. Collectively, these comparative analyses suggest that the community structure and various functional genes have undergone strong selection in the nutrient poor desert mineral soils and high-elevation atmospheric conditions. PMID:25566214

  7. Interannual variability of tropospheric trace gases and aerosols: The role of biomass burning emissions

    NASA Astrophysics Data System (ADS)

    Voulgarakis, Apostolos; Marlier, Miriam E.; Faluvegi, Greg; Shindell, Drew T.; Tsigaridis, Kostas; Mangeon, Stéphane

    2015-07-01

    Fires are responsible for a range of gaseous and aerosol emissions. However, their influence on the interannual variability of atmospheric trace gases and aerosols has not been systematically investigated from a global perspective. We examine biomass burning emissions as a driver of interannual variability of large-scale abundances of short-lived constituents such as carbon monoxide (CO), hydroxyl radicals (OH), ozone, and aerosols using the Goddard Institute for Space Studies ModelE composition-climate model and a range of observations, with an emphasis on satellite information. Our model captures the observed variability of the constituents examined in most cases, but with substantial underestimates in boreal regions. The strongest interannual variability on a global scale is found for carbon monoxide (~10% for its global annual burden), while the lowest is found for tropospheric ozone (~1% for its global annual burden). Regionally, aerosol optical depth shows the largest variability which exceeds 50%. Areas of strong variability of both aerosols and CO include the tropical land regions (especially Equatorial Asia and South America) and northern high latitudes, while even regions in the northern midlatitudes experience substantial interannual variability of aerosols. Ozone variability peaks over equatorial Asia in boreal autumn, partly due to varying biomass burning emissions, and over the western and central Pacific in the rest of the year, mainly due to meteorological fluctuations. We find that biomass burning emissions are almost entirely responsible for global CO interannual variability, and similarly important for OH variability. The same is true for global and regional aerosol variability, especially when not taking into account dust and sea-salt particles. We show that important implications can arise from such interannual influences for regional climate and air quality.

  8. Airborne measurements of different trace gases during the AROMAT-2 campaign with an Avantes spectrometer

    NASA Astrophysics Data System (ADS)

    Bösch, Tim; Meier, Andreas; Schönhardt, Anja; Peters, Enno; Richter, Andreas; Ruhtz, Thomas; Burrows, John

    2016-04-01

    Differential Optical Absorption Spectroscopy (DOAS) is a well-known, versatile, and frequently used technique for the analysis of trace gases within the atmosphere. Although DOAS has been used for several decades, airborne DOAS has become more popular during the last years because of the possibility of measuring in high lateral resolutions with the help of imaging instruments. Here, we present results of the AROMAT-2 campaign in Romania in summer 2015. The introduced measurements were taken using a nadir viewing Avantes spectrometer on board of a Cessna aircraft which flew over Bucharest and the Turceni power plant in Romania. The instrument covers the wavelength region of 287 - 551nm at a spectral resolution of 0.13nm and has a temporal resolution of 0.5s, translating to about 450m in flight direction at 3000m flight attitude. The field of view of the instrument was set to 8.1 degrees, resulting in a pixel size across track of about 420m. Compared to the imaging DOAS instrument AirMAP which was also operated from the aircraft, the signal to noise ratio of the simple nadir viewing spectrometer is slightly better, which allows an analysis of less abundant species and interesting spectral features. The results show a day-to-day variation of NO2 over the city of Bucharest as well as spectral features over lakes in the city, which can be attributed to algae. Furthermore, we were able to measure large emission plumes of NO2 and SO2 over the Turceni power plant, which could be observed over long spatial distances. In addition, the results from the Avantes instrument were used for comparison with measurements of the imaging spectrometer AirMAP and good agreement was found, providing independent verification of the imager data.

  9. Analysis of high-purity germanium dioxide by ETV-ICP-AES with preliminary concentration of trace elements.

    PubMed

    Medvedev, Nickolay S; Shaverina, Anastasiya V; Tsygankova, Alphiya R; Saprykin, Anatoly I

    2016-08-01

    The paper presents a combined technique of germanium dioxide analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) with preconcentration of trace elements by distilling off matrix and electrothermal (ETV) introduction of the trace elements concentrate into the ICP. Evaluation of metrological characteristics of the developed technique of high-purity germanium dioxide analysis was performed. The limits of detection (LODs) for 25 trace elements ranged from 0.05 to 20ng/g. The accuracy of proposed technique is confirmed by "added-found" («or spiking») experiment and comparing the results of ETV-ICP-AES and ICP-AES analysis of high purity germanium dioxide samples.

  10. Evolution of trace gases and particles emitted by a chaparral fire in California

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Craven, J. S.; Taylor, J. W.; McMeeking, G. R.; Yokelson, R. J.; Burling, I. R.; Urbanski, S. P.; Wold, C. E.; Seinfeld, J. H.; Coe, H.; Alvarado, M. J.; Weise, D. R.

    2011-08-01

    Biomass burning (BB) is a major global source of trace gases and particles. Accurately representing the production and evolution of these emissions is an important goal for atmospheric chemical transport models. We measured a suite of gases and aerosols emitted from an 81 ha prescribed fire in chaparral fuels on the central coast of California, US on 17 November 2009. We also measured post-emission chemical changes in the isolated downwind plume for ~4 h of smoke aging. The measurements were carried out on board a Twin Otter aircraft outfitted with an airborne Fourier transform infrared spectrometer (AFTIR), aerosol mass spectrometer (AMS), single particle soot photometer (SP2), nephelometer, LiCor CO2 analyzer, a chemiluminescence ozone instrument, and a wing-mounted meteorological probe. Our measurements included: CO2; CO; NOx; NH3; non-methane organic compounds; organic aerosol (OA); inorganic aerosol (nitrate, ammonium, sulfate, and chloride); aerosol light scattering; refractory black carbon (rBC); and ambient temperature, relative humidity, barometric pressure, and three-dimensional wind velocity. The molar ratio of excess O3 to excess CO in the plume (ΔO3/ΔCO) increased from -0.005 to 0.102 in 4.5 h. Excess acetic and formic acid (normalized to excess CO) increased by factors of 1.7 ± 0.4 and 7.3 ± 3.0 (respectively) over the same aging period. Based on the rapid decay of C2H4 we infer an in-plume average OH concentration of 5.3 (±1.0) × 106 molecules cm-3, consistent with previous studies showing elevated OH concentrations in biomass burning plumes. Ammonium, nitrate, and sulfate all increased with plume aging. The observed ammonium increase was a factor of 3.9 ± 2.6 in about 4 h, but accounted for just ~36 % of the gaseous ammonia lost on a molar basis. Some of the gas phase NH3 loss may have been due to condensation on, or formation of, particles below the AMS detection range. NOx was converted to PAN and particle nitrate with PAN production being

  11. Evolution of trace gases and particles emitted by a chaparral fire in California

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Craven, J. S.; Taylor, J. W.; McMeeking, G. R.; Yokelson, R. J.; Burling, I. R.; Urbanski, S. P.; Wold, C. E.; Seinfeld, J. H.; Coe, H.; Alvarado, M. J.; Weise, D. R.

    2012-02-01

    Biomass burning (BB) is a major global source of trace gases and particles. Accurately representing the production and evolution of these emissions is an important goal for atmospheric chemical transport models. We measured a suite of gases and aerosols emitted from an 81 hectare prescribed fire in chaparral fuels on the central coast of California, US on 17 November 2009. We also measured physical and chemical changes that occurred in the isolated downwind plume in the first ~4 h after emission. The measurements were carried out onboard a Twin Otter aircraft outfitted with an airborne Fourier transform infrared spectrometer (AFTIR), aerosol mass spectrometer (AMS), single particle soot photometer (SP2), nephelometer, LiCor CO2 analyzer, a chemiluminescence ozone instrument, and a wing-mounted meteorological probe. Our measurements included: CO2; CO; NOx; NH3; non-methane organic compounds; organic aerosol (OA); inorganic aerosol (nitrate, ammonium, sulfate, and chloride); aerosol light scattering; refractory black carbon (rBC); and ambient temperature, relative humidity, barometric pressure, and three-dimensional wind velocity. The molar ratio of excess O3 to excess CO in the plume (ΔO3/ΔCO) increased from -5.13 (±1.13) × 10-3 to 10.2 (±2.16) × 10-2 in ~4.5 h following smoke emission. Excess acetic and formic acid (normalized to excess CO) increased by factors of 1.73 ± 0.43 and 7.34 ± 3.03 (respectively) over the same time since emission. Based on the rapid decay of C2H4 we infer an in-plume average OH concentration of 5.27 (±0.97) × 106 molec cm-3, consistent with previous studies showing elevated OH concentrations in biomass burning plumes. Ammonium, nitrate, and sulfate all increased over the course of 4 h. The observed ammonium increase was a factor of 3.90 ± 2.93 in about 4 h, but accounted for just ~36% of the gaseous ammonia lost on a molar basis. Some of the gas phase NH3 loss may have been due to condensation on, or formation of, particles

  12. Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania, 41° S

    NASA Astrophysics Data System (ADS)

    Lawson, S. J.; Keywood, M. D.; Galbally, I. E.; Gras, J. L.; Cainey, J. M.; Cope, M. E.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Bentley, S. T.; Meyer, C. P.; Ristovski, Z.; Goldstein, A. H.

    2015-07-01

    with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2-4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meterological events on BB emissions. Emission factors (EF) were derived for a range of trace gases, some never before reported for Australian conditions, (including hydrogen, phenol and toluene) using a calculated ER to CO and a published CO EF. The EF derived for most species are comparable to other temperate Australian studies but lower than Northern Hemisphere temperate studies. This work demonstrates the substantial impact that BB plumes have on the composition of marine air, and the significant changes that can occur as the plume is diluted and interacts with other emission sources. We also provide new trace gas and particle EF for temperate southern Australia.

  13. Summer 2009 wildfires in Portugal: Emission of trace gases and aerosol composition

    NASA Astrophysics Data System (ADS)

    Alves, Célia; Vicente, Ana; Nunes, Teresa; Gonçalves, Cátia; Fernandes, Ana Patrícia; Mirante, Fátima; Tarelho, Luís; Sánchez de la Campa, Ana M.; Querol, Xavier; Caseiro, Alexandre; Monteiro, Cristina; Evtyugina, Margarita; Pio, Casimiro

    2011-01-01

    In summer 2009, emissions of trace gases and aerosols from several wildfires occurring in Portugal were sampled. A portable high-volume sampler was used to collect sequentially, on quartz fibre filters, coarse (PM 2.5-10) and fine (PM 2.5) smoke particles. Tedlar air sampling bags have been used for complementary chemical characterisation of the gaseous phase. The carbonaceous content (elemental and organic carbon, EC/OC) of particulate matter was analysed by a thermal-optical transmission technique. The levels of almost 50 elements were quantified by inductively coupled plasma-mass spectrometry. The water-soluble ions were obtained by ion chromatography. Emission factors of species that are favoured by the smouldering phase (e.g. CO) were above the values reported in the literature for biomass burning in other ecosystems. The CO emission factors were 231 ± 117 g kg -1 biomass (dry basis) burned. Emissions of compounds that are promoted in fresh plumes and during the flaming phase, such as CO 2, were generally lower than those proposed for savannah and tropical forest fires. The CO 2 emission factors ranged from about 1000 to 1700 g kg -1. Total hydrocarbons, PM 2.5, PM 10 and OC presented variable emissions, but in general substantially higher than values reported for wildfires in African and Amazonian biomes. The emission factors obtained in Portugal were as follows (in g kg -1 biomass, dry basis): 6-350 for total hydrocarbons, 0.5-42 for PM 2.5, 1-60 for PM 10, and 0.2-42 for OC (in PM 10). The organic carbon-to-elemental carbon ratios measured in the present study largely exceeded those obtained by other researchers. The aerosol mass was dominated by organic matter (OC/PM 2.5 = 50 ± 18%, OC/PM 2.5-10 = 36 ± 18%). The metal elements represented, on average, 1.23 and 0.91%, while the measured water-soluble ions accounted for 2.6 and 2.1% of the PM 2.5 and PM 2.5-10 mass, respectively. Carbonates accounted for 0.15-3.1% (average = 0.83%) of PM 2.5-10. The

  14. Black carbon and trace gases over South Asia: Measurements and Regional Climate model simulations

    NASA Astrophysics Data System (ADS)

    Bhuyan, Pradip; Pathak, Binita; Parottil, Ajay

    2016-07-01

    Trace gases and aerosols are simulated with 50 km spatial resolution over South Asian CORDEX domain enclosing the Indian sub-continent and North-East India for the year 2012 using two regional climate models RegCM4 coupled with CLM4.5 and WRF-Chem 3.5. Both models are found to capture the seasonality in the simulated O3 and its precursors, NOx and CO and black carbon concentrations together with the meteorological variables over the Indian Subcontinent as well as over the sub-Himalayan North-Eastern region of India including Bangladesh. The model simulations are compared with the measurements made at Dibrugarh (27.3°N, 94.6°E, 111 m amsl). Both the models are found to capture the observed diurnal and seasonal variations in O3 concentrations with maximum in spring and minimum in monsoon, the correlation being better for WRF-Chem (R~0.77) than RegCM (R~0.54). Simulated NOx and CO is underestimated in all the seasons by both the models, the performance being better in the case of WRF-Chem. The observed difference may be contributed by the bias in the estimation of the O3 precursors NOx and CO in the emission inventories or the error in the simulation of the meteorological variables which influences O3 concentration in both the models. For example, in the pre-monsoon and winter season, the WRF-Chem model simulated shortwave flux overestimates the observation by ~500 Wm-2 while in the monsoon and post monsoon season, simulated shortwave flux is equivalent to the observation. The model predicts higher wind speed in all the seasons especially during night-time. In the post-monsoon and winter season, the simulated wind pattern is reverse to observation with daytime low and night-time high values. Rainfall is overestimated in all the seasons. RegCM-CLM4.5 is found to underestimate rainfall and other meteorological parameters. The WRF-Chem model closely captured the observed values of black carbon mass concentrations during pre-monsoon and summer monsoon seasons, but

  15. Characteristics of aerosol particles and trace gases in ship exhaust plumes

    NASA Astrophysics Data System (ADS)

    Drewnick, F.; Diesch, J.; Borrmann, S.

    2011-12-01

    Gaseous and particulate matter from marine vessels gain increasing attention due to their significant contribution to the anthropogenic burden of the atmosphere, implying the change of the atmospheric composition and the impact on local and regional air quality and climate (Eyring et al., 2010). As ship emissions significantly affect air quality of onshore regions, this study deals with various aspects of gas and particulate plumes from marine traffic measured near the Elbe river mouth in northern Germany. In addition to a detailed investigation of the chemical and physical particle properties from different types of commercial marine vessels, we will focus on the chemistry of ship plumes and their changes while undergoing atmospheric processing. Measurements of the ambient aerosol, various trace gases and meteorological parameters using a mobile laboratory (MoLa) were performed on the banks of the Lower Elbe which is passed on average, daily by 30 ocean-going vessels reaching the port of Hamburg, the second largest freight port of Europe. During 5 days of sampling from April 25-30, 2011 170 commercial marine vessels were probed at a distance of about 1.5-2 km with high temporal resolution. Mass concentrations in PM1, PM2.5 and PM10 and number as well as PAH and black carbon (BC) concentrations in PM1 were measured; size distribution instruments covered the size range from 6 nm up to 32 μm. The chemical composition of the non-refractory aerosol in the submicron range was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase species analyzers monitored various trace gas concentrations in the air and a weather station provided meteorological parameters. Additionally, a wide spectrum of ship information for each vessel including speed, size, vessel type, fuel type, gross tonnage and engine power was recorded via Automatic Identification System (AIS) broadcasts. Although commercial marine vessels powered by diesel engines consume high

  16. Separation of carbon dioxide and sulfur dioxide gases using room-temperature ionic liquid (hmim)(Tf2N)

    SciTech Connect

    A. Yokozeki; Mark B. Shiflett

    2009-09-15

    To understand capturing and/or enhanced gaseous selectivity of industrial flue gases containing CO{sub 2} and SO{sub 2} using room-temperature ionic liquids, we have developed a ternary equation of state (EOS) model for a CO{sub 2}/SO{sub 2}/1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ((hmim)(Tf2N)) system. The present model is based on a generic RK (Redlich-Kwong) EOS, with empirical binary interaction parameters of each binary system. These interaction parameters have been determined using our measured VLE (vapor-liquid-equilibrium) data for SO{sub 2}/(hmim)(Tf2N) and CO{sub 2}/(hmim)(Tf2N) and literature data for CO{sub 2}/SO{sub 2}. The validity of the present EOS has been checked by conducting ternary VLE experiments for the present system. With this EOS, isothermal ternary phase diagrams and solubility (VLE) behaviors have been calculated for various (T, P, and feed compositions) conditions. For large and equimolar CO{sub 2}/SO{sub 2} mole ratios, the gaseous selectivity is nearly independent of the amount of the ionic liquid addition. However, for small CO{sub 2}/SO{sub 2} mole ratios the addition of the ionic liquid significantly increases the selectivity. The strong absorption of CO{sub 2} and SO{sub 2} in this ionic liquid may be practical for the simultaneous capture of these acid gases. 39 refs., 8 figs., 4 tabs.

  17. Application of ion chemistry and the SIFT technique to the quantitative analysis of trace gases in air and on breath

    NASA Astrophysics Data System (ADS)

    Smith, David; Španěl, Patrik

    Our major objective in this paper is to describe a new method we have developed for the analysis of trace gases at partial pressures down to the ppb level in atmospheric air, with special emphasis on the detection and quantification of trace gases on human breath. It involves the use of our selected ion flow tube (Sift) technique which we previously developed and used extensively for the study of gas phase ionic reactions occurring in ionized media such as the terrestrial atmosphere and interstellar gas clouds. Before discussing this analytical technique we describe the results of our very recent Sift and flowing afterglow (FA) studies of the reactions of the H3O+ and OH- ions, of their hydrates H3O+(H2O)1,2,3 and OH- (H2O)1,2, and of NO+ and O2+, with several hydrocarbons and oxygen-bearing organic molecules, studies that are very relevant to our trace gas analytical studies. Then follows a detailed discussion of the application of our Sift technique to trace gas analysis, after which we present some results obtained for the analyses of laboratory air, the breath of a healthy non-smoking person, the breath of a person who regularly smokes cigarettes, the complex vapours emitted by banana and onion, and the molecules present in a butane/air flame. We show how the quantitative analysis of breath can be achieved from only a single exhalation and in real time (the time response of the instrument is only about 20 ms). We also show how the time variation of breath gases over long time periods can be followed, using the decay of ethanol on the breath after the ingestion of distilled liquor as an example, yet simultaneously following several other trace gases including acetone and isoprene which are very easily detected on the breath of all individuals because of their relatively high partial pressures (typically 100 to 1000 ppb). The breath of a smoker is richer in complex molecules, some nitrogen containing organics apparently being very evident at the 5 to 50 ppb level

  18. Analysis of the horizontal distributions of trace gases and aerosols in summer 2013 during the MADCAT campaign in Mainz, Germany

    NASA Astrophysics Data System (ADS)

    Remmers, Julia; Beirle, Steffen; Wagner, Thomas

    2016-04-01

    With the MAX-DOAS technique it is possible to retrieve vertical profiles of trace gases and aerosols in the lower troposphere. Often these instruments monitor the atmosphere in one azimuthal direction only. Therefore horizontal variability is not resolved. Especially the comparison to satellite data close to strong emission sources (one main application of MAX-DOAS) is possibly biased. Many new developed MAX-DOAS instruments are capable to measure automatically in more than one azimuthal direction. During the MADCAT campaign in summer 2013 in Mainz, Germany, several instruments of this kind were operated simultaneously, which provides the opportunity to monitor the horizontal distribution of trace gases and aerosols with a high temporal and spatial resolution. The observed variation for different azimuth angles does not only reflect gradients in the trace gas concentrations, but also differences in the light path length, which is affected by sun and viewing geometry as well as aerosol distribution. Information about the aerosol profile, the total AOD and the phase function is gathered from a Ceilometer and an Aeronet sun photometer on the same site. To distinguish between the different effects comparisons with radiative transfer models are performed. Here especially the influence of the simplified model of Henyey-Greenstein phase functions against measured phase functions from Aeronet is investigated. Also the influence on the observed azimuthal gradients of different wind patterns and cloud conditions is studied.

  19. Oil and gas exploration system and method for detecting trace amounts of hydrocarbon gases in the atmosphere

    DOEpatents

    Wamsley, Paula R.; Weimer, Carl S.; Nelson, Loren D.; O'Brien, Martin J.

    2003-01-01

    An oil and gas exploration system and method for land and airborne operations, the system and method used for locating subsurface hydrocarbon deposits based upon a remote detection of trace amounts of gases in the atmosphere. The detection of one or more target gases in the atmosphere is used to indicate a possible subsurface oil and gas deposit. By mapping a plurality of gas targets over a selected survey area, the survey area can be analyzed for measurable concentration anomalies. The anomalies are interpreted along with other exploration data to evaluate the value of an underground deposit. The system includes a differential absorption lidar (DIAL) system with a spectroscopic grade laser light and a light detector. The laser light is continuously tunable in a mid-infrared range, 2 to 5 micrometers, for choosing appropriate wavelengths to measure different gases and avoid absorption bands of interference gases. The laser light has sufficient optical energy to measure atmospheric concentrations of a gas over a path as long as a mile and greater. The detection of the gas is based on optical absorption measurements at specific wavelengths in the open atmosphere. Light that is detected using the light detector contains an absorption signature acquired as the light travels through the atmosphere from the laser source and back to the light detector. The absorption signature of each gas is processed and then analyzed to determine if a potential anomaly exists.

  20. Oceanic Trace Gases Numeric Data Packages from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products include numeric data packages, publications, trend data, atlases, models, etc. and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Most data sets or packages, many with numerous data files, are free to download from CDIAC's ftp area. The collection provides access to the Oceanographic Numeric Data Packages (NDPs).

  1. Shock-tube thermochemistry tables for high-temperature gases. Volume 5: Carbon dioxide

    NASA Technical Reports Server (NTRS)

    Menard, W. A.; Horton, T. E.

    1971-01-01

    Equilibrium thermodynamic properties and species concentrations for carbon dioxide are tabulated for moving, standing, and reflected shock waves. Initial pressures range from 6.665 to 6665 N/sq m (0.05 to 50.0 torr), and temperatures from 2,000 to over 80,000K. In this study, 20 molecular and atomic species were considered.

  2. Trace rare gases optical emission spectroscopy: nonintrusive method for measuring electron temperatures in low-pressure, low-temperature plasmas.

    PubMed

    Malyshev, M V; Donnelly, V M

    1999-11-01

    Trace rare gases optical emission spectroscopy (TRG-OES) is a new, nonintrusive method for determining electron temperatures (T(e)) and, under some conditions, estimating electron densities (n(e)) in low-temperature, low-pressure plasmas. The method is based on a comparison of atomic emission intensities from trace amounts of rare gases (an equimixture of He, Ne, Ar, Kr, and Xe) added to the plasma, with intensities calculated from a model. For Maxwellian electron energy distribution functions (EEDFs), T(e) is determined from the best fit of theory to the experimental measurements. For non-Maxwellian EEDFs, T(e) derived from the best fit describes the high-energy tail of the EEDF. This method was reported previously, and was further developed and successfully applied to several laboratory and commercial plasma reactors. It has also been used in investigations of correlations between high-T(e) and plasma-induced damage to thin gate oxide layers. In this paper, we provide a refined mechanism for the method and include a detailed description of the generation of emission from the Paschen 2p manifold of rare gases both from the ground state and through metastable states, a theoretical model to calculate the number density of metastables (n(m)) of the rare gases, a practical procedure to compute T(e) from the ratios of experimental-to-theoretical intensity ratios, a way to determine the electron density (n(e)), a discussion of the range of sensitivity of TRG-OES to the EEDF, and an estimate of the accuracy of T(e). The values of T(e) obtained by TRG-OES in a transformer-coupled plasma reactor are compared with those obtained with a Langmuir probe for a wide range of pressures and powers. The differences in T(e) from the two methods are explained in terms of the EEDF dependence on pressure.

  3. Adsorption and dissociation of acidic trace gases on ice surfaces - caught in the act with core level spectroscopy

    NASA Astrophysics Data System (ADS)

    Waldner, Astrid; Orlando, Fabrizio; Ammann, Markus; Kleibert, Armin; Huthwelker, Thomas; Peter, Thomas; Bartels-Rausch, Thorsten

    2015-04-01

    Chemistry and physical processes in Earth's ice and snow cover can change the composition of the atmosphere and the contaminant content of the cryosphere. They have thus direct impacts on geochemical cycles and the climate system. Our ability to predict the fate of chemicals in snow or air masses in exchange with the cryosphere on a regional scale or to model those in snow chemistry models is currently hampered by our limited understanding of the underlying mechanisms on a molecular level. So far, direct experimental observations under environmentally relevant conditions of the ice surface and of the adsorption of trace gases to it are very limited. The unique approach of this study is to combine two surface sensitive spectroscopic methods to directly probe the hydrogen-bonding network at the ice surface ( ~1 nm depth) and the concentration, depth profile (~1 to 10 nm), and dissociation degree of the dopant. We present first core-electron photoemission (XPS) and partial electron yield X-ray absorption (NEXAFS) measurements of formic acid adsorbed to ice at 240 K. The analysis of oxygen NEXAFS spectra reveals information on changes in the hydrogen-bonding network of the ice surface upon adsorption of formic acid. Depth profiles based on XPS measurements indicate that the adsorbed acid stays at the ice surface. Furthermore we obtained a preliminary estimation of the degree of formic acid dissociation at the ice surface. Results are compared to earlier core-electron studies of several trace gases adsorbed to ice at 240 K and compared to results from more traditional method to and snow to reveal fundamental aspects of the ice surface and how it interacts with dopants. Even with the focus on adsorption of acidic trace gases to ice, results of this study will thus be of high relevance also for other chemical processes in ice and snow. This is of interest not only in environmental science but also in material science, cryobiology, and astrophysics.

  4. An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems

    NASA Astrophysics Data System (ADS)

    Pape, L.; Ammann, C.; Nyfeler-Brunner, A.; Spirig, C.; Hens, K.; Meixner, F. X.

    2009-03-01

    We present an automated dynamic chamber system which is optimised for continuous unattended flux measurements of multiple non-reactive and reactive trace gases on grassland ecosystems. Main design features of our system are (a) highly transparent chamber walls consisting of chemically inert material, (b) individual purging flow units for each chamber, and (c) a movable lid for automated opening and closing of the chamber. The purging flow rate was chosen high enough to keep the mean residence time of the chamber air below one minute. This guarantees a proven efficient mixing of the chamber volume and a fast equilibration after lid closing. The dynamic chamber system is able to measure emission as well as deposition fluxes of trace gases. For the latter case, the modification of the turbulent transport by the chamber (compared to undisturbed ambient conditions) is quantitatively described by a bulk resistance concept. Beside a detailed description of the design and functioning of the system, results of field applications at two grassland sites are presented. In the first experiment, fluxes of five trace gases (CO2, H2O, NO, NO2, O3) were measured simultaneously on small grassland plots. It showed that the dynamic chamber system is able to detect the characteristic diurnal cycles with a sufficient temporal resolution. The results also demonstrated the importance of considering the chemical source/sink in the chamber due to gas phase reactions for the reactive compounds of the NO-NO2-O3 triad. In a second field experiment, chamber flux measurements of CO2 and methanol were compared to simultaneous independent eddy covariance flux measurements on the field scale. The fluxes obtained with the two methods showed a very good agreement indicating a minimal disturbance of the chambers on the physiological activity of the enclosed vegetation.

  5. An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems

    NASA Astrophysics Data System (ADS)

    Pape, L.; Ammann, C.; Nyfeler-Brunner, A.; Spirig, C.; Hens, K.; Meixner, F. X.

    2008-08-01

    We present an automated dynamic chamber system which is optimised for continuous unattended flux measurements of multiple non-reactive and reactive trace gases on grassland ecosystems. Main design features of our system are (a) highly transparent chamber walls consisting of chemically inert material, (b) individual purging flow units for each chamber, and (c) a movable lid for automated opening and closing of the chamber. The purging flow rate was chosen high enough to keep the mean residence time of the chamber air below one minute. This guarantees a proven efficient mixing of the chamber volume and a fast equilibration after lid closing. The dynamic chamber system is able to measure emission as well as deposition fluxes of trace gases. For the latter case, the modification of the turbulent transport by the chamber (compared to undisturbed ambient conditions) is quantitatively described by a bulk resistance concept. Beside a detailed description of the design and functioning of the system, results of field applications at two grassland sites are presented. In the first experiment, fluxes of five trace gases (CO2, H2O, NO, NO2, O3) were measured simultaneously on small grassland plots. It showed that the dynamic chamber system is able to detect the characteristic diurnal cycles with a sufficient temporal resolution. The results also demonstrated the importance of considering the chemical source/sink in the chamber due to gas phase reactions for the reactive compounds of the NO-NO2-O3 triad. In a second field experiment, chamber flux measurements of CO2 and methanol were compared to simultaneous independent eddy covariance flux measurements on the field scale. The fluxes obtained with the two methods showed a very good agreement indicating a minimal disturbance of the chambers on the physiological activity of the enclosed vegetation.

  6. Characteristics of trace gases and aerosols at top of urban canopy layer in Nanjing of China from one year observational study

    NASA Astrophysics Data System (ADS)

    Wang, Tijian

    2013-04-01

    To understand the physical and chemical processes of air pollution formation in urban and their linkage with climate change in Yangtze River Delta(YRD), the fast developing area in China, a monitoring site was built on the top of a high building in the center of Nanjing. The site was set up to investigate the long term variations of trace gases and aerosols, which may play important roles in air pollution and climate change in regional scale. From one year measurement records, the annual average concentrations of ozone, sulfur dioxide, carbon monoxide, carbon dioxide, nitric oxide, total reactive nitrogen, water vapor are reported as 161.9±19.4 ppb, 93.8±8.9 ppb, 3856.7±412.1 ppb, 565.1±20.0 ppm, 173.6±15.6 ppb, 230.8±24.9 ppb, 34.76±7.2x10-3, respectively. PM10, PM2.5, visibility, black carbon, back scattering of particles(BSP), single scattering albedo(SSA), aerosol optical depth(AOD) and Angstrom wavelength exponent (AWE) are 115±113.1 μg/m3, 54±46.1 μg/m3, 9780±5594 m, 3055.9±2102.3 ng/m3, 66.3±97.5 Mm-1, 0.5±2.4, 0.7±0.38 and 1.22±0.28, respectively. Measurement show that the levels of air pollutants in YRD in East China are high compared to Pearl River Delta(PRD) in South China and Jing-Jin-Ji (JJJ) in North China, suggesting a possible stronger effect on atmospheric environment, climate change and human health in this region, which should be further addressed in the future study.

  7. Utilization of carbon dioxide in industrial flue gases for the cultivation of microalga Chlorella sp.

    PubMed

    Kao, Chien-Ya; Chen, Tsai-Yu; Chang, Yu-Bin; Chiu, Tzai-Wen; Lin, Hsiun-Yu; Chen, Chun-Da; Chang, Jo-Shu; Lin, Chih-Sheng

    2014-08-01

    The biomass and lipid productivity of Chlorella sp. MTF-15 cultivated using aeration with flue gases from a coke oven, hot stove or power plant in a steel plant of the China Steel Corporation in Taiwan were investigated. Using the flue gas from the coke oven, hot stove or power plant for cultivation, the microalgal strain obtained a maximum specific growth rate and lipid production of (0.827 d(-1), 0.688 g L(-1)), (0.762 d(-1), 0.961 g L(-1)), and (0.728 d(-1), 0.792 g L(-1)), respectively. This study demonstrated that Chlorella sp. MTF-15 could efficiently utilize the CO₂, NOX and SO₂ present in the different flue gases. The results also showed that the growth potential, lipid production and fatty acid composition of the microalgal strain were dependent on the composition of the flue gas and on the operating strategy deployed.

  8. Dynamics of a geothermal field traced by noble gases: Cerro Prieto, Mexico

    SciTech Connect

    Mazor, E.; Truesdell, A.H.

    1981-01-01

    Noble gases have been measured mass spectrometrically in samples collected during 1977 from producing wells at Cerro Prieto. Positive correlations between concentrations of radiogenic (He, /sup 40/Ar) and atmospheric noble gases (Ne, Ar, and Kr) suggest the following dynamic model: the geothermal fluids originated from meteoric water penetrated to more than 2500 m depth (below the level of first boiling) and mixed with radiogenic helium and argon-40 formed in the aquifer rocks. Subsequently, small amounts of steam were lost by a Raleigh process (0 to 3%) and mixing with shallow cold water occurred (0 to 30%). Noble gases are sensitive tracers of boiling in the initial stages of 0 to 3% steam separation and complement other tracers, such as Cl or temperature, which are effective only beyond this range.

  9. Dynamics of a geothermal field traced by noble gases: Cerro Prieto, Mexico

    USGS Publications Warehouse

    Mazor, E.; Truesdell, A.H.

    1984-01-01

    Noble gases have been measured mass spectrometrically in samples collected during 1977 from producing wells at Cerro Prieto. Positive correlations between concentrations of radiogenic (He and 40Ar) and atmospheric noble gases (Ne, Ar and Kr) suggest the following dynamic model: the geothermal fluids originated from meteoric water that penetrated to more than 2500 m depth (below the level of first boiling) and mixed with radiogenic He and 40Ar formed in the aquifer rocks. Subsequently, small amounts of steam were lost by a Raleigh process (0 - 30%) and mixing with shallow cold water occurred (0 - 30%). Noble gases are sensitive tracers of boiling in the initial stages of 0 - 3% steam separation and complement other tracers, such as C1 or temperature, which are effective only beyond this range. ?? 1984.

  10. Analysis of trace gases at ppb levels by proton transfer reaction mass spectrometry (PTR-MS)

    NASA Astrophysics Data System (ADS)

    Lindinger, W.; Hansel, A.

    1997-05-01

    A proton transfer reaction mass spectrometry (PTR-MS) system has been developed which allows for on-line measurements of trace gas components with concentrations as low as 1 ppb. The method is based on reactions of 0963-0252/6/2/004/img1 ions, which perform non-dissociative proton transfer to most of the common organic trace constituents but do not react with any of the components present in clean air. Examples of medical applications by means of breath analysis, examples of environmental trace gas analysis and examples in the field of food chemistry demonstrate the wide applicability of the method.

  11. Atmos/Atlas 3 Infrared Profile Measurements of Trace Gases in The November 1994 Tropical and Subtropical Upper Troposphere

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Gunson, M. R.; Wang, P.-H.; Arduini, R. F.; Baum, B. A.; Minnis, P.; Minnis, P.; Goldman, A.; Abrams, M. C.; Zander, R.; Mahieu, E.; Mahieu, E.; Salawitch, R. J.; Michelsen, H. A.; Irion, F. W.; Newchurch, M. J.

    1998-01-01

    Vertical mixing ratio profiles of four relatively long-lives gases, HCN, C2H2, CO, and C2H6, have been retrieved from 0.01/cm resolution infrared solar occultation spectra recorded between latitudes of 5.3degN and 31.4degN. The observations were obtained by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer during the Atmospheric Laboratory for Applications and Science (ATLAS) 3 shuttle flight, 3-12 November 1994. Elevated mixing ratios below the tropopause were measured for these gases during several of the occultations. The positive correlations obtained between the simultaneously measured mixing ratios suggest that the enhancements are likely the result of surface emissions, most likely biomass burning and/or urban industrial activities, followed by common injection via deep convective transport of the gases to the upper troposphere. The elevated levels of HCN may account for at least part of the "missing NO," in the upper troposphere. Comparisons of the observations with values measured during a recent aircraft campaign are presented.

  12. Long-term MAX-DOAS measurement of trace gases and aerosol in the Environmental Research Station Schneefernerhaus

    NASA Astrophysics Data System (ADS)

    Wang, Zhuoru; Hao, Nan; Hendrick, François; Van Roozendael, Michel; Holla, Robert; Valks, Pieter

    2016-04-01

    The Environmental Research Station Schneefernerhaus (Umwelt Forschungsstation Schneefernerhaus, UFS) is located immediately under the summit of Zugspitze (2962 m), the highest mountain of Germany, at a height of 2650 m. The UFS is a rare observation site in Germany with mostly clean and unpolluted air. It is ideal for both stratospheric composition measurements and trace gas measurements in the free-troposphere. It is optimal for detecting pollution events in the free-troposphere, which are indications of short- or long-range transport of air pollutants. A MAX-DOAS instrument has been working in the UFS since February 2011. With the zenith spectrum of each cycle used as the reference, the differential slant column densities (DSCDs) of trace gases are calculated from the spectra with Differential Optical Absorption Spectroscopy (DOAS) method. The DSCDs of both O4 and NO2 are calculated in two different wavelength intervals, 338-370 nm in the UV region and 440-490 nm in the VIS region. For HCHO and HONO, optimal fitting windows have been determined in the UV region. A retrieval algorithm, based on the radiative transfer model LIDORT and the optimal estimation technique, is used to provide information on the vertical profiles and vertical column densities (VCDs) of aerosol and trace gases. Meanwhile, zenith-sky radiance spectra during twilight hours are analyzed using DOAS method to derive the total vertical column densities (VCDs) of O3 and NO2. A zenith spectrum measured in the noon of a summer day was chosen as the reference spectrum. The slant column densities (SCDs) of O3 and NO2, which are the direct product of the DOAS analysis, are then converted into VCDs using the air mass factors (AMFs) derived by radiative transfer calculations. This work presents the results of the MAX-DOAS measurement in the UFS from 2012 to 2015, including aerosol (derived from O4 measurement), NO2, HCHO, and HONO, etc. The vertical profiles as well as the seasonal and diurnal variation

  13. Tracing the Complex Ice Cover Evolution of Lake Vida, Antarctica Through Noble Gases

    NASA Astrophysics Data System (ADS)

    Malone, J. L.; Castro, M. C.; Hall, C. M.; Doran, P. T.; Kenig, F.; McKay, C. P.

    2008-12-01

    Unlike other lakes in the McMurdo Dry Valleys in Antarctica, Lake Vida has a very thick (~19 m) ice cover and a liquid brine body of unusually high salinity (~245 g/L). Because noble gases (He, Ne, Ar, Kr and Xe) are conservative in nature, they can be used to understand physical processes taking place during ice formation (e.g., partitioning of noble gases between the ice and residual liquid, bubble formation at the ice-liquid interface) thus, providing information with respect to the temporal evolution of the dry valley lakes. In an attempt to constrain the conditions under which the atypical Lake Vida ice cover formed and evolved, we collected 19 ice samples along a vertical profile from the surface down to a depth of ~14 m as well as three liquid brine samples from briny ice at a depth of ~16 m for analysis of all noble gases. Our results show that the broad pattern of noble gas concentrations for the Lake Vida ice cover and associated brines is fundamentally different from that expected for air saturated water (ASW). Overall, ice samples are relatively enriched in He, slightly depleted in Ne, and strongly depleted in the heavier noble gases (Ar, Kr, Xe) with respect to ASW. By contrast, brine samples are very enriched in heavy noble gases. To understand the mechanisms responsible for the observed noble gas distribution and fractionation in the Lake Vida cover, a conceptual three-phase (ice, brine, bubbles) partition model was tested. The model allows the lighter noble gases (He and Ne) to reside interstitially in ice while Ar, Kr, and Xe are totally excluded, causing supersaturation in the residual liquid as freezing progresses and formation of gas bubbles occurs at the ice-liquid interface. These bubbles are subsequently incorporated into the ice. While the general noble gas enrichment and depletion patterns of the model are consistent with our brine and ice data, quantitative agreement with output values is not as good under similar model conditions (e

  14. Origin and migration of hydrocarbon gases and carbon dioxide, Bekes Basin, southeastern Hungary

    USGS Publications Warehouse

    Clayton, J.L.; Spencer, C.W.; Koncz, I.; Szalay, A.

    1990-01-01

    The Bekes Basin is a sub-basin within the Pannonian Basin, containing about 7000 m of post-Cretaceous sedimentary rocks. Natural gases are produced from reservoirs (Precambrian to Tertiary in age) located on structural highs around the margins of the basin. Gas composition and stable carbon isotopic data indicate that most of the flammable gases were derived from humic kerogen contained in source rocks located in the deep basin. The depth of gas generation and vertical migration distances were estimated using quantitative source rock maturity-carbon isotope relationships for methane compared to known Neogene source rock maturity-depth relationships in the basin. These calculations indicate that as much as 3500 m of vertical migration has occured in some cases. Isotopically heavy (> - 7 > 0) CO2 is the predominant species present in some shallow reservoirs located on basin-margin structural highs and has probably been derived via long-distance vertical and lateral migration from thermal decompositon of carbonate minerals in Mesozoic and older rocks in the deepest parts of the basin. A few shallow reservoirs (< 2000m) contain isotopically light (-50 to -60%0) methane with only minor amounts of C2+ homologs (< 3% v/v). This methane is probably mostly microbial in origin. Above-normal pressures, occuring at depths greater than 1800 m, are believed to be the principal driving force for lateral and vertical gas migration. These pressures are caused in part by active hydrocarbon generation, undercompaction, and thermal decomposition of carbonates. 

  15. Carbon dioxide removal from flue gases by absorption/ desorption in aqueous diethanolamine solutions.

    PubMed

    Kierzkowska-Pawlak, Hanna; Chacuk, Andrzej

    2010-08-01

    The carbon dioxide (CO2) desorption rate from CO2- loaded aqueous diethanolamine (DEA) solutions was measured using a stirred cell with a flat gas-liquid interface. The measurements were performed in the temperature range of 293.15-313.15 K and an amine concentration range of 10-20% mass DEA. Measurements were based on a semibatch isothermal absorption of the gas until the equilibrium state was reached, followed by desorption, which was initiated by the pressure release in the system. A simplified mass transfer model based on the film theory coupled with CO2, mass balance was developed to interpret the experimental data. On the basis of the proposed model, the initial mass transfer rates were calculated from the experimental results. The calculated initial desorption rates enabled estimation of the enhancement factor for CO2 mass transfer from aqueous DEA solutions. Analysis of the experimental data showed that desorption took place in the diffusive mass transfer regime.

  16. Carbon dioxide separation from flue gases: a technological review emphasizing reduction in greenhouse gas emissions.

    PubMed

    Songolzadeh, Mohammad; Soleimani, Mansooreh; Takht Ravanchi, Maryam; Songolzadeh, Reza

    2014-01-01

    Increasing concentrations of greenhouse gases (GHGs) such as CO2 in the atmosphere is a global warming. Human activities are a major cause of increased CO2 concentration in atmosphere, as in recent decade, two-third of greenhouse effect was caused by human activities. Carbon capture and storage (CCS) is a major strategy that can be used to reduce GHGs emission. There are three methods for CCS: pre-combustion capture, oxy-fuel process, and post-combustion capture. Among them, post-combustion capture is the most important one because it offers flexibility and it can be easily added to the operational units. Various technologies are used for CO2 capture, some of them include: absorption, adsorption, cryogenic distillation, and membrane separation. In this paper, various technologies for post-combustion are compared and the best condition for using each technology is identified. PMID:24696663

  17. Carbon Dioxide Separation from Flue Gases: A Technological Review Emphasizing Reduction in Greenhouse Gas Emissions

    PubMed Central

    Songolzadeh, Mohammad; Soleimani, Mansooreh; Takht Ravanchi, Maryam; Songolzadeh, Reza

    2014-01-01

    Increasing concentrations of greenhouse gases (GHGs) such as CO2 in the atmosphere is a global warming. Human activities are a major cause of increased CO2 concentration in atmosphere, as in recent decade, two-third of greenhouse effect was caused by human activities. Carbon capture and storage (CCS) is a major strategy that can be used to reduce GHGs emission. There are three methods for CCS: pre-combustion capture, oxy-fuel process, and post-combustion capture. Among them, post-combustion capture is the most important one because it offers flexibility and it can be easily added to the operational units. Various technologies are used for CO2 capture, some of them include: absorption, adsorption, cryogenic distillation, and membrane separation. In this paper, various technologies for post-combustion are compared and the best condition for using each technology is identified. PMID:24696663

  18. Carbon dioxide separation from flue gases: a technological review emphasizing reduction in greenhouse gas emissions.

    PubMed

    Songolzadeh, Mohammad; Soleimani, Mansooreh; Takht Ravanchi, Maryam; Songolzadeh, Reza

    2014-01-01

    Increasing concentrations of greenhouse gases (GHGs) such as CO2 in the atmosphere is a global warming. Human activities are a major cause of increased CO2 concentration in atmosphere, as in recent decade, two-third of greenhouse effect was caused by human activities. Carbon capture and storage (CCS) is a major strategy that can be used to reduce GHGs emission. There are three methods for CCS: pre-combustion capture, oxy-fuel process, and post-combustion capture. Among them, post-combustion capture is the most important one because it offers flexibility and it can be easily added to the operational units. Various technologies are used for CO2 capture, some of them include: absorption, adsorption, cryogenic distillation, and membrane separation. In this paper, various technologies for post-combustion are compared and the best condition for using each technology is identified.

  19. CARBON TRACE GASES IN LAKE AND BEAVER POND ICE NEAR THOMPSON, MANITOBA, CANADA

    EPA Science Inventory

    Concentrations of CO2, CO, and CH4 were measured in beaver pond and lake ice in April 1996 near Thompson, Manitoba to derive information on possible impacts of ice melting on corresponding atmospheric trace gas concentrations. CH4 concentrations in beaver pond and lake ice ranged...

  20. Origin, speciation, and fluxes of trace-element gases at Augustine volcano, Alaska: Insights into magma degassing and fumarolic processes

    SciTech Connect

    Symonds, R.B.; Rose, W.I. ); Reed, M.H. )

    1992-02-01

    Thermochemical modeling predicts that trace elements in the Augustine gas are transported from near-surface magma as simple chloride, oxychloride, sulfide, and elemental gas species. However, Si, Ca, Al, Mg, Ti, V, and Cr are actually more concentrated in solids, beta-quartz (SiO{sub 2}), wollastonite (CaSiO{sub 3}), anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}), diopside (CaMgSi{sub 2}O{sub 6}), sphene (CaTiSiO{sub 5}), V{sub 2}O{sub 3}(c), and Cr{sub 2}O{sub 3}(c), respectively, than in their most abundant gaseous species, SiF{sub 4}, CaCl{sub 2}, AlF{sub 2}O, MgCl{sub 2}, TiCl{sub 4}, VOCl{sub 3}, and CrO{sub 2}Cl{sub 2}. Using the calculated distribution of gas species and the COSPEC SO{sub 2} fluxes, the authors have estimated the emission rates for many species. Such forecasts could be useful to evaluate the effects of these trace species on atmospheric chemistry. Because of the high volatility of metal chlorides, the extremely HCl-rich Augustine volcanic gases are favorable for transporting metals from magma. Thermochemical modeling shows that equilibrium degassing of magma near 870C can account for the concentrations of Fe, Na, K, Mn, Cu, Ni, and part of the Mg in the gases escaping from the dome fumaroles on the 1986 lava dome. Nonvolatile elements in the gas condensates came from eroded rock particles that dissolved in the authors' samples or, for Si, from contamination from the silica sampling tube. Erosion is more prevalent in the pyroclastic flow fumaroles than in the summit vents, reflecting physical differences in the fumarole walls: ash vs. lava. Trace element contents of volcanic gases show enormous variability because of differences in the intensive parameters of degassing magma and variable amounts of wall rock erosion in volcanic fumaroles.

  1. Origin, speciation, and fluxes of trace-element gases at Augustine volcano, Alaska: Insights into magma degassing and fumarolic processes

    NASA Astrophysics Data System (ADS)

    Symonds, Robert B.; Reed, Mark H.; Rose, William I.

    1992-02-01

    Thermochemical modeling predicts that trace elements in the Augustine gas are transported from near-surface magma as simple chloride (NaCl, KCl, FeCl 2, ZnCl 2, PbCl 2, CuCl, SbCl 3, LiCl, MnCl 2, NiCl 2, BiCl, SrCl 2), oxychloride (MoO 2Cl 2), sulfide (AsS), and elemental (Cd) gas species. However, Si, Ca, Al, Mg, Ti, V, and Cr are actually more concentrated in solids, beta-quartz (SiO 2), wollastonite (CaSiO 3), anorthite (CaAl 2Si 2O 8), diopside (CaMgSi 2O 6), sphene (CaTiSiO 5), V 2O 3(c), and Cr 2O 3(c), respectively, than in their most abundant gaseous species, SiF 4, CaCl 2, AlF 2O, MgCl 2 TiCl 4, VOCl 3, and CrO 2Cl 2. These computed solids are not degassing products, but reflect contaminants in our gas condensates or possible problems with our modeling due to "missing" gas species in the thermochemical data base. Using the calculated distribution of gas species and the COSPEC SO 2 fluxes, we have estimated the emission rates for many species (e.g., COS, NaCl, KCl, HBr, AsS, CuCl). Such forecasts could be useful to evaluate the effects of these trace species on atmospheric chemistry. Because of the high volatility of metal chlorides (e.g., FeCl 2, NaCl, KCl, MnCl 2, CuCl), the extremely HCl-rich Augustine volcanic gases are favorable for transporting metals from magma. Thermochemical modeling shows that equilibrium degassing of magma near 870°C can account for the concentrations of Fe, Na, K, Mn, Cu, Ni and part of the Mg in the gases escaping from the dome fumaroles on the 1986 lava dome. These calculations also explain why gases escaping from the lower temperature but highly oxidized moat vents on the 1976 lava dome should transport less Fe, Na, K, Mn and Ni, but more Cu; oxidation may also account for the larger concentrations of Zn and Mo in the moat gases. Nonvolatile elements (e.g., Al, Ca, Ti, Si) in the gas condensates came from eroded rock particles that dissolved in our samples or, for Si, from contamination from the silica sampling tube. Only a

  2. Emissions of Trace Gases and Particles from Savanna Fires in Southern Africa

    NASA Technical Reports Server (NTRS)

    Sinha, Parikhit; Hobbs, Peter V.; Yokelson, Robert J.; Bertschi, Isaac T.; Blake, Donald R.; Simpson, Isobel J.; Gao, Song; Kirchstetter, Thomas W.; Novakov, Tica

    2003-01-01

    Airborne measurements made on initial smoke from 10 savanna fires in southern Africa provide quantitative data on emissions of 50 gaseous and particulate species, including carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, methane, ammonia, dimethyl sulfide, nonmethane organic compounds, halocarbons, gaseous organic acids, aerosol ionic components, carbonaceous aerosols, and condensation nuclei (CN). Measurements of several of the gaseous species by gas chromatography and Fourier transform infrared spectroscopy are compared. Emission ratios and emission factors are given for eight species that have not been reported previously for biomass burning of savanna in southern Africa (namely, dimethyl sulfide, methyl nitrate, five hydrocarbons, and particles with diameters from 0.1 to 3 microns). The emission factor that we measured for ammonia is lower by a factor of 4, and the emission factors for formaldehyde, hydrogen cyanide, and CN are greater by factors of about 3, 20, and 3 - 15, respectively, than previously reported values. The new emission factors are used to estimate annual emissions of these species from savanna fires in Africa and worldwide.

  3. In-Situ Monitoring of Trace Gases in a Non-Urban Environment

    SciTech Connect

    Mioduszewski, John R; Yu, Xiao-Ying; Morris, Victor R; Berkowitz, Carl M; Flaherty, Julia E

    2011-01-01

    A set of commercial instruments measuring carbon monoxide (CO), ozone (O3), sulfur dioxide (SO2), and nitrogen oxides [nitric oxide (NO), nitrogen dioxide (NO2), and odd nitrogens (NOX)] was integrated and deployed in a non–urban environment. The deployment occurred between July 2, 2007 and August 7, 2007 in Richland, WA. The mixing ratios of all species were lower than in most rural–suburban environments, and strong diurnal patterns were observed. NO2 was depleted by photochemically formed ozone during the day and replenished at night as ozone was destroyed. The highest ozone concentration during these episodes was 45 ppb. The overall average was 15 ppb with readings approaching near zero at times. This observation is low compared to average daytime summer readings of 60–80 ppb in highly populated and industrialized urban areas in the Pacific Northwest region. Back-trajectory analysis and prevailing weather conditions both indicated that much of the ozone was transported locally or was produced in–situ. Analysis of SO2 as a tracer for O3 advection further indicated lack of long–range regional transport of pollutants to Richland. We also present results of analysis of high ozone episodes and comparisons relative to other areas in the Pacific Northwest region. These results provide a useful sample data set to study the historical record of air quality in rural Eastern Washington.

  4. Re-Evaluation of the Lifetimes of Ozone-Depleting Substances and Related Trace Gases

    NASA Astrophysics Data System (ADS)

    Reimann, Stefan; Ko, Malcolm; Newman, Paul; Strahan, Susan

    2013-04-01

    Estimating the average lifetime of a chemical in the atmosphere is crucial to understanding their current and future atmospheric concentrations. Furthermore, for ozone depleting substances (ODSs) and greenhouse gases information on their lifetimes are of paramount importance for obtaining estimates for ozone depletion and climate forcing. Because the lifetimes of ODSs are also used to predict how the future concentrations change with emissions, they also have implications on policy decisions for limiting future release of hydrochlorofluorocarbons (HCFCs) and other replacement compounds under the Montreal Protocol. During the last 25 years, various methods have been used to derive lifetimes of ODSs and values have changed accordingly. Within the last several years evidence is growing that the lifetimes of certain ODSs are possibly somewhat longer than published values. The "Lifetime of halogen source gases" activity under the World Climate Research Programme (WCRP)/Stratospheric Processes And their Role in Climate (SPARC) project has convened a working group to re-evaluate these ODS lifetimes. The goal was to estimate the numerical values for lifetimes and their uncertainties, and to quantify how the values may depend on factors such as the use of different lifetime definitions (e.g. steady-state/instantaneous lifetimes) and changing climate. First results of the report will be shown and implications will be discussed.

  5. Laboratory studies of interaction between trace gases and sulphuric acid or sulphate aerosols using flow-tube reactors

    NASA Astrophysics Data System (ADS)

    Leu, Ming-Taun

    Stratospheric ozone provides a protective shield for humanity and the global biosphere from harmful ultraviolet solar radiation. In past decades, theoretical models for the calculation of ozone balance frequently used gas-phase reactions alone in their studies. Since the discovery of the Antarctic ozone hole in 1985, however, it has been demonstrated that knowledge of heterogeneous reactions is needed to understand this significant natural event owing to the anthropogenic emission of chlorofluorocarbons. In this review I will briefly discuss the experimental techniques for the research of heterogeneous chemistry carried out in our laboratory. These experimental instruments include flow-tube reactors, an electron-impact ionization mass spectrometer, a chemical ionization mass spectrometer and a scanning mobility particle spectrometer. Numerous measurements of uptake coefficient (or reaction probability) and solubility of trace gases in liquid sulphuric acid have been performed under the ambient conditions in the upper troposphere and lower stratosphere, mainly 190-250 K and 40-80 wt% of H

  6. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems.

    PubMed

    Warr, Oliver; Rochelle, Christopher A; Masters, Andrew J; Ballentine, Christopher J

    2016-01-01

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively. PMID:26827363

  7. Effect of variation in argon content of calibration gases on determination of atmospheric carbon dioxide.

    PubMed

    Min, Deullae; Kang, Namgoo; Moon, Dong Min; Lee, Jin Bok; Lee, Dong Soo; Kim, Jin Seog

    2009-12-15

    Carbon dioxide (CO(2)) is a greenhouse gas that makes by far the largest contribution to the global warming of the Earth's atmosphere. For the measurements of atmospheric CO(2) a non-dispersive infrared analyzer (NDIR) and gas chromatography are conventionally being used. We explored whether and to what degree argon content can influence the determination of atmospheric CO(2) using the comparison of CO(2) concentrations between the sample gas mixtures with varying Ar amounts at 0 and 18.6 mmol mol(-1) and the calibration gas mixtures with Ar at 8.4, 9.1, and 9.3 mmol mol(-1). We newly discovered that variation of Ar content in calibration gas mixtures could undermine accuracy for precise and accurate determination of atmospheric CO(2) in background air. The differences in CO(2) concentration due to the variation of Ar content in the calibration gas mixtures were negligible (<+/-0.03 micromol mol(-1)) for NDIR systems whereas they noticeably increased (<+/-1.09 micromol mol(-1)) especially for the modified GC systems to enhance instrumental sensitivity. We found that the thermal mass flow controller is the main source of the differences although such differences appeared only in the presence of a flow restrictor in GC systems. For reliable monitoring of real atmospheric CO(2) samples, one should use calibration gas mixtures that contain Ar content close to the level (9.332 mmol mol(-1)) in the ambient air as possible. Practical guidelines were highlighted relating to selection of appropriate analytical approaches for the accurate and precise measurements of atmospheric CO(2). In addition, theoretical implications from the findings were addressed.

  8. Field measurements of trace gases and aerosols emitted by peat fires in Central Kalimantan, Indonesia, during the 2015 El Niño

    NASA Astrophysics Data System (ADS)

    Stockwell, Chelsea E.; Jayarathne, Thilina; Cochrane, Mark A.; Ryan, Kevin C.; Putra, Erianto I.; Saharjo, Bambang H.; Nurhayati, Ati D.; Albar, Israr; Blake, Donald R.; Simpson, Isobel J.; Stone, Elizabeth A.; Yokelson, Robert J.

    2016-09-01

    Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional-global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm), and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs; grams of a compound per kilogram biomass burned) for up to ˜ 90 gases, including CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc. The modified combustion efficiency (MCE) of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n = 35), indicating essentially pure smoldering combustion, and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g kg-1) were carbon dioxide (1564 ± 77), carbon monoxide (291 ± 49), methane (9.51 ± 4.74), hydrogen cyanide (5.75 ± 1.60), acetic acid (3.89 ± 1.65), ammonia (2.86 ± 1.00), methanol (2.14 ± 1.22), ethane (1.52 ± 0.66), dihydrogen (1.22 ± 1.01), propylene (1.07 ± 0.53), propane (0.989 ± 0.644), ethylene (0.961 ± 0.528), benzene (0.954 ± 0.394), formaldehyde (0.867 ± 0.479), hydroxyacetone (0.860 ± 0.433), furan (0.772 ± 0.035), acetaldehyde (0.697 ± 0.460), and acetone (0.691 ± 0.356). These field data support significant revision

  9. Photoacoustic monitoring of trace gases by use of a diode-based difference frequency laser source.

    PubMed

    Fischer, C; Sigrist, M W; Yu, Q; Seiter, M

    2001-10-15

    We present a compact mid-infrared laser spectrometer for trace-gas monitoring. Difference frequency generation in periodically poled LiNbO(3) is used as laser source, yielding a tuning range 3.2-3.7mum at a linewidth of 154 MHz. The relatively high average power of 3 to 5 mW favors detection with a small resonant photoacoustic gas cell. Measurements of methane yield a detection limit in the low parts in 10(6) by volume concentration range. PMID:18049679

  10. Using FLEXPART-WRF to Identify Source Regions Influencing Arctic Trace Gases and Aerosols During the Summer 2014 NETCARE Campaign

    NASA Astrophysics Data System (ADS)

    Thomas, J. L.

    2015-12-01

    In July and August 2014 the Canadian Network on Aerosols and Climate: Addressing Key Uncertainties in Remote Canadian Regions (NETCARE) project conducted aircraft and ship based campaigns with the goal of identifying both emissions and atmospheric processes influencing Arctic trace gas and aerosol concentrations. The aircraft campaign was conducted using the Alfred Wegener Institute's POLAR 6 aircraft (based in Resolute Bay, Canada) and the ship based campaign was conducted onboard the CCGS Amundsen (icebreaker and Arctic Ocean research vessel). Here, we use the Weather Research and Forecasting Model (WRF) to study meteorology and transport patterns that influence airmasses sampled during the aircraft campaign (5-21 July 2012) and research Legs 1a and 1b for Amundsen (1a: 8 - 24 July Quebec City to Resolute and 24 July - 14 August Resolute to Kugluktuk). The FLEXible PARTicle dispersion model driven by WRF meteorology (FLEXPART-WRF) run in backwards mode is used to study source regions that influenced enhanced concentrations in trace gases including DMS and NH3 as well as aerosols. Links between biomass burning in Northern Canada and measurements during the campaign are discussed. Finally FLEXPART-WRF run in forward mode is used to study links between shipping emissions from the Amundsen and enhanced pollution sampled by the POLAR 6 aircraft when both were operating in the same region of Lancaster Sound during the campaigns.

  11. Measurement of gas/water uptake coefficients for trace gases active in the marine environment

    SciTech Connect

    Davidovits, P. . Dept. of Chemistry); Worsnop, D.W.; Zahniser, M.S.; Kolb, C.E. . Center for Chemical and Environmental Physics)

    1992-02-01

    Ocean produced reduced sulfur compounds including dimethylsulfide (DMS), hydrogen sulfide (H{sub 2}S), carbon disulfide (CS{sub 2}), methyl mercaptan (CH{sub 3}CH) and carbonyl sulfide (OCS) deliver a sulfur burden to the atmosphere which is roughly equal to sulfur oxides produced by fossil fuel combustion. These species and their oxidation products dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO{sub 2}) and methane sulfonic acid (MSA) dominate aerosol and CCN production in clean marine air. Furthermore, oxidation of reduced sulfur species will be strongly influenced by NO{sub x}/O{sub 3} chemistry in marine atmospheres. The multiphase chemical processes for these species must be understood in order to study the evolving role of combustion produced sulfur oxides over the oceans. We have measured the chemical and physical parameters affecting the uptake of reduced sulfur compounds, their oxidation products, ozone, and nitrogen oxides by the ocean's surface, and marine clouds, fogs, and aerosols. These parameters include: gas/surface mass accommodation coefficients; physical and chemically modified (effective) Henry's law constants; and surface and liquid phase reaction constants. These parameters are critical to understanding both the interaction of gaseous trace species with cloud and fog droplets and the deposition of trace gaseous species to dew covered, fresh water and marine surfaces.

  12. Production of sulfur gases and carbon dioxide by synthetic weathering of crushed drill cores from the Santa Cruz porphyry copper deposit near Casa Grande, Pinal County, Arizona

    USGS Publications Warehouse

    Hinkle, M.E.; Ryder, J.L.; Sutley, S.J.; Botinelly, T.

    1990-01-01

    Samples of ground drill cores from the southern part of the Santa Cruz porphyry copper deposit, Casa Grande, Arizona, were oxidized in simulated weathering experiments. The samples were also separated into various mineral fractions and analyzed for contents of metals and sulfide minerals. The principal sulfide mineral present was pyrite. Gases produced in the weathering experiments were measured by gas chromatography. Carbon dioxide, oxygen, carbonyl sulfide, sulfur dioxide and carbon disulfide were found in the gases; no hydrogen sulfide, organic sulfides, or mercaptans were detected. Oxygen concentration was very important for production of the volatiles measured; in general, oxygen concentration was more important to gas production than were metallic element content, sulfide mineral content, or mineral fraction (oxide or sulfide) of the sample. The various volatile species also appeared to be interactive; some of the volatiles measured may have been formed through gas reactions. ?? 1990.

  13. Trapping, chemistry, and export of trace gases in the South Asian summer monsoon observed during CARIBIC flights in 2008

    NASA Astrophysics Data System (ADS)

    Rauthe-Schöch, Armin; Baker, Angela K.; Schuck, Tanja J.; Brenninkmeijer, Carl A. M.; Zahn, Andreas; Hermann, Markus; Stratmann, Greta; Ziereis, Helmut; van Velthoven, Peter F. J.; Lelieveld, Jos

    2016-03-01

    The CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) passenger aircraft observatory performed in situ measurements at 10-12 km altitude in the South Asian summer monsoon anticyclone between June and September 2008. These measurements enable us to investigate this atmospheric region (which so far has mostly been observed from satellites) using the broad suite of trace gases and aerosol particles measured by CARIBIC. Elevated levels of a variety of atmospheric pollutants (e.g. carbon monoxide, total reactive nitrogen oxides, aerosol particles, and several volatile organic compounds) were recorded. The measurements provide detailed information about the chemical composition of air in different parts of the monsoon anticyclone, particularly of ozone precursors. While covering a range of 3500 km inside the monsoon anticyclone, CARIBIC observations show remarkable consistency, i.e. with distinct latitudinal patterns of trace gases during the entire monsoon period. Using the CARIBIC trace gas and aerosol particle measurements in combination with the Lagrangian particle dispersion model FLEXPART, we investigated the characteristics of monsoon outflow and the chemical evolution of air masses during transport. The trajectory calculations indicate that these air masses originated mainly from South Asia and mainland Southeast Asia. Estimated photochemical ages of the air were found to agree well with transport times from a source region east of 90-95° E. The photochemical ages of the air in the southern part of the monsoon anticyclone were systematically younger (less than 7 days) and the air masses were mostly in an ozone-forming chemical mode. In its northern part the air masses were older (up to 13 days) and had unclear ozone formation or destruction potential. Based on analysis of forward trajectories, several receptor regions were identified. In addition to predominantly westward transport, we found evidence for

  14. Trapping, chemistry and export of trace gases in the South Asian summer monsoon observed during CARIBIC flights in 2008

    NASA Astrophysics Data System (ADS)

    Rauthe-Schöch, A.; Baker, A. K.; Schuck, T. J.; Brenninkmeijer, C. A. M.; Zahn, A.; Hermann, M.; Stratmann, G.; Ziereis, H.; van Velthoven, P. F. J.; Lelieveld, J.

    2015-03-01

    The CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) passenger aircraft observatory performed in situ measurements at 10-12 km altitude in the South Asian summer monsoon anticyclone between June and September 2008. These measurements enable us to investigate this atmospheric region, which so far has mostly been observed from satellites, using the broad suite of trace gases and aerosols measured by CARIBIC. Elevated levels of a range of atmospheric pollutants were recorded e.g. carbon monoxide, total reactive nitrogen oxides, aerosol particles and several volatile organic compounds. The measurements provide detailed information about the chemical composition of air in different parts of the monsoon anticyclone, particularly of ozone precursors. While covering a range of 3500 km inside the monsoon anticyclone, CARIBIC observations show remarkable consistency, i.e. with regular latitudinal patterns of trace gases during the entire monsoon period. Trajectory calculations indicate that these air masses originated mainly from South Asia and Mainland Southeast Asia. Using the CARIBIC trace gas and aerosol measurements in combination with the Lagrangian particle dispersion model FLEXPART we investigated the characteristics of monsoon outflow and the chemical evolution of air masses during transport. Estimated photochemical ages of the air were found to agree well with transport times from a source region east of 95° E. The photochemical ages of the air in the southern part of the monsoon anticyclone were consistently younger (less than 7 days) and the air masses mostly in an ozone forming chemical regime. In its northern part the air masses were older (up to 13 days) and had unclear ozone formation or destruction potential. Based on analysis of forward trajectories several receptor regions were identified. In addition to predominantly westward transport, we found evidence for efficient transport (within 10 days) to

  15. A Novel Miniaturised Infrared Imaging Spectrometer for the Measurement of Atmospheric Trace Gases

    NASA Astrophysics Data System (ADS)

    Mortimer, A. H.

    2012-04-01

    A novel, ultra-compact Static Imaging Fourier Transform Spectrometer, SIFTS, with no moving parts has been developed for the remote and in-situ detection of atmospheric gases. This technique has previously been demonstrated in the visible spectral region (400 to 1100nm) using a CCD detector. This paper the author presents the results of the infrared version of the SIFTS instrument, which uses an uncooled microbolometer detector array to measure infrared spectra (7 to 14μm) with a resolution of up 4 cm-1 and temporal resolution of 30Hz. The technique is based on a static optical configuration whereby light is split into two paths and made to recombine along a focal plane producing an interference pattern. The spectral information is returned using a detector array to digitally capture the interferogram which can then be processed into a spectrum by the application of a Fourier transform. The novel optical design has reduced the optics required to only 3 optical components and the detector array, to generate and measure the interferogram. The experimental performance of the SIFTS instrument has verified the theoretical models, which has shown that the spectral resolution is for the infrared instrument is 4cm-1. The Connes advantage, inherent to the Michelson spectrometer Fourier Transform Spectrometer (FTS), whereby the spectral wavelength accuracy is referenced to a stabilised laser has also been demonstrated in the SIFTS instrument. This has been implemented through the use of an expanded internal laser diode with Distributed Bragg Reflector (DFB) which acts as the calibration source used to maintain the wavelength stability of the SIFTS instrument. As there are no moving components, the instrument is compact, light and insensitive to mechanical vibration, additionally the speed of measurement is determined by the frame rate of the detector array. Thus, this instrument has a temporal advantage over common Michelson FTIR instruments. For example, this technique has

  16. Distributions of Trace Gases and Aerosols during the Dry Biomass Burning Season in Southern Africa

    NASA Technical Reports Server (NTRS)

    Sinha, Parikhit; Hobbs, Peter V.; Yokelson, Robert J.; Blake, Donald R.; Gao, Song; Kirchstetter, Thomas W.

    2003-01-01

    Vertical profiles in the lower troposphere of temperature, relative humidity, sulfur dioxide (SO2), ozone (O3), condensation nuclei (CN), and carbon monoxide (CO), and horizontal distributions of twenty gaseous and particulate species, are presented for five regions of southern Africa during the dry biomass burning season of 2000. The regions are the semiarid savannas of northeast South Africa and northern Botswana, the savanna-forest mosaic of coastal Mozambique, the humid savanna of southern Zambia, and the desert of western Namibia. The highest average concentrations of carbon dioxide (CO2), CO, methane (CH4), O3, black particulate carbon, and total particulate carbon were in the Botswana and Zambia sectors (388 and 392 ppmv, 369 and 453 ppbv, 1753 and 1758 ppbv, 79 and 88 ppbv, 2.6 and 5.5 micrograms /cubic meter and 13.2 and 14.3 micrograms/cubic meter). This was due to intense biomass burning in Zambia and surrounding regions. The South Africa sector had the highest average concentrations of SO2, sulfate particles, and CN (5.1 ppbv, 8.3 micrograms/cubic meter, and per 6400 cubic meter , respectively), which derived from biomass burning and electric generation plants and mining operations within this sector. Air quality in the Mozambique sector was similar to the neighboring South Africa sector. Over the arid Namibia sector there were polluted layers aloft, in which average SO2, O3, and CO mixing ratios (1.2 ppbv, 76 ppbv, and 3 10 ppbv, respectively) were similar to those measured over the other more polluted sectors. This was due to transport of biomass smoke from regions of widespread savanna burning in southern Angola. Average concentrations over all sectors of CO2 (386 +/- 8 ppmv), CO (261 +/- 81 ppbv), SO2 (2.5 +/- 1.6 ppbv), O3 (64 +/- 13 ppbv), black particulate carbon (2.3 +/- 1.9 microgram/cubic meter), organic particulate carbon (6.2 +/- 5.2 microgram/cubic meter), total particle mass (26.0 +/- 4.7 microgram/cubic meter), and potassium particles (0

  17. Air Quality Impacts of Atmospheric Particles & Trace Gases: Field Studies in Diverse Environments

    NASA Astrophysics Data System (ADS)

    Mwaniki, George R.

    Air pollution impacts occur at all scales, meaning that policies and air quality management practices must be implemented and coordinated at the local, regional, national, and global scales. This dissertation is part of a continuing effort to improve our understanding of various air quality related issues in different environments. The dissertation consists of four studies. In the first study, wintertime chemical composition of water-soluble particulate matter with aerodynamic diameter less than 2.5 microm (PM2.5) was monitored in the Treasure Valley region near Boise, Idaho. This study was aimed at understanding the major drivers of wintertime PM2.5 within the locality of Boise and its suburbs. From this study, organics and particulate nitrate were the dominant contributors to the PM2.5 mass during wintertime. In the second study, particle size distribution, light scattering coefficient, speciated water soluble PM2.5, and cloud condensation nuclei (CCN) concentration were monitored in a mixed deciduous forest in Northern Michigan during the Community Atmosphere-Biosphere Interactions Experiment (CABINEX-2009). The overall goal of this study was to understand on how emissions of biogenic volatile organic compounds (BVOC) affect the gas-phase and particle-phase chemistry in the near-canopy environment, and the implications on local and regional air quality. From this study aerosol derived from the oxidation of BVOCs exhibited reduced hygroscopicity and CCN activation potential compared to aerosols derived from anthropogenic activities. The third study employed the eddy covariance (EC) technique to understand source-sink interactions of carbon dioxide (CO2), methane (CH 4), carbon monoxide (CO) and nitrous oxide (N2O) in Xi'an, China. In this study urban vegetation were found to play a major role in regulating CO2 emissions within the city while vehicular activities were a major driver for CO and CH4 fluxes. In the fourth study, visibility degradation effects of

  18. Initial Composition, Transformations, and Transport of Particles and Trace Gases From Mexican Biomass Burning

    NASA Astrophysics Data System (ADS)

    Burling, I. R.; Yokelson, R. J.; Christian, T. J.; Akagi, S.; Urbanski, S.; Wiedinmyer, C.; Crounse, J. D.; Decarlo, P.; Clarke, A. D.

    2008-12-01

    As part of the MILAGRO project we investigated the amount, transport, and chemical composition of emissions from biomass burning (BB) in Mexico. Up to 48 trace gas and particle species were measured. BB near Mexico City (MC) and in the Yucatan was sampled from the NCAR C-130 in March 2006. During the same month, a Twin Otter aircraft deployed by the University of Montana was used to sample fires in the above areas and also forest, grass, and agricultural fires throughout much of the rest of Mexico. BB adjacent to MC accounted for about 30% of the CO and half or more of the fine particle mass in the MC-area outflow. The Yucatan measurements now provide the most comprehensive data available on the emissions from BB in tropical dry forests: the ecosystem that accounts for the most biomass burned globally. Rapid changes in ozone and many other trace gas species were observed in one BB plume. The Δ PM2.5/Δ CO ratio increased by a factor of ~ 2.6 in < 2 hours after emission as measured by both light scattering and an aerosol mass spectrometer. This is the best field evidence to date of significant secondary aerosol formation in BB plumes. During April-May 2007, ground-based, portable FTIR and particle measuring systems were deployed throughout central Mexico to characterize the emissions from garbage burning, cooking fires, brick-making kilns, and other ubiquitous, but poorly characterized sources. The first detailed chemical speciation of garbage burning emissions included the observation of extremely high HCl levels (Δ HCl/Δ CO 3.5-18%). Thus, garbage burning could be an important source of atmospheric chlorine in some regions. In addition, the HCl results suggest that large amounts of other chlorinated compounds may be emitted. Further measurements are needed, especially for highly toxic chlorinated organic compounds. Cooking fires are the second largest global source of BB emissions. The measurements of trace gas and particle emissions from cooking fires included

  19. Dynamics of Sulfur Dioxide in the Marine Boundary During Trace P

    NASA Astrophysics Data System (ADS)

    Thornton, D. C.; Tu, F.; Bandy, A. R.; Kim, M.; Thornhill, L.; Barrick, J. D.; Anderson, B.

    2002-12-01

    An atmospheric pressure ionization mass spectrometer (APIMS) was employed to obtain 25 Hz sulfur dioxide (SO2) meausrements during the NASA Trace P field experiment. The APIMS was deployed on the NASA Wallops P-3B, which was equiped with the total air motion measurement system (TAMMS). The APIMS SO2 signal was recorded on the TAMMS data system to insure that the data was recorded on the same time base to allow processing of the data for eddy correlation measurements of SO2 with the vertical wind velocity from TAMMS. A preliminary estimate of the SO2 deposition velocity will be presented. At the high data sampling rates the dynamics of boundary layer could be studied for the effects on the SO2 distribution in conjunction with high data rate water vapor and temperature data from TAMMS. The turbulence data showed that the well mixed layer (within the planetary boundary layer) often was approximately 500 m with an intermittently turbulent layer above. The vertical distribution of SO2 was often constrained by the dynamics of these layers. In some cases the highest SO2 concentrations were in the well mixed layer and at other times the highest SO2 concentrations were in the less well mixed layer above. This partitioning could also be seen for water vapor and sometimes for carbon monoxide. In some cases it appeared that the continental boundary layer air had overrun the marine mixed layer during frontal progress through the experiment area. This partitioning can greatly affect the loss rates and mechanisms of SO2 in the absence of convection. When SO2 is predominantly above the well mixed layer, SO2 loss to the sea surface is primarily controlled by entraiment into the well mixed layer, which is a relatively slow process. When the SO2 is primarily in the well mixed layer its lifetime during transport can be much shorter than during transport aloft unless convection through the boundary layer occurs. The transport of SO2 in and around clouds was also observed during Trace P

  20. Tropospheric methane in northern Finland: seasonal variations, transport patterns and correlations with other trace gases

    NASA Astrophysics Data System (ADS)

    Aalto, Tuula; Hatakka, Juha; Lallo, Marko

    2007-04-01

    Methane mixing ratios have been continuously observed at Pallas, Finland since winter 2004. The seasonal variation in monthly means was ca. 40 ppb, showing largest mixing ratios in winter and also high values during late summer. Examination of back-trajectories showed that the air masses with elevated methane mixing ratios arrived from continental Eastern and Central Europe while low methane mixing ratios were connected with Atlantic and Arctic air masses. During summer, air masses with highest mixing ratios arrived from Northwestern Russia indicating wetland sources, while the influence of southern emissions became more significant in winter. Methane was positively correlated with carbon dioxide and negatively correlated with ozone in winter. The average slope of the selected wintertime background hourly mean mixing ratios was 7.0 +/- 1.2 ppb(CH4)/ppm(CO2). Nocturnal summertime low-altitude measurements above a local wetland source indicated slopes of about 10 +/- 1 ppb(CH4)/ppm(CO2). The different slopes reflect the differences in emission parameters.

  1. Airborne Observations of Ozone and Other Trace Gases Upwind of National Parks in California and Nevada

    NASA Technical Reports Server (NTRS)

    Iraci, Laura T.

    2016-01-01

    The Alpha Jet Atmospheric eXperiment (AJAX) is a research project based at Moffett Field, CA, which collects airborne measurements of ozone, carbon dioxide, methane, water vapor, and formaldehyde, as well as 3-D winds, temperature, pressure, and location. Since its first science flight in 2011, AJAX has developed a wide a variety of mission types, combining vertical profiles (from approximately 8 km to near surface), boundary layer legs, and plume sampling as needed. With an ongoing five-year data set, the team has sampled over 160 vertical profiles, a dozen wildfires, and numerous stratospheric ozone intrusions. Our largest data collection includes 55 vertical profiles at Railroad Valley, NV, approximately 100 miles southwest of Great Basin National Park, and many of those flights include comparisons to surface monitors in the Nevada Rural Ozone Initiative network. We have also collected a smaller set of measurements northwest of Joshua Tree National Park, and are looking to develop partnerships that can put this data to use to assess or improve air quality in nearby Parks. AJAX also studies the plumes emitted by wildfires in California, as most emissions inventories are based on prescribed fires. We have sampled a dozen fires, and results will be presented from several, including the Rim (2013), Soberanes and Cedar (2016) Fires.

  2. Fourier Transform Infrared (FT-IR) Spectroscopy of Atmospheric Trace Gases HCl, NO and SO2

    NASA Technical Reports Server (NTRS)

    Haridass, C.; Aw-Musse, A.; Dowdye, E.; Bandyopadhyay, C.; Misra, P.; Okabe, H.

    1998-01-01

    Fourier Transform Infrared (FT-IR) spectral data have been recorded in the spectral region 400-4000/cm of hydrogen chloride and sulfur dioxide with I/cm resolution and of nitric oxide with 0.25 cm-i resolution, under quasi-static conditions, when the sample gas was passed through tubings of aluminum, copper, stainless steel and teflon. The absorbance was measured for the rotational lines of the fundamental bands of (1)H(35)Cl and (1)H(37)Cl for pressures in the range 100-1000 Torr and for the (14)N(16)O molecule in the range 100-300 Torr. The absorbance was also measured for individual rotational lines corresponding to the three modes of vibrations (upsilon(sub 1) - symmetric stretch, upsilon(sub 2) - symmetric bend, upsilon(sub 3) - anti-symmetric stretch) of the SO2 molecule in the pressure range 25-150 Torr. A graph of absorbance versus pressure was plotted for the observed rotational transitions of the three atmospherically significant molecules, and it was found that the absorbance was linearly proportional to the pressure range chosen, thereby validating Beer's law. The absorption cross-sections were determined from the graphical slopes for each rotational transition recorded for the HCl, NO and SO2 species. Qualitative and quantitative spectral changes in the FT-IR data will be discussed to identify and characterize various tubing materials with respect to their absorption features.

  3. Flux measurements of energy and trace gases in urban Houston, Texas

    NASA Astrophysics Data System (ADS)

    Boedeker, I.; Schade, G. W.; Adams, S.; Park, C.

    2008-12-01

    We describe the setup and some first year results of a new flux measurements tower in an urban area. An existing radio communications tower 4 km north of downtown Houston was equipped with micrometeorological instrumentation and trace gas sampling lines in spring 2007. Wind speed, temperature and relative humidity are recorded at five levels between 12 and 60 m above ground; 3-D wind speed measurements, solar and net radiances, and trace gas sampling are established from the 60 m level. A closed path IRGA is used for CO2 and water vapor fluxes, and independent instrumentation for criteria pollutant and VOC fluxes. Two CSI data loggers and software control the measurements, and EdiRe software is used to analyze turbulence data and compute fluxes. A project description is provided at http://atmo.tamu.edu/yellowcabtower. Surface properties as calculated from the gradient measurements show the site to be surprisingly uniform, with displacement heights between 5 and 9 m and roughness lengths between 0.4 and 0.7 m, despite urban heterogeneity. The latter is investigated through visible/near IR orthoimagery and LIDAR data, which are incorporated into a local GIS. Net radiation was also only marginally affected by surface heterogeneity. At this urban location it is balanced by roughly equal amounts of sensible heat, latent heat, and storage fluxes. Latent heat flux, however, is smaller outside the growing season, with an equivalent increase in winter storage fluxes, as expected. Significant differences are also observed with direction during summer, showing decreased Bowen ratios and lower CO2 emissions from sectors with a larger urban tree canopy cover in the footprint. The largely mature, dominantly oak urban canopy cover alleviates approximately 100 W m- 2 during typical summer days. On the other hand, anthropogenic CO2 emissions dominate over photosynthetic uptake all year round. Measured carbon fluxes peak during morning rush-hour traffic, especially when increasing

  4. Determination of carbon monoxide, methane and carbon dioxide in refinery hydrogen gases and air by gas chromatography.

    PubMed

    Kamiński, Marian; Kartanowicz, Rafal; Jastrzebski, Daniel; Kamiński, Marcin M

    2003-03-14

    This paper illustrates a method for determining trace amounts of CO, CH4 and CO2 with the detection limit of 0.15, 0.15 and 0.20 microg/l, respectively, in refinery hydrogen gases or in air. A simple modification of a gas chromatograph equipped with a flame-ionization detector is presented. A Porapak Q column, additionally connected with a short molecular sieve 5A packed column and a catalytic hydrogenation reactor on the Ni catalyst have been applied. The principle of the analytical method proposed is the separation of CO from O2 before the introduction of CO to the methanizer. The analytical procedure and examples of the results obtained have been presented. The modification applied makes it possible to use the GC instrument for other determinations, requiring utilization of the Porapak Q column and the flame-ionization detector. In such cases, the short molecular sieve 5A column and the methanizer can be by-passed.

  5. Laser photoacoustic analysis of trace gases emitted during electro-knife surgery on human tissue

    NASA Astrophysics Data System (ADS)

    Sigrist, Markus W.; Naegele, Markus; Lauchenauer, Daniel; Hollmann, Ralph; Kammer, Erich

    2002-06-01

    We present a fully automated mobile laser spectrometer with photoacoustic (PA) detection for trace gas analysis. A novel PA cell design permits extracavity measurements with detection limits in the sub-ppb concentration range. The setup also allows measurements with low-power sources such as quantum cascade lasers (QCL). The multicomponent capability as an important feature of the spectrometer is realized by the implementation of two sealed-off CO2 lasers with 12CO2 and 13CO2 fillings covering the spectral range between 868 cm-1 and 1088 cm-1 with 132 laser lines. The performance is demonstrated with measurements on air samples with a priori unknown composition. In particular we report on the analysis of samples taken during surgery on human breast tissue with a high-frequency (HF) electro-knife in a hospital. Besides advantages of less bleeding and lower risk of infection, the drawback of this technique is the generated fume, which in general contains dozens of species at low concentrations, some of them presumably harmful to the patient and the medical team. Our analysis of an unfiltered fume sample revealed a total of 15 species. Most of their concentrations were below the allowed workplace concentrations (if at all available). 2-Furan-carboxaldehyde (C5H4O2), however, exceeded this value of 2 ppm considerably.

  6. High spatial resolution imaging of methane and other trace gases with the airborne Hyperspectral Thermal Emission Spectrometer (HyTES)

    NASA Astrophysics Data System (ADS)

    Hulley, Glynn C.; Duren, Riley M.; Hopkins, Francesca M.; Hook, Simon J.; Vance, Nick; Guillevic, Pierre; Johnson, William R.; Eng, Bjorn T.; Mihaly, Jonathan M.; Jovanovic, Veljko M.; Chazanoff, Seth L.; Staniszewski, Zak K.; Kuai, Le; Worden, John; Frankenberg, Christian; Rivera, Gerardo; Aubrey, Andrew D.; Miller, Charles E.; Malakar, Nabin K.; Sánchez Tomás, Juan M.; Holmes, Kendall T.

    2016-06-01

    Currently large uncertainties exist associated with the attribution and quantification of fugitive emissions of criteria pollutants and greenhouse gases such as methane across large regions and key economic sectors. In this study, data from the airborne Hyperspectral Thermal Emission Spectrometer (HyTES) have been used to develop robust and reliable techniques for the detection and wide-area mapping of emission plumes of methane and other atmospheric trace gas species over challenging and diverse environmental conditions with high spatial resolution that permits direct attribution to sources. HyTES is a pushbroom imaging spectrometer with high spectral resolution (256 bands from 7.5 to 12 µm), wide swath (1-2 km), and high spatial resolution (˜ 2 m at 1 km altitude) that incorporates new thermal infrared (TIR) remote sensing technologies. In this study we introduce a hybrid clutter matched filter (CMF) and plume dilation algorithm applied to HyTES observations to efficiently detect and characterize the spatial structures of individual plumes of CH4, H2S, NH3, NO2, and SO2 emitters. The sensitivity and field of regard of HyTES allows rapid and frequent airborne surveys of large areas including facilities not readily accessible from the surface. The HyTES CMF algorithm produces plume intensity images of methane and other gases from strong emission sources. The combination of high spatial resolution and multi-species imaging capability provides source attribution in complex environments. The CMF-based detection of strong emission sources over large areas is a fast and powerful tool needed to focus on more computationally intensive retrieval algorithms to quantify emissions with error estimates, and is useful for expediting mitigation efforts and addressing critical science questions.

  7. Woody encroachment by nitrogen-fixing species: impacts on nitrogen biogeochemistry expressed through nitrogen trace gases

    NASA Astrophysics Data System (ADS)

    Sparks, J. P.; West, J. B.; Boutton, T. W.

    2011-12-01

    Woody plant encroachment is a globally important vegetation change that continues to transform former grasslands or savannas into woodlands. This dramatic and geographically widespread phenomenon appears to be driven primarily by human land use changes, including reduced fire frequency and heavy livestock grazing. Observed effects of increased woody plant abundance in grasslands generally include alterations of above- and belowground productivity, changes in the chemistry of litter inputs, modifications to rooting depths and distributions, altered biogeochemical and hydrologic processes, and changes in microclimate and energy balance. These changes to fundamental ecosystem characteristics have strong, but relatively poorly understood, potential to modify biogeochemical processes that can themselves influence regional and global climate through biogeochemistry-climate feedbacks. In addition, in South Texas woody encroachment has occurred across a complex landscape differing in soil type and water retention. This work tests the hypothesis that woody encroachment, in addition to increasing total nitrogen stocks in the system, has increased nitrogen losses due to increased rates of nitrogen soil gas efflux. Under dry soil conditions and in contrast to this hypothesis, reactive nitrogen soil efflux (NO + NOy + NH3) was 21.53 ± 3.4 ng N m-2 s-1 in intact grasslands compared to 6.23 ± 1.6 ng N m-2 s-1 in woodlands on the same soil type. The non-reactive nitrogen gas, nitrous oxide, was similar in magnitude between the grassland and encroached sites (~ 7 ng N m-2 s-1). Under moist soil conditions, the magnitude of flux increased and order of magnitude, but did not change the relative ranking. Measurements of soil respiration rate and microbial biomass suggest higher microbial activity in the encroached environment and potentially higher rates of immobilization by plants and microbes. Landscape position had a large overall effect on soil nitrogen trace gas efflux with

  8. Numerical modelling of the transport of trace gases including methane in the subsurface of Mars

    NASA Astrophysics Data System (ADS)

    Stevens, Adam H.; Patel, Manish R.; Lewis, Stephen R.

    2015-04-01

    We model the transport of gas through the martian subsurface in order to quantify the timescales of release of a trace gas with a source at depth using a Fickian model of diffusion through a putative martian regolith column. The model is then applied to the case of methane to determine if diffusive transport of gas can explain previous observations of methane in the martian atmosphere. We investigate which parameters in the model have the greatest effect on transport timescales and show that the calculated diffusivity is very sensitive to the pressure profile of the subsurface, but relatively insensitive to the temperature profile, though diffusive transport may be affected by other temperature dependent properties of the subsurface such as the local vapour pressure. Uncertainties in the structure and physical conditions of the martian subsurface also introduce uncertainties in the timescales calculated. It was found that methane may take several hundred thousand Mars-years to diffuse from a source at depth. Purely diffusive transport cannot explain transient release that varies on timescales of less than one martian year from sources such as serpentinization or methanogenic organisms at depths of more than 2 km. However, diffusion of gas released by the destabilisation of methane clathrate hydrates close to the surface, for example caused by transient mass wasting events or erosion, could produce a rapidly varying flux of methane into the atmosphere of more than 10-3 kg m-2 s-1 over a duration of less than half a martian year, consistent with observations of martian methane variability. Seismic events, magmatic intrusions or impacts could also potentially produce similar patterns of release, but are far more complex to simulate.

  9. Linking aerosol size and optical properties to trace gases emitted from biomass burning in real-time

    NASA Astrophysics Data System (ADS)

    McMeeking, G. R.; Carrico, C. M.; Stockwell, C.; Yokelson, R. J.; Veres, P. R.; DeMott, P. J.; Kreidenweis, S. M.

    2014-12-01

    Biomass burning aerosols have large impacts on regional and global climate that are partly determined by their optical properties. The optical properties of aerosol depend on their size and composition, which in turn are related to fire combustion processes. Here we investigate relationships between a large suite of trace gases and aerosol size and optical properties to better understand processes governing the optical properties of fresh biomass burning aerosol emissions. We examined over 100 individual burns of biomass fuels during the Fire Laboratory at Missoula Experiment 4 (FLAME 4). Emissions were measured directly from an exhaust stack designed to capture all emissions from relatively small-scale fires burned at the base of a large burn chamber. Trace gas species were measured using a combination of an open-path Fourier transform infrared spectrometer (OP-FTIR) and proton-transfer mass spectrometer (PTR-MS). Aerosol optical properties at 870 nm were measured using a photoacoustic extinctiometer (PAX) and particle size distributions were measured using a Fast Mobility Particle Sizer (FMPS) and Aerodynamic Particle Sizer. The rapid response of the instruments allowed for comparisons of the emissions and particle properties over the duration of the fire. For example, we observed correlations between aerosol absorption, particle size, and gas-phase species associated with different types of combustion such as flaming and smoldering. We also report fire-integrated emissions for aerosol absorption and scattering coefficients and compare these to other fire-integrated properties. Many of our burn experiments examined a number of fuels that had not before been characterized in laboratory conditions, including a number of peat fuels, African savanna grasses and crop residuals.

  10. Interactions of atmospheric particulate and trace gases with clouds at Cheeka Peak, WA

    NASA Astrophysics Data System (ADS)

    Samberg, Tristine Marie

    1997-12-01

    Measurements of various aerosol, trace gas, and cloud water constituents were made during two intensive observation periods at the Cheeka Peak Observatory (CPO) on the Washington state coast. These measurements were a part of the second and third Cloud and Aerosol Chemistry Experiments (CAChE 2 and CAChE 3) conducted from April 19 to May 18, 1994 and August 30 to September 23, 1994, respectively. Gas phase hydrogen peroxide was measured continuously during these two time periods. Cloud water samples were analyzed for major ion constituents and aqueous hydrogen peroxide. The cloud water samples collected during CAChE 2 represented bulk collection, whereas the cloud water samples collected during CAChE 3 were segregated into two size fractions, with mean droplet diameter of approximately 12 μm and 13 μm. Major ion concentrations (e.g., Na+, NH4+, H+, NO3/sp-, SO4/sp=, etc.) were higher than previously observed at Cheeka Peak, but comparable to other West coast locations. Despite the small difference in collected droplet size, size dependence was observed for several species. Seasalt ions and NO3/sp- were more concentrated in the larger drops, whereas peroxide was more concentrated in the smaller drops. Size dependence was not observed for MSA, non seasalt sulfate (nss-SO4/sp=) and NH4+, and was only weakly observed for H+. Cloud-free gas phase H2O2 and organic peroxide average concentrations were on the order of a few hundred pptv and did not vary much by wind sector; slightly higher concentrations were observed from the continental sector. In general, these concentrations were lower than those measured at east coast sites. Average cloudwater H2O2 concentrations for both CAChE experiments were approximately 35 μM and indicated conditions at Cheeka Peak were never oxidant-limited.. Evidence for sulfate production via H2O2 oxidation was observed but was not conclusive. Finally, a preliminary comparison was made between predictions of a size-resolved cloud chemical

  11. Investigating atmospheric transport processes of trace gases with ICON-ART on different scales

    NASA Astrophysics Data System (ADS)

    Schröter, Jennifer; Ruhnke, Roland; Rieger, Daniel; Vogel, Heike; Vogel, Bernhard

    2016-04-01

    We have extended the global ICON [1] (ICOsahedral Nonhydrostatic) modelling framework by introducing ICON-ART [2]. ICON is jointly developed by the German Weather Service (DWD) and Max-Planck-Institute for Meteorology (MPI-M), and is used for numerical weather prediction as well as for future climate predictions. ICON-ART is developed at the KIT with the goal to simulate interactions between trace substances and the state of the atmosphere. For the dynamics (transport and diffusion) of gaseous tracers, the original ICON tracer framework is used. A process splitting approach separates the physical processes. In this study, we present results of the ICON-ART extension, including the full gas-phase chemistry module. This module uses the kpp formalism [3] to generate chemistry modules and the photolysis module is based on Cloud-J7.3 [4]. Photolysis rates are calculated online based on the meteorological state of the atmosphere, as well as on the actual ozone profile and cloud optical parameters. Two simulations are performed with ICON-ART. The first one with physics parameterisations for the numerical weather prediction (NWP) and the second one with that for climate simulation in order to investigate the dynamical influence on the distribution of long-lived as well as of short-lived species by comparing both simulations. The results are evaluated with other model results and with observation. In addition to that, we use aircraft campaign data to validate the results on the regional scale for short term simulations by using the NWP physics. [1] Zängl, G., Reinert, D., Ripodas, P., and Baldauf, M.: The ICON (ICOsahedral Non-hydrostatic) modelling framework of DWD and MPI-M: Description of the non-hydrostatic dynamicalcore, Q. J. Roy. Meteor. Soc,141, 563-579, doi:10.1002/qj.2378, 2015 [2] Rieger, D., Bangert, M., Bischoff-Gauss, I., Förstner, J., Lundgren, K., Reinert, D., Schröter, J., Vogel, H., Zängl, G., Ruhnke, R., and Vogel, B.: ICON-ART 1.0 - a new online

  12. Spatiotemporal Patterns of Urban Trace Gases and Pollutants Observed with a Light Rail Vehicle Platform in Salt Lake City, UT

    NASA Astrophysics Data System (ADS)

    Mitchell, L.; Crosman, E.; Fasoli, B.; Leclair-Marzolf, L.; Jacques, A.; Horel, J.; Lin, J. C.; Bowling, D. R.; Ehleringer, J. R.

    2015-12-01

    Urban environments are characterized by both spatial complexity and temporal variability, each of which present challenges for measurement strategies aimed at constraining estimates of greenhouse gas emissions and air quality. To address these challenges we initiated a project in December 2014 to measure trace species (CO2, CH4, O3, and Particulate Matter) by way of a Utah Transit Authority (UTA) light rail vehicle whose route traverses the Salt Lake Valley in Utah on an hourly basis, retracing the same route through commercial, residential, suburban, and rural typologies. Light rail vehicles present advantages as a measurement platform, including the absence of in-situ fossil fuel emissions, repeated transects across a urban region that provides both spatial and temporal information, and relatively low operating costs. We present initial results from the first year of operations including the spatiotemporal patterns of greenhouse gases and pollutants across Salt Lake City, UT with an emphasis on criteria pollutants, identification of sources, and future applications of this measurement platform.

  13. Effects of Higher Hydrocarbon Chemistry On Tropospheric Trace Gases and The Yield of Co From Hydrocarbon Oxidation

    NASA Astrophysics Data System (ADS)

    von Kuhlmann, R.; Lawrence, M. G.; Crutzen, P. J.

    Non-methane hydrocarbons are known to be emitted in large amounts from anthro- pogenic and biogenic sources. The impact of these emissions on key tropospheric trace gases, such as O3, CO, NOx, and OH are investigated using the Model of Atmospheric Transport and Chemistry, Max-Planck-Institute for Chemistry version (MATCH-MPIC). This study expands upon previous work by the use of detailed bud- gets in order to elucidate further the underlying mechanisms of the changes. Isoprene alone, which is emitted in large amounts by tropical ecosystems, is found to contribute more than half of the overall effect of hydrocarbons in the tropics. The model's budget- ing capabilities are further used to determine the yield of CO from methane, isoprene and other hydrocarbons. While 92% of methane is converted to CO, the yields for iso- prene and the sum of other hydrocarbons is lower, both being 39% on a per carbon ba- sis. A detailed analysis of the loss-pathways are also presented and show that a major loss occurs through deposition of soluble intermediates of isoprene oxidation, partic- ularly hydroxy-hydroperoxides, which are explicitly treated in the chemical scheme. The results are compared and discussed with previous estimates from the literature, which shows that the uncertainty in CO production is likely significant compared to the uncertainties in the direct emissions.

  14. A fiber optic sensor with a metal organic framework as a sensing material for trace levels of water in industrial gases.

    PubMed

    Ohira, Shin-Ichi; Miki, Yusuke; Matsuzaki, Toru; Nakamura, Nao; Sato, Yu-ki; Hirose, Yasuo; Toda, Kei

    2015-07-30

    Industrial gases such as nitrogen, oxygen, argon, and helium are easily contaminated with water during production, transfer and use, because there is a high volume fraction of water in the atmosphere (approximately 1.2% estimated with the average annual atmospheric temperature and relative humidity). Even trace water (<1 parts per million by volume (ppmv) of H2O, dew point < -76 °C) in the industrial gases can cause quality problems in the process such as production of semiconductors. Therefore, it is important to monitor and to control trace water levels in industrial gases at each supplying step, and especially during their use. In the present study, a fiber optic gas sensor was investigated for monitoring trace water levels in industrial gases. The sensor consists of a film containing a metal organic framework (MOF). MOFs are made of metals coordinated to organic ligands, and have mesoscale pores that adsorb gas molecules. When the MOF, copper benzene-1,3,5-tricarboxylate (Cu-BTC), was used as a sensing material, we investigated the color of Cu-BTC with water adsorption changed both in depth and tone. Cu-BTC crystals appeared deep blue in dry gases, and then changed to light blue in wet gases. An optical gas sensor with the Cu-BTC film was developed using a light emitting diode as the light source and a photodiode as the light intensity detector. The sensor showed a reversible response to trace water, did not require heating to remove the adsorbed water molecules. The sample gas flow rate did not affect the sensitivity. The obtained limit of detection was 40 parts per billion by volume (ppbv). The response time for sample gas containing 2.5 ppmvH2O was 23 s. The standard deviation obtained for daily analysis of 1.0 ppmvH2O standard gas over 20 days was 9%. Furthermore, the type of industrial gas did not affect the sensitivity. These properties mean the sensor will be applicable to trace water detection in various industrial gases. PMID:26320652

  15. 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)

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

    2012-04-01

    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

  16. Shallow borehole array for measuring fluxes of reduced trace gases in Greenland as an analogue for volatile emission on Mars

    NASA Astrophysics Data System (ADS)

    Pratt, L. M.

    2011-12-01

    -packer-optic-capillary system as a technology demonstration of semi-autonomous drilling for planetary exploration. Carbon and hydrogen isotopic compositions for methane and ethane will be determined in the field using Integrated Cavity Output Spectroscopy and Cavity Ring Down Spectroscopy. Continuous permafrost is present at the study site down to 300 m depth with temperatures dropping to -3 degrees C at a depth of about 4 meters, providing a relatively shallow and pristine setting for an instrumented study of reduced trace gases in soil, fractured bedrock, and groundwater constituting the active layer.

  17. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2013-02-01

    In October-November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4-27.9% of non-methane organic compounds (NMOCs) and ~ 21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in the first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13-195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~ 20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also

  18. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2012-09-01

    In October-November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4-27.9% of non-methane organic compounds (NMOCs) and ~21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13-195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also support an

  19. Use of Satellite and Surface Observations of Trace Gases to Evaluate the Impact of Fire Emissions on Air Quality in Euro-Mediterranean Area

    NASA Astrophysics Data System (ADS)

    Messina, P.; Turquety, S.; Anav, A.; Stromatas, S.; Menut, L.; Coheur, P.-F.; R'honi, Y.; Bessagnet, B.; Clerbaux, C.

    2012-11-01

    Wildfires are one of the main source of trace gases and aerosols. However, their impact remains poorly quantified due to large uncertainties on the emissions, but also on transport processes and chemical evolution of the pollution plumes. Satellite data, due to their high spatial coverage, can be a powerful tool for monitoring pollution plumes transport, although the information remains vertically integrated, implying limited vertical resolution. Here we present an evaluation of the effects, provided by fire emissions, on atmospheric trace gases composition. Therefore, simulations by the regional chemistry-transport model CHIMERE are performed using an high resolution fire emissions scenario. Comparison between satellite observations and model output is then conducted, focusing on the strong biomass burning episodes that occurred in late summer 2007 in Greece.

  20. Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results

    NASA Astrophysics Data System (ADS)

    Wallraff, H. G.

    2013-11-01

    A model of avian goal-oriented navigation is described that is based on two empirical findings building a bridge from ornithology to atmospheric chemistry. (1) To orient their courses homeward from distant unfamiliar areas, homing pigeons require long-term exposure to undisturbed winds at the home site and olfactory access to the environmental air at home and abroad. (2) Above Germany, ratios among some atmospheric trace gases vary along differently oriented spatial gradients as well as depending on wind direction. The model emulates finding (1) by utilising the analysed air samples on which finding (2) is based. Starting with an available set of 46 omnipresent compounds, virtual pigeons determine the profile of relative weights among them at each of 96 sites regularly distributed around a central home site within a radius of 200 km and compare this profile with corresponding profiles determined at home under varying wind conditions. Referring to particular similarities and dissimilarities depending on home-wind direction, they try to estimate, at each site, the compass direction they should fly in order to approach home. To make the model work, an iterative algorithm imitates evolution by modifying sensitivity to the individual compounds stepwise at random. In the course of thousands of trial-and-error steps it gradually improves homeward orientation by selecting smaller sets of most useful and optimally weighted substances from whose proportional configurations at home and abroad it finally derives navigational performances similar to those accomplished by real pigeons. It is concluded that the dynamic chemical atmosphere most likely contains sufficient spatial information for home-finding over hundreds of kilometres of unfamiliar terrain. The underlying chemo-atmospheric processes remain to be clarified.

  1. Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results

    NASA Astrophysics Data System (ADS)

    Wallraff, H. G.

    2013-07-01

    A model of avian goal-oriented navigation is described that is based on two empirical findings: (1) To orient their courses homeward from distant unfamiliar areas, homing pigeons require long-term exposure to undisturbed winds at the home site and olfactory access to the environmental air at home and abroad. (2) Above Germany, ratios among some atmospheric trace gases vary along differently oriented spatial gradients and in dependence on wind direction. The model emulates finding (1) by utilising the analysed air samples on which finding (2) is based. Starting with an available set of 46 omnipresent compounds, virtual pigeons determine the profile of relative weights among them at each of 96 sites regularly distributed around a central home site within a radius of 200 km and compare this profile with corresponding profiles determined at home under varying wind conditions. Referring to particular similarities and dissimilarities depending on home-wind direction, they try to estimate, at each site, the compass direction they should fly in order to approach home. To make the model working, an iterative algorithm imitates evolution by modifying sensitivity to the individual compounds stepwise at random. In the course of thousands of trial-and-error steps it gradually improves homeward orientation by selecting smaller sets of most useful and optimally weighted substances from whose proportional configurations at home and abroad it finally derives navigational performances similar to those accomplished by real pigeons. It is concluded that the dynamic chemical atmosphere most likely contains sufficient spatial information for home-finding over hundreds of kilometres of unfamiliar terrain. The underlying chemo-atmospheric processes remain to be clarified.

  2. Fire emissions in Euro-Mediterranean area: evaluation of the impact on trace gases composition using satellite and surface observations

    NASA Astrophysics Data System (ADS)

    Messina, P.; Turquety, S.; Stromatas, S.; Menut, L.; Anav, A.; Coheur, P.-F.; R'honi, Y.; Bessagnet, B.; Clerbaux, C.

    2012-04-01

    Wildfires are one of the main sources of trace gases and aerosols. However, their impact remains poorly quantified due to large uncertainties especially on the emissions, as well as on the transport processes and chemical evolution of the pollution plumes. In the framework of APIFLAME project a new high resolution fire emission inventory is developed. Simulations performed with the regional chemistry transport model CHIMERE, are carried out in order to assess the effect of the emissions scenarios on air quality in Europe and Mediterranean basin. For a comprehensive evaluation of the processes involved with fire emissions and a validation of simulations, the modeled species are compared to satellite observations and ground measurements. The latter data have good accuracy with high temporal resolution, but they are collected at specific locations and, in general for our case study, are far away from the location where wildfires occur. On the other hand, the satellite data, due to their high spatial coverage, can be a useful tool for monitoring pollution plumes transport, but their vertical resolution is often limited to a total column amount. In this study, the modeled concentrations are compared to the ground measurements (CO, O3 and NO2 concentrations) that come from AirBase database, and to CO partial columns and CO, NH3 and C2H4 total columns from the IASI instrument, to NO2 and CH2O total columns from GOME2 (both on MetOp-A satellite) and to NO2 total columns from OMI (on Aura). In the presented work we focus on strong biomass burning episodes that occurred in summer 2007. Particular attention is given to the evolution of the plume characteristics. The same fire inventory setup is used for both reanalysis and near-real time analysis. The first evaluation of the air quality forecasting system including fires will be presented.

  3. The natural flux of greenhouse gases in the case of monitoring the flux of juvenile carbon dioxide in the Hranice Karst

    NASA Astrophysics Data System (ADS)

    Geršl, Milan; Stepišnik, Uroš; Mareček, Jan; Geršlová, Eva; Hammerschmiedt, Michal

    2015-04-01

    Located in the Teplice nad Bečvou district 40 km SE of Olomouc (Czech Republic), the hydrothermal Hranice Karst with the Zbrašov Aragonite Caves has been developed in the sequence of Palaeozoic limestones as a result of deep influx of thermal water charged with subcrustal carbon dioxide (CO2). This area of discharge of juvenile carbon dioxide is a unique place where one can study the long-term natural production of a greenhouse gas and confront it with the anthropogenic production. As a result, the continuous measurements of the properties of the cave microclimate with additional seasonal measurements of flux of carbon dioxide give rise to a rare pool of data that cover natural routes of greenhouse gases. Repeated seasonal analysis of the ratio of stable carbon isotopes in carbon dioxide (d13C around -5 ) (Meyberg - Rinne, 1995)has suggested the juvenile (mantle) origin of this gas. Isotopic analyses in the mineral water of dissolved gases (He) show that some part of these gases come from the upper mantle of the Earth. The lower floors of the caves are filled with carbon dioxide producing so-called gas lakes in the area. Concentrations of the gas commonly reach 40 % by volume. In 1999, for example, the average concentration in the Gallas dome was 84.9 % by volume. Flux of CO2 (g.m-2.d-1) was measured on the surface and in the cave. The homogenisation chamber and the pumping test were applied to evaluate the CO2 flux. The average CO2 flux in the soil ranged from 74 to 125 g.m-2.d-1, reflecting the venting of subcrustal CO2 in the Hranice area (Geršl et al., 2012). In the Zbrašov Aragonite Caves the CO2 concentration in the atmosphere fluctuates from 0,X to 85 % with the measured constant flux being 32 894 g.m-2.d-1. Since 2005, the CO2 concentrations in the cave area have been reported by an automatic monitoring system at 10 cave sites. CO2 concentrations are recorded in 5-min intervals. Interpretation can be put into the context of measuring concentrations of

  4. Laboratory shock emplacement of noble gases, nitrogen, and carbon dioxide into basalt, and implications for trapped gases in shergottite EETA 79001

    NASA Technical Reports Server (NTRS)

    Wiens, R. C.; Pepin, R. O.

    1988-01-01

    Basalts from the Servilleta flows, Taos, NM, described by Lofgren (1983) were analyzed by mass spectrometry for shock-implanted noble gases, N2, and CO2 (which were isotopically labeled) after an exposure to 20-60 GPa shock in the presence of 0.0045-3.0 atm of ambient gas. The results were compared with data available on the constituents of the EETA 79001 meteorite. As expected, the samples shocked in this study attained emplacement efficiencies significantly lower than those apparent for lithology C of EETA 79001. Possible explanations for this difference include atmospheric overpressure at the time of EETA 79001 exposure to shock, the trapping of gas already in vugs by the intruding melt material, or the collapse of gas-filled vugs to form gas-laden glass inclusions.

  5. The Amazon Tall Tower Observatory (ATTO): overview of pilot measurements on ecosystem ecology, meteorology, trace gases, and aerosols

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.; Acevedo, O. C.; Araùjo, A.; Artaxo, P.; Barbosa, C. G. G.; Barbosa, H. M. J.; Brito, J.; Carbone, S.; Chi, X.; Cintra, B. B. L.; da Silva, N. F.; Dias, N. L.; Dias-Júnior, C. Q.; Ditas, F.; Ditz, R.; Godoi, A. F. L.; Godoi, R. H. M.; Heimann, M.; Hoffmann, T.; Kesselmeier, J.; Könemann, T.; Krüger, M. L.; Lavric, J. V.; Manzi, A. O.; Lopes, A. P.; Martins, D. L.; Mikhailov, E. F.; Moran-Zuloaga, D.; Nelson, B. W.; Nölscher, A. C.; Santos Nogueira, D.; Piedade, M. T. F.; Pöhlker, C.; Pöschl, U.; Quesada, C. A.; Rizzo, L. V.; Ro, C.-U.; Ruckteschler, N.; Sá, L. D. A.; de Oliveira Sá, M.; Sales, C. B.; dos Santos, R. M. N.; Saturno, J.; Schöngart, J.; Sörgel, M.; de Souza, C. M.; de Souza, R. A. F.; Su, H.; Targhetta, N.; Tóta, J.; Trebs, I.; Trumbore, S.; van Eijck, A.; Walter, D.; Wang, Z.; Weber, B.; Williams, J.; Winderlich, J.; Wittmann, F.; Wolff, S.; Yáñez-Serrano, A. M.

    2015-09-01

    The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It has already been changed significantly by human activities, and more pervasive change is expected to occur in the coming decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric conditions and that will be operated over coming decades to monitor change in the Amazon region, as human perturbations increase in the future. The Amazon Tall Tower Observatory (ATTO) has been set up in a pristine rain forest region in the central Amazon Basin, about 150 km northeast of the city of Manaus. Two 80 m towers have been operated at the site since 2012, and a 325 m tower is nearing completion in mid-2015. An ecological survey including a biodiversity assessment has been conducted in the forest region surrounding the site. Measurements of micrometeorological and atmospheric chemical variables were initiated in 2012, and their range has continued to broaden over the last few years. The meteorological and micrometeorological measurements include temperature and wind profiles, precipitation, water and energy fluxes, turbulence components, soil temperature profiles and soil heat fluxes, radiation fluxes, and visibility. A tree has been instrumented to measure stem profiles of temperature, light intensity, and water content in cryptogamic covers. The trace gas measurements comprise continuous monitoring of carbon dioxide, carbon monoxide, methane, and ozone at five to eight different heights, complemented by a variety of additional species measured during intensive campaigns (e.g., VOC, NO, NO2, and OH reactivity). Aerosol optical, microphysical, and chemical measurements are being made above the canopy as well as in the canopy space. They include aerosol light scattering and absorption, fluorescence, number and volume size distributions, chemical

  6. Modeling Soil Climate Controls on the Exchange of Trace Gases Between the Terrestrial Biosphere and the Atmosphere

    NASA Astrophysics Data System (ADS)

    Frolking, Stephen Edward

    Soil temperature and moisture profiles (soil climate) have a strong influence on the rate of trace gas exchange between the terrestrial biosphere and the atmosphere through the controls exerted on microbial processes and the physical exchange of gases. Principal controls of biological denitrification in mineral soils are the availability of carbon and nitrogen substrates and the soil anaerobic status. A process-oriented model of decomposition and denitrification in soils (DNDC) was modified to have a more detailed portrayal of these controls. In particular, a diffusive soil gas phase was added, along with a method for determining anaerobic and aerobic fractional volume within a soil profile. The model generally overestimated N2O fluxes when compared to field data from a sandy soil in Costa Rica, but captured the timing and shape of the brief flux episodes. Several modeling shortcomings are discussed, including the nature of the carbon substrates and the nature and dynamics of soil anaerobic fractional volume. Methane flux from wetland soils is generally correlated with soil temperature and depth to water table. A model of peat soil climate was developed and applied to a small, poor fen in southern New Hampshire. Temperature profiles and ice depth are in good agreement with field data, but depth to water table is more problematic. Field-based flux correlations to soil temperature, depth to water table, and weighted recent precipitation were developed. When used with the wetland soil climate model, much of the seasonal and shorter period flux variability was captured. The model was then driven by local weather data for 1926-1986; flux variability was dependent on both summer season temperatures and summer precipitation patterns. It is estimated that a five-year field study would capture most of the inter -annual variability. Sensitivity of northern peatland methane flux to climate variability was studied by combining data on flux rates, inundation areas, and summer

  7. Airborne measurements and emission estimates of greenhouse gases and other trace constituents from the 2013 California Yosemite Rim wildfire

    NASA Astrophysics Data System (ADS)

    Yates, E. L.; Iraci, L. T.; Singh, H. B.; Tanaka, T.; Roby, M. C.; Hamill, P.; Clements, C. B.; Lareau, N.; Contezac, J.; Blake, D. R.; Simpson, I. J.; Wisthaler, A.; Mikoviny, T.; Diskin, G. S.; Beyersdorf, A. J.; Choi, Y.; Ryerson, T. B.; Jimenez, J. L.; Campuzano-Jost, P.; Loewenstein, M.; Gore, W.

    2016-02-01

    This paper presents airborne measurements of multiple atmospheric trace constituents including greenhouse gases (such as CO2, CH4, O3) and biomass burning tracers (such as CO, CH3CN) downwind of an exceptionally large wildfire. In summer 2013, the Rim wildfire, ignited just west of the Yosemite National Park, California, and burned over 250,000 acres of the forest during the 2-month period (17 August to 24 October) before it was extinguished. The Rim wildfire plume was intercepted by flights carried out by the NASA Ames Alpha Jet Atmospheric eXperiment (AJAX) on 29 August and the NASA DC-8, as part of SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys), on 26 and 27 August during its intense, primary burning period. AJAX revisited the wildfire on 10 September when the conditions were increasingly smoldering, with slower growth. The more extensive payload of the DC-8 helped to bridge key measurements that were not available as part of AJAX (e. g. CO). Data analyses are presented in terms of emission ratios (ER), emission factors (EF) and combustion efficiency and are compared with previous wildfire studies. ERs were 8.0 ppb CH4 (ppm CO2)-1 on 26 August, 6.5 ppb CH4 (ppm CO2)-1 on 29 August and 18.3 ppb CH4 (ppm CO2)-1 on 10 September 2013. The increase in CH4 ER from 6.5 to 8.0 ppb CH4 (ppm CO2)-1 during the primary burning period to 18.3 ppb CH4 (ppm CO2)-1 during the fire's slower growth period likely indicates enhanced CH4 emissions from increased smoldering combustion relative to flaming combustion. Given the magnitude of the Rim wildfire, the impacts it had on regional air quality and the limited sampling of wildfire emissions in the western United States to date, this study provides a valuable dataset to support forestry and regional air quality management, including observations of ERs of a wide number of species from the Rim wildfire.

  8. Autonomous Long-Path DOAS Measurements of Tropospheric Trace Gases at Neumayer Station III, Antarctica: First Results

    NASA Astrophysics Data System (ADS)

    Nasse, Jan-Marcus; Frieß, Udo; Pöhler, Denis; Weller, Rolf; Platt, Ulrich

    2016-04-01

    Reactive Halogen Species (RHS, like IO, BrO, ClO, etc.) have an important impact on atmospheric chemistry. In Polar Regions, the role of halogen radical chemistry has been subject of intensive research for more than two decades. Among the most prominent effects of RHS on the Polar atmosphere are the change of the oxidative capacity of the troposphere including wide-spread and frequently virtually complete destruction of tropospheric ozone, in particular during springtime, as well as the oxidation and subsequent deposition of gaseous elemental mercury. The number of field observations and the understanding of the underlying processes varies greatly between bromine, iodine and chlorine compounds. While elevated BrO concentrations resulting from autocatalytic processes (the so-called bromine explosion mechanism) are frequently observed, the abundance and influence of iodine is still subject to discussions and available observations give no consistent picture. With only a few direct observations of chlorine compounds, such as ClO and OClO, the role of tropospheric chlorine chemistry remains poorly understood to date, despite strong evidence for its relevance. The lack of observations of chlorine radicals is mainly due to the challenging detection, particularly in the case of ClO. Scattered sunlight DOAS measurements, which are available from a number of Polar locations, are not sensitive for ClO, due to insufficient radiation intensity in the UV spectral region (<308nm) where this molecule is absorbing. Here we present the overall design and first results of a novel Long Path DOAS (Differential Optical Absorption Spectroscopy) instrument with an active light source suitable for the detection of ClO. It has been set up at the German Research Station Neumayer III in coastal Antarctica during the summer season 2015/16 and is planned to operate autonomously for at least one year. The instrument is able to detect - in addition to ClO - many trace gases absorbing in the UV

  9. Airborne Measurements and Emission Estimates of Greenhouse Gases and Other Trace Constituents From the 2013 California Yosemite Rim Wildfire

    NASA Technical Reports Server (NTRS)

    Yates, E. L.; Iraci, L. T.; Singh, H. B.; Tanaka, T.; Roby, M. C.; Hamill, P.; Clements, C. B.; Lareau, N.; Contezac, J.; Blake, D. R.; Simpson, I. J.; Wisthaler, A.; Mikoviny, T.; Diskin, G. S.; Beyersdorf, A. J.; Choi, Y.; Ryerson, T. B.; Jimenez, J. L.; Campuzano-Jost, P.; Loewenstein, M.; Gore, W.

    2015-01-01

    This paper presents airborne measurements of multiple atmospheric trace constituents including greenhouse gases (such as CO2, CH4, O3) and biomass burning tracers (such as CO, CH3CN) downwind of an exceptionally large wildfire. In summer 2013, the Rim wildfire, ignited just west of the Yosemite National Park, California, and burned over 250,000 acres of the forest during the 2-month period (17 August to 24 October) before it was extinguished. The Rim wildfire plume was intercepted by flights carried out by the NASA Ames Alpha Jet Atmospheric eXperiment (AJAX) on 29 August and the NASA DC-8, as part of SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys), on 26 and 27 August during its intense, primary burning period. AJAX revisited the wildfire on 10 September when the conditions were increasingly smoldering, with slower growth. The more extensive payload of the DC-8 helped to bridge key measurements that were not available as part of AJAX (e. g. CO). Data analyses are presented in terms of emission ratios (ER), emission factors (EF) and combustion efficiency and are compared with previous wildfire studies. ERs were 8.0 ppb CH4/(ppm CO2) on 26 August, 6.5 ppb CH4 (ppm CO2)1 on 29 August and 18.3 ppb CH4 (ppm CO2)1 on 10 September 2013. The increase in CH4 ER from 6.5 to 8.0 ppb CH4/(ppm CO2) during the primary burning period to 18.3 ppb CH4/(ppm CO2) during the fire's slower growth period likely indicates enhanced CH4 emissions from increased smoldering combustion relative to flaming combustion. Given the magnitude of the Rim wildfire, the impacts it had on regional air quality and the limited sampling of wildfire emissions in the western United States to date, this study provides a valuable dataset to support forestry and regional air quality management, including observations of ERs of a wide number of species from the Rim wildfire.

  10. Measurement of Trace Water Vapor in a Carbon Dioxide Removal Assembly Product Stream

    NASA Technical Reports Server (NTRS)

    Wormhoudt, Joda; Shorter, Joanne H.; McManus, J. Barry; Nelson, David D.; Zahniser, Mark S.; Freedman, Andrew; Campbell, Melissa; Chang, Clarence T.; Smith, Frederick D.

    2004-01-01

    The International Space Station Carbon Dioxide Removal Assembly (CDRA) uses regenerable adsorption technology to remove carbon dioxide (COP) from cabin air. Product water vapor measurements from a CDRA test bed at the NASA Marshall Space Flight Center were made using a tunable infrared diode laser differential absorption spectrometer (TILDAS) provided by NASA Glenn Research Center. The TILDAS instrument exceeded all the test specifications, including sensitivity, dynamic range, time response, and unattended operation. During the COP desorption phase, water vapor concentrations as low as 5 ppmv were observed near the peak of CO2 evolution, rising to levels of approx. 40 ppmv at the end of a cycle. Periods of high water concentration (>100 ppmv) were detected and shown to be caused by an experimental artifact. Measured values of total water vapor evolved during a single desorption cycle were as low as 1 mg.

  11. Dating of young groundwater using four anthropogenic trace gases (SF6, SF5CF3, CFC-12 and Halon-1301): methodology and first results.

    PubMed

    Bartyzel, Jakub; Rozanski, Kazimierz

    2016-01-01

    A dedicated, GC-based analytical system is presented which allows detection of four anthropogenic trace gases (SF6, SF5CF3, CFC-12 and Halon-1301) in a single water sample, with detection limits and measurement uncertainties sufficiently low to employ them as quantitative indicators of groundwater age. The gases dissolved in water are extracted in the field using the method based on a dynamic head-space concept. In the laboratory, the investigated gases are cryogenically enriched, separated and measured using an electron capture detector. Reproducibility of the analyses is in the order of 2-5 %. The investigated tracers were measured in several production wells located in the recharge area of an intensively exploited aquifer in southern Poland. While the piston-flow ages of groundwater in the investigated wells revealed internal consistency, they appeared to be generally smaller than the ages derived from time series of tritium content in those wells, interpreted by lumped-parameter models. This difference stems mainly from significantly longer travel times of tritium through the unsaturated zone, when compared to the gaseous tracers being used. The results of this study highlight the benefits of using multiple tracing in quantifying timescales of groundwater flow in shallow aquifer systems. PMID:26863003

  12. Aerodynamics control of a cave with a high environmental stability by trace gases monitoring (Castañar de Íbor, Spain)

    NASA Astrophysics Data System (ADS)

    Sanchez-Moral, S.; Fernandez-Cortes, A.; Cuezva, S.; Canaveras, J. C.; Abella, R.

    2009-04-01

    High-accuracy monitoring of a "low energy" cave (Castañar de Íbor, Spain) determined the temporal evolution of the aerodynamics processes and ventilation rate by tracking CO2 and 222Rn levels over a twelve-month period. Beside the general patterns of cave microclimate throughout an annual cycle, some particular microclimatic processes are described with regard to the gases exchange between cave and outer atmosphere. Special attention is paid to the key role of the isolation effect of host rock and soil on the confined cave atmosphere, determined by the water saturation state of this double-membrane. In this sense we focus on the complicate microclimatic functional relationship between the meteorological and cave microclimate conditions and the diffusion and flow of trace gases from the fractures and the pore system of soil and host rock to cave atmosphere. Finally, inferences are drawn about the physical mechanisms controlling the short-term fluctuations of trace gases levels on cave air, such as barometric fluxes and forced ventilation due to uncontrolled opening of cave entrance. The application of the knowledge regarding mass and energy fluxes involved in the subterranean environments is also discussed.

  13. Dating of young groundwater using four anthropogenic trace gases (SF6, SF5CF3, CFC-12 and Halon-1301): methodology and first results.

    PubMed

    Bartyzel, Jakub; Rozanski, Kazimierz

    2016-01-01

    A dedicated, GC-based analytical system is presented which allows detection of four anthropogenic trace gases (SF6, SF5CF3, CFC-12 and Halon-1301) in a single water sample, with detection limits and measurement uncertainties sufficiently low to employ them as quantitative indicators of groundwater age. The gases dissolved in water are extracted in the field using the method based on a dynamic head-space concept. In the laboratory, the investigated gases are cryogenically enriched, separated and measured using an electron capture detector. Reproducibility of the analyses is in the order of 2-5 %. The investigated tracers were measured in several production wells located in the recharge area of an intensively exploited aquifer in southern Poland. While the piston-flow ages of groundwater in the investigated wells revealed internal consistency, they appeared to be generally smaller than the ages derived from time series of tritium content in those wells, interpreted by lumped-parameter models. This difference stems mainly from significantly longer travel times of tritium through the unsaturated zone, when compared to the gaseous tracers being used. The results of this study highlight the benefits of using multiple tracing in quantifying timescales of groundwater flow in shallow aquifer systems.

  14. Measuring fluxes of trace gases and energy between ecosystems and the atmosphere - the state and future of the eddy covariance method.

    PubMed

    Baldocchi, Dennis

    2014-12-01

    The application of the eddy covariance flux method to measure fluxes of trace gas and energy between ecosystems and the atmosphere has exploded over the past 25 years. This opinion paper provides a perspective on the contributions and future opportunities of the eddy covariance method. First, the paper discusses the pros and cons of this method relative to other methods used to measure the exchange of trace gases between ecosystems and the atmosphere. Second, it discusses how the use of eddy covariance method has grown and evolved. Today, more than 400 flux measurement sites are operating world-wide and the duration of the time series exceed a decade at dozens of sites. Networks of tower sites now enable scientists to ask scientific questions related to climatic and ecological gradients, disturbance, changes in land use, and management. The paper ends with discussions on where the field of flux measurement is heading. Topics discussed include role of open access data sharing and data mining, in this new era of big data, and opportunities new sensors that measure a variety of trace gases, like volatile organic carbon compounds, methane and nitrous oxide, and aerosols, may yield.

  15. More than just CO2: Multiple trace gas exchange measurements at a temperate mountain grassland

    NASA Astrophysics Data System (ADS)

    Wohlfahrt, Georg; Hammerle, Albin; Hörtnagl, Lukas; Bamberger, Ines; Hansel, Armin

    2015-04-01

    Ecosystems exchange a large number of different trace gases to/from the atmosphere, however the vast majority of FLUXNET sites quantifies only the fluxes of carbon dioxide and when assessing the carbon or greenhouse gas balance neglect other carbon or greenhouse gas fluxes. This causes an overestimation of the role of carbon dioxid exchange for the ecosystem carbon and greenhouse gas balance, the magnitude of which is largely unconstrained Here we use the eddy covariance method (and variants thereof) with a large variety of analytical methods to quantify the exchange of multiple trace gases to/from a mountain grassland, partly for a time period of over a decade. The monitored trace gas fluxes cover: carbon dioxide, methane, nitrous oxide, carbon monoxide and several volatile organic compounds. The main result of our study is that carbon dioxide is the major contributor to the gaseous carbon and greenhouse gas budget at this temperate mountain grassland, which however may be significantly modulated by other trace gases may, at least during some years. Differences between source and sink periods for the different trace gases and the underlying drivers are discussed and annual budgets, for some compounds covering multiple years up to decades, are presented. We conclude that multiple trace gas flux measurements help to elucidate the importance of the exchange of carbon dioxide for the ecosystem carbon and greenhouse gas budget.

  16. Chemical Gradient and Inter-hemispheric Distribution of Selected Organic Trace Gases in the Tropical Tropopause Layer Over the Western Pacific

    NASA Astrophysics Data System (ADS)

    Navarro, M. A.; Atlas, E. L.; Schauffler, S.; Donets, V.; Lueb, R.; Hendershot, R.; Gabbard, S.; Saiz-Lopez, A.; Rodriguez, X.; Kinnison, D. E.; Lamarque, J. F.; Zhu, X.; Pope, L.

    2014-12-01

    Hydrocarbons and short-lived species play an important role in the chemistry of the upper troposphere/lower stratosphere (UT/LS) region. Their distribution, vertical structure and variability provide information about emission sources and transport. Furthermore, the characterization of short-lived organic halogens defines the reactive halogen budget and the conditions for the stratospheric chemistry that affects ozone depletion rates. The chemical composition of the air masses entering the stratosphere depends on the chemical and physical processes that occur during their transitions through the Tropical Tropopause Layer (TTL). It is well known that convective systems effectively transport short-lived trace gases to the UT. However, the overall impact of these processes on the distribution and budget of trace gases is not well known since only high altitude aircraft can reach this region of the atmosphere (>13-14 Km) During the recent field campaign of the Airborne Tropical Tropopause Experiment (ATTREX) and the Convective Transport of Active Species in the Tropics (CONTRAST), carried out in Guam during January-March 2014, the Whole Air Samplers (GWAS and AWAS) collected approximately 1200 samples to examine the tropical convection of the west pacific and its influence on the distribution of the short-lived species from the bottom of the TTL to the lower stratosphere. Measurement of a wide range of hydrocarbons, halocarbons, organic nitrates and solvents were carried out in the field using a combination of gas chromatography with mass selective, flame ionization, and electron capture detectors. In addition, model simulations of selected hydrocarbon and organic trace gases were performed with the chemistry climate model CAM-Chem to evaluate the chemical gradients and inter-hemispheric distributions. In this presentation we will show the gradients and inter-hemispheric distributions from the measurements and compare them with the model results.

  17. Application of ion-induced nucleation mass spectrometry in the analysis of trace gases evolved from a polyimide film during the thermal curing stages

    NASA Technical Reports Server (NTRS)

    Smith, A. C.

    1982-01-01

    Trace gases evolved from a polyimide film during its thermal curing stages have been studied using ion-induced nucleation mass spectrometry. The technique involved exposing the test gas sample to a low energy beta source and recording the masses of the ion-induced molecular clusters formed in the reaction chamber. On the basis of the experimentally observed molecular cluster spectra, it has been concluded that the dominant trace component had a molecular weight of 87 atomic mass units. This component has been identified as a molecule of dimethylacetamide (DMAC) which had been used as a solvent in the preparation of the test polyimide specimen. This identification has been further confirmed by comparing the spectra of the test gas sample and the DMAC calibration sample obtained with a conventional mass spectrometer. The advantages of the ion-induced nucleation mass spectrometer versus the conventional mass spectrometer are discussed.

  18. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, Santi; Kulkarni, Sudhir S.

    1986-01-01

    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 plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

  19. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, S.; Kulkarni, S.S.

    1986-08-26

    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 plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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

  1. Determination of trace impurities in titanium dioxide by direct solid sampling electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Dočekal, Bohumil; Vojtková, Blanka

    2007-03-01

    A true direct solid sampling electrothermal atomic absorption spectrometry method with Zeeman-effect background correction (Analytik Jena ZEEnit 60 AAS) was developed for the determination of As, Cd, Hg, Pb, Sb and Zn in powdered titanium dioxide of pharmaceutical, food and cosmetics grade. The interaction of the titanium matrix and graphite surface of the sample carrier boat in a transversely heated graphite tube atomizer was investigated. Conversion of titanium dioxide to interfering TiO 2-TiC-liquid phase, running out the sampling boat, was observed at temperatures above 2000 °C. The temperature program was optimized accordingly for these volatile analytes in atomization and cleaning steps in order to prevent this interference and to prolong significantly the analytical lifetime of the boat to more than one thousand runs. For all elements, calibration by aqueous standard addition method, by wet-chemically analyzed samples with different content of analytes and/or by dosing one sample in different amounts, were proved as adequate quantification procedures. Linear dynamic calibration working ranges can be considerably expanded up to two orders of magnitude within one measurement run by applying three-field dynamic mode of the Zeeman background correction system. The results obtained by true direct solid sampling technique are compared with those of other independent, mostly wet-chemical methods. Very low limits of detection (3 σ criterion) of true solid sampling technique of 21, 0.27, 24, 3.9, 6.3 and 0.9 ng g - 1 were achieved for As, Cd, Hg, Pb, Sb and Zn, respectively.

  2. Trace Gas Emissions Data from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, and models and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. Collections under the broad heading of Trace Gas Emissions are organized as Fossil-Fuel CO2 Emissions, Land-Use CO2 Emissions, Soil CO2 Emissions, and Methane.

  3. Simultaneous removal of SO2 and trace As2O3 from flue gas: mechanism, kinetics study, and effect of main gases on arsenic capture.

    PubMed

    Li, Yuzhong; Tong, Huiling; Zhuo, Yuqun; Li, Yan; Xu, Xuchang

    2007-04-15

    Sulfur dioxide (SO2) and trace elements are pollutants derived from coal combustion. This study focuses on the simultaneous removal of S02 and trace arsenic oxide (As2O3) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range. Experiments have been performed on a thermogravimetric analyzer (TGA). The interaction mechanism between As2O3 and CaO is studied via XRD detection. Calcium arsenate [Ca3(AsO4)2] is found to be the reaction product in the range of 600-1000 degrees C. The ability of CaO to absorb As2O3 increases with the increasing temperature over the range of 400-1000 degrees C. Through kinetics analysis, it has been found that the rate constant of arsenate reaction is much higher than that of sulfate reaction. SO2 presence does not affect the trace arsenic capture either in the initial reaction stage when CaO conversion is relatively low or in the later stage when CaO conversion is very high. The product of sulfate reaction, CaS04, is proven to be able to absorb As2O3. The coexisting CO2 does not weaken the trace arsenic capture either.

  4. Analysis of minerals containing dissolved traces of the fluid phase components water and carbon dioxide

    NASA Technical Reports Server (NTRS)

    Freund, Friedemann

    1991-01-01

    Substantial progress has been made towards a better understanding of the dissolution of common gas/fluid phase components, notably H2O and CO2, in minerals. It has been shown that the dissolution mechanisms are significantly more complex than currently believed. By judiciously combining various solid state analytical techniques, convincing evidence was obtained that traces of dissolved gas/fluid phase components undergo, at least in part, a redox conversion by which they split into reduced H2 and and reduced C on one hand and oxidized oxygen, O(-), on the other. Analysis for 2 and C as well as for any organic molecules which may form during the process of co-segregation are still impeded by the omnipresent danger of extraneous contamination. However, the presence of O(-), an unusual oxidized form of oxygen, has been proven beyond a reasonable doubt. The presence of O(-) testifies to the fact that a redox reaction must have taken place in the solid state involving the dissolved traces of gas/fluid phase components. Detailed information on the techniques used and the results obtained are given.

  5. Uncertainties in the current knowledge of some atmospheric trace gases associated with U.S. agriculture: a review.

    PubMed

    Krupa, Sagar; Booker, Fitzerald; Bowersox, Van; Lehmann, Christopher; Lehmann, Chris Topher; Grantz, David

    2008-08-01

    Approximately 80 different crop species are grown in the United States in widely differing geographic areas, climatic and edaphic conditions, and management practices. Although the majority of cultivated acreage in the United States is planted with only about 10 primary crops, uncertainties associated with trace gas emissions arise from: (1) limited data availability, (2) inaccurate estimates because of large temporal and spatial variability in trace gas composition and magnitude of trace gas emissions from agricultural activities, (3) differing characteristics of pollutant emissions from highly dispersed animal feed-lots, and (4) limited understanding of the emissions of semi-volatile organic compounds (SVOCs) associated with agriculture. Although emission issues are of concern, so also is atmospheric deposition to cropping systems, including wet and dry nitrogen, minerals, and organic compounds. These can have feedback effects on trace gas emissions. Overall, the many gaps in our understanding of these aspects of agricultural systems deserve serious attention.

  6. Detection of Matrix Elements and Trace Impurities in Cu(In, Ga)Se2 Photovoltaic Absorbers Using Surface Analytical Techniques.

    PubMed

    Kim, Min Jung; Lee, Jihye; Kim, Seon Hee; Kim, Haidong; Lee, Kang-Bong; Lee, Yeonhee

    2015-10-01

    Chalcopyrite Cu(In, Ga)Se2 (CIGS) thin films are well known as the next-generation solar cell materials notable for their high absorption coefficient for solar radiation, suitable band gap, and ability for deposition on flexible substrate materials, allowing the production of highly flexible and lightweight solar panels. To improve solar cell performances, a quantitative and depth-resolved elemental analysis of photovoltaic thin films is much needed. In this study, Cu(In, Ga)Se2 thin films were prepared on molybdenum back contacts deposited on soda-lime glass substrates via three-stage evaporation. Surface analyses via AES and SIMS were used to characterize the CIGS thin films and compare their depth profiles. We determined the average concentration of the matrix elements, Cu, In, Ga, and Se, using ICP-AES, XRF, and EPMA. We also obtained depth profiling results using TOF-SIMS, magnetic sector SIMS and AES, and APT, a sub-nanometer resolution characterization technique that enables three-dimensional elemental mapping. The SIMS technique, with its high detection limit and ability to obtain the profiles of elements in parallel, is a powerful tool for monitoring trace elements in CIGS thin films. To identify impurities in a CIGS layer, the distribution of trace elements was also observed according to depth by SIMS and APT.

  7. The tropical forest and fire emissions experiment: Trace gases emitted by smoldering logs and dung from deforestation and pasture fires in Brazil

    NASA Astrophysics Data System (ADS)

    Christian, Ted J.; Yokelson, Robert J.; Carvalho, JoãO. A.; Griffith, David W. T.; Alvarado, Ernesto C.; Santos, José C.; Neto, Turibio Gomes Soares; Veras, Carlos A. Gurgel; Hao, Wei Min

    2007-09-01

    Earlier work showed that Amazonian biomass burning produces both lofted and initially unlofted emissions in large amounts. A mobile, Fourier transform infrared spectrometer (FTIR) measured the unlofted emissions of 17 trace gases from residual smoldering combustion (RSC) of logs as part of the Tropical Forest and Fire Emissions Experiment (TROFFEE) during the 2004 Amazonian dry season. The RSC emissions were highly variable and the few earlier RSC measurements lay near the high end of combustion efficiency observed in this study. Fuel consumption by RSC was ˜5% of total for a planned deforestation fire. Much regional RSC probably occurs in the residual woody debris burned during pasture maintenance fires. RSC could increase estimated total fire emissions for the Amazon region by 20-50% for several important VOC. FTIR emissions measurements of burning dung (in a pasture) showed high emission ratios for acetic acid and ammonia to CO (6.6 ± 3.4% and 8.9 ± 2.1%). Large emissions of nitrogen containing trace gases from burning dung and crop waste could mean that biomass burning in India produces more particle mass than previously assumed. Measurements of late-stage kiln emissions suggested that VOC/CO may increase as carbonization is extended. A cook stove emitted many VOC and NH3 far outside the range observed for open wood cooking fires. Enclosed/vented cooking stoves may change the chemistry of the smoke that is emitted.

  8. Detection of Matrix Elements and Trace Impurities in Cu(In, Ga)Se2 Photovoltaic Absorbers Using Surface Analytical Techniques.

    PubMed

    Kim, Min Jung; Lee, Jihye; Kim, Seon Hee; Kim, Haidong; Lee, Kang-Bong; Lee, Yeonhee

    2015-10-01

    Chalcopyrite Cu(In, Ga)Se2 (CIGS) thin films are well known as the next-generation solar cell materials notable for their high absorption coefficient for solar radiation, suitable band gap, and ability for deposition on flexible substrate materials, allowing the production of highly flexible and lightweight solar panels. To improve solar cell performances, a quantitative and depth-resolved elemental analysis of photovoltaic thin films is much needed. In this study, Cu(In, Ga)Se2 thin films were prepared on molybdenum back contacts deposited on soda-lime glass substrates via three-stage evaporation. Surface analyses via AES and SIMS were used to characterize the CIGS thin films and compare their depth profiles. We determined the average concentration of the matrix elements, Cu, In, Ga, and Se, using ICP-AES, XRF, and EPMA. We also obtained depth profiling results using TOF-SIMS, magnetic sector SIMS and AES, and APT, a sub-nanometer resolution characterization technique that enables three-dimensional elemental mapping. The SIMS technique, with its high detection limit and ability to obtain the profiles of elements in parallel, is a powerful tool for monitoring trace elements in CIGS thin films. To identify impurities in a CIGS layer, the distribution of trace elements was also observed according to depth by SIMS and APT. PMID:26726401

  9. TRACE GAS CONCENTRATIONS IN SMALL STREAMS OF THE GEORGIA PIEDMONT

    EPA Science Inventory

    Seventeen headwater watersheds within the SFBR watershed ranging from 0.5 to 3.4 km2 were selected. We have been monitoring concentrations of the trace gases nitrous oxide, methane, and carbon dioxide, and other parameters (T, conductivity, dissolved oxygen, pH, nutrients, flow r...

  10. Influence of trace metals on carbon dioxide evolution from a Yolo soil

    SciTech Connect

    Chang, F.-H.; Broadbent, F.E.

    1982-01-01

    We measured carbon dioxide production in Yolo silt loam amended with alfalfa meal and sewage sludge after the addition of solutions of chromium, cadmium, copper, lead, manganese, and zinc at concentrations ranging from 0 to 400 parts per million. Quantities of these metals extractable with water, KNO/sub 3/, DTPA, and HNO/sub 3/ were determined at the end of the experiment. Threshold concentrations of metals, defined as the concentration required for 10 percent inhibition of CO/sub 2/ production, were in the sequence Pb>Cd>Cu>Mn = Zn. An addition of only 8.6 ppm of Cr to this soil is sufficient to inhibit CO/sub 2/ evolution by 10 percent, whereas the addition of about 27 ppm of Pb would be required to produce the same effect.

  11. Where do California's greenhouse gases come from?

    SciTech Connect

    Fischer, Marc

    2009-01-01

    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.

  12. Where do California's greenhouse gases come from?

    ScienceCinema

    Fischer, Marc

    2016-07-12

    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.

  13. Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

    USGS Publications Warehouse

    Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

    2014-01-01

    Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

  14. Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

    NASA Astrophysics Data System (ADS)

    Porubsky, W. P.; Weston, N. B.; Moore, W. S.; Ruppel, C.; Joye, S. B.

    2014-04-01

    Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

  15. Turbulent fluxes and transfer of trace gases from ship-based measurements during TexAQS 2006

    NASA Astrophysics Data System (ADS)

    Grachev, Andrey A.; Bariteau, Ludovic; Fairall, Christopher W.; Hare, Jeffrey E.; Helmig, Detlev; Hueber, Jacques; Lang, E. Kathrin

    2011-07-01

    Air-sea/land turbulent fluxes of momentum, sensible heat, water vapor, carbon dioxide, and ozone are discussed on the basis of eddy covariance measurements made aboard the NOAA R/V Ronald H. Brown during the Texas Air Quality Study (TexAQS) in August-September 2006. The TexAQS 2006 field campaign focused on air pollution meteorology associated primarily with ozone and aerosol transport in the Houston/Galveston region and the nearby coastal zone. The ship-based complement of instrumentation was used for the boundary layer measurements over water (the Gulf of Mexico and various harbors/bay areas) and "over land" (specifically, 80 km inside the Houston Ship Channel). In this study we focus on direct comparisons of TexAQS 2006 flux observations with the Coupled Ocean-Atmosphere Response Experiment (COARE) bulk flux algorithm to investigate possible coastal and urban area influences. It is found that the average neutral drag coefficient can be about an order of magnitude larger over very rough urban areas than over the sea surface. However, a similar effect was not observed for the scalar transfer; that is, the neutral Stanton and Dalton numbers do not change significantly over different footprint surfaces. Our data suggest that the TexAQS 2006 region was generally a sink for surface ozone whether over water or over land. The turbulent flux of carbon dioxide was mostly negative (uptake by the surface) for measurements over waters of the Gulf of Mexico and some bays, but the flux becomes positive (release to the air) for inland regions. Both ozone and carbon dioxide turbulent fluxes above land were larger in magnitude compared to the over water measurements.

  16. Organic Halogen and Related Trace Gases in the Tropical Atmosphere: Results from Recent Airborne Campaigns Over the Pacific

    NASA Astrophysics Data System (ADS)

    Atlas, E. L.; Navarro, M. A.; Donets, V.; Schauffler, S.; Lueb, R.; Hendershot, R.; Gabbard, S.; Hornbrook, R. S.; Apel, E. C.; Riemer, D. D.; Pan, L.; Salawitch, R. J.; Nicely, J. M.; Montzka, S. A.; Miller, B.; Moore, F. L.; Elkins, J. W.; Hintsa, E. J.; Campos, T. L.; Quack, B.; Zhu, X.; Pope, L.

    2014-12-01

    Organic halogen gases, especially containing bromine and iodine, play a significant role as precursors to active halogen chemistry and ozone catalytic loss. Much of the reactive organic halogen originates from biological processes in the surface ocean, which can be quite variable by season and location. The tropics and coastal margins are potentially important sources that are being examined. The recent coordinated CONTRAST/ATTREX/CAST missions were conducted in the Western Tropical Pacific, a region that is a major transport pathway for tropospheric air entering the stratosphere. One of the goals of the missions was to identify sources, distributions, and transport of organic halogens from the ocean surface into the tropical lower stratosphere. The missions were conducted during the NH winter season, Jan-Feb, 2014. In this presentation, we will discuss the distributions and variability of organic halogen gases in the study region and will examine the input of organic halogen species into the Tropical Tropopause Layer (TTL). Comparison with other tracers, such as methyl nitrate and NMHC, will help identify source regions for these gases. We will focus on the measurements obtained in the CONTRAST and ATTREX missions with data from in-situ GC/MS measurements and whole air samples collected on the NSF GV and NASA Global Hawk aircraft. Comparisons with other recent airborne campaigns, such as HIPPO and TC4, and with several ship-based studies will provide an additional context for evaluating the variability of organic halogen species in the tropical atmosphere and their role in transporting reactive halogen compounds into the UT/LS.

  17. Spatial Variation of Methane and Other Trace Gases Detected on Mars: Interpretation with a General Circulation Model

    NASA Technical Reports Server (NTRS)

    Forget, F.; Haberle, B.; Montmessin, F.

    2005-01-01

    Several teams have recently reported the detection of methane in the Martian atmosphere [1-3]. Although the detection is at the limit of the instrument capacities, one of the most surprising findings by some of these teams is the apparent strong spatial variations observed in spite of the fact that a gas like methane was expected to have a relatively long lifetime in the Martian atmosphere and thus be well mixed. To better quantitatively understand how such spatial variations can form on Mars, we have performed multiple realistic 3D general circulation model simulations in which gases with different sources, lifetime or sinks are released and transported in the Martian atmosphere.

  18. High resolution imaging Fourier transform spectrometer with no moving components for the measurement of atmospheric trace gases

    NASA Astrophysics Data System (ADS)

    Mortimer, H.

    2014-12-01

    A high resolution Static Imaging Fourier Transform Spectrometer, SIFTS, with no moving parts has been developed for the detection of atmospheric gases. The instrument has been shown to have high spectral resolution (4 cm-1) and temporal resolution (10kHz) resolution in both the mid and near infrared and moderate spectral resolution (14cm-1) in the visible. This instrument has been developed for the remote sensing and in-situ measurements of atmospheric gases. It has been identified that due to the low mass and compact size of the instrument system, that the SIFTS could be deployed as a remote sensing instrument onboard a Earth Observation satellite or Unmanned Aerial Vehicle (UAV), or conversely as a radiosonde instrument for in-situ measurements of atmospheric gases. The technique is based on a static optical configuration whereby light is split into two paths and made to recombine along a focal plane producing an interference pattern. The spectral information is returned using a detector array to digitally capture the interferogram which can then be processed into a spectrum by applying a Fourier transform. As there are no moving components, the speed of measurement is determined by the frame rate of the detector array. Thus, this instrument has a temporal advantage over common Michelson FTIR instruments. Using a high speed Toshiba CCD line array, sensitive over the spectral region of 400 - 1100nm, spectra have been recorded at a rate of one every 100 microseconds. Using an uncooled microbolometer infrared detector array, sensitive over the spectral region of 2 to 15μm, the gases NH3, O3 and CH4 have been used to demonstrate the sensitivity of the SIFTS instrument. It has been shown that the Signal to Noise of the SIFTSMIR is >1200 using an integration time of 77msec. The novel optical design has reduced the optics to only 3 optical components, and the detector array, to generate and measure the interferogram. The experimental performance of the SIFTS instrument

  19. Use of molecular modeling to determine the interaction and competition of gases within coal for carbon dioxide sequestration

    SciTech Connect

    Jeffrey D. Evanseck; Jeffry D. Madura; Jonathan P. Mathews

    2006-04-21

    Molecular modeling was employed to both visualize and probe our understanding of carbon dioxide sequestration within a bituminous coal. A large-scale (>20,000 atoms) 3D molecular representation of Pocahontas No. 3 coal was generated. This model was constructed based on a the review data of Stock and Muntean, oxidation and decarboxylation data for aromatic clustersize frequency of Stock and Obeng, and the combination of Laser Desorption Mass Spectrometry data with HRTEM, enabled the inclusion of a molecular weight distribution. The model contains 21,931 atoms, with a molecular mass of 174,873 amu, and an average molecular weight of 714 amu, with 201 structural components. The structure was evaluated based on several characteristics to ensure a reasonable constitution (chemical and physical representation). The helium density of Pocahontas No. 3 coal is 1.34 g/cm{sup 3} (dmmf) and the model was 1.27 g/cm{sup 3}. The structure is microporous, with a pore volume comprising 34% of the volume as expected for a coal of this rank. The representation was used to visualize CO{sub 2}, and CH{sub 4} capacity, and the role of moisture in swelling and CO{sub 2}, and CH{sub 4} capacity reduction. Inclusion of 0.68% moisture by mass (ash-free) enabled the model to swell by 1.2% (volume). Inclusion of CO{sub 2} enabled volumetric swelling of 4%.

  20. A new WRF-Chem treatment for studying regional-scale impacts of cloud processes on aerosol and trace gases in parameterized cumuli

    NASA Astrophysics Data System (ADS)

    Berg, L. K.; Shrivastava, M.; Easter, R. C.; Fast, J. D.; Chapman, E. G.; Liu, Y.; Ferrare, R. A.

    2015-02-01

    A new treatment of cloud effects on aerosol and trace gases within parameterized shallow and deep convection, and aerosol effects on cloud droplet number, has been implemented in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) version 3.2.1 that can be used to better understand the aerosol life cycle over regional to synoptic scales. The modifications to the model include treatment of the cloud droplet number mixing ratio; key cloud microphysical and macrophysical parameters (including the updraft fractional area, updraft and downdraft mass fluxes, and entrainment) averaged over the population of shallow clouds, or a single deep convective cloud; and vertical transport, activation/resuspension, aqueous chemistry, and wet removal of aerosol and trace gases in warm clouds. These changes have been implemented in both the WRF-Chem chemistry packages as well as the Kain-Fritsch (KF) cumulus parameterization that has been modified to better represent shallow convective clouds. Testing of the modified WRF-Chem has been completed using observations from the Cumulus Humilis Aerosol Processing Study (CHAPS). The simulation results are used to investigate the impact of cloud-aerosol interactions on regional-scale transport of black carbon (BC), organic aerosol (OA), and sulfate aerosol. Based on the simulations presented here, changes in the column-integrated BC can be as large as -50% when cloud-aerosol interactions are considered (due largely to wet removal), or as large as +40% for sulfate under non-precipitating conditions due to sulfate production in the parameterized clouds. The modifications to WRF-Chem are found to account for changes in the cloud droplet number concentration (CDNC) and changes in the chemical composition of cloud droplet residuals in a way that is consistent with observations collected during CHAPS. Efforts are currently underway to port the changes described here to the latest version of WRF-Chem, and it is anticipated

  1. Source gases: Concentrations, emissions, and trends

    NASA Technical Reports Server (NTRS)

    Fraser, Paul J.; Harriss, Robert; Penkett, Stuart A.; Makide, Yoshihiro; Sanhueza, Eugenio; Alyea, Fred N.; Rowland, F. Sherwood; Blake, Don; Sasaki, Toru; Cunnold, Derek M.

    1991-01-01

    Source gases are defined as those gases that influence levels of stratospheric ozone (O3) by transporting species containing halogen, hydrogen, and nitrogen to the stratosphere. Examples are the CFC's, methane (CH4), and nitrous oxide (N2O). Other source gases that also come under consideration in an atmospheric O3 context are those that are involved in the O3 or hydroxyl (OH) radical chemistry of the troposphere. Examples are CH4, carbon monoxide (CO), and nonmethane hydrocarbons (NMHC's). Most of the source gases, along with carbon dioxide (CO2) and water vapor (H2O), are climatically significant and thus affect stratospheric O3 levels by their influence on stratospheric temperatures. Carbonyl sulphide (COS) could affect stratospheric O3 through maintenance of the stratospheric sulphate aerosol layer, which may be involved in heterogeneous chlorine-catalyzed O3 destruction. The previous reviews of trends and emissions of source gases, either from the context of their influence on atmospheric O3 or global climate change, are updated. The current global abundances and concentration trends of the trace gases are given in tabular format.

  2. Tunable diode laser based, one component instrument for open path measurements of trace concentrations of atmospheric gases

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. I.; Nadezhdinskij, A. I.; Stepanov, E. V.; Blokh, M. A.

    1993-02-01

    A simple tunable diode laser based system for routine monitoring of concentrations of atmospheric gases was developed. The instrument operation is based on a PbSnSe diode laser emitting radiation at about 4.7 microns, and InSb photodiodes. Usually, the laser operates in multimode regime with an optical power of about 0.1 mW in the mode. The system consists of the emitter-receiver unit (including optical elements and a cryostat with liquid nitrogen, which contains the diode laser and two InSb photodetectors) and the retroreflector. The instrument has two limitations: (1) the gas should have absorption lines within the mid-IR spectral region (4-8 microns) and (2) the gas should be stable enough while in the instrument's cell to allow periodic calibration of the instument. The instrument, which in the manufacturing stage, is presently used for carbon monoxide monitoring.

  3. EDDY RESOLVING NUTRIENT ECODYNAMICS IN THE GLOBAL PARALLEL OCEAN PROGRAM AND CONNECTIONS WITH TRACE GASES IN THE SULFUR, HALOGEN AND NMHC CYCLES

    SciTech Connect

    S. CHU; S. ELLIOTT

    2000-08-01

    Ecodynamics and the sea-air transfer of climate relevant trace gases are intimately coupled in the oceanic mixed layer. Ventilation of species such as dimethyl sulfide and methyl bromide constitutes a key linkage within the earth system. We are creating a research tool for the study of marine trace gas distributions by implementing coupled ecology-gas chemistry in the high resolution Parallel Ocean Program (POP). The fundamental circulation model is eddy resolving, with cell sizes averaging 0.15 degree (lat/long). Here we describe ecochemistry integration. Density dependent mortality and iron geochemistry have enhanced agreement with chlorophyll measurements. Indications are that dimethyl sulfide production rates must be adjusted for latitude dependence to match recent compilations. This may reflect the need for phytoplankton to conserve nitrogen by favoring sulfurous osmolytes. Global simulations are also available for carbonyl sulfide, the methyl halides and for nonmethane hydrocarbons. We discuss future applications including interaction with atmospheric chemistry models, high resolution biogeochemical snapshots and the study of open ocean fertilization.

  4. Trace gas emissions from chaparral and boreal forest fires

    NASA Technical Reports Server (NTRS)

    Cofer, Wesley R., III; Levine, Joel S.; Sebacher, Daniel I.; Winstead, Edward L.; Riggan, Philip J.; Stocks, Brian J.; Brass, James A.; Ambrosia, Vincent G.

    1989-01-01

    Using smoke samples collected during low-level helicopter flights, the mixing ratios of CO2, CO, CH4, total nonmethane hydrocarbons, H2, and N2O over burning chaparral in southern California and over a burning boreal forest site in northern Ontario, Canada, were determined. Carbon dioxide-normalized emission ratios were determined for each trace gas for conditions of flaming, mixed, and smoldering combustion. The emission ratios for these trace gases were found to be highest for the smoldering combustion, generally thought to be the least efficient combustion stage. However, high emission ratios for these gases could be also produced during very vigorous flaming combustion.

  5. Measurement of gas/water uptake coefficients for trace gases active in the marine environment. [Annual report

    SciTech Connect

    Davidovits, P.; Worsnop, D.W.; Zahniser, M.S.; Kolb, C.E.

    1992-02-01

    Ocean produced reduced sulfur compounds including dimethylsulfide (DMS), hydrogen sulfide (H{sub 2}S), carbon disulfide (CS{sub 2}), methyl mercaptan (CH{sub 3}CH) and carbonyl sulfide (OCS) deliver a sulfur burden to the atmosphere which is roughly equal to sulfur oxides produced by fossil fuel combustion. These species and their oxidation products dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO{sub 2}) and methane sulfonic acid (MSA) dominate aerosol and CCN production in clean marine air. Furthermore, oxidation of reduced sulfur species will be strongly influenced by NO{sub x}/O{sub 3} chemistry in marine atmospheres. The multiphase chemical processes for these species must be understood in order to study the evolving role of combustion produced sulfur oxides over the oceans. We have measured the chemical and physical parameters affecting the uptake of reduced sulfur compounds, their oxidation products, ozone, and nitrogen oxides by the ocean`s surface, and marine clouds, fogs, and aerosols. These parameters include: gas/surface mass accommodation coefficients; physical and chemically modified (effective) Henry`s law constants; and surface and liquid phase reaction constants. These parameters are critical to understanding both the interaction of gaseous trace species with cloud and fog droplets and the deposition of trace gaseous species to dew covered, fresh water and marine surfaces.

  6. Constraining Gas Diffusivity-Soil Water Content Relationships in Forest Soils Using Surface Chamber Fluxes and Depth Profiles of Multiple Trace Gases

    NASA Astrophysics Data System (ADS)

    Dore, J. E.; Kaiser, K.; Seybold, E. C.; McGlynn, B. L.

    2012-12-01

    Forest soils are sources of carbon dioxide (CO2) to the atmosphere and can act as either sources or sinks of methane (CH4) and nitrous oxide (N2O), depending on redox conditions and other factors. Soil moisture is an important control on microbial activity, redox conditions and gas diffusivity. Direct chamber measurements of soil-air CO2 fluxes are facilitated by the availability of sensitive, portable infrared sensors; however, corresponding CH4 and N2O fluxes typically require the collection of time-course physical samples from the chamber with subsequent analyses by gas chromatography (GC). Vertical profiles of soil gas concentrations may also be used to derive CH4 and N2O fluxes by the gradient method; this method requires much less time and many fewer GC samples than the direct chamber method, but requires that effective soil gas diffusivities are known. In practice, soil gas diffusivity is often difficult to accurately estimate using a modeling approach. In our study, we apply both the chamber and gradient methods to estimate soil trace gas fluxes across a complex Rocky Mountain forested watershed in central Montana. We combine chamber flux measurements of CO2 (by infrared sensor) and CH4 and N2O (by GC) with co-located soil gas profiles to determine effective diffusivity in soil for each gas simultaneously, over-determining the diffusion equations and providing constraints on both the chamber and gradient methodologies. We then relate these soil gas diffusivities to soil type and volumetric water content in an effort to arrive at empirical parameterizations that may be used to estimate gas diffusivities across the watershed, thereby facilitating more accurate, frequent and widespread gradient-based measurements of trace gas fluxes across our study system. Our empirical approach to constraining soil gas diffusivity is well suited for trace gas flux studies over complex landscapes in general.

  7. Dating and tracing groundwater resources in central Québec with noble gases, 14C and water chemistry

    NASA Astrophysics Data System (ADS)

    Vautour, G.; Pinti, D. L.; Castro, M. C.; Barbecot, F.; Larocque, M.; Hall, C. M.

    2011-12-01

    Canada water supply is derived mainly from lakes and rivers while groundwater accounts for less than 30% of the demand. Climatic and anthropogenic stress is endangering this natural resource. This study is part of a Quebec-funded program to characterize groundwater resources from major basins to ensure adequate water quality and management. The Bécancour River catchment area, 200 km NE of Montréal, is studied for this purpose. The region extends from the Appalachian Mts. down to the St. Lawrence River. Water chemistry shows the occurrence of Ca,Na-HCO3, Ca-HCO3, Na-HCO3 and NaCl waters, mainly recharged in the Appalachians and flowing to the St. Lawrence River. Aquifers are also recharged locally through Quaternary sandy deposits throughout the plain. Main aquifers are found both in unconfined and confined Quaternary sands intercalated with clays, and also locally in fractured Ordovician carbonates. To identify groundwater flow paths and to estimate water residence times, a multi-isotopic study involving noble gases, 14C and U, Th isotopes was initiated. Noble gas preliminary results were obtained on two transects, one along the downward flow path and the second perpendicular to the first, along a deeper sinclinorium with NaCl waters (TDS =170-705 mg/L). The 3He/4He ratios versus 4He/20Ne clearly points to mixing between three water bodies. The first has been recharged very recently displaying a near-atmospheric ratio of 0.79 Ra (Ra=atmospheric 3He/4He ratio of 1.386 x 10-6) and a 4He/20Ne of 0.2 close to the Air Saturated Water value, i.e. the ratio of atmospheric He and Ne dissolved in groundwater. The second water body is slightly older and shows the occurrence of tritiogenic 3He (3Hetri) excesses up to 1.07x10-13 ccSTP/g. These waters are found along the transect parallel to the main flow path. Using a local tritium decay curve and measured 3Hetri, an age of 19-20 years is suggested. The third water body contains large amounts of radiogenic 4He produced by U

  8. CONTRACE - Convective transport of trace gases into the middle and upper troposphere over Europe: Budget and impact on chemistry

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Contrace Team

    2003-04-01

    The objective of the CONTRACE project is to investigate the impact of convective transported (and/or frontal lifting of) air masses from the boundary layer on the trace gas composition and budget in the middle and upper troposphere over Europe. The first airborne field experiment was carried out from Southern Germany in fall 2001. The DLR research aircraft Falcon was equipped with a complex instrumentation to measure NO, NOy, CO, CO2, O3, J(NO2), acetone, SO2, ions, H2O2, formaldehyde, NMHC, J(O1D) and particles. An extensive set of chemical and meteorological forecast products, including trajectory calculations, was developed and used in combination with satellite images (METEOSAT and GOES) to plan the flights. A passive tracer for surface emissions (CO) was included in the forecast models to separate the regional and intercontinental transport of polluted air masses. During all CONTRACE flights in the free troposphere polluted layers with different origin (European/North American) and distinctly enhanced trace gas mixing ratios (especially NOy and CO) were successfully observed. On November 14th the chemical forecast models indicated lifting of surface emissions in the Mediterranean area ahead of a cold front system that passed over Central and Southern Europe. The airborne measurements showed that these emissions were lifted up to 3 km altitude over Corsica. Further, several pollution layers were found in the middle and upper troposphere (4-7 km) over Corsica. The outflow from nearby thunderstorms to west probably caused these enhancements in the CO (120 ppbv), NO (1.5 ppbv) and NOy (3 ppbv) signals. For the first time it succeeded to guide the Falcon aircraft very precisely into pollution plumes transported all the way from North America. Until now these plumes had only been observed by coincidence. The forecast models showed how pollution plumes were lifted over Eastern North America, ahead of approaching cold fronts, in so-called warm conveyor belts (WCB) and

  9. Investigation of reactions between trace gases and functional CuO nanospheres and octahedrons using NEXAFS-TXM imaging

    NASA Astrophysics Data System (ADS)

    Henzler, Katja; Heilemann, Axel; Kneer, Janosch; Guttmann, Peter; Jia, He; Bartsch, Eckhard; Lu, Yan; Palzer, Stefan

    2015-12-01

    In order to take full advantage of novel functional materials in the next generation of sensorial devices scalable processes for their fabrication and utilization are of great importance. Also understanding the processes lending the properties to those materials is essential. Among the most sought-after sensor applications are low-cost, highly sensitive and selective metal oxide based gas sensors. Yet, the surface reactions responsible for provoking a change in the electrical behavior of gas sensitive layers are insufficiently comprehended. Here, we have used near-edge x-ray absorption fine structure spectroscopy in combination with x-ray microscopy (NEXAFS-TXM) for ex-situ measurements, in order to reveal the hydrogen sulfide induced processes at the surface of copper oxide nanoparticles, which are ultimately responsible for triggering a percolation phase transition. For the first time these measurements allow the imaging of trace gas induced reactions and the effect they have on the chemical composition of the metal oxide surface and bulk. This makes the new technique suitable for elucidating adsorption processes in-situ and under real operating conditions.

  10. Investigation of reactions between trace gases and functional CuO nanospheres and octahedrons using NEXAFS-TXM imaging.

    PubMed

    Henzler, Katja; Heilemann, Axel; Kneer, Janosch; Guttmann, Peter; Jia, He; Bartsch, Eckhard; Lu, Yan; Palzer, Stefan

    2015-01-01

    In order to take full advantage of novel functional materials in the next generation of sensorial devices scalable processes for their fabrication and utilization are of great importance. Also understanding the processes lending the properties to those materials is essential. Among the most sought-after sensor applications are low-cost, highly sensitive and selective metal oxide based gas sensors. Yet, the surface reactions responsible for provoking a change in the electrical behavior of gas sensitive layers are insufficiently comprehended. Here, we have used near-edge x-ray absorption fine structure spectroscopy in combination with x-ray microscopy (NEXAFS-TXM) for ex-situ measurements, in order to reveal the hydrogen sulfide induced processes at the surface of copper oxide nanoparticles, which are ultimately responsible for triggering a percolation phase transition. For the first time these measurements allow the imaging of trace gas induced reactions and the effect they have on the chemical composition of the metal oxide surface and bulk. This makes the new technique suitable for elucidating adsorption processes in-situ and under real operating conditions. PMID:26631608

  11. An automated analyzer to measure surface-atmosphere exchange fluxes of water soluble inorganic aerosol compounds and reactive trace gases.

    PubMed

    Thomas, Rick M; Trebs, Ivonne; Otjes, René; Jongejan, Piet A C; Ten Brink, Harry; Phillips, Gavin; Kortner, Michael; Meixner, Franz X; Nemitz, Eiko

    2009-03-01

    Here, we present a new automated instrument for semicontinuous gradient measurements of water-soluble reactive trace gas species (NH3, HNO3, HONO, HCl, and SO2) and their related aerosol compounds (NH4+, NO3-, Cl-, SO4(2-)). Gas and aerosol samples are collected simultaneously at two heights using rotating wet-annular denuders and steam-jet aerosol collectors, respectively. Online (real-time) analysis using ion chromatography (IC) for anions and flow injection analysis (FIA) for NH4+ and NH3 provide a half-hourly averaged gas and aerosol gradients within each hour. Through the use of syringe pumps, IC preconcentration columns, and high-quality purified water, the system achieves detection limits (3sigma-definition) under field conditions of typically: 136/207,135/114, 29/ 22,119/92, and 189/159 ng m(-3) for NH3/NH4+, HNO3/NO3-, HONO/ NO2-, HCl/Cl- and SO2/SO4(2-), respectively. The instrument demonstrates very good linearity and accuracy for liquid and selected gas phase calibrations over typical ambient concentration ranges. As shown by examples from field experiments, the instrument provides sufficient precision (3-9%), even at low ambient concentrations, to resolve vertical gradients and calculate surface-atmosphere exchange fluxes undertypical meteorological conditions of the atmospheric surface layer using the aerodynamic gradient technique. PMID:19350912

  12. Investigation of reactions between trace gases and functional CuO nanospheres and octahedrons using NEXAFS-TXM imaging

    PubMed Central

    Henzler, Katja; Heilemann, Axel; Kneer, Janosch; Guttmann, Peter; Jia, He; Bartsch, Eckhard; Lu, Yan; Palzer, Stefan

    2015-01-01

    In order to take full advantage of novel functional materials in the next generation of sensorial devices scalable processes for their fabrication and utilization are of great importance. Also understanding the processes lending the properties to those materials is essential. Among the most sought-after sensor applications are low-cost, highly sensitive and selective metal oxide based gas sensors. Yet, the surface reactions responsible for provoking a change in the electrical behavior of gas sensitive layers are insufficiently comprehended. Here, we have used near-edge x-ray absorption fine structure spectroscopy in combination with x-ray microscopy (NEXAFS-TXM) for ex-situ measurements, in order to reveal the hydrogen sulfide induced processes at the surface of copper oxide nanoparticles, which are ultimately responsible for triggering a percolation phase transition. For the first time these measurements allow the imaging of trace gas induced reactions and the effect they have on the chemical composition of the metal oxide surface and bulk. This makes the new technique suitable for elucidating adsorption processes in-situ and under real operating conditions. PMID:26631608

  13. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis – Part II: Evaluation of measured and modeled trace gases and particle size distributions

    SciTech Connect

    Ochoa, Carlos; Baumgardner, Darrel; Grutter, M.; Allan, James D.; Fast, Jerome D.; Rappengluck, B.

    2012-10-31

    This study extends the work of Baumgardner et al. (2009) in which measurements of trace gases and particles at a remote, high-altitude mountain site 60 km from Mexico City were analyzed with respect to the origin of air masses. In the current evaluation, the temperature, water vapor, ozone (O3), carbon monoxide (CO), acyl peroxy nitrate (APN) and particle size distributions (PSDs) of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM) were simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. The model prediction of the diurnal trends of the gases were well correlated with the measurements before the regional boundary layer reached the measurement site but underestimated the concentrations after that time. The differences are caused by an overly rapid growth of the boundary layer by the model with too much dilution. There also appears to be more O3 produced by photochemical production, downwind of the emission sources, than predicted by the model. The measured and modeled PSDs compare very well with respect to their general shape and diameter of the peak concentrations. The spectra are log normally distributed with most of the mass in the accumulation mode and the geometric diameter centered at 200 ±20 nm, with little observed or predicted change with respect to the origin of the air mass or the time when the RBL is above the Altzomoni research. Only the total mass changed with time and air mass origin. The invariability of the average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation after six hours of aging downwind of the major sources of anthropogenic emissions in Mexico’s Megapolis.

  14. Effects of moisture and burning on soil-atmosphere exchange of trace carbon gases in a southern African savanna

    NASA Astrophysics Data System (ADS)

    Zepp, Richard G.; Miller, William L.; Burke, Roger A.; Parsons, Dirk A. B.; Scholes, Mary C.

    1996-10-01

    Soil fluxes of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) were measured during a period of extreme drought at semi-arid savanna sites located in the Kruger National Park (KNP), South Africa, as part of the SAFARI-92 experiments (Sept., 1992). Soil respiration in this savanna was little affected by burning, but was strongly stimulated by addition of moisture. Mean soil respiration from the dry soil was 0.4 g C m-2 d-1 in open savanna plots that had been burned biennially and 0.5 g C m-2 d-1 in woody savanna plots. A light natural rain (about 0.6 mm) increased the CO2 flux in the open savanna sites by 5-fold but the effect was short-lived. A simulated heavy rain (25 mm of added distilled water) increased CO2 fluxes by over an order of magnitude in both burned and control sites and the emissions remained over 5 times pre-wetting values during a week of drying. Over 65% of our measurements indicated no significant soil-atmosphere methane exchange; most of the few non-zero measurements indicated a small (<1 mg CH4-C m-2 d-1) flux of methane to the atmosphere. Soil-atmosphere CH4 exchange was not significantly affected by either burning the grass layer or by the addition of distilled water to the soil. The net soil CO fluxes, which generally increased with increasing soil temperature, were positive up to 356 × 109 molecules cm-2 s-1 with an average of 8.8 × 1010 molecules cm-2 s-1 for the untreated open savanna plots. After burning, the fluxes rose by over an order of magnitude but dropped back to preburn levels within a few days. Observed CO fluxes were higher than those previously reported for southern Africa savannas during non-drought conditions. Added moisture had little effect on CO fluxes during the 3-week period of SAFARI-92.

  15. Emission factors of fine particles, carbonaceous aerosols and traces gases from road vehicles: Recent tests in an urban tunnel in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Zhang, Yanli; Wang, Xinming; Li, Guanghui; Yang, Weiqiang; Huang, Zhonghui; Zhang, Zhou; Huang, Xinyu; Deng, Wei; Liu, Tengyu; Huang, Zuzhao; Zhang, Zhanyi

    2015-12-01

    Motor vehicles contribute primarily and secondarily to air quality problems due to fine particle (PM2.5) and ozone (O3) pollution in China's megacities. Characterizing vehicle emission with the rapid change of vehicle numbers and fleet compositions is vital for both bottom-up emission survey and top-down source apportioning. To obtain emission factors (EFs) of PM2.5, carbonaceous aerosols and trace gases for road vehicles, in urban Guangzhou we conducted a field campaign in 2014 in the Zhujiang Tunnel, a heavily burdened tunnel with about 40,000 motor vehicles passing through each of its two separated bores per day. PM2.5 and volatile organic compounds (VOCs) were sampled for offline analysis while trace gases including SO2, NOx and CO were measured online and in situ. An eddy covariance system with an integrated 3-D sonic anemometer was also adopted to measure CO2 and winds inside the tunnel. We recorded an average fleet composition of 61% light-duty gasoline vehicles (LDVs) + 12% heavy-duty diesel vehicles (HDVs) + 27% liquefied petroleum gas vehicles (LPGVs), and EFs of 82.7 ± 28.3, 19.3 ± 4.7 and 13.3 ± 3.3 mg veh-1 km-1, respectively, for PM2.5, organic carbon (OC) and elemental carbon (EC). These EFs were respectively 23.4%, 18.3% and 72.3% lower when compared to that measured in the same tunnel in 2004. EFs of PM2.5, OC and EC were higher at night time (148 ± 126, 29 ± 24 and 21 ± 18 mg veh-1 km-1, respectively) due to significantly elevated fractions of HDVs in the traffic fleets. An average ratio of OC to EC 1.45 from this tunnel study was much higher than that of ∼0.5 in previous tunnel studies. The EFs of SO2, NOx, CO, CO2 and NMHCs for road traffic were also obtained from our tunnel tests, and they were 20.7 ± 2.9, (1.29 ± 0.2)E+03, (3.10 ± 0.68)E+03, (3.90 ± 0.49)E+05, and 448 ± 39 mg veh-1 km-1, respectively.

  16. A new WRF-Chem treatment for studying regional-scale impacts of cloud processes on aerosol and trace gases in parameterized cumuli

    DOE PAGES

    Berg, L. K.; Shrivastava, M.; Easter, R. C.; Fast, J. D.; Chapman, E. G.; Liu, Y.; Ferrare, R. A.

    2015-02-24

    A new treatment of cloud effects on aerosol and trace gases within parameterized shallow and deep convection, and aerosol effects on cloud droplet number, has been implemented in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) version 3.2.1 that can be used to better understand the aerosol life cycle over regional to synoptic scales. The modifications to the model include treatment of the cloud droplet number mixing ratio; key cloud microphysical and macrophysical parameters (including the updraft fractional area, updraft and downdraft mass fluxes, and entrainment) averaged over the population of shallow clouds, or a single deep convectivemore » cloud; and vertical transport, activation/resuspension, aqueous chemistry, and wet removal of aerosol and trace gases in warm clouds. These changes have been implemented in both the WRF-Chem chemistry packages as well as the Kain–Fritsch (KF) cumulus parameterization that has been modified to better represent shallow convective clouds. Testing of the modified WRF-Chem has been completed using observations from the Cumulus Humilis Aerosol Processing Study (CHAPS). The simulation results are used to investigate the impact of cloud–aerosol interactions on regional-scale transport of black carbon (BC), organic aerosol (OA), and sulfate aerosol. Based on the simulations presented here, changes in the column-integrated BC can be as large as –50% when cloud–aerosol interactions are considered (due largely to wet removal), or as large as +40% for sulfate under non-precipitating conditions due to sulfate production in the parameterized clouds. The modifications to WRF-Chem are found to account for changes in the cloud droplet number concentration (CDNC) and changes in the chemical composition of cloud droplet residuals in a way that is consistent with observations collected during CHAPS. Efforts are currently underway to port the changes described here to the latest version of WRF-Chem, and it

  17. A new WRF-Chem treatment for studying regional-scale impacts of cloud processes on aerosol and trace gases in parameterized cumuli

    SciTech Connect

    Berg, L. K.; Shrivastava, M.; Easter, R. C.; Fast, J. D.; Chapman, E. G.; Liu, Y.; Ferrare, R. A.

    2015-02-24

    A new treatment of cloud effects on aerosol and trace gases within parameterized shallow and deep convection, and aerosol effects on cloud droplet number, has been implemented in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) version 3.2.1 that can be used to better understand the aerosol life cycle over regional to synoptic scales. The modifications to the model include treatment of the cloud droplet number mixing ratio; key cloud microphysical and macrophysical parameters (including the updraft fractional area, updraft and downdraft mass fluxes, and entrainment) averaged over the population of shallow clouds, or a single deep convective cloud; and vertical transport, activation/resuspension, aqueous chemistry, and wet removal of aerosol and trace gases in warm clouds. These changes have been implemented in both the WRF-Chem chemistry packages as well as the Kain–Fritsch (KF) cumulus parameterization that has been modified to better represent shallow convective clouds. Testing of the modified WRF-Chem has been completed using observations from the Cumulus Humilis Aerosol Processing Study (CHAPS). The simulation results are used to investigate the impact of cloud–aerosol interactions on regional-scale transport of black carbon (BC), organic aerosol (OA), and sulfate aerosol. Based on the simulations presented here, changes in the column-integrated BC can be as large as –50% when cloud–aerosol interactions are considered (due largely to wet removal), or as large as +40% for sulfate under non-precipitating conditions due to sulfate production in the parameterized clouds. The modifications to WRF-Chem are found to account for changes in the cloud droplet number concentration (CDNC) and changes in the chemical composition of cloud droplet residuals in a way that is consistent with observations collected during CHAPS. Efforts are currently underway to port the changes described here to the latest version of WRF-Chem, and it is

  18. Airborne and ground-based measurements of the trace gases and particles emitted from prescribed fires in the United States

    SciTech Connect

    Burling, Ian; Yokelson, Robert J.; Akagi, Sheryl; Urbanski, Shawn; Wold, Cyle E.; Griffith, David WT; Johnson, Timothy J.; Reardon, James; Weise, David

    2011-12-07

    We measured the emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous suggestions that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured the emissions in the convective smoke plume from our airborne platform at the same time the unlofted residual smoldering combustion emissions were measured with our ground-based platform after the flame front passed through. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including significant 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts of smoke that disperses at ground level, and we show that the normally-ignored unlofted emissions can also significantly impact estimates of total emissions. Preliminary evidence of large emissions of monoterpenes was seen in the residual smoldering spectra, but we have not yet quantified these emissions. These data should lead to an improved capacity to model the impacts of biomass burning in similar

  19. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    NASA Astrophysics Data System (ADS)

    Burling, I. R.; Yokelson, R. J.; Akagi, S. K.; Urbanski, S. P.; Wold, C. E.; Griffith, D. W. T.; Johnson, T. J.; Reardon, J.; Weise, D. R.

    2011-12-01

    We have measured emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our ground-based platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts for smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.

  20. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    SciTech Connect

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.; Warneke, C.; Stockwell, C. E.; de Gouw, J.; Akagi, S. K.; Urbanski, S. P.; Veres, P.; Roberts, J. M.; Kuster, W. C.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Hosseini, S.; Miller, J. W.; Cocker III, D. R.; Jung, H.; Weise, D. R.

    2013-01-01

    Vegetative fuels commonly consumed in prescribed fires were collected from five locations in the southeastern and southwestern U.S. and burned in a series of 77 fires at the U.S. Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. An additional 152 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. As phase II of this study, we conducted airborne and ground-based sampling of the emissions from real prescribed fires mostly in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These extensive field measurements of emission factors (EF) for temperate biomass burning are useful both for modeling and to examine the representativeness of our lab fire EF. The lab/field EF ratio for the pine understory fuels was not statistically different from one, on average. However, our lab EF for “smoldering compounds” emitted by burning the semi

  1. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    NASA Astrophysics Data System (ADS)

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.; Warneke, C.; Stockwell, C. E.; de Gouw, J.; Akagi, S. K.; Urbanski, S. P.; Veres, P.; Roberts, J. M.; Kuster, W. C.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Hosseini, S.; Miller, J. W.; Cocker, D. R., III; Jung, H.; Weise, D. R.

    2013-01-01

    An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF) are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for the pine understory fuels was not

  2. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    NASA Astrophysics Data System (ADS)

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.; Warneke, C.; Stockwell, C. E.; de Gouw, J.; Akagi, S. K.; Urbanski, S. P.; Veres, P.; Roberts, J. M.; Kuster, W. C.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Hosseini, S.; Miller, J. W.; Cocker, D. R., III; Jung, H.; Weise, D. R.

    2012-08-01

    An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds - NMOC) were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF) are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for the pine understory fuels was not

  3. Effects of land use on surface–atmosphere exchanges of trace gases and energy in Borneo: comparing fluxes over oil palm plantations and a rainforest

    PubMed Central

    Fowler, David; Nemitz, Eiko; Misztal, Pawel; Di Marco, Chiara; Skiba, Ute; Ryder, James; Helfter, Carole; Cape, J. Neil; Owen, Sue; Dorsey, James; Gallagher, Martin W.; Coyle, Mhairi; Phillips, Gavin; Davison, Brian; Langford, Ben; MacKenzie, Rob; Muller, Jennifer; Siong, Jambery; Dari-Salisburgo, Cesare; Di Carlo, Piero; Aruffo, Eleonora; Giammaria, Franco; Pyle, John A.; Hewitt, C. Nicholas

    2011-01-01

    This paper reports measurements of land–atmosphere fluxes of sensible and latent heat, momentum, CO2, volatile organic compounds (VOCs), NO, NO2, N2O and O3 over a 30 m high rainforest canopy and a 12 m high oil palm plantation in the same region of Sabah in Borneo between April and July 2008. The daytime maximum CO2 flux to the two canopies differs by approximately a factor of 2, 1200 mg C m−2 h−1 for the oil palm and 700 mg C m−2 h−1 for the rainforest, with the oil palm plantation showing a substantially greater quantum efficiency. Total VOC emissions are also larger over the oil palm than over the rainforest by a factor of 3. Emissions of isoprene from the oil palm canopy represented 80 per cent of the VOC emissions and exceeded those over the rainforest in similar light and temperature conditions by on average a factor of 5. Substantial emissions of estragole (1-allyl-4-methoxybenzene) from the oil palm plantation were detected and no trace of this VOC was detected in or above the rainforest. Deposition velocities for O3 to the rainforest were a factor of 2 larger than over oil palm. Emissions of nitrous oxide were larger from the soils of the oil palm plantation than from the soils of the rainforest by approximately 25 per cent. It is clear from the measurements that the large change in the species composition generated by replacing rainforest with oil palm leads to profound changes in the net exchange of most of the trace gases measured, and thus on the chemical composition of the boundary layer over these surfaces. PMID:22006962

  4. Effects of land use on surface-atmosphere exchanges of trace gases and energy in Borneo: comparing fluxes over oil palm plantations and a rainforest.

    PubMed

    Fowler, David; Nemitz, Eiko; Misztal, Pawel; Di Marco, Chiara; Skiba, Ute; Ryder, James; Helfter, Carole; Cape, J Neil; Owen, Sue; Dorsey, James; Gallagher, Martin W; Coyle, Mhairi; Phillips, Gavin; Davison, Brian; Langford, Ben; MacKenzie, Rob; Muller, Jennifer; Siong, Jambery; Dari-Salisburgo, Cesare; Di Carlo, Piero; Aruffo, Eleonora; Giammaria, Franco; Pyle, John A; Hewitt, C Nicholas

    2011-11-27

    This paper reports measurements of land-atmosphere fluxes of sensible and latent heat, momentum, CO(2), volatile organic compounds (VOCs), NO, NO(2), N(2)O and O(3) over a 30 m high rainforest canopy and a 12 m high oil palm plantation in the same region of Sabah in Borneo between April and July 2008. The daytime maximum CO(2) flux to the two canopies differs by approximately a factor of 2, 1200 mg C m(-2) h(-1) for the oil palm and 700 mg C m(-2) h(-1) for the rainforest, with the oil palm plantation showing a substantially greater quantum efficiency. Total VOC emissions are also larger over the oil palm than over the rainforest by a factor of 3. Emissions of isoprene from the oil palm canopy represented 80 per cent of the VOC emissions and exceeded those over the rainforest in similar light and temperature conditions by on average a factor of 5. Substantial emissions of estragole (1-allyl-4-methoxybenzene) from the oil palm plantation were detected and no trace of this VOC was detected in or above the rainforest. Deposition velocities for O(3) to the rainforest were a factor of 2 larger than over oil palm. Emissions of nitrous oxide were larger from the soils of the oil palm plantation than from the soils of the rainforest by approximately 25 per cent. It is clear from the measurements that the large change in the species composition generated by replacing rainforest with oil palm leads to profound changes in the net exchange of most of the trace gases measured, and thus on the chemical composition of the boundary layer over these surfaces.

  5. Carbon Dioxide Collection and Purification System for Mars

    NASA Technical Reports Server (NTRS)

    Clark, D. Larry; Trevathan, Joseph R.

    2001-01-01

    One of the most abundant resources available on Mars is the atmosphere. The primary constituent, carbon dioxide, can be used to produce a wide variety of consumables including propellants and breathing air. The residual gases can be used for additional pressurization tasks including supplementing the oxygen partial pressure in human habitats. A system is presented that supplies pure, high-pressure carbon dioxide and a separate stream of residual gases ready for further processing. This power-efficient method freezes the carbon dioxide directly from the atmosphere using a pulse-tube cryocooler. The resulting CO2 mass is later thawed in a closed pressure vessel, resulting in a compact source of liquefied gas at the vapor pressure of the bulk fluid. Results from a demonstration system are presented along with analysis and system scaling factors for implementation at larger scales. Trace gases in the Martian atmosphere challenge the system designer for all carbon dioxide acquisitions concepts. The approximately five percent of other gases build up as local concentrations of CO2 are removed, resulting in diminished performance of the collection process. The presented system takes advantage of this fact and draws the concentrated residual gases away as a useful byproduct. The presented system represents an excelient volume and mass solution for collecting and compressing this valuable Martian resource. Recent advances in pulse-tube cryocooler technology have enabled this concept to be realized in a reliable, low power implementation.

  6. Measurements of Trace Gases and Particles in Fresh and Aged Smoke from a Chaparral Fire in California

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Craven, J. S.; Taylor, J. W.; McMeeking, G. R.; Yokelson, R. J.; Burling, I. R.; Alvarado, M. J.; Seinfeld, J.; Coe, H.; Urbanski, S. P.

    2010-12-01

    /cm3, providing further evidence that significant OH concentrations can occur in biomass burning plumes. A detailed photochemical model simulated many of the trace gas observations well when it included a heterogeneous HONO source. These results are compared with other plume aging studies conducted in Africa and Mexico and they confirm the rapid post-emission plume chemistry that can occur on time scales of just minutes to hours. Understanding the evolution of biomass burning smoke is a critical step towards improving the accuracy of chemical transport models.

  7. Analysis of motor vehicle emissions over eastern Los Angeles, California from in-situ airborne measurements of trace gases and particulates during CalNex

    NASA Astrophysics Data System (ADS)

    Pollack, I. B.; Ryerson, T. B.; Trainer, M.; Frost, G. J.; Holloway, J. S.; McKeen, S. A.; Peischl, J.; Fahey, D. W.; Perring, A.; Schwarz, J. P.; Spackman, J. R.

    2010-12-01

    In-situ measurements of trace gases and particulates were acquired on the instrumented NOAA WP-3D aircraft during the CalNex (California Research at the Nexus of Air Quality and Climate Change) field study in May and June 2010. Multiple daytime research flights under similar meteorological conditions provide a sufficient data set for characterizing automobile emissions over the eastern Los Angeles (eLA) area of the South Coast air basin. Ratios of nitrogen oxides (NOx) and black carbon (BC) to carbon monoxide (CO) are used to isolate emissions of light duty vehicles from those of medium/heavy duty diesel trucks. Observations in the mixed boundary layer for the eLA area are separated according to latitude, longitude, and altitude. Industrial influences are eliminated by filtering the data according to SO2 mixing ratio and wind direction. The resulting correlations show weekday-to-weekend differences in enhancement ratios of NOx to CO and BC to CO, indicating a general tendency for higher emissions from heavy duty vehicles during the week. The CalNex data over eLA in 2010 will be compared to eLA data from a research flight in May 2002 by the WP-3D aircraft during the Intercontinental Transport and Chemical Transformation (ITCT) field study.

  8. Study of trace gases in the Martian atmosphere: Groundbased observation using SUBARU/IRCS and development of radiative transfer model for MEX/PFS limb observation

    NASA Astrophysics Data System (ADS)

    Aoki, S.; Nakagawa, H.; Kasaba, Y.; Giuranna, M.; Geminale, A.; Sindoni, G.; Sagawa, H.; Mendrok, J.; Kasai, Y.; Formisano, V.

    2012-09-01

    We observed Martian atmosphere to investigate CH4, H2O, and HDO on 30 November 2011, 4-5 January 2012, and 12 April 2012 using SUBARU/ IRCS. This observation aims to verify CH4 on Mars, constrain its source, and investigate the distribution of H2O/HDO ratio. Our observation covered possible source areas of CH4, i.e. the areas where the extend plumes of CH4 were detected by previous groundbased and MEX/PFS observations [1,2] and the potential mud volcanism areas [3,4]. This paper will show some preliminary results. Vertical profiles of these trace gases are crucial for understanding their chemistry and transportation. Limb observations by MEX/PFS are a powerful tool to retrieve vertical profiles of H2O, CO, and CH4. For this purpose, we adapted the SARTre model, a radiative transfer code which includes multiple scattering for limb geometry observations developed for the terrestrial atmosphere [5], to the Martian atmosphere. In order to validate our model, SARTre model for Martian limb, we first compared of our synthetic spectra in nadir geometry with the result from ARS [6] which has been widely used for previous studies of MEX/PFS nadir-observation. We concluded that the difference between them is small offset (below 3%) in the spectral range between 3000 and 3030 cm-1.

  9. Demonstration of superconducting sub-millimeter-wave limb emission sounder (SMILES) for observing trace gases in the middle atmosphere using the exposed facility of the Japanese experimental module (JEM) of the international space station

    NASA Astrophysics Data System (ADS)

    Masuko, Harunobu; Manabe, Takeshi; Seta, Masumichi; Kasai, Yasuko; Ochiai, Satoshi; Irimajiri, Yoshihisa; Inatani, Junji; Ikeda, Naomi; Nishibori, Toshiyuki; Iida, Yukiei; Fujii, Yasunori

    1999-01-01

    The sub-millimeter wavelength region is advantageous for high-precision observations of trace species in the stratosphere. A Superconducting Sub-Millimeter-wave Limb Emission Sounder (SMILES) is scheduled to demonstrate the measurements of extremely faint sub-millimeter-wave emissions of the atmospheric trace gases on the Exposed Facility (EF) of the Japanese Experimental Module (JEM) of the International Space Station in 2003. The applications of superconductivity and mechanical 4K-refrigerator in space will be demonstrated in the experiment. JEM/SMILES obtains the diurnal and seasonal variability in the global three-dimensional distributions of the stratospheric trace gases for quantitative understanding of the stratospheric ozone depletion and its effect on the climate change with respect to the relationships among chemical reaction processes and their relationships with atmospheric dynamics. JEM/SMILES utilizes the 640GHz band to measure the vertical profiles of trace gases involved in the stratospheric ozone depletion such as chlorine monoxide (CLO), bromine monoxide (BrO), etc., along with atmospheric temperature. JEM/SMILES employs Superconductor-Insulator-Superconductor (SIS) mixers to improve measurement precision and spatial resolution, thereby enabling us to quantitatively understand the interactive processes between chemistry and dynamics.

  10. Photochemistry of biogenic gases

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1989-01-01

    The relationship between the biosphere and the atmosphere is examined, emphasizing the composition and photochemistry and chemistry of the troposphere and stratosphere. The reactions of oxygen, ozone, and hydroxyl are reviewed and the fate of the biogenic gases ammonia, methane, reduced sulfur species, reduced halogen species, carbon monoxide, nitric oxide, nitrous oxide, nitrogen, and carbon dioxide are described. A list is given of the concentration and sources of the various gases.

  11. Raman spectra and cross sections of ammonia, chlorine, hydrogen sulfide, phosgene, and sulfur dioxide toxic gases in the fingerprint region 400-1400 cm-1

    NASA Astrophysics Data System (ADS)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Jeys, T. H.

    2016-02-01

    Raman spectra of ammonia (NH3), chlorine (Cl2), hydrogen sulfide (H2S), phosgene (COCl2), and sulfur dioxide (SO2) toxic gases have been measured in the fingerprint region 400-1400 cm-1. A relatively compact (<2'x2'x2'), sensitive, 532 nm 10 W CW Raman system with double-pass laser and double-sided collection was used for these measurements. Two Raman modes are observed at 934 and 967 cm-1 in NH3. Three Raman modes are observed in Cl2 at 554, 547, and 539 cm-1, which are due to the 35/35 35/37, and 37/37 Cl isotopes, respectively. Raman modes are observed at 870, 570, and 1151 cm-1 in H2S, COCl2, and SO2, respectively. Values of 3.68 ± 0.26x10-32 cm2/sr (3.68 ± 0.26x10-36 m2/sr), 1.37 ± 0.10x10-30 cm2/sr (1.37 ± 0.10x10-34 m2/sr), 3.25 ± 0.23x10-31 cm2/sr (3.25 ± 0.23x10-35 m2/sr), 1.63 ± 0.14x10-30 cm2/sr (1.63 ± 0.14x10-34 m2/sr), and 3.08 ± 0.22x10-30 cm2/sr (and 3.08 ± 0.22x10-34 m2/sr) were determined for the differential Raman cross section of the 967 cm-1 mode of NH3, sum of the 554, 547, and 539 cm-1 modes of Cl2, 870 cm-1 mode of H2S, 570 cm-1 mode of COCl2, and 1151 cm-1 mode of SO2, respectively, using the differential Raman cross section of 3.56 ± 0.14x10-31 cm2/sr (3.56 ± 0.14x10-35 m2/sr) for the 1285 cm-1 mode of CO2 as the reference.

  12. The Influence of Urban Emissions on Background Aerosols and Trace Gases in Amazonia as Seen in the GoAmazon2014/2015 Experiment.

    NASA Astrophysics Data System (ADS)

    Artaxo, P.; Martin, S. T.; Barbosa, H. M.; Brito, J.; Carbone, S.; Rizzo, L. V.; Andreae, M. O.; Pöhlker, C.; Souza, R. A. F. D.

    2015-12-01

    presented together with air mass trajectories following the evolution of aerosol and trace gases in GoAmazon2014. Research funded by INCT Global Change, CNPq and FAPESP.

  13. TRACKING THE EMISSION OF CARBON DIOXIDE BY NATION, SECTOR, AND FUEL TYPE: A TRACE GAS ACCOUNTING SYSTEM (TGAS)

    EPA Science Inventory

    The paper describes a new way to estimate an efficient econometric model of global emissions of carbon dioxide (CO2) by nation, sector, and fuel type. Equations for fuel intensity are estimated for coal, oil, natural gas, electricity, and heat for six sectors: agricultural, indus...

  14. Agricultural fires in the southeastern U.S. during SEAC4RS: Emissions of trace gases and particles and evolution of ozone, reactive nitrogen, and organic aerosol

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoxi; Zhang, Y.; Huey, L. G.; Yokelson, R. J.; Wang, Y.; Jimenez, J. L.; Campuzano-Jost, P.; Beyersdorf, A. J.; Blake, D. R.; Choi, Y.; St. Clair, J. M.; Crounse, J. D.; Day, D. A.; Diskin, G. S.; Fried, A.; Hall, S. R.; Hanisco, T. F.; King, L. E.; Meinardi, S.; Mikoviny, T.; Palm, B. B.; Peischl, J.; Perring, A. E.; Pollack, I. B.; Ryerson, T. B.; Sachse, G.; Schwarz, J. P.; Simpson, I. J.; Tanner, D. J.; Thornhill, K. L.; Ullmann, K.; Weber, R. J.; Wennberg, P. O.; Wisthaler, A.; Wolfe, G. M.; Ziemba, L. D.

    2016-06-01

    Emissions from 15 agricultural fires in the southeastern U.S. were measured from the NASA DC-8 research aircraft during the summer 2013 Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign. This study reports a detailed set of emission factors (EFs) for 25 trace gases and 6 fine particle species. The chemical evolution of the primary emissions in seven plumes was examined in detail for ~1.2 h. A Lagrangian plume cross-section model was used to simulate the evolution of ozone (O3), reactive nitrogen species, and organic aerosol (OA). Observed EFs are generally consistent with previous measurements of crop residue burning, but the fires studied here emitted high amounts of SO2 and fine particles, especially primary OA and chloride. Filter-based measurements of aerosol light absorption implied that brown carbon (BrC) was ubiquitous in the plumes. In aged plumes, rapid production of O3, peroxyacetyl nitrate (PAN), and nitrate was observed with ΔO3/ΔCO, ΔPAN/ΔNOy, and Δnitrate/ΔNOy reaching ~0.1, ~0.3, and ~0.3. For five selected cases, the model reasonably simulated O3 formation but underestimated PAN formation. No significant evolution of OA mass or BrC absorption was observed. However, a consistent increase in oxygen-to-carbon (O/C) ratios of OA indicated that OA oxidation in the agricultural fire plumes was much faster than in urban and forest fire plumes. Finally, total annual SO2, NOx, and CO emissions from agricultural fires in Arkansas, Louisiana, Mississippi, and Missouri were estimated (within a factor of ~2) to be equivalent to ~2% SO2 from coal combustion and ~1% NOx and ~9% CO from mobile sources.

  15. Modeling soil climate controls on the exchange of trace gases between the terrestrial biosphere and the atmosphere. Ph.D. Thesis

    SciTech Connect

    Frolking, S.E.

    1993-12-31

    Soil temperature and moisture profiles (soil climate) have a strong influence on the rate of trace gas exchange between the terrestrial biosphere and the atmosphere through the controls exerted on microbial processes and the physical exchange of gases. Principal controls of biological denitrification in mineral soils are the availability of carbon and nitrogen substrates and the soil anaerobic status. A process-oriented model of decomposition and denitrification in soils (DNDC) was modified to have a more detailed portrayal of these controls. In particular, a diffusive soil gas phase was added, along with a method for determining anaerobic and aerobic fractional volume within a soil profile. The model generally overestimated N2O fluxes when compared to field data from a sandy soil in Costa Rica, but captured the timing and shape of the brief flux episodes. Several modelling shortcomings are discussed, including the nature of the carbon substrates and the nature and dynamics of soil anaerobic fractional volume. Methane flux from wetland soils is generally correlated with soil temperature and depth to water table. A model of peat soil climate was developed and applied to a small, poor fen in southern New Hampshire. Temperature profiles and ice depth are in good agreement with field data, but depth to water table is more problematic. Field-based flux correlations to soil temperature, depth to water table, and weighted recent precipitation were developed. When used with the wetland soil climate model, much of the seasonal and shorter period flux variability was captured. The model was then driven by local weather data for 1926-1986; flux variability was dependent on both summer season temperatures and summer precipitation patterns. It is estimated that a five-year field study would capture most of the inter-annual variability.

  16. A study for development of emission factors for trace gases and carbonaceous particulate species from in situ burning of wheat straw in agricultural fields in india

    NASA Astrophysics Data System (ADS)

    Sahai, Shivraj; Sharma, C.; Singh, D. P.; Dixit, C. K.; Singh, Nahar; Sharma, P.; Singh, K.; Bhatt, S.; Ghude, S.; Gupta, V.; Gupta, Raj K.; Tiwari, M. K.; Garg, S. C.; Mitra, A. P.; Gupta, Prabhat K.

    Major crops subject to field burning of crop residue (FBCR) generated an estimated 284 Tg of residue in India, of which 40% was contributed by wheat in the year 2000. About 7.5% of this total generated wheat straw was subjected to on-site burning, that is expected to emit large amounts of trace gases and particulate matter (PM) to the atmosphere, whose country-specific estimates and emission factors (EFs) are presently not available. An in situ experiment for wheat straw burning was undertaken for developing India specific EFs. The EFs of CO2, CH4, CO, N2O, NOx, NO and NO2 were found to be 1787±36, 3.6±2.7, 28.1±20.1, 0.74±0.46, 1.70±1.68, 0.78±0.71 and 0.56±0.47gkg-1, whereas those for organic carbon (OC), black carbon (BC) and total carbon (TC) were 0.3±0.1, 0.2±0.1, and 0.5±0.2gkg-1, respectively. Although these EFs have been generated from a single field experiment nevertheless they address important information gap on FBCR in the region. Further, the total emissions of CH4, CO2, CO, N2O, NOx, NO, NO2, OC, BC and TC from wheat straw burning in India for the year 2000 was estimated as 68±51, 34435±682, 541±387, 14±9, 33±32, 15±14, 11±9, 6±2, 3±1 and 10±4 Gg, respectively.

  17. Continental pollution in the western Mediterranean basin: vertical profiles of aerosol and trace gases measured over the sea during TRAQA 2012 and SAFMED 2013

    NASA Astrophysics Data System (ADS)

    Di Biagio, C.; Doppler, L.; Gaimoz, C.; Grand, N.; Ancellet, G.; Raut, J.-C.; Beekmann, M.; Borbon, A.; Sartelet, K.; Attié, J.-L.; Ravetta, F.; Formenti, P.

    2015-08-01

    In this study we present airborne observations of aerosol and trace gases obtained over the sea in the western Mediterranean basin during the TRAQA (TRansport and Air QuAlity) and SAFMED (Secondary Aerosol Formation in the MEDiterranean) campaigns in summer 2012 and 2013. A total of 23 vertical profiles were measured up to 5000 m above sea level over an extended area (40-45° N and 2° W-12° E) including the Gulf of Genoa, southern France, the Gulf of Lion, and the Spanish coast. During TRAQA and SAFMED the study area experienced a wide range of meteorological conditions which favoured pollution export from different sources located around the basin. Also, several events of dust outflows were measured during the campaigns. Observations from the present study show that continental pollution largely affects the western Mediterranean both close to coastal regions and in the open sea as far as ~ 250 km from the coastline. The measured aerosol scattering coefficient varies between ~ 20 and 120 Mm-1, while carbon monoxide (CO) and ozone (O3) mixing ratios are in the range of 60-165 and 30-85 ppbv, respectively. Pollution reaches 3000-4000 m in altitude and presents a very complex and highly stratified structure characterized by fresh and aged layers both in the boundary layer and in the free troposphere. Within pollution plumes the measured particle concentration in the Aitken (0.004-0.1 μm) and accumulation (0.1-1.0 μm) modes is between ~ 30 and 5000-6000 scm-3 (standard cm-3), which is comparable to the aerosol concentration measured in continental areas under pollution conditions. Additionally, our measurements indicate the presence of highly concentrated Aitken layers (10 000-15 000 scm-3) observed both close to the surface and in the free troposphere, possibly linked to the influence of new particle formation (NPF) episodes over the basin.

  18. Application of the LIRIC algorithm for the characterization of aerosols during the Airborne Romanian Measurements of Aerosols and Trace gases (AROMAT) campaign

    NASA Astrophysics Data System (ADS)

    Stefanie, Horatiu; Nicolae, Doina; Nemuc, Anca; Belegante, Livio; Toanca, Florica; Ajtai, Nicolae; Ozunu, Alexandru

    2015-04-01

    The ESA/ESTEC AROMAT campaign (Airborne Romanian Measurements of Aerosols and Trace gases) was held between 1st and 14th of September 2014 with the purpose to test and inter-compare newly developed airborne and ground-based instruments dedicated to air quality studies in the context of validation programs of the forthcoming European Space Agency satellites (Sentinel 5P, ADM-Aeolus and EarthCARE). Ground-based remote sensing and airborne in situ measurements were made in southern Romania in order to assess the level and the variability of NO2 and particulate matter, focusing on two areas of interest: SW (Turceni), where many coal based power plants are operating, and SE (Bucharest), affected by intense traffic and partially by industrial pollution. In this paper we present the results obtained after the application of the Lidar - Radiometer Inversion Code (LIRIC) algorithm on combined lidar and sunphotometer data collected at Magurele, 6 km South Bucharest. Full lidar data sets in terms of backscatter signals at 355, 532 and 1064 nm, as well as depolarization at 532 nm were used and combined with Aerosol Robotic Network (AERONET) data, in order to retrieve the profiles of aerosol volume concentrations, separated as fine, spherical and spheroidal coarse modes. Preliminary results showed that aerosols generated by traffic and industrial activities were present in the Planetary Boundary Layer, while biomass burning aerosols transported from the Balkan Peninsula were detected in the upper layers. Acknowledgements: ***This work has been supported by Programme for Research- Space Technology and Advanced Research - STAR, project number 55/2013 - CARESSE. ***The financial support by the European Community's FP7 - PEOPLE 2011 under ITaRS Grant Agreement n° 289923 is gratefully acknowledged.

  19. Fiberoptic evanescent wave infrared spectroscopy of gases in liquids

    NASA Astrophysics Data System (ADS)

    Bunimovich, D.; Belotserkovsky, E.; Katzir, A.

    1995-04-01

    Silver halide optical fibers were used as attenuated total reflection elements for infrared evanescent wave spectroscopy of gases in liquids. The evanescent wave absorption spectra of chlorodifluoromethane (Freon-22) and carbon dioxide gases (CO2) in water were studied and the dependence on vapor pressure of the gas and temperature was investigated. Absorption peaks were easily traced and correlated well with those in the literature. The use of the infrared (IR) fibers in the fiberoptic evanescent wave spectroscopy system bypasses the difficulty of ordinary IR spectroscopy related to the strong IR absorption of most liquid solvents, and provides a flexible, easy, and inexpensive way of determining the presence and concentration of gases in liquids to within about 5% accuracy.

  20. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons,...

  1. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons,...

  2. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons,...

  3. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons,...

  4. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons,...

  5. Atmospheric pollutants and trace gases

    SciTech Connect

    Ranieri, A.; Schenone, G.; Lencioni, L.; Soldatini, G.F.

    1994-03-01

    Pumpkin [Cucurbita pepo (L.) cv. Ambassador] plants were grown under either nonfiltered or filtered ambient air in open-top field chambers (OTCs) near the urban area of Milan, Northern Italy. The effects of ambient air pollution on the enzymatic detoxfication system of the leaves, both in terms of activity and isoform pattern were investigated. The data on air quality showed that ozone was the main phytotoxic pollutant present in ambient air, reaching a 7 h mean of 63 nL L{sup -1} and a maximum hourly peak of 104 nL L{sup -1} The peroxidase and catalase activities increased fourfold and twofold, respectively in the nonfiltered air plants In comparison to the filtered air ones. The peroxidase patterns were very modified in the polluted plants. In contrast no significant changes were found in the activity and isoenzyme pattern of superoxide dismutase. The data reported here suggest that in field-grown pumpkin plants exposed to ambient levels of photooxidants, a stimulation of the peroxddase-catalase detoxification system takes place. 32 refs., 3 figs., 3 tabs.

  6. Satellite detection of effects due to increased atmospheric carbon dioxide.

    PubMed

    Kiehl, J T

    1983-11-01

    The use of satellites to detect climatic changes due to increased carbon dioxide was investigated. This method has several advantages over ground-based methods of monitoring climatic change. Calculations indicate that, by monitoring the outgoing longwave flux for small intervals in the 15-micrometer spectral region, changes in stratospheric temperatures due to doubled atmospheric carbon dioxide are large enough to be detected above the various sources of noise. This method can be extended to other spectral regions so that causal links between changes in outgoing longwave radiation due to other trace gases and the thermal structure of the atmosphere could be established. PMID:17746202

  7. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    SciTech Connect

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2013-02-01

    In October-November 2011 we measured the trace gas emission factors from 7 prescribed fires in South Carolina, U.S. using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analyses. The fires were intended to emulate high-intensity burns as they were lit during the dry season and in most cases represented stands that had not been treated with prescribed burns in 10+ years, if at all. A total of 97 trace gas species are reported here from both airborne and ground-based platforms making this one of the most detailed field studies of fire emissions to date. The measurements included the first data for a suite of monoterpene compounds emitted via distillation of plant tissues during real fires. The known chemistry of the monoterpenes and their measured abundance of ~0.40% of CO (molar basis), ~3.9% of NMOC (molar basis), and ~21% of organic aerosol (mass basis), suggests that they impacted post-emission formation of ozone, aerosol, and small organic trace gases such as methanol and formaldehyde in the sampled plumes. The variability in the terpene emissions in South Carolina (SC) fire plumes was high and, in general, the speciation of the emitted gas-phase non-methane organic compounds was surprisingly different from that observed in a similar study in nominally similar pine forests in North Carolina ~20 months earlier. It is likely that the slightly different ecosystems, time of year and the precursor variability all contributed to the variability in plume chemistry observed in this study and in the literature. The ΔHCN/ΔCO emission ratio, however, is fairly consistent at 0.9 ± 0.06 % for airborne fire measurements in coniferous-dominated ecosystems further confirming the value of HCN as a good biomass burning indicator/tracer. The SC results also support an earlier finding that C3-C4 alkynes may be of use as biomass burning indicators on the time-scale of

  8. Community Radiative Transfer Model Applications - A Study of the Retrieval of Trace Gases in the Atmosphere from Cross-track Infrared Sounder (CrIS) Data of a Full-spectral Resolution

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Nalli, N. R.; Tan, C.; Zhang, K.; Iturbide, F.; Wilson, M.; Zhou, L.

    2015-12-01

    The Community Radiative Transfer Model (CRTM) [3] operationally supports satellite radiance assimilation for weather forecasting, sensor data verification, and the retrievals of satellite products. The CRTM has been applied to UV and visible sensors, infrared and microwave sensors. The paper will demonstrate the applications of the CRTM, in particular radiative transfer in the retrieva algorithm. The NOAA Unique CrIS/ATMS Processing System (NUCAPS) operationally generates vertical profiles of atmospheric temperature (AVTP) and moisture (AVMP) from Suomi NPP Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) measurements. Current operational CrIS data have reduced spectral resolution: 1.25 cm-1 for a middle wave band and 2.5 cm-1 for a short-wave wave band [1]. The reduced spectral data largely degraded the retrieval accuracy of trace gases. CrIS full spectral data are also available now which have single spectral resolution of 0.625 cm-1 for all of the three bands: long-wave band, middle wave band, and short-wave band. The CrIS full-spectral resolution data is critical to the retrieval of trace gases such as O3, CO [2], CO2, and CH4. In this paper, we use the Community Radiative Transfer Model (CRTM) to study the impact of the CrIS spectral resolution on the retrieval accuracy of trace gases. The newly released CRTM version 2.2.1 can simulates Hamming-apodized CrIS radiance of a full-spectral resolution. We developed a small utility that can convert the CRTM simulated radiance to un-apodized radiance. The latter has better spectral information which can be helpful to the retrievals of the trace gases. The retrievals will be validated using both NWP model data as well as the data collected during AEROSE expeditions [4]. We will also discuss the sensitivity on trace gases between apodized and un-apodized radiances. References[1] Gambacorta, A., et al.(2013), IEEE Lett., 11(9), doi:10.1109/LGRS.2014.230364, 1639-1643. [2] Han, Y., et

  9. Measurements of Atmospheric Trace Gases Over NW Pacific During IOC 2002 Cruise - Pollutants Transported From East Asia and Biogenic Species Emitted From Ocean

    NASA Astrophysics Data System (ADS)

    Kato, S.; Ui, T.; Uematsu, M.; Kajii, Y.

    2002-12-01

    The R/V Melville cruised from Osaka (Japan) on May 1st to Hawaii on Jun 5th, as a project of Intergovernmental Oceanographic Commission (IOC) 2002. During this cruise, atmospheric trace gases (O3, CO, DMS, many hydrocarbons, and halocarbons) were measured. It is expected that polluted air as well as Kosa from east Asia is transported to the Pacific in this season. On the west Pacific near from Japan, the concentrations of anthropogenic species were strongly affected by the meteorological condition. And the hydrocarbon concentrations have not very large difference at the east of Japan (about 145°E) and at 170°E in the same latitude. On 170°E, the ship cruised straight from 50°N to about 20°N, and latitudinal profile of atmospheric species in the Pacific was observed. There are clear concentration decrease from higher latitude to lower latitude for CO, O3, hydrocarbons, and short lived halocarbons. There is a large gap at around 30°N, since maritime air prevail at lower latitude. The ratios of hydrocarbons and CO give some information about their sources. CO and ethane have similar lifetime in the atmosphere, but the ratio ([ethane]/[CO]) decreased drastically as the distance from the land. CO is supplied by the oxidation of CH4 and hydrocarbons also on the ocean, in addition to the transportation of anthropogenically generated CO from land. Therefore concentration decrease of CO is smaller than that of hydrocarbons far from the anthropogenic source area. Biogenically generated species emitted from the ocean (DMS, ethene, propene, isoprene, CH3Br) were also measured during the cruise. Their trends are totally different from anthropogenic hydrocarbons. Higher concentrations of bogenic generated species were observed at lower latitude, where more activated biogenic activity is expected. Similar trend of ethene, propene, and DMS were observed. Especially, ethene and propene have good correlation. Since these species have relatively high reactivity in the

  10. Black carbon and its correlation with trace gases at a rural site in Beijing: Top-down constraints from ambient measurements on bottom-up emissions

    NASA Astrophysics Data System (ADS)

    Wang, Yuxuan; Wang, Xuan; Kondo, Yutaka; Kajino, Mizuo; Munger, J. William; Hao, Jiming

    2011-12-01

    The mass concentrations of black carbon (BC) were measured continuously at Miyun, a rural site near Beijing, concurrently with some trace gases (CO, CO2, NOy, SO2) during the nonheating seasons of 2010 (April to October). The average concentration of BC was 2.26 ± 2.33 μg m-3. About 70%-100% of the air masses arriving at the site from June to September were from the source region of Beijing and the North China Plain (NCP), while in the spring, 40% were of continental background origin. BC had moderate to strong positive correlations with CO (R2 = 0.51), NOy (R2 = 0.58), and CO2 (nonsummer, R2 = 0.54), but not with SO2 (R2 < 0.1). The observed ΔBC/ΔCO ratio was 0.0050 ± 0.0001 μg m-3/ppbv for the regional air masses (excluding the influence of biomass burning). This ratio increased by 68% to 0.0084 ± 0.0004 μg m-3/ppbv after excluding the influence of wet deposition. Accounting further for the impact of atmospheric processes on the observation, we derived an average top-down BC/CO emission ratio of 0.0095 ± 0.002 μg m-3/ppbv for the source region of Beijing and NCP that is 18%-21% lower than the average emission ratio from the bottom-up inventory of Zhang et al. (2009), whereas the difference is substantially lower than the uncertainty of emissions for either species. The difference between the mean bottom-up and top-down emission ratios is most likely to be attributed to the residential sector, which needs to have a lower share in the total emissions of BC or a much lower BC/CO emission ratio. The industry and transportation sectors are found to be dominant sources of BC from Beijing and the NCP rather than from the residential sector as suggested by the bottom-up inventory.

  11. Detections and Sensitive Upper Limits for Methane and Related Trace Gases on Mars during 2003-2014, and planned extensions in 2016

    NASA Astrophysics Data System (ADS)

    Mumma, Michael J.; Villanueva, Geronimo L.; Novak, Robert E.

    2015-11-01

    Five groups report methane detections on Mars; all results suggest local release and high temporal variability [1-7]. Our team searched for CH4 on many dates and seasons and detected it on several dates [1, 9, 10]. TLS (Curiosity rover) reported methane upper limits [6], and then detections [7] that were consistent in size with earlier reports and that also showed rapid modulation of CH4 abundance.[8] argued that absorption features assigned to Mars 12CH4 by [1] might instead be weak lines of terrestrial 13CH4. If not properly removed, terrestrial 13CH4 signatures would appear on the blue wing of terrestrial 12CH4 even when Mars is red-shifted - but they do not (Fig. S6 of [1]), demonstrating that terrestrial signatures were correctly removed. [9] demonstrated that including the dependence of δ13CH4 with altitude did not affect the residual features, nor did taking δ13CH4 as zero. Were δ13CH4 important, its omission would have overemphasized the depth of 13CH4 terrestrial absorption, introducing emission features in the residual spectra [1]. However, the residual features are seen in absorption, establishing their origin as non-terrestrial - [8] now agrees with this view.We later reported results for multiple organic gases (CH4, CH3OH, H2CO, C2H6, C2H2, C2H4), hydroperoxyl (HO2), three nitriles (N2O, NH3, HCN) and two chlorinated species (HCl, CH3Cl) [9]. Most of these species cannot be detected with current space assets, owing to instrumental limitations (e.g., spectral resolving power). However, the high resolution infrared spectrometers (NOMAD, ACS) on ExoMars 2016 (Trace Gas Orbiter) will begin measurements in late 2016. In solar occultation, TGO sensitivities will far exceed prior capabilities.We published detailed hemispheric maps of H2O and HDO on Mars, inferring the size of a lost early ocean [10]. In 2016, we plan to acquire 3-D spatial maps of HDO and H2O with ALMA, and improved maps of organics with iSHELL/NASA-IRTF.References: [1] Mumma et al. Sci09

  12. Continental pollution in the Western Mediterranean Basin: vertical profiles of aerosol and trace gases measured over the sea during TRAQA 2012 and SAFMED 2013

    NASA Astrophysics Data System (ADS)

    Di Biagio, C.; Doppler, L.; Gaimoz, C.; Grand, N.; Ancellet, G.; Raut, J.-C.; Beekmann, M.; Borbon, A.; Sartelet, K.; Attié, J.-L.; Ravetta, F.; Formenti, P.

    2015-03-01

    In this study we present airborne observations of aerosol and trace gases obtained over the sea in the Western Mediterranean Basin during the TRAQA (TRansport and Air QuAlity) and SAFMED (Secondary Aerosol Formation in the MEDiterranean) campaigns in summers 2012 and 2013. A total of 23 vertical profiles were measured up to 5000 m a.s.l. over an extended area (40-45° N latitude and 2° W-12° E longitude) including the Gulf of Genoa, Southern France, the Gulf of Lion, and the Spanish coast. TRAQA and SAFMED successfully measured a wide range of meteorological conditions which favoured the pollution export from different sources located around the basin. Also, several events of dust outflows were measured during the campaigns. Observations from the present study indicate that continental pollution largely affects the Western Mediterranean both close to coastal regions and in the open sea as far as ~250 km from the coastline. Aerosol layers not specifically linked with Saharan dust outflows are distributed ubiquitously which indicates quite elevated levels of background pollution throughout the Western Basin. The measured aerosol scattering coefficient varies between ~20 and 120 M m-1, while carbon monoxide (CO) and ozone (O3) mixing ratios are in the range of 60-170 and 30-85 ppbv, respectively. Pollution reaches 3000-4000 m in altitude and presents a very complex and highly stratified structure characterized by fresh and aged layers both in the boundary layer and in the free troposphere. Within pollution plumes the measured particle concentration in the Aitken (0.004-0.1 μm) and accumulation (0.1-1.0 μm) modes is between ˜ 100 and 5000-6000 s cm-3 (standard cm-3), which is comparable to the aerosol concentration measured in continental urban areas. Additionally, our measurements indicate the presence of highly concentrated Aitken layers (10 000-15 000 s cm-3) observed both close to the surface and in the free troposphere, possibly linked to the influence of new

  13. Combining moving inlets for measuring gradients of reactive trace gases and thoron measurements for the determination of near surface fluxes -first results from the Amazon rain forest-

    NASA Astrophysics Data System (ADS)

    Sörgel, Matthias; Artaxo, Paulo; Kesselmeier, Jürgen; Quesada, Carlos Alberto; Ferreira de Souza, Rodrigo Augusto; Trebs, Ivonne; Vega, Oscar; Yañez-Serrano, Ana Maria

    2016-04-01

    For many compounds of interest no fast response sensors for the determination of eddy covariance fluxes are available. Therefore, flux-gradient relationships are used. The most common are the aerodynamic gradient method and the modified Bowen ratio method. For those approaches some assumptions have to be made which restrict their use. An alternative approach to calculate these fluxes might be given by the "thoron clock" method. The radon isotope Thoron (220Rn) is exhaled from the soil and has a half life time of 56 seconds. Therefore, it exists in measureable amounts only close to the ground and is hardly advected. Its only source is the radioactive decay of Thorium in soil. As it is a noble gas Thoron is not influenced by biochemical processes in air. Consequently, its concentration profile only depends on vertical mixing and the radioactive decay which is a physical constant. According to Lehmann et al. (1999) and Plake and Trebs (2013) a transport-time can be directly calculated from two heights thoron concentration/activity for the layer in-between without further assumptions. From this transport time the transfer velocity is derived which is then applied to calculate the fluxes of other (reactive) trace gases. A major advantage of the method is that the transport-time is known and using the measured concentration profile the chemical loss of a compound can be directly calculated and corrected for. We have applied this method for a first time in the Amazon rainforest during a field campaign at the ATTO site 150 km North East of Manaus in the dry season of 2014. We measured gradients of NO, NO2, O3, HONO and VOCs by using a movable inlet on a lift system close to the forest floor (0.19 m, 0.52 m and 1.59 m). A Thoron profile was measure in parallel at the lower two heights. First results of the gradients, the transport times and some preliminary flux values will be presented. References: Lehmann, B.E., Lehmann, M., Neftel, A .: 220 Radon calibration of near

  14. Geochemical Impacts of Carbon Dioxide, Brine, Trace Metal and Organic Leakage into an Unconfined, Oxidizing Limestone Aquifer

    SciTech Connect

    Bacon, Diana H.; Dai, Zhenxue; Zheng, Liange

    2014-12-31

    An important risk at CO2 storage sites is the potential for groundwater quality impacts. As part of a system to assess the potential for these impacts a geochemical scaling function has been developed, based on a detailed reactive transport model of CO2 and brine leakage into an unconfined, oxidizing carbonate aquifer. Stochastic simulations varying a number of geochemical parameters were used to generate a response surface predicting the volume of aquifer that would be impacted with respect to regulated contaminants. The brine was assumed to contain several trace metals and organic contaminants. Aquifer pH and TDS were influenced by CO2 leakage, while trace metal concentrations were most influenced by the brine concentrations rather than adsorption or desorption on calcite. Organic plume sizes were found to be strongly influenced by biodegradation.

  15. Geochemical Impacts of Carbon Dioxide, Brine, Trace Metal and Organic Leakage into an Unconfined, Oxidizing Limestone Aquifer

    DOE PAGES

    Bacon, Diana H.; Dai, Zhenxue; Zheng, Liange

    2014-12-31

    An important risk at CO2 storage sites is the potential for groundwater quality impacts. As part of a system to assess the potential for these impacts a geochemical scaling function has been developed, based on a detailed reactive transport model of CO2 and brine leakage into an unconfined, oxidizing carbonate aquifer. Stochastic simulations varying a number of geochemical parameters were used to generate a response surface predicting the volume of aquifer that would be impacted with respect to regulated contaminants. The brine was assumed to contain several trace metals and organic contaminants. Aquifer pH and TDS were influenced by CO2more » leakage, while trace metal concentrations were most influenced by the brine concentrations rather than adsorption or desorption on calcite. Organic plume sizes were found to be strongly influenced by biodegradation.« less

  16. Groundwater Quality Impacts Related to Carbon Dioxide, Brine and Trace Metal Leakage into a Shallow, Unconfined Limestone Aquifer

    NASA Astrophysics Data System (ADS)

    Bacon, D. H.; Hou, Z.; Dai, Z.; Zheng, L.

    2012-12-01

    Accurate prediction of the impact of leaks related to geologic carbon sequestration on groundwater quality is limited by the complexity of subsurface aquifers and the geochemical reactions that control drinking water compositions. As a result, there is a high uncertainty associated with predictions, hampering monitoring plans, interpretation of the monitoring results, and mitigation plans for a given site. As a part of the National Risk Assessment Program (NRAP), funded by the U.S. Department of Energy, a model of the Edwards Aquifer in Texas has been developed to examine the geochemical impacts of leakage of CO2 and brine containing trace metals into an oxidizing unconfined, carbonate aquifer. We use STOMP-CO2-R, which is a multiphase flow simulator, coupled with the reactive transport module ECKEChem, both developed at PNNL, to simulate CO2 sequestration in deep saline formations and the associated reactions with formation minerals. The limestone almost entirely consists of calcite, with lesser amounts of dolomite and trace metals adsorbed on minor amounts of clay and iron oxides. A reduced order model of this more complex chemistry and physics based model has been developed to be included in a framework for quantifying the overall risks associated with CO2 injection, leaks and groundwater impacts. The aquifer model uses reduced-order models, provided by other NRAP groups, of CO2 and brine leakage from wellbores and faults as inputs. Geochemical input parameters were varied to determine parameter sensitivity and to generate a response surface of output variables. The output variables were pH < 6.5 or TDS > 500 ppm plume size and CO2 flux to atmosphere, as well the volume of aquifer with trace metal concentrations greater than their U.S. Environmental Protection Agency Maximum Contaminant Levels. The uncertain input parameters were CO2/brine leak rate, brine composition, mineral surface area and volumetric percent, equilibrium coefficients, and kinetic rates

  17. Microlith-based Structured Sorbent for Carbon Dioxide, Humidity, and Trace Contaminant Control in Manned Space Habitats

    NASA Technical Reports Server (NTRS)

    Junaedi, Christian; Roychoudhury, SUbir; Howard, David F.; Perry, Jay L.; Knox, James C.

    2011-01-01

    To support continued manned space exploration, the development of atmosphere revitalization systems that are lightweight, compact, durable, and power efficient is a key challenge. The systems should be adaptable for use in a variety of habitats and should offer operational functionality to either expel removed constituents or capture them for closedloop recovery. As mission durations increase and exploration goals reach beyond low earth orbit, the need for regenerable adsorption processes for continuous removal of CO2 and trace contaminants from cabin air becomes critical. Precision Combustion, Inc. (PCI) and NASA Marshall (MSFC) have been developing an Engineered Structured Sorbents (ESS) approach based on PCI s patented Microlith technology to meet the requirements of future, extended human spaceflight explorations. This technology offers the inherent performance and safety attributes of zeolite and other sorbents with greater structural integrity, regenerability, and process control, thereby providing potential durability and efficiency improvements over current state-of-the-art systems. The major advantages of the ESS explored in this study are realized through the use of metal substrates to provide structural integrity (i.e., less partition of sorbents) and enhanced thermal control during the sorption process. The Microlith technology also offers a unique internal resistive heating capability that shows potential for short regeneration time and reduced power requirement compared to conventional systems. This paper presents the design, development, and performance results of the integrated adsorber modules for removing CO2, water vapor, and trace chemical contaminants. A related effort that utilizes the adsorber modules for sorption of toxic industrial chemicals is also discussed. Finally, the development of a 4-person two-leg ESS system for continuous CO2 removal is also presented.

  18. Assessing the climatic effect of carbon dioxide and other trace gases using an interactive two-dimensional climate-chemistry model. Final report, December 1992--August 1996

    SciTech Connect

    Ko, M.K.W.

    1996-12-31

    In the recent IPCC report, the role of tropospheric aerosols, stratospheric aerosols, and natural solar variability have also been identified as having sizable effects on climate, both by direct perturbation of the radiative balance and indirectly by changing ozone. Although the effect of changing CO{sub 2} is by far the dominant factor on a century time scale, the effects from the other identified factors are important on a decade time scale. It is important to understand the mechanisms that relate these changes to climatic responses. Developing appropriate numerical models with the capability to simulate these mechanisms will enable one to correctly interpret the observed climate changes that have occurred to data, as well as predict future changes in climate. It is presently impractical to run comprehensive 3-D general circulation model simulations of the interactions between atmospheric chemistry and the rest of the climate system on time scales of decades to centuries. Thus, 2-D models and other lower resolution models play an essential role in understanding the complex interactions of the integrated climate system.

  19. Comparison of ground-based FTIR measurements and EMAC model simulations of trace-gases columns near St. Petersburg (Russia) in 2009-2013

    NASA Astrophysics Data System (ADS)

    Virolainen, Yana; Makarova, Maria; Ionov, Dmitry; Polyakov, Alexander; Kirner, Oliver; Timofeyev, Yury; Poberovsky, Anatoly; Imhasin, Hamud

    2014-05-01

    The comparison of simulated atmospheric gases abundances with various experimental data is the very important stage of the numerical models validation and improvement process. In this study, we compare and discuss the observational data obtained from ground-based direct solar absorption measurements of high spectral-resolution FTIR spectrometer Bruker 125 HR operated at the Peterhof station (59.82 N, 29.88 E) with the 3-dimensional model EMAC (ECHAM5/MESSy Atmospheric Chemistry) calculations. The FTIR spectrometer has a maximum optical path difference of 180 cm, yielding a spectral resolution of unapodized spectra up to 0.005 cm-1. Two detectors, MCT (Mercury-Cadmium-Telluride) and InSb (Indium-Antimonide), cover the spectral range of 650-5400 cm-1 that includes many distinct and overlapping absorption lines, and allow the retrieval of a large number of atmospheric constituents. We applied two inversion codes using within NDACC infrared community: SFIT2 and PROFFIT for the retrieval of atmospheric gases column amounts from FTIR recorded spectra. The EMAC model is a numerical chemistry and climate simulation system that includes sub-models describing troposphere and middle atmosphere processes and their interaction with oceans, land and human influences. The simulation includes a comprehensive atmospheric chemistry setup for the troposphere, the stratosphere and the lower mesosphere. We applied the EMAC (ECHAM5 version 5.3.01, MESSy version 1.10) in the T42L39MA-resolution, i.e. with a spherical truncation of T42 (corresponding to a quadratic Gaussian grid of approximately 2.8 by 2.8 degrees in latitude and longitude) with 39 vertical hybrid pressure levels up to 0.01 hPa. The model simulation allows the comparison of the tropospheric gases (H2O, CO, CH4, and N2O) as well as the stratospheric gases (HCl, HNO3, NO2, O3 and ClONO2) that have been being continuously retrieved at the Peterhof station since 2009. In the study, we analyze the daily and monthly means of

  20. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-12-01

    products and/or from the diluent used to lower the viscosity of the extracted bitumen (i.e., C4-C9 alkanes, C5-C6 cycloalkanes, C6-C8 aromatics), together with CO; and (2) emissions associated with the mining effort, such as upgraders (i.e., CO2, CO, CH4, NO, NO2, NOy, SO2, C2-C4 alkanes, C2-C4 alkenes, C9 aromatics, short-lived solvents such as C2Cl4 and C2HCl3, and longer-lived species such as HCFC-22 and HCFC-142b). Prominent in the second group, SO2 and NO were remarkably enhanced over the oil sands, with maximum mixing ratios of 38.7 ppbv and 5.0 ppbv, or 383× and 319× the local background, respectively. These SO2 levels are comparable to maximum values measured in heavily polluted megacities such as Mexico City and are attributed to coke combustion. By contrast, relatively poor correlations between CH4, ethane and propane suggest low levels of natural gas leakage despite its heavy use at the surface mining sites. Instead the elevated CH4 levels are attributed to methanogenic tailings pond emissions. In addition to the emission of many trace gases, the natural drawdown of OCS by vegetation was absent above the surface mining operations, presumably because of the widespread land disturbance. Unexpectedly, the mixing ratios of α-pinene and β-pinene were much greater over the oil sands (up to 217 pptv and 610 pptv, respectively) than over vegetation in the background boundary layer (20±7 pptv and 84±24 pptv, respectively), and the pinenes correlated well with several industrial tracers that were elevated in the oil sands plumes. Because so few independent measurements from the oil sands mining industry exist, this study provides an important initial characterization of trace gas emissions from oil sands surface mining operations.

  1. Surface acoustic wave gas sensor for nitrogen dioxide using phthalocyanines as chemical interfaces. Effects of nitric oxide, halogen gases, and prolonged heat treatment

    SciTech Connect

    Nieuwenhuizen, M.S.; Nederlof, A.J.

    1988-02-01

    The effect of CO, NO, and O/sub 2/ on the response of a SAW (surface acoustic wave) chemosensor for NO/sub 2/ has been studied. A description is given of the measuring equipment existing of a mass flow controlled automatic gas dilution system. Copper and iron phthalocyanine were used as the chemical interface. Simultaneously, the influence of ambient atmospheres (N/sub 2/ and O/sub 2/) was investigated. Predictions from ultraviolet-visible experiments in solution do not hold for gaseous environments. Also the effect of electronegative gases like the halogens was studied. Response up to 40 times the NO/sub 2/ response was measured. Prolonged heat treatment affects the sensitivity for NO/sub 2/ negatively as well as the response time. This asks for a more stable chemical interface. All results are discussed in terms of general performance criteria for gas sensors such as selectivity, sensitivity, response time, reversibility, and stability.

  2. Electronegative gases

    SciTech Connect

    Christophorou, L.G.

    1981-01-01

    Recent knowledge on electronegative gases essential for the effective control of the number densities of free electrons in electrically stressed gases is highlighted. This knowledge aided the discovery of new gas dielectrics and the tailoring of gas dielectric mixtures. The role of electron attachment in the choice of unitary gas dielectrics or electronegative components in dielectric gas mixtures, and the role of electron scattering at low energies in the choice of buffer gases for such mixtures is outlined.

  3. Parameterization of the absorption of the H2O continuum, CO2, O2, and other trace gases in the Fu-Liou solar radiation program

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Zeng, Qingcun; Gu, Y.; Liou, K. N.

    2005-07-01

    The absorption properties of the water vapor continuum and a number of weak bands for H2O, O2, CO2, CO, N2O, CH4, and O3 in the solar spectrum are incorporated into the Fu-Liou radiation parameterization program by using the correlated k-distribution method (CKD) for the sorting of absorption lines. The overlap absorption of the H2O lines and the H2O continuum (2500 14500 cm-1) are treated by taking the two gases as a single-mixture gas in transmittance calculations. Furthermore, in order to optimize the computation efforts, CO2 and CH4 in the spectral region 2850 5250 cm-1 are taken as a new single-mixture gas as well. For overlap involving other absorption lines in the Fu-Liou spectral bands, the authors adopt the multiplication rule for transmittance computations under which the absorption spectra for two gases are assumed to be uncorrelated. Compared to the line-by-line (LBL) computation, it is shown that the errors in fluxes introduced by these two approaches within the context of the CKD method are small and less than 0.48% for the H2O line and continuum in the 2500 14500 cm-1solar spectral region, ˜1% for H2O (line)+H2O (continuum)+CO2+CH4 in the spectral region 2850 5250 cm-1,and ˜1.5% for H2O (line)+H2O (continuum)+O2 in the 7700 14500 cm-1 spectral region. Analysis also demonstrates that the multiplication rule over a spectral interval as wide as 6800 cm-1 can produce acceptable errors with a maximum percentage value of about 2% in reference to the LBL calculation. Addition of the preceding gases increases the absorption of solar radiation under all sky conditions. For clear sky, the increase in instantaneous solar absorption is about 9% 13% (˜12 W m-2) among which the H2O continuum produces the largest increase, while the contributions from O2 and CO2 rank second and third, respectively. In cloudy sky, the addition of absorption amounts to about 6 9 W m-2. The new, improved program with the incorporation of the preceding gases produces a smaller solar

  4. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from fuels common in the US

    NASA Astrophysics Data System (ADS)

    Gilman, J. B.; Lerner, B. M.; Kuster, W. C.; Goldan, P. D.; Warneke, C.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2015-12-01

    A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern US. A gas chromatograph-mass spectrometry (GC-MS) instrument provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectroscopy (OP-FTIR) instrument and three different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the US Department of Agriculture's Fire Sciences Laboratory in Missoula, Montana and were used as the basis for a number of emission factors reported by Yokelson et al. (2013). The relative magnitude and composition of the gases emitted varied by individual fuel type and, more broadly, by the three geographic fuel regions being simulated. Discrete emission ratios relative to carbon monoxide (CO) were used to characterize the composition of gases emitted by mass; reactivity with the hydroxyl radical, OH; and potential secondary organic aerosol (SOA) precursors for the 3 different US fuel regions presented here. VOCs contributed less than 0.78 % ± 0.12 % of emissions by mole and less than 0.95 % × 0.07 % of emissions by mass (on average) due to the predominance of CO2, CO, CH4, and NOx emissions; however, VOCs contributed 70-90 (±16) % to OH reactivity and were the only measured gas-phase source of SOA precursors from combustion of biomass. Over 82 % of the VOC emissions by mole were unsaturated compounds including highly reactive alkenes and aromatics and photolabile oxygenated VOCs (OVOCs) such as formaldehyde. OVOCs contributed 57-68 % of the VOC mass emitted, 41-54 % of VOC-OH reactivity, and aromatic-OVOCs such as benzenediols, phenols, and benzaldehyde

  5. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from temperate fuels common in the United States

    NASA Astrophysics Data System (ADS)

    Gilman, J. B.; Lerner, B. M.; Kuster, W. C.; Goldan, P. D.; Warneke, C.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2015-08-01

    A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern United States. A gas chromatograph-mass spectrometer (GC-MS) provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectrometer (OP-FTIR) and 3 different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the U.S. Department of Agriculture's Fire Sciences Laboratory in Missoula, Montana. The relative magnitude and composition of the gases emitted varied by individual fuel type and, more broadly, by the 3 geographic fuel regions being simulated. Emission ratios relative to carbon monoxide (CO) were used to characterize the composition of gases emitted by mass; reactivity with the hydroxyl radical, OH; and potential secondary organic aerosol (SOA) precursors for the 3 different US fuel regions presented here. VOCs contributed less than 0.78 ± 0.12 % of emissions by mole and less than 0.95 ± 0.07 % of emissions by mass (on average) due to the predominance of CO2, CO, CH4, and NOx emissions; however, VOCs contributed 70-90 (±16) % to OH reactivity and were the only measured gas-phase source of SOA precursors from combustion of biomass. Over 82 % of the VOC emissions by mole were unsaturated compounds including highly reactive alkenes and aromatics and photolabile oxygenated VOCs (OVOCs) such as formaldehyde. OVOCs contributed 57-68 % of the VOC mass emitted, 42-57 % of VOC-OH reactivity, and aromatic-OVOCs such as benzenediols, phenols, and benzaldehyde were the dominant potential SOA precursors. In addition, ambient air measurements of emissions from the Fourmile Canyon Fire

  6. Use of satellite data to constrain the model-calculated atmospheric lifetime for N2O - Implications for other trace gases

    NASA Technical Reports Server (NTRS)

    Ko, Malcolm K. W.; Sze, Nien Dak; Weisenstein, Debra K.

    1991-01-01

    Model calculations of the zonal-mean concentrations of N2O in the upper stratosphere are presented showing that about 80 percent of N2O is removed in the stratosphere between 30 deg N and 30 deg S. A comparison of calculated N2O values with remote data on N2O concentrations obtained from Nimbus 7 SAMS instrument indicated that the two-dimensional model of Ko and Sze (1982) may have underestimated the concentration of N2O in the tropical lower stratosphere. It is concluded that the calculated lifetimes for N2O and chlorofluorocarbon-source gases could be 30 percent shorter than previously reported values.

  7. Nighttime chemical evolution of aerosol and trace gases in a power plant plume: Implications for secondary organic nitrate and organosulfate aerosol formation, NO3 radical chemistry, and N2O5 heterogeneous hydrolysis

    SciTech Connect

    Zaveri, R.A.; Kleinman, L.; Berkowitz, C. M.; Brechtel, F. J.; Gilles, M. K.; Hubbe, J. M.; Jayne, J. T.; Laskin, A.; Madronich, S.; Onasch, T. B.; Pekour, M. S.; Springston, S. R.; Thornton, J. A.; Tivanski, A. V.; Worsnop, D. R.

    2010-06-01

    Nighttime chemical evolution of aerosol and trace gases in a coal-fired power plant plume was monitored with the Department of Energy Grumman Gulfstream-1 aircraft during the 2002 New England Air Quality Study field campaign. Quasi-Lagrangian sampling in the plume at increasing downwind distances and processing times was guided by a constant-volume balloon that was released near the power plant at sunset. While no evidence of fly ash particles was found, concentrations of particulate organics, sulfate, and nitrate were higher in the plume than in the background air. The enhanced sulfate concentrations were attributed to direct emissions of gaseous H{sub 2}SO{sub 4}, some of which had formed new particles as evidenced by enhanced concentrations of nucleation-mode particles in the plume. The aerosol species were internally mixed and the particles were acidic, suggesting that particulate nitrate was in the form of organic nitrate. The enhanced particulate organic and nitrate masses in the plume were inferred as secondary organic aerosol, which was possibly formed from NO{sub 3} radical-initiated oxidation of isoprene and other trace organic gases in the presence of acidic sulfate particles. Microspectroscopic analysis of particle samples suggested that some sulfate was in the form of organosulfates. Microspectroscopy also revealed the presence of sp{sup 2} hybridized C = C bonds, which decreased with increasing processing time in the plume, possibly because of heterogeneous chemistry on particulate organics. Constrained plume modeling analysis of the aircraft and tetroon observations showed that heterogeneous hydrolysis of N{sub 2}O{sub 5} was negligibly slow. These results have significant implications for several issues related to the impacts of power plant emissions on air quality and climate.

  8. Blood gases

    MedlinePlus

    ... are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the ... oxygen (PaO2): 75 - 100 mmHg Partial pressure of carbon dioxide (PaCO2): 38 - 42 mmHg Arterial blood pH: 7. ...

  9. Simultaneous quantification of methane and carbon dioxide fluxes reveals that a shallow arctic methane seep is a net sink for greenhouse gases

    NASA Astrophysics Data System (ADS)

    Pohlman, J.; Greinert, J.; Ruppel, C. D.; Silyakova, A.; Vielstädte, L.; Magen, C.; Casso, M.; Bunz, S.; Mienert, J.

    2015-12-01

    Warming of high-latitude continental-margin oceans has the potential to release large quantities of carbon from gas hydrate and other sedimentary reservoirs. To assess how carbon mobilized from the seafloor might amplify global warming or alter ocean chemistry, a robust analysis of the concentrations and isotopic content of methane and carbon dioxide (CO2) in the water column and atmosphere is required. To this effect, a gas analysis system consisting of three cavity ring-down spectrometers was developed to obtain a real-time, three-dimensional characterization of the distribution and isotopic variability of methane and CO2 at a shallow (<100 m water depth) bubbling methane seep offshore of western Svalbard. Surface water methane concentrations from the continuous-flow CRDS system agreed remarkably well with discrete samples analyzed by the GC-based headspace analysis technique and with a CRDS-based discrete sample analysis module. Reliable carbon isotope data were also obtained from the CRDSs once an isotopic calibration routine was applied. The resulting data revealed that CO2 uptake from the atmosphere within the surface water methane plume overlying the gas seep was elevated by 36-45% relative to surrounding waters. In comparison to the positive radiative forcing effect expected from the methane emissions, the negative radiative forcing potential from CO2 uptake was 32-43 times greater. Lower water temperatures, elevated chlorophyll-fluorescence and 13C-enriched CO2 within the surface methane plume suggest that bubble-driven upwelling of cold, nutrient-rich water stimulated CO2 uptake by phytoplankton. The observation that a shallow methane seep has a net negative radiative forcing effect challenges the widely-held perception that methane seeps contribute to the global atmospheric greenhouse gas burden.

  10. Adsorption equilibrium and kinetics for multiple trace impurities in various gas streams on activated carbon

    SciTech Connect

    Golden, T.C.; Kumar, R. )

    1993-01-01

    Equilibrium and kinetic adsorption data for seven trace impurities (propylene, Freon-12 (CF[sub 2]Cl[sub 2]), n-butane, methylene chloride, acetone, n-hexane, toluene, and Freon-22 (CHFCl[sub 2])) from various carrier gases (helium, nitrogen, methane, carbon dioxide, and a mixture of methane and carbon dioxide) are provided. Activated carbon at several temperatures and pressures is used as the adsorbent. Two empirical characteristic curves, one relating equilibrium isotherms of trace impurities with their physical properties and the other relating mass-transfer coefficients with equilibrium properties, are generated. These can be used to predict equilibrium capacities and mass-transfer zone lengths for multiple trace impurities from a carrier gas and design a thermal swing adsorption clean-up system.

  11. The role of trace gas flux networks in biogeosciences

    SciTech Connect

    Baldocch, Dennis; Reichstein, Markus; Papale, D.; Koteen, Laurie; Vargas, Rodrigo; Agarwal, D. A.; Cook, Robert B.

    2012-01-01

    Vast networks of meteorological sensors ring the globe, providing continuous measurements of an array of atmospheric state variables such as temperature, humidity, rainfall, and the concentration of carbon dioxide [New etal., 1999; Tans etal., 1996]. These measurements provide input to weather and climate models and are key to detecting trends in climate, greenhouse gases, and air pollution. Yet to understand how and why these atmospheric state variables vary in time and space, biogeoscientists need to know where, when, and at what rates important gases are flowing between the land and the atmosphere. Tracking trace gas fluxes provides information on plant or microbial metabolism and climate-ecosystem interactions. The existence of trace gas flux networks is a relatively new phenomenon, dating back to research in 1984. The first gas flux measurement networks were regional in scope and were designed to track pollutant gases such as sulfur dioxide, ozone, nitric acid, and nitrogen dioxide. Atmospheric observations and model simulations were used to infer the depositional rates of these hazardous chemicals [Fowler etal., 2009; Meyers etal., 1991]. In the late 1990s, two additional trace gas flux measurement networks emerged. One, the United States Trace Gas Network (TRAGNET), was a short-lived effort that measured trace gas emissions from the soil and plants with chambers distributed throughout the country [Ojima etal., 2000]. The other, FLUXNET, was an international endeavor that brought many regional networks together to measure the fluxes of carbon dioxide, water vapor, and sensible heat exchange with the eddy covariance technique [Baldocchi etal., 2001]. FLUXNET, which remains active today, currently includes more than 400 tower sites, dispersed across most of the world's climatic zones and biomes, with sites in North and South America, Europe, Asia, Africa, and Australia. More recently, several specialized networks have emerged, including networks dedicated to

  12. Impact of western Siberia heat wave 2012 on greenhouse gases and trace metal concentration in thaw lakes of discontinuous permafrost zone

    NASA Astrophysics Data System (ADS)

    Pokrovsky, O. S.; Shirokova, L. S.; Kirpotin, S. N.; Kulizhsky, S. P.; Vorobiev, S. N.

    2013-08-01

    During the anomalously hot summer in 2012, surface air temperatures in Western Siberia were 5 to 15 °C higher than those observed during the previous period of > 30 yr. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating of water in thermokarst ponds and lakes in discontinuous permafrost zones and compare these observations to previous field results obtained when the temperature was normal during the summer of 2010 in the same region. In 2012, thermokarst bodies of water shrank significantly, water levels dropped approximately 50 cm in large lakes and small (< 10-100 m2) ponds, and shallow soil depressions disappeared. Based on samples from ~ 40 bodies of water collected previously and in 2012, first-order features of changes in chemical composition in response to increased water temperatures (from 14.1 ± 2.2 to 23.8 ± 2.3 °C in 2010 and 2012, respectively) were established. In these thermokarst bodies of water that covered a full range of surface areas, the average conductivity and pH were almost unchanged, whereas dissolved organic carbon (DOC), Cl- and SO42- concentrations were higher by a factor of ~ 2 during summer 2012 compared to periods with normal temperatures. Similarly, most divalent metals and insoluble trivalent and tetravalent elements were more concentrated by a factor of 1.7-2.4 in the summer of 2012 than normal periods. The average concentrations of dissolved CO2 and CH4 during the hot summer of 2012 increased by factors of 1.4 and 4.9, respectively. For most of the trace elements bound to colloids, the degree of colloidal binding decreased by a factor of 1.44 ± 0.33 (for an average of 40 elements) during the hot summer of 2012 compared to normal periods. Increases in CO2 and CH4 concentrations with the decreasing size of the body of water were well-pronounced during the hot summer of 2012. The concentrations of CO2 and CH4 rose by factors of 5 and 150, respectively, in small (≤ 102 m2

  13. Present state of knowledge of the upper atmosphere: An assessment report; processes that control ozone and other climatically important trace gases

    NASA Technical Reports Server (NTRS)

    Watson, R. T.; Geller, M. A.; Stolarski, R. S.; Hampson, R. F.

    1986-01-01

    The state of knowledge of the upper atmosphere was assessed as of January 1986. The physical, chemical, and radiative processes which control the spatial and temporal distribution of ozone in the atmosphere; the predicted magnitude of ozone perturbations and climate changes for a variety of trace gas scenarios; and the ozone and temperature data used to detect the presence or absence of a long term trend were discussed. This assessment report was written by a small group of NASA scientists, was peer reviewed, and is based primarily on the comprehensive international assessment document entitled Atmospheric Ozone 1985: Assessment of Our Understanding of the Processes Controlling Its Present Distribution and Change, to be published as the World Meteorological Organization Global Ozone Research and Monitoring Project Report No. 16.

  14. Greenhouse Gases

    MedlinePlus

    ... Greenhouse Gases Come From Outlook for Future Emissions Recycling and Energy Nonrenewable Sources Oil and Petroleum Products ... Power Wave Power Ocean Thermal Energy Conversion Biomass Wood and Wood Waste Waste-to-Energy (MSW) Landfill ...

  15. Seasonal Variation and Ecosystem Dependence of Emission Factors for Selected Trace Gases and PM2.5 for Southern African Savanna Fires

    NASA Technical Reports Server (NTRS)

    Korontzi, S.; Ward, D. E.; Susott, R. A.; Yokelson, R. J.; Justice, C. O.; Hobbs, P. V.; Smithwick, E. A. H.; Hao, W. M.

    2003-01-01

    In this paper we present the first early dry season (early June-early August) emission factor measurements for carbon dioxide (CO2), carbon monoxide (CO), methane (Ca), nonmethane hydrocarbons (NMHC), and particulates with a diameter less than 2.5 microns (pM2.5) for southern African grassland and woodland fires. Seasonal emission factors for grassland fires correlate linearly with the proportion of green grass, used as a surrogate for the fuel moisture content, and are higher for products of incomplete combustion in the early part of the dry season compared with later in the dry season. Models of emission factors for NMHC and PM(sub 2.5) versus modified combustion efficiency (MCE) are statistically different in grassland compared with woodland ecosystems. We compare predictions based on the integration of emissions factors from this study, from the southern African Fire-Atmosphere Research Initiative 1992 (SAFARI-92), and from SAFARI-2000 with those based on the smaller set of ecosystem-specific emission factors to estimate the effects of using regional-average rather than ecosystem-specific emission factors. We also test the validity of using the SAFARI-92 models for emission factors versus MCE to predict the early dry season emission factors measured in this study. The comparison indicates that the largest discrepancies occur at the low end (0.907) and high end (0.972) of MCE values measured in this study. Finally, we combine our models of MCE versus proportion of green grass for grassland fires with emission factors versus MCE for selected oxygenated volatile organic compounds measured in the SAFARI-2000 campaign to derive the first seasonal emission factors for these compounds. The results of this study demonstrate that seasonal variations in savanna fire emissions are important and should be considered in modeling emissions at regional to continental scales.

  16. Impacts of an African Green Revolution on Greenhouse Gases and Pollution Precursors: Nonlinear Trace N Gas Emission Responses to Incremental Increases in Fertilizer Inputs in a Western Kenyan Maize Field

    NASA Astrophysics Data System (ADS)

    Hickman, J. E.; Palm, C.

    2011-12-01

    Over the last several decades, agricultural soils in many parts of sub-Saharan Africa have become depleted of nitrogen (N) and other nutrients, creating challenges to achieving food security in many countries. At only 7 kg N ha-1 yr-1, average fertilizer application rates in the region are an order of magnitude lower than typical rates in the United States, and well below optimal levels. Increased use of nutrient inputs is a centerpiece of most African Green Revolution strategies, making it important to quantify the impacts of this change in practices as farmers begin moving towards 50-80 kg N ha-1 yr-1. Increased N inputs are invariably accompanied by losses of trace N gases to the atmosphere, including the greenhouse gas nitrous oxide (N2O), and nitric oxide (NO), a precursor to tropospheric ozone pollution. Several investigations of greenhouse gas emissions and one investigation of NO emissions from sub-Saharan agricultural systems have been conducted over the last 20 years, but they are few in number and were not designed to identify potentially important thresholds in the response of trace gas emissions to fertilization rate. Here we examine the response function of NO and N2O emissions to 6 different levels of inorganic fertilizer additions in a maize field in Yala, Kenya during the 2011 long rainy season. We used a randomized complete block design incorporating inorganic fertilizer treatments of 0, 50, 75, 100, 150, and 200 kg N ha-1 in 4 blocks. After each of 2 fertilizer applications, we measured trace gas fluxes daily, and conducted weekly measurements until trace gas emissions subsided to control levels. We fit the data to linear and exponential models relating N gas emissions to N input levels, and conducted a model comparison using AIC. Preliminary analysis suggests that NO emissions do respond in a non-linear fashion over the course of 67 days, as has been found in several commercial agroecosystems for N2O. Although N2O emissions responded linearly

  17. Agriculture's share in the emission of trace gases affecting the climate and some cause-oriented proposals for sufficiently reducing this share.

    PubMed

    Isermann, K

    1994-01-01

    This paper discusses agriculture's share in the world-wide emissions of climate-affecting gases and in the global warming potential (GWP). Proposals also are presented to reduce these emissions adequately, using a cause-oriented approach. Largely due to the fertilization and cultivation of agriculture as well as the burning of biomass, agriculture has a very high share in the anthropogenic emissions of NH(3), N(2)O, CH(4) and CO at >95%, 81%, 70% and 52%, respectively, while its share in the NO(x) and CO(2) emissions is relatively small at 35% and 21%. The GWP of agriculture, based on annually 16.1 x 10(9) tons of CO(2), approaches 63% of the GWP of the energy sector or 80% of the GWP of its CO(2) emissions. At 34% and 32%, respectively, the main originators in the GWP of agriculture would seem to be CO(2) (changing land use) and CH(4) (animal husbandry/rice cropping/biomass burning) followed at 15% by NO(2) (technical and biological N fixation/(cultivation and recultivation/biomass burning) and 10% and 9% by CO and NO(x). The GWP of 3 German dairy cows corresponds with 13.2 tonnes CO(2) per year the GWP of two average German automobiles. However, the ozone-destroying effect of N(2)O and the climate-relevant effects of NH(3) are not yet included here. As with the therapy for other 'modern' boundary-crossing environmental damages, such as acidification or eutrophication, global climate change therapy likewise needs a therapy for the respective effects of reactive compounds of carbon, nitrogen, phosphorous, and sulfur also emitted by agriculture. Proposals for reducing these emissions within the agricultural sector include need-oriented plant, animal and human nutrition, more efficient external and internal nutrient recycling, the cessation of further clearing by burning, along with intensified afforestation mainly in the tropics, targeted measures to reduce nutrient losses/emissions, and measures for more efficient use of nutrients in plant, animal and human

  18. Analysis of gases in the Earth's crust

    NASA Astrophysics Data System (ADS)

    Jenden, P. D.

    1986-05-01

    To investigate the origin and fate of natural gas in the Earth's crust, approximately 700 gas samples have been analyzed for chemical composition and stable isotopic ratios of carbon, hydrogen, nitrogen, sulfur and oxygen. During the current reporting period, helium isotope measurements confirmed the presence of mantle volatiles in the Sacramento basin, a dry gas province in northern California. Methane carbon isotope ratios and N2/Ar ratios suggest that Sacramento basin commercial gases with up to 88% nitrogen are derived from metasedimentary rocks. Studies of seep gases in Los Angeles indicate that ethane and higher hydrocarbons may be retarded during natural gas migration and the propane is selectively attacked during bacterial alteration. Carbon dioxide reduction and acetate dissimilation, the two main pathways for microbial methane formation, are characterized by different methane hydrogen isotope ratios. Hydrogen isotope ratios of methane and carbon isotope ratios of carbon dioxide and ethane help to distinguish microbial gases, thermogenic gases, and mixed gases.

  19. Field measurements of trace gases emitted by prescribed fires in southeastern US pine forests using an open-path FTIR system

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Burling, I. R.; Mendoza, A.; Johnson, T. J.; Cameron, M.; Griffith, D. W. T.; Paton-Walsh, C.; Weise, D. R.; Reardon, J.; Yokelson, R. J.

    2014-01-01

    We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, US measured during the fall of 2011. The fires were more intense than many prescribed burns because the fuels included mature pine stands not subjected to prescribed fire in decades that were lit following an extended drought. Emission factors were measured with a fixed open-path Fourier transform infrared (OP-FTIR) system that was deployed on the fire control lines. We compare these emission factors to those measured with a roving, point sampling, land-based FTIR and an airborne FTIR deployed on the same fires. We also compare to emission factors measured by a similar OP-FTIR system deployed on savanna fires in Africa. The data suggest that the method used to sample smoke can strongly influence the relative abundance of the emissions that are observed. The majority of fire emissions were lofted in the convection column and were sampled by the airborne FTIR. The roving, ground-based, point sampling FTIR measured the contribution of individual residual smoldering combustion fuel elements scattered throughout the burn site. The OP-FTIR provided a ~ 30 m path-integrated sample of emissions transported to the fixed path via complex ground-level circulation. The OP-FTIR typically probed two distinct combustion regimes, "flaming-like" (immediately after adjacent ignition and before the adjacent plume achieved significant vertical development) and "smoldering-like." These two regimes are denoted "early" and "late", respectively. The path-integrated sample of the ground-level smoke layer adjacent to the fire from the OP-FTIR provided our best estimate of fire-line exposure to smoke for wildland fire personnel. We provide a table of estimated fire-line exposures for numerous known air toxics based on synthesizing results from several studies. Our data suggest that peak exposures are more likely to challenge permissible exposure limits for wildland fire personnel than shift

  20. Field measurements of trace gases emitted by prescribed fires in southeastern US pine forests using an open-path FTIR system

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Burling, I. R.; Mendoza, A.; Johnson, T. J.; Cameron, M.; Griffith, D. W. T.; Paton-Walsh, C.; Weise, D. R.; Reardon, J.; Yokelson, R. J.

    2013-07-01

    We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, US measured during the fall of 2011. The fires were more intense than many prescribed burns because the fuels included mature pine stands not subjected to prescribed fire in decades that were lit following an extended drought. The emission factors were measured with a fixed open-path Fourier transform infrared (OP-FTIR) system that was deployed on the fire control lines. We compare these emission factors to those measured with a roving, point sampling, land-based FTIR and an airborne FTIR that were deployed on the same fires. We also compare to emission factors measured by a similar OP-FTIR system deployed on savanna fires in Africa. The data suggest that the method used to sample smoke can strongly influence the relative abundance of the emissions that are observed. The majority of the fire emissions were lofted in the convection column and they were sampled by the airborne FTIR along with the downwind chemistry. The roving, ground-based, point sampling FTIR measured the contribution of actively located individual residual smoldering combustion fuel elements scattered throughout the burn site. The OP-FTIR provided a ~30 m path-integrated sample of emissions transported to the fixed path via complex ground-level circulation. The OP-FTIR typically probed two distinct combustion regimes, "flaming-like" (immediately after adjacent ignition and before the adjacent plume achieved significant vertical development) and "smoldering-like." These two regimes are denoted "early" and "late", respectively. The emission factors from all three systems were plotted versus modified combustion efficiency and for some species (e.g. CH4 and CH3OH) they fit a single trend suggesting that the different emission factors for these species were mainly due to the specific mix of flaming and smoldering that each system sampled. For other species, the different fuels sampled also likely

  1. A new laboratory facility to study the interactions of aerosols, cloud droplets/ice crystals, and trace gases in a turbulent environment: The Π Chamber

    NASA Astrophysics Data System (ADS)

    Cantrell, W. H., II; Chang, K.; Ciochetto, D.; Niedermeier, D.; Bench, J.; Shaw, R. A.

    2014-12-01

    A detailed understanding of gas-aerosol-cloud interaction within the turbulent atmosphere is of prime importance for an accurate understanding of Earth's climate system. As one example: While every cloud droplet began as an aerosol particle, not every aerosol particle becomes a cloud droplet. The particle to droplet transformation requires that the particle be exposed to some critical concentration of water vapor, which differs for different combinations of particle size and chemical composition. Similarly, the formation of ice particles in mixed phase clouds is also catalyzed by aerosol particles. Even in the simplest scenarios it is challenging to gain a full understanding of the aerosol activation and ice nucleation processes. At least two other factors contribute significantly to the complexity observed in the atmosphere. First, aerosols and cloud particles are not static entities, but are continuously interacting with their chemical environment, and therefore changing in their properties. Second, clouds are ubiquitously turbulent, so thermodynamic and compositional variables, such as water vapor or other trace gas concentrations, fluctuate in space and time. Indeed, the coupling between turbulence and microphysical processes is one of the major research challenges in cloud physics. We have developed a multiphase, turbulent reaction chamber, (dubbed the Π Chamber, after the internal volume of 3.14 cubic meters) designed to address the problems outlined above. It is capable of pressures ranging from sea level to ~ 100 mbar, and can sustain temperatures of +40 to -55 ºC. We can independently control the temperatures on the surfaces of three heat transfer zones. This allows us to establish a temperature gradient between the floor and ceiling inducing Rayleigh-Benard convection and inducing a turbulent environment. Interior surfaces are electropolished stainless steel to facilitate cleaning before and after chemistry experiments. At present, supporting

  2. Ground-based Measurements of Vertical Profiles and Columns of Atmospheric Trace Gases Over Toronto Using a New High-Resolution Fourier Transform Infrared Spectrometer

    NASA Astrophysics Data System (ADS)

    Wiacek, A.; Yashcov, D.; Strong, K.; Boudreau, L.; Rochette, L.; Roy, C.

    2002-12-01

    The University of Toronto Atmospheric Observatory (TAO) has recently been established at Toronto, Canada. TAO includes several instruments, with a DA8 Fourier Transform Spectrometer (DA8 FTS, manufactured by ABB Bomem Inc., Québec, Canada) serving as the primary instrument at the facility. The geographic position of TAO (43.66°N, 79.40°W) makes it well suited for long-term measurements of mid-latitude stratospheric ozone and related species, while its urban setting enables measurements of tropospheric pollution. The DA8 FTS is based on a Michelson interferometer with a maximum optical path difference of 250 cm, providing a maximum unapodized resolution of 0.0026 cm-1. It is currently equipped with KBr and CaF2 beamsplitters, and InSb and HgCdTe detectors, for coverage of the spectral range from 700 to 4100 cm-1. A new heliostat (manufactured by Aim Controls Inc., California, USA) provides active solar tracking, collecting the incoming solar radiation and directing it into the FTS. The TAO DA8 FTS incorporates a new optical design recently developed by ABB Bomem Inc., which results in a fixed optical axis through the beamsplitter (and a fixed focal point on the detector) as well as a more stable modulation efficiency. The new instrument optics will be discussed. Next, the performance of the instrument will be examined in the context of standard NDSC (Network for the Detection of Stratospheric Change) trace gas column and vertical profile retrieval techniques, which use least squares fitting algorithms (SFIT, SFIT2). TAO has been operational (weather permitting) since October 2001. We have been retrieving columns and vertical profiles of HCl, HF, CH4, OCS, C2H6, CO, N2O and NO2 since May 2002. A detailed error analysis of retrieved columns and vertical profiles has been undertaken for the above species. Future plans for the TAO FTS include comparing our measurements with satellite measurements made by MOPITT, OSIRIS, and the upcoming ACE and MAESTRO instruments

  3. Field measurements of trace gases emitted by prescribed fires in southeastern U.S. pine forests using an open-path FTIR system

    SciTech Connect

    Akagi, Sheryl; Burling, Ian R.; Mendoza, Albert; Johnson, Timothy J.; Cameron, Melanie; Griffith, David WT; Paton-Walsh, C.; Weise, David; Reardon, James; Yokelson, Robert J.

    2014-01-08

    We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, U.S. measured during the fall of 2011. The fires were an attempt to simulate high-intensity burns and the fuels included mature pine stands not frequently subjected to prescribed fire that were lit following a sustained period of drought. In this work we focus on the emission factor measurements made using a fixed open-path gas analyzer Fourier transform infrared (FTIR) system. We compare these emission factors with those measured using a roving, point sampling, land-based FTIR and an airborne FTIR that were deployed on the same fires. We also compare to emission factors measured by a similar open-path FTIR system deployed on savanna fires in Africa. The data suggest that the method in which the smoke is sampled can strongly influence the relative abundance of the emissions that are observed. The airborne FTIR probed the bulk of the emissions, which were lofted in the convection column and the downwind chemistry while the roving ground-based point sampling FTIR measured the contribution of individual residual smoldering combustion fuel elements scattered throughout the burn site. The open-path FTIR provided a fixed path-integrated sample of emissions produced directly upwind mixed with emissions that were redirected by wind gusts, or right after ignition and before the adjacent plume achieved significant vertical development. It typically probed two distinct combustion regimes, “flaming-like” (immediately after adjacent ignition) and “smoldering-like”, denoted “early” and “late”, respectively. The calculated emission factors from open-path measurements were closer to the airborne than to the point measurements, but this could vary depending on the calculation method or from fire to fire given the changing MCE and dynamics over the duration of a typical burn. The emission factors for species whose emissions are not highly fuel dependent (e.g. CH4 and

  4. Diffusion of D-alpha-tocopherol (1); carbon dioxide (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) D-alpha-tocopherol; (2) carbon dioxide

  5. Diffusion of DL-alpha-tocopherol (1); carbon dioxide (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) DL-alpha-tocopherol; (2) carbon dioxide

  6. Diffusion of benzoic acid (1); carbon dioxide (2); methanol (3)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) benzoic acid; (2) carbon dioxide; (3) methanol

  7. Diffusion of benzoic acid (1); carbon dioxide (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) benzoic acid; (2) carbon dioxide

  8. A comparison of hydrocarbon gases from natural sources in the northwestern United States

    SciTech Connect

    Lorenson, T.D.; Kvenvolden, K.A. )

    1993-01-01

    The northwestern United States hosts a remarkable quantity and variety of thermal springs, seeps, and other natural-gas sources. Although many studies have dealt with the liquids and nonhydrocarbon gases emanating from these sources, few have focused on hydrocarbon gases. Of these gases, methane in particular is now recognized as an important reactive trace gas in the Earth's atmosphere that plays a significant role in global warming because of its greenhouse properties. To understand better the magnitude and occurrence of emissions of hydrocarbons from natural sources to the atmosphere, we have begun a survey of these gases throughout the northwestern United States. This area encompasses a number of different tectonic provinces: The Yellowstone hot spot, the northern Basin and Range Province, the Cascade volcanic arc, and the Cascadia subduction complex. Each province hosts springs and seeps with some unique compositions owing to the geological processes operating there. Methane is present in each area at concentration levels ranging from about 2 parts per million by volume (ppm-v) to 95.6 percent (by volume). Hydrothermal activity in the Yellowstone area produces spring gases containing less than 4 percent methane, with carbon dioxide as the balance gas. The Grand Teton National Park area, immediately to the south, has a wide variety of gas compositions with either methane, carbon dioxide, or nitrogen as the primary gas component. Where methane is abundant, higher molecular weight hydrocarbon gases (ethane, ethene, propane, propene, isobutane, and n-butane) are also found in ppm-v concentrations. In the northern Great Basin, thermal springs and seeps typically occur along fault zones at the base of mountain ranges. Methane concentrations range from 0.2 to 47 percent, with higher molecular weight hydrocarbon concentrations from 0 to 3,100 ppm-v. 47 refs., 8 figs., 4 tabs.

  9. Removal of sulphur dioxide from flue gases

    SciTech Connect

    Ersoy-Mericboyu, A.

    1999-08-01

    Mixtures of Ca(OH){sub 2} and different siliceous materials such as fly ash, bentonite, silica fume, and diatomite were hydrated to produce reactive SO{sub 2} sorbents. It was observed that these sorbents showed a better reactivity toward SO{sub 2} than the Ca(OH){sub 2} itself. This behavior is closely related to the pozzolanic nature of the hydrated sorbents and to the greater surface area. The reactivity of the sorbents was strongly influenced by the source of siliceous material and the hydration conditions. The total sulphation capacities of the sorbents were determined at 338 K with a synthetic gaseous mixture containing 5,000 ppm SO{sub 2} and 55% relative humidity. Depending on the chemical and physical properties of the sorbents, the SO{sub 2} captures ranged from 1.20 to 5.58 mmol SO{sub 2}/g sorbent. The amount of SO{sub 2} capture increased with the increasing surface area of the sorbent. The utilization of Ca(OH){sub 2} with SO{sub 2} improved significantly when Ca(OH){sub 2} was hydrated with siliceous materials first and later exposed to SO{sub 2}.

  10. Trace gas emissions from burning Florida wetlands

    NASA Technical Reports Server (NTRS)

    Cofer, Wesley R., III; Levine, Joel S.; Lebel, Peter J.; Winstead, Edward L.; Koller, Albert M., Jr.; Hinkle, C. Ross

    1990-01-01

    Measurements of biomass burn-produced trace gases were obtained using a helicopter at low altitudes above burning Florida wetlands on November 9, 1987, and from both helicopter and light-aircraft samplings on November 7, 1988. Carbon dioxide normalized emission ratios for carbon monoxide, hydrogen, methane, total nonmethane hydrocarbons, and nitrous oxide were obtained over burning graminoid wetlands consisting primarily of Spartina bakeri and Juncus roemerianus. Some interspersed scrub oak and saw palmetto were also burned. No significant differences were observed in the emission ratios determined for these gases from samples collected over flaming, mixed, and smoldering phases of combustion during the 1987 fire. Combustion-categorized differences in emission ratios were small for the 1988 fire. Combustion efficiency was relatively good (low emission ratios for reduced gases) for both fires. It is believed that the consistently low emission ratios were a unique result of graminoid wetlands fires, in which the grasses and rushes burned rapidly down to standing water and were quickly extinguished. Consequently, the efficiency of the combustion was good and the amount and duration of smoldering combustion was greatly deminished.

  11. Toxic gases.

    PubMed Central

    Matthews, G.

    1989-01-01

    An overview of the widespread use of gases and some volatile solvents in modern society is given. The usual circumstances in which undue exposure may occur are described. The most prominent symptoms and general principles of diagnosis and treatment are given and are followed by more specific information on the commoner, more toxic materials. While acute poisonings constitute the greater part of the paper, some indication of chronic disorders arising from repeated or prolonged exposure is also given. PMID:2687827

  12. Ground-based imaging differential optical absorption spectroscopy of atmospheric gases.

    PubMed

    Lohberger, Falko; Hönninger, Gerd; Platt, Ulrich

    2004-08-20

    We describe a compact remote-sensing instrument that permits spatially resolved mapping of atmospheric trace gases by passive differential optical absorption spectroscopy (DOAS) and present our first applications of imaging of the nitrogen dioxide contents of the exhaust plumes of two industrial emitters. DOAS permits the identification and quantification of various gases, e.g., NO2, SO2, and CH2O, from their specific narrowband (differential) absorption structures with high selectivity and sensitivity. With scattered sunlight as the light source, DOAS is used with an imaging spectrometer that is simultaneously acquiring spectral information on the incident light in one spatial dimension (column). The second spatial dimension is scanned by a moving mirror. PMID:15352396

  13. 40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... actions addressing the pollutant greenhouse gases (GHGs). 52.22 Section 52.22 Protection of Environment... greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases (GHGs) means the air pollutant as defined in § 86.1818-12(a) of this chapter as the aggregate group of six greenhouse gases: Carbon dioxide,...

  14. 40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... actions addressing the pollutant greenhouse gases (GHGs). 52.22 Section 52.22 Protection of Environment... greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases (GHGs) means the air pollutant as defined in § 86.1818-12(a) of this chapter as the aggregate group of six greenhouse gases: Carbon dioxide,...

  15. 40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... actions addressing the pollutant greenhouse gases (GHGs). 52.22 Section 52.22 Protection of Environment... greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases (GHGs) means the air pollutant as defined in § 86.1818-12(a) of this chapter as the aggregate group of six greenhouse gases: Carbon dioxide,...

  16. 40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... actions addressing the pollutant greenhouse gases (GHGs). 52.22 Section 52.22 Protection of Environment... greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases (GHGs) means the air pollutant as defined in § 86.1818-12(a) of this chapter as the aggregate group of six greenhouse gases: Carbon dioxide,...

  17. 40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... actions addressing the pollutant greenhouse gases (GHGs). 52.22 Section 52.22 Protection of Environment... greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases (GHGs) means the air pollutant as defined in § 86.1818-12(a) of this chapter as the aggregate group of six greenhouse gases: Carbon dioxide,...

  18. Noble Gases

    NASA Astrophysics Data System (ADS)

    Podosek, F. A.

    2003-12-01

    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

  19. Effect of Greenhouse Gases Dissolved in Seawater.

    PubMed

    Matsunaga, Shigeki

    2015-12-30

    A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

  20. Emissions of organic trace gases from savanna fires in southern Africa during the 1992 Southern African Fire Atmosphere Research Initiative and their impact on the formation of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Koppmann, R.; Khedim, A.; Rudolph, J.; Poppe, D.; Andreae, M. O.; Helas, G.; Welling, M.; Zenker, T.

    1997-08-01

    CO, CH4, and organic trace gases were measured in air samples collected during several flights with a DC-3 aircraft through the plumes from savanna fires and agricultural fires during the SAFARI 92 campaign in southern Africa in September and October 1992. In all samples a variety of higher molecular weight organic compounds was found, most of which are very reactive. More than 70 of the roughly 140 major components present could be identified. Typically, mixing ratios of several hundred parts per billion carbon of organic compounds were measured inside the plumes, corresponding to an emission ratio of total organic carbon relative to CO2 of up to 1%. About 50% of these emissions were in the form of oxygenated and unsaturated compounds. The contributions of still unknown compounds to the total emission of organic compounds add up to another 20-30%. The observed emission ratios relative to CO2 show a considerable variation depending on the fuel type and the burning stages of the fire. The lowest value of the emission ratio of the sum of all identified organic compounds relative to CO2 was found for a sugar cane fire with (1.7±0.7)×10-3 (ppb C/ppb CO2). For a large savanna fire in Kruger National Park the ratio was (7.4±1.6)×10-3 (ppb C/ppb CO2). The highest value was (13.7±0.9)×10-3 (ppb C/ppb CO2) for an uncontrolled fire of mainly wood and shrub in the Drakensberg region. Results of model calculations show that in biomass-burning plumes, reactive organic compounds contribute significantly to the formation of ozone, especially during the initial phase of photochemical processing.

  1. Trace gases in the Antarctic Atmosphere

    NASA Technical Reports Server (NTRS)

    Heidt, L. E.; Pollock, W. H.; Lueb, R. A.; Henry, B. E.; Vedder, J. F.

    1989-01-01

    Whole-air samples collected aboard the NASA ER-2 and DC-8 aircraft as part of the Airborne Antarctic Ozone Experiment were analyzed in a field laboratory set up at Punta Arenas, Chile. Mixing ratios obtained from gas chromatographic analyses of these samples are presented for CH4, CO, N2O, CFCl3, CF2Cl2, C2F3Cl3, CH3CCl3, and CCl4. A comparison of CFCl3/N2O mixing ratios from the flights of September 16-29, 1987 provides evidence of sustained subsidence.

  2. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    EPA Science Inventory

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA F...

  3. AIR INFILTRATION MEASUREMENTS USING TRACER GASES: A LITERATURE REVIEW

    EPA Science Inventory

    The report gives results of a literature review of air filtration measurements using tracer gases, including sulfur hexafluoride, hydrogen, carbon monoxide, carbon dioxide, nitrous oxide, and radioactive argon and krypton. Sulfur hexafluoride is the commonest tracer gas of choice...

  4. Stable Isotope Measurements of Carbon Dioxide, Methane, and Hydrogen Sulfide Gas Using Frequency Modulation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nowak-Lovato, K.

    2014-12-01

    Seepage from enhanced oil recovery, carbon storage, and natural gas sites can emit trace gases such as carbon dioxide, methane, and hydrogen sulfide. Trace gas emission at these locations demonstrate unique light stable isotope signatures that provide information to enable source identification of the material. Light stable isotope detection through surface monitoring, offers the ability to distinguish between trace gases emitted from sources such as, biological (fertilizers and wastes), mineral (coal or seams), or liquid organic systems (oil and gas reservoirs). To make light stable isotope measurements, we employ the ultra-sensitive technique, frequency modulation spectroscopy (FMS). FMS is an absorption technique with sensitivity enhancements approximately 100-1000x more than standard absorption spectroscopy with the advantage of providing stable isotope signature information. We have developed an integrated in situ (point source) system that measures carbon dioxide, methane and hydrogen sulfide with isotopic resolution and enhanced sensitivity. The in situ instrument involves the continuous collection of air and records the stable isotope ratio for the gas being detected. We have included in-line flask collection points to obtain gas samples for validation of isotopic concentrations using our in-house isotope ratio mass spectroscopy (IRMS). We present calibration curves for each species addressed above to demonstrate the sensitivity and accuracy of the system. We also show field deployment data demonstrating the capabilities of the system in making live dynamic measurements from an active source.

  5. Carbon dioxide-brine-rock interactions in a carbonate reservoir capped by shale: Experimental insights regarding the evolution of trace metals

    NASA Astrophysics Data System (ADS)

    Marcon, Virginia; Kaszuba, John P.

    2015-11-01

    Trace metal behavior provides important information regarding fluid-rock interactions in CO2-charged water-rock systems and constrains potential environmental impacts. Hydrothermal experiments evaluated mechanisms of release, evolution, and subsequent scavenging of trace metals at 160 °C and 25 MPa. Experiments were designed to simulate two theoretical locations within a CO2-charged reservoir: (1) at the contact between a shale caprock and carbonate reservoir and (2) deeper within a carbonate reservoir, away from the shale. CO2 injection into brine (ionic strength = 3.3 mol/kg) decreased the pH by 1-2 units; concomitant mineral dissolution elevated Ba, Co, Cu, Pb, and V concentrations in the brine at both simulated locations within the reservoir. Additionally, Fe, Ni, and Zn concentrations increased in the mixed shale-carbonate experiment; Ba and Cd concentrations increased in the carbonate-only experiment. However, concentrations of Fe, Ba, Cr, and Pb in the mixed shale-carbonate experiment and Cr, Pb, V, and Zn within the carbonate-only experiment subsequently decreased as a result of precipitation of sulfides (Fe and Co sulfides), oxides, and clays. At the conclusion of the experiments, Fe, Pb, and Cr exceeded U.S. Environmental Protection Agency maximum contaminant limits in both experiments. In addition, zinc exceeded the limits at the simulated shale-carbonate contact and Ba, Cu, and Cd exceeded the limits in the simulated carbonate reservoir. Experimentally observed trends of decreasing Fe and Pb concentrations suggest these trace metals become less of an environmental concern as CO2-water-rock reactions evolve with time. The shale caprock plays an active role in trace metal evolution. The shale is a large source of metals, but also provides metal sinks such as primary clays, secondary smectites, and other silicates that are not found deeper within the carbonate reservoir, away from the shale. This potential mechanism of self-healing mitigates, but does not

  6. Trace Gas Retrievals from the GeoTASO Aircraft Instrument

    NASA Astrophysics Data System (ADS)

    Nowlan, C. R.; Liu, X.; Leitch, J. W.; Liu, C.; Gonzalez Abad, G.; Chance, K.; Cole, J.; Delker, T.; Good, W. S.; Murcray, F.; Ruppert, L.; Soo, D.; Loughner, C.; Follette-Cook, M. B.; Janz, S. J.; Kowalewski, M. G.; Pickering, K. E.; Zoogman, P.; Al-Saadi, J. A.

    2015-12-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is a passive remote sensing instrument capable of making 2-D measurements of trace gases and aerosols from aircraft. The instrument measures backscattered UV and visible radiation, allowing the retrieval of trace gas amounts below the aircraft at horizontal resolutions on the order of 250 m x 250 m. GeoTASO was originally developed under NASA's Instrument Incubator Program as a test-bed instrument for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) decadal survey mission, and is now also part of risk reduction for the upcoming Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Environment Monitoring Spectrometer (GEMS) geostationary satellite missions. We present spatially resolved observations of ozone, nitrogen dioxide, formaldehyde and sulfur dioxide over urban areas and power plants from flights during the DISCOVER-AQ field campaigns in Texas and Colorado, as well as comparisons with observations made by ground-based Pandora spectrometers, in situ monitoring instruments and other aircraft instruments deployed during these campaigns. These measurements at various times of day are providing a very useful data set for testing and improving TEMPO and GEMS retrieval algorithms, as well as demonstrating prototype validation strategies.

  7. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

    NASA Astrophysics Data System (ADS)

    Stockwell, Chelsea E.; Christian, Ted J.; Goetz, J. Douglas; Jayarathne, Thilina; Bhave, Prakash V.; Praveen, Puppala S.; Adhikari, Sagar; Maharjan, Rashmi; DeCarlo, Peter F.; Stone, Elizabeth A.; Saikawa, Eri; Blake, Donald R.; Simpson, Isobel J.; Yokelson, Robert J.; Panday, Arnico K.

    2016-09-01

    The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) campaign took place in and around the Kathmandu Valley and in the Indo-Gangetic Plain (IGP) of southern Nepal during April 2015. The source characterization phase targeted numerous important but undersampled (and often inefficient) combustion sources that are widespread in the developing world such as cooking with a variety of stoves and solid fuels, brick kilns, open burning of municipal solid waste (a.k.a. trash or garbage burning), crop residue burning, generators, irrigation pumps, and motorcycles. NAMaSTE produced the first, or rare, measurements of aerosol optical properties, aerosol mass, and detailed trace gas chemistry for the emissions from many of the sources. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared (FTIR) spectroscopy, whole-air sampling (WAS), and photoacoustic extinctiometers (PAX; 405 and 870 nm) based on field work with a moveable lab sampling authentic sources. The primary aerosol optical properties reported include emission factors (EFs) for scattering and absorption coefficients (EF Bscat, EF Babs, in m2 kg-1 fuel burned), single scattering albedos (SSAs), and absorption Ångström exponents (AAEs). From these data we estimate black and brown carbon (BC, BrC) emission factors (g kg-1 fuel burned). The trace gas measurements provide EFs (g kg-1) for CO2, CO, CH4, selected non-methane hydrocarbons up to C10, a large suite of oxygenated organic compounds, NH3, HCN, NOx, SO2, HCl, HF, etc. (up to ˜ 80 gases in all). The emissions varied significantly by source, and light absorption by both BrC and BC was important for many sources. The AAE for dung-fuel cooking fires (4.63 ± 0.68) was significantly higher than for wood-fuel cooking fires (3.01 ± 0.10). Dung-fuel cooking fires also emitted high levels of NH3 (3.00 ± 1.33 g kg-1), organic acids (7.66 ± 6.90 g kg-1), and HCN (2.01 ± 1.25 g kg-1), where the latter could

  8. Catalytic desulfurization of industrial waste gases

    SciTech Connect

    Dupin, Th.

    1985-07-30

    Industrial waste gases containing objectionable/polluting compounds of sulfur, e.g., H/sub 2/S, SO/sub 2/ and such organosulfur derivatives as COS, CS/sub 2/ and mercaptans, are catalytically desulfurized, e.g., by Claus process, employing an improved catalyst comprising titanium dioxide and calcium, barium, strontium or magnesium sulfate.

  9. Variations in PM2.5, TSP, BC, and trace gases (NO2, SO2, and O3) between haze and non-haze episodes in winter over Xi'an, China

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Shen, Zhenxing; Cao, Junji; Zhang, Renjian; Zhang, Leiming; Huang, R.-J.; Zheng, Chenjia; Wang, Linqing; Liu, Suixin; Xu, Hongmei; Zheng, Chunli; Liu, Pingping

    2015-07-01

    To investigate chemical profiles and formation mechanisms of aerosol particles in winter haze events, daily PM2.5 and TSP, 5-min BC, and 15-min trace gases (SO2, NO2, and O3) were measured continuously during Dec. 1-31, 2012 in Xi'an. Chemical analysis was also conducted for nine water-soluble inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, and SO42-), organic carbon (OC), elemental carbon (EC), and eight carbon fractions (OC1, OC2, OC3, OC4, EC1, EC2, EC3, and OP) in both PM2.5 and TSP samples. Higher levels of TSP, PM2.5, BC, SO2, and NO2, and lower levels of O3 were observed during haze periods in comparison with non-haze days. The sum of the major secondary ionic species (NH4+, NO3-, and SO42-) in PM2.5 or TSP during haze periods was about 3 times of that during non-haze days. Ion balance calculations showed that PM2.5 samples were acidic during haze periods and were close to neutral during non-haze days. The mean carbon levels were 52.9 μg m-3 and 82.1 μg m-3 in PM2.5 and TSP, respectively, during haze events, which were ∼1.5 times of those during non-haze days. The diurnal variations of BC during non-haze days showed a bimodal distribution with two peaks coincided with traffic rush hours. This was not the case during haze periods, which exhibited a relatively smooth pattern but with high concentration levels, providing evidence of particle accumulation. The ratios of SO42 - /EC, NO3-/EC, and NH4+/EC sharply increased during haze periods, indicating the important pathway of secondary inorganic species formation through aqueous-phase transformation under high relative humidity condition. This study also highlights that wintertime secondary organic carbon (SOC) formation can be an important contributor to carbonaceous aerosol, especially during haze periods.

  10. In situ measurements of trace gases and aerosol optical properties at a rural site in northern China during East Asian Study of Tropospheric Aerosols: An International Regional Experiment 2005

    NASA Astrophysics Data System (ADS)

    Li, Can; Marufu, Lackson T.; Dickerson, Russell R.; Li, Zhanqing; Wen, Tianxue; Wang, Yuesi; Wang, Pucai; Chen, Hongbin; Stehr, Jeffrey W.

    2007-11-01

    In situ measurements of trace gases and aerosol optical properties were made in March 2005 at Xianghe (39.798°N, 116.958°E, 35 m), a rural site about 70 km southeast, and generally downwind of the Beijing metropolitan area. High pollutant levels were observed during the experiment, with CO (1.09 ± 1.02 ppmv, average ± standard deviation), SO2 (17.8 ± 15.7 ppbv), NOy (26.0 ± 24.0 ppbv), aerosol scattering coefficients (bsp, (468 ± 472) × 10-6 m-1), and aerosol absorption coefficients (bap, (65 ± 75) × 10-6 m-1) all much higher than observed at some rural sites in the United States. O3 (29.1 ± 16.5 ppbv) was relatively low during this study, suggesting inactive photochemical processes. Strong synoptic fluctuations in pollutant levels were detected every 4-5 days during the experiment, as cold fronts passing over the region drastically reduced the ground-level pollution. Very little precipitation was measured during the whole observational period, implying pollutant uplift and transport by rain-free cold fronts and dry convection. The single scattering albedo (SSA) observed (0.81 in the morning and 0.85 in the afternoon) indicates strongly absorbing aerosols near surface. The observed CO/SO2 ratio (35.8) is higher than inventory values, but closer to the updated CO inventory of Streets et al. (2006) than to Streets et al. (2003) or Wang et al. (2005). The observed CO/NOy ratio agrees better with inventories. Further analysis suggests that such comparisons may shed some light on the quality of emission inventories, but quantification of any error requires more extensive measurements over longer period and larger areas, as well as direct characterization of emission sources, especially mobile sources and small boilers. Using black carbon (BC)/CO ratio from the experiment, BC emissions from China are estimated at about 1300 Gg (109 g)/yr, but could be as high as 2600 Gg/yr.

  11. Using ICP-qMS to trace the uptake of nanoscale titanium dioxide by microalgae-potential disadvantages of vegetable reference material.

    PubMed

    Potouridis, Theodoros; Völker, Johannes; Alsenz, Heiko; Oetken, Matthias; Püttmann, Wilhelm

    2014-04-01

    As nanoscale materials have gained in economic importance over recent years, concerns about accumulation in the environment and, consequently, analysis of nanoparticles in biological material have increasingly become the focus of scientific research. A nanomaterial used in a wide range of food, consumer and household products is titanium dioxide (nTiO2). Monitoring of nTiO2 via determination of elemental titanium (Ti) can be very challenging because of a variety of possible interferences. This work describes problems during the development of a quantification method for titanium dioxide (TiO2) using inductively coupled plasma-quadrupole mass spectrometry (ICP-qMS). To evaluate the analytical method, certified vegetable reference material NCS DC 73349 was used. Interestingly, measurements of NCS DC 73349 seemed to result in acceptable recovery values-however, this was without considering interferences or conceivable differences in the natural isotopic abundance of the certified titanium calibration solution and NCS DC 73349. Actually, recoveries were lower than initially assumed. The potential interferences causing augmented recovery could be attributed to the presence of the elements sulfur (S) and phosphorus (P), which were able to form oxide ions and nitrogen-interfering species. The effect of such interfering cluster ions could be prevented by dry ashing as a sample preparation step, to evaporate S and P, before digestion with aqua regia in a high-pressure asher (HPA). Final practicability of the analysis method was proved by monitoring the uptake of nTiO2 by the microalgae Scenedesmus acutus in an environmental exposure study.

  12. Using ICP-qMS to trace the uptake of nanoscale titanium dioxide by microalgae-potential disadvantages of vegetable reference material.

    PubMed

    Potouridis, Theodoros; Völker, Johannes; Alsenz, Heiko; Oetken, Matthias; Püttmann, Wilhelm

    2014-04-01

    As nanoscale materials have gained in economic importance over recent years, concerns about accumulation in the environment and, consequently, analysis of nanoparticles in biological material have increasingly become the focus of scientific research. A nanomaterial used in a wide range of food, consumer and household products is titanium dioxide (nTiO2). Monitoring of nTiO2 via determination of elemental titanium (Ti) can be very challenging because of a variety of possible interferences. This work describes problems during the development of a quantification method for titanium dioxide (TiO2) using inductively coupled plasma-quadrupole mass spectrometry (ICP-qMS). To evaluate the analytical method, certified vegetable reference material NCS DC 73349 was used. Interestingly, measurements of NCS DC 73349 seemed to result in acceptable recovery values-however, this was without considering interferences or conceivable differences in the natural isotopic abundance of the certified titanium calibration solution and NCS DC 73349. Actually, recoveries were lower than initially assumed. The potential interferences causing augmented recovery could be attributed to the presence of the elements sulfur (S) and phosphorus (P), which were able to form oxide ions and nitrogen-interfering species. The effect of such interfering cluster ions could be prevented by dry ashing as a sample preparation step, to evaporate S and P, before digestion with aqua regia in a high-pressure asher (HPA). Final practicability of the analysis method was proved by monitoring the uptake of nTiO2 by the microalgae Scenedesmus acutus in an environmental exposure study. PMID:24604322

  13. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-08-01

    lower the viscosity of the extracted bitumen (i.e., C4-C9 alkanes, C5-C6 cycloalkanes, C6-C8 aromatics), together with CO; and (2) emissions associated with the mining effort (i.e., CO2, CO, CH4, NO, NO2, NOy, SO2, C2-C4 alkanes, C2-C4 alkenes, C9 aromatics, short-lived solvents such as C2Cl4 and C2HCl3, and longer-lived species such as HCFC-22 and HCFC-142b). Prominent in the second group, SO2 and NO were remarkably enhanced over the oil sands, with maximum enhancements of 38.7 and 5.0 ppbv, or 383 and 319× the local background, respectively. The SO2 enhancements are comparable to maximum values measured in heavily polluted megacities such as Mexico City and are attributed to coke combustion. By contrast, relatively poor correlations between CH4 ethane and propane suggest low natural gas leakage despite its heavy use at the surface mining sites. In addition to the emission of many trace gases, the natural drawdown of OCS by vegetation was absent above the surface mining operations, presumably because of the widespread land disturbance. Unexpectedly, the mixing ratios of α- and β-pinene were much higher over the oil sands (up to 217 and 610 pptv, respectively) than over vegetation in the background boundary layer (20±7 and 84±24 pptv, respectively), and the pinenes correlated well with several industrial tracers that were elevated in the oil sands plumes. Because so few independent measurements from the oil sands mining industry exist, this study provides an important initial characterization of trace gas emissions from oil sands surface mining operations.

  14. Non-thermal plasma for exhaust gases treatment

    NASA Astrophysics Data System (ADS)

    Alva R., Elvia; Pacheco P., Marquidia; Gómez B., Fernando; Pacheco P., Joel; Colín C., Arturo; Sánchez-Mendieta, Víctor; Valdivia B., Ricardo; Santana D., Alfredo; Huertas C., José; Frías P., Hilda

    2015-09-01

    This article describes a study on a non-thermal plasma device to treat exhaust gases in an internal combustion engine. Several tests using a plasma device to treat exhaust gases are conducted on a Honda GX200-196 cm3 engine at different rotational speeds. A plasma reactor could be efficient in degrading nitrogen oxides and particulate matter. Monoxide and carbon dioxide treatment is minimal. However, achieving 1%-3% degradation may be interesting to reduce the emission of greenhouse gases.

  15. 40 CFR 60.333 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for sulfur dioxide. 60.333... Turbines § 60.333 Standard for sulfur dioxide. On and after the date on which the performance test required... stationary gas turbine any gases which contain sulfur dioxide in excess of 0.015 percent by volume at...

  16. 40 CFR 60.183 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for sulfur dioxide. 60.183... Smelters § 60.183 Standard for sulfur dioxide. (a) On and after the date on which the performance test... furnace, or converter gases which contain sulfur dioxide in excess of 0.065 percent by volume. (b)...

  17. 40 CFR 60.163 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for sulfur dioxide. 60.163... Smelters § 60.163 Standard for sulfur dioxide. (a) On and after the date on which the performance test... converter any gases which contain sulfur dioxide in excess of 0.065 percent by volume, except as provided...

  18. 40 CFR 60.163 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for sulfur dioxide. 60.163... Smelters § 60.163 Standard for sulfur dioxide. (a) On and after the date on which the performance test... converter any gases which contain sulfur dioxide in excess of 0.065 percent by volume, except as provided...

  19. 40 CFR 60.333 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for sulfur dioxide. 60.333... Turbines § 60.333 Standard for sulfur dioxide. On and after the date on which the performance test required... stationary gas turbine any gases which contain sulfur dioxide in excess of 0.015 percent by volume at...

  20. 40 CFR 60.333 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for sulfur dioxide. 60.333... Turbines § 60.333 Standard for sulfur dioxide. On and after the date on which the performance test required... stationary gas turbine any gases which contain sulfur dioxide in excess of 0.015 percent by volume at...

  1. 40 CFR 60.333 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for sulfur dioxide. 60.333... Turbines § 60.333 Standard for sulfur dioxide. On and after the date on which the performance test required... stationary gas turbine any gases which contain sulfur dioxide in excess of 0.015 percent by volume at...

  2. 40 CFR 60.163 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for sulfur dioxide. 60.163... Smelters § 60.163 Standard for sulfur dioxide. (a) On and after the date on which the performance test... converter any gases which contain sulfur dioxide in excess of 0.065 percent by volume, except as provided...

  3. 40 CFR 60.183 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for sulfur dioxide. 60.183... Smelters § 60.183 Standard for sulfur dioxide. (a) On and after the date on which the performance test... furnace, or converter gases which contain sulfur dioxide in excess of 0.065 percent by volume. (b)...

  4. 40 CFR 60.183 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for sulfur dioxide. 60.183... Smelters § 60.183 Standard for sulfur dioxide. (a) On and after the date on which the performance test... furnace, or converter gases which contain sulfur dioxide in excess of 0.065 percent by volume. (b)...

  5. 40 CFR 60.183 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for sulfur dioxide. 60.183... Smelters § 60.183 Standard for sulfur dioxide. (a) On and after the date on which the performance test... furnace, or converter gases which contain sulfur dioxide in excess of 0.065 percent by volume. (b)...

  6. 40 CFR 60.183 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for sulfur dioxide. 60.183... Smelters § 60.183 Standard for sulfur dioxide. (a) On and after the date on which the performance test... furnace, or converter gases which contain sulfur dioxide in excess of 0.065 percent by volume. (b)...

  7. 40 CFR 60.163 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for sulfur dioxide. 60.163... Smelters § 60.163 Standard for sulfur dioxide. (a) On and after the date on which the performance test... converter any gases which contain sulfur dioxide in excess of 0.065 percent by volume, except as provided...

  8. 40 CFR 60.333 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for sulfur dioxide. 60.333... Turbines § 60.333 Standard for sulfur dioxide. On and after the date on which the performance test required... stationary gas turbine any gases which contain sulfur dioxide in excess of 0.015 percent by volume at...

  9. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    NASA Astrophysics Data System (ADS)

    Nowlan, C. R.; Liu, X.; Leitch, J. W.; Chance, K.; González Abad, G.; Liu, C.; Zoogman, P.; Cole, J.; Delker, T.; Good, W.; Murcray, F.; Ruppert, L.; Soo, D.; Follette-Cook, M. B.; Janz, S. J.; Kowalewski, M. G.; Loughner, C. P.; Pickering, K. E.; Herman, J. R.; Beaver, M. R.; Long, R. W.; Szykman, J. J.; Judd, L. M.; Kelley, P.; Luke, W. T.; Ren, X.; Al-Saadi, J. A.

    2015-12-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a testbed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas in September 2013. Measurements of backscattered solar radiation between 420-465 nm collected on four days during the campaign are used to determine slant column amounts of NO2 at 250 m × 250 m spatial resolution with a fitting precision of 2.2 × 1015 molecules cm-2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.91 for the most polluted day). NO2 slant columns from GeoTASO also agree well with preliminary retrievals from the GEO-CAPE Airborne Simulator (GCAS) which flew on the NASA King Air B200 (r = 0.84, slope = 0.94). Enhanced NO2 is resolvable over areas of traffic NOx emissions and near individual petrochemical facilities.

  10. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    NASA Astrophysics Data System (ADS)

    Nowlan, Caroline R.; Liu, Xiong; Leitch, James W.; Chance, Kelly; González Abad, Gonzalo; Liu, Cheng; Zoogman, Peter; Cole, Joshua; Delker, Thomas; Good, William; Murcray, Frank; Ruppert, Lyle; Soo, Daniel; Follette-Cook, Melanie B.; Janz, Scott J.; Kowalewski, Matthew G.; Loughner, Christopher P.; Pickering, Kenneth E.; Herman, Jay R.; Beaver, Melinda R.; Long, Russell W.; Szykman, James J.; Judd, Laura M.; Kelley, Paul; Luke, Winston T.; Ren, Xinrong; Al-Saadi, Jassim A.

    2016-06-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas, in September 2013. Measurements of backscattered solar radiation between 420 and 465 nm collected on 4 days during the campaign are used to determine slant column amounts of NO2 at 250 m × 250 m spatial resolution with a fitting precision of 2.2 × 1015 moleculescm-2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements and r = 0.74 overall), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.85). NO2 slant columns from GeoTASO also agree well with preliminary retrievals from the GEO-CAPE Airborne Simulator (GCAS) which flew on the NASA King Air B200 (r = 0.81, slope = 0.91). Enhanced NO2 is resolvable over areas of traffic NOx emissions and near individual petrochemical facilities.

  11. Bisphosphine dioxides

    DOEpatents

    Moloy, Kenneth G.

    1990-01-01

    A process for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

  12. Bisphosphine dioxides

    SciTech Connect

    Moloy, K.G.

    1990-02-20

    A process is described for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

  13. Method for removing sulfur dioxide

    SciTech Connect

    Ermini, E.

    1980-12-16

    Sulfur dioxide is removed from waste gases generated in a thermoelectric plant by contacting the gases countercurrently with an aqueous alkaline solution having a ph of about 9-12 and containing both sodium hydroxide and manganic hydroxide, whereby the sulfur dioxide reacts with the sodium hydroxide to form sodium sulfite until the ph of the solution is about 6-7 and the sodium hydroxide is substantially exhausted and wherein the sulfur dioxide then reacts with the manganic hydroxide to form manganese sulfite. The resultant sodium sulfite and manganese sulfite are oxidized and transformed into sodium sulfate and manganese sulfate respectively, by the action of oxygen in the mixture, in the presence of the manganic ion and also by the direct oxidizing action of the manganic ion.

  14. Effects of anomalous high temperatures on carbon dioxide, methane, dissolved organic carbon and trace element concentrations in thaw lakes in Western Siberia in 2012

    NASA Astrophysics Data System (ADS)

    Pokrovsky, O. S.; Shirokova, L. S.; Kirpotin, S. N.; Kulizhsky, S. P.; Vorobiev, S. N.

    2013-04-01

    During the anomalous hot summer in 2012, surface air temperatures in Western Siberia were 5 to 10 °C higher than those observed during the previous period of > 30 yr. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating of water in thermokarst ponds and lakes in discontinuous permafrost zones and compare these observations to previous field results obtained when the temperature was normal during the summer of 2010 in the same region. Thermokarst bodies of water shrank significantly, water levels dropped approximately 50 cm in large lakes and small (< 10-100 m2) ponds, and shallow soil depressions disappeared. Based on samples from ~ 40 bodies of water collected previously and in 2012, first-order features of changes in chemical composition in response to increased water temperatures (from 14.1 ± 2.2 to 23.8 ± 2.3 °C in 2010 and 2012, respectively) were established. In these thermokarst bodies of water that covered a full range of surface areas, the average conductivity and pH were almost unchanged, whereas dissolved organic carbon (DOC), Cl- and SO42- concentrations were higher by a factor of ~ 2 during summer 2012 compared to periods with normal temperatures. Similarly, most divalent metals and insoluble trivalent and tetravalent elements were more concentrated by a factor of 1.7-2.4 in the summer of 2012 than normal periods. The average concentrations of dissolved CO2 and CH4 during the hot summer of 2012 increased by factors of 1.4 and 4.9, respectively. For most of the trace elements bound to colloids, the degree of colloidal binding decreased by a factor of 1.44 ± 0.33 (for an average of 40 elements) during the hot summer of 2012 compared to normal periods. Increases in CO2 and CH4 concentrations with the decreasing size of the body of water were well-pronounced during the hot summer of 2012. The concentrations of CO2 and CH4 significantly increased by factors of 5 and 150, respectively, in small (

  15. Tunable pulsed carbon dioxide laser

    NASA Technical Reports Server (NTRS)

    Megie, G. J.; Menzies, R. T.

    1981-01-01

    Transverse electrically-excited-atmosphere (TEA) laser is continuously tunable over several hundred megahertz about centers of spectral lines of carbon dioxide. It is operated in single longitudinal mode (SLM) by injection of beam from continuous-wave, tunable-waveguide carbon dioxide laser, which serves as master frequency-control oscillator. Device measures absorption line of ozone; with adjustments, it is applicable to monitoring of atmospheric trace species.

  16. A new atmospherically relevant oxidant of sulphur dioxide.

    PubMed

    Mauldin, R L; Berndt, T; Sipilä, M; Paasonen, P; Petäjä, T; Kim, S; Kurtén, T; Stratmann, F; Kerminen, V-M; Kulmala, M

    2012-08-01

    Atmospheric oxidation is a key phenomenon that connects atmospheric chemistry with globally challenging environmental issues, such as climate change, stratospheric ozone loss, acidification of soils and water, and health effects of air quality. Ozone, the hydroxyl radical and the nitrate radical are generally considered to be the dominant oxidants that initiate the removal of trace gases, including pollutants, from the atmosphere. Here we present atmospheric observations from a boreal forest region in Finland, supported by laboratory experiments and theoretical considerations, that allow us to identify another compound, probably a stabilized Criegee intermediate (a carbonyl oxide with two free-radical sites) or its derivative, which has a significant capacity to oxidize sulphur dioxide and potentially other trace gases. This compound probably enhances the reactivity of the atmosphere, particularly with regard to the production of sulphuric acid, and consequently atmospheric aerosol formation. Our findings suggest that this new atmospherically relevant oxidation route is important relative to oxidation by the hydroxyl radical, at least at moderate concentrations of that radical. We also find that the oxidation chemistry of this compound seems to be tightly linked to the presence of alkenes of biogenic origin.

  17. Separation of Carbon Dioxide from Flue Gas Using Ion Pumping

    SciTech Connect

    Aines, R; Bourcier, W L; Johnson, M R

    2006-04-21

    We are developing a new way of separating carbon dioxide from flue gas based on ionic pumping of carbonate ions dissolved in water. Instead of relying on large temperature or pressure changes to remove carbon dioxide from solvent used to absorb it from flue gas, the ion pump increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, which can be removed from the downstream side of the ion pump as a nearly pure gas. This novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas. The slightly basic water used as the extraction medium is impervious to trace acid gases that destroy existing solvents, and no pre-separation is necessary. The simple, robust nature of the process lends itself to small separation plants. Although the energy cost of the ion pump is significant, we anticipate that it will be compete favorably with the current 35% energy penalty of chemical stripping systems in use at power plants. There is the distinct possibility that this simple method could be significantly more efficient than existing processes.

  18. 75 FR 17331 - Public Hearings for the Mandatory Reporting Rule for Greenhouse Gases

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ... Reporting of Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide.'' These two notices... above certain threshold levels monitor and report emissions and carbon dioxide injection and geologic... Systems, proposed 40 CFR part 98, subpart W), EPA-HQ-OAR-2009-0926 (Carbon Dioxide Injection and...

  19. Diffusion of 1,1-dimethylethyl-benzene (1); carbon dioxide (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) 1,1-dimethylethyl-benzene; (2) carbon dioxide

  20. Diffusion of cis-5,8,11,14,17-eicosapentaenoic acid (1); carbon dioxide (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) cis-5,8,11,14,17-eicosapentaenoic acid; (2) carbon dioxide

  1. Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

    SciTech Connect

    Ho, C.S.; Smith, M.D.

    1986-01-01

    The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

  2. Analytical methods for toxic gases from thermal degradation of polymers

    NASA Technical Reports Server (NTRS)

    Hsu, M.-T. S.

    1977-01-01

    Toxic gases evolved from the thermal oxidative degradation of synthetic or natural polymers in small laboratory chambers or in large scale fire tests are measured by several different analytical methods. Gas detector tubes are used for fast on-site detection of suspect toxic gases. The infrared spectroscopic method is an excellent qualitative and quantitative analysis for some toxic gases. Permanent gases such as carbon monoxide, carbon dioxide, methane and ethylene, can be quantitatively determined by gas chromatography. Highly toxic and corrosive gases such as nitrogen oxides, hydrogen cyanide, hydrogen fluoride, hydrogen chloride and sulfur dioxide should be passed into a scrubbing solution for subsequent analysis by either specific ion electrodes or spectrophotometric methods. Low-concentration toxic organic vapors can be concentrated in a cold trap and then analyzed by gas chromatography and mass spectrometry. The limitations of different methods are discussed.

  3. Generating Water-Soluble Noxious Gases: An Overhead Projector Demonstration

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Oliver-Hoyo, Maria; Hur, Chinhyu

    1998-12-01

    A simple, inexpensive apparatus to generate and collect water-soluble noxious gases as an overhead projector demonstration can be made from two small beakers and a Petri dish. The detection and generation of sulfur dioxide and nitrogen dioxide are described. Sulfur dioxide dissolved in water is detected using an acid-base indicator, decolorizing of anthocyanin, or reduction of permanganate. The SO2 is generated by addition of sulfite or bisulfite to a strong acid or by the addition of concentrated sulfuric acid to sugars. Nitrogen dioxide is generated by mixing copper and nitric acid and detected using an acid-base indicator.

  4. Trace gas emissions from biomass burning in tropical Australian savannas

    SciTech Connect

    Hurst, D.F.; Griffith, D.W.T.; Cook, G.D.

    1994-08-20

    The trace gas emissions of biomass burning was measured during the 1991 and 1992 dry seasons (April through October) at the Kapalga Research Station in Kakadu National Park, Northern Territory, Australia. Over 100 smoke samples from savannah fires were collected, from the ground and from aircraft flying at 50 to 700 meters above the fires. The samples were analyzed for carbon dioxide, carbon monoxide, nitrous oxides, and other carbon and nitrogen compounds using gas phase Fourier transform infrared (FTIR) spectroscopy, matrix isolation FTIR spectroscopy, and chemiluminescence techniques. This paper describes the results of the gas analyses and discusses the potential impacts of these gases on regional atmospheric chemistry.49 refs., 4 figs., 7 tabs.

  5. Diurnal cycle of greenhouse gases and biogenic hydrocarbons during summer near Cool, CA

    NASA Astrophysics Data System (ADS)

    Flowers, B. A.; Floerchinger, C.; Knighton, W. B.; Dubey, M. K.; Herndon, S. C.; Kelley, P.; Luke, W. T.; Shaw, W. J.; Barnard, J.; Laulainen, N.; Zaveri, R. A.

    2010-12-01

    Photosynthesis by forests is a large sink for atmospheric carbon dioxide (CO2) and also a large source of biogenic volatile organics (VOCs) that produce aerosols, nucleate clouds, and interact with nitrogen oxides (NOx) to produce ozone. To elucidate these complex biogeochemical mechanisms, we performed continuous high temporal resolution measurements of CO2, VOC, trace gases, and aerosol in June 2010 at the T1 site, 70 km from Sacramento, CA, during the Carbonaceous Aerosol and Radiative Effects Study (CARES) in June 2010. Throughout the month we find that diurnal profiles exhibit minima in CO2 and maxima in isoprene during daytime. Both their amplitudes are modulated strongly by cloud cover consistent with a common photosynthetic mechanism. In contrast, we find that diurnal monoterpene profiles peak at night while CO2 is at its maxima. Their amplitudes are modulated by temperature and boundary layer height. The monoterpenes and CO2 cycle show larger increases at warmer temperatures, suggesting respiration as a common driver. Additional measurements of CH4, CO, benzene, toluene, NO, NOy and O3 are used to define biogeochemical cycling of greenhouse gases and are demonstrated as a baseline for separating anthropogenic and biogenic emissions and observing transport of greenhouse gases and air pollution.

  6. Miniaturized Hollow-Waveguide Gas Correlation Radiometer (GCR) for Trace Gas Detection in the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Wilson, Emily L.; Georgieva, E. M.; Melroy, H. R.

    2012-01-01

    Gas correlation radiometry (GCR) has been shown to be a sensitive and versatile method for detecting trace gases in Earth's atmosphere. Here, we present a miniaturized and simplified version of this instrument capable of mapping multiple trace gases and identifying active regions on the Mars surface. Reduction of the size and mass of the GCR instrument has been achieved by implementing a lightweight, 1 mm inner diameter hollow-core optical fiber (hollow waveguide) for the gas correlation cell. Based on a comparison with an Earth orbiting CO2 gas correlation instrument, replacement of the 10 meter mUltipass cell with hollow waveguide of equivalent pathlength reduces the cell mass from approx 150 kg to approx 0.5 kg, and reduces the volume from 1.9 m x 1.3 m x 0.86 m to a small bundle of fiber coils approximately I meter in diameter by 0.05 m in height (mass and volume reductions of >99%). This modular instrument technique can be expanded to include measurements of additional species of interest including nitrous oxide (N2O), hydrogen sulfide (H2S), methanol (CH3OH), and sulfur dioxide (SO2), as well as carbon dioxide (CO2) for a simultaneous measure of mass balance.

  7. Ocean chemistry: Fingerprints of a trace nutrient

    NASA Astrophysics Data System (ADS)

    Resing, Joseph A.; Barrett, Pamela M.

    2014-07-01

    Lack of dissolved iron in the sea limits biological productivity and the uptake of carbon dioxide. The sources of dissolved iron in the North Atlantic Ocean have been identified from isotopic variations of this trace nutrient. See Letter p.212

  8. Removal of contaminant gases from an electrolytic urine pretreatment process. [in spacecraft life support systems

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Putnam, D. F.

    1977-01-01

    The effluent gas stream from an electrolytic urine pretreatment process was analyzed by gas chromatography-mass spectroscopy and wet chemical methods to determine its composition. The major constituents were identified as: hydrogen, carbon dioxide, oxygen, nitrogen, water vapor, and chlorine. The trace impurities were chlorinated light hydrocarbons, and a number of other organic impurities in the low ppm range. Several methods of removing all of the undesirable gases to levels acceptable for return to a space cabin atmosphere were investigated experimentally. A subsystem concept comprised of the following sequential unit processes and operations was successfully demonstrated: (1) raw urine scrubbing, (2) silica gel sorption, (3) dilution with cabin air, and (4) catalytic oxidation.

  9. Simultaneous removal of SO2 and trace SeO2 from flue gas: effect of product layer on mass transfer.

    PubMed

    Li, Yuzhong; Tong, Huiling; Zhuo, Yuqun; Chen, Changhe; Xu, Xuchang

    2006-07-01

    Sulfur dioxide (SO2) and trace elements are all pollutants derived from coal combustion. This study relates to the simultaneous removal of sulfur and trace selenium dioxide (SeO2) by calcium oxide (CaO) adsorption in the medium temperature range, especially the mass transfer effect of sulfate product layer on trace elements. Through experiments on CaO adsorbing different concentrations of SO2 gases, conclusions can be drawn that although the product layer introduces extra mass transfer resistance into the sorbent-gas reaction process, the extent of CaO adsorption ability loss due to this factor decreases with decreasing SO2 concentration. When the gas concentration is at trace level, the loss of CaO adsorption ability can be neglected. Subsequent experiments on CaO adsorbing trace SeO2 gas suggest that the sulfate product layer, whether it is thick or thin, has no obvious effect on the CaO ability to adsorb trace SeO2 gas.

  10. Blood Gases Test

    MedlinePlus

    ... ordered when someone has symptoms of an oxygen/carbon dioxide or pH imbalance, such as difficulty breathing, shortness ... A person is not getting rid of enough carbon dioxide There is a problem with a person's kidney ...

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

    NASA Technical Reports Server (NTRS)

    Steel, Emily; McLinden, Matthew

    2012-01-01

    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

  12. Shipboard monitoring of non-CO2 greenhouse gases in Asia and Oceania using commercially cargo vessels

    NASA Astrophysics Data System (ADS)

    Nara, H.; Tanimoto, H.; Mukai, H.; Nojiri, Y.; Tohjima, Y.; Machida, T.; Hashimoto, S.

    2011-12-01

    The National Institute for Environmental Studies (NIES) has been performing a long-term program for monitoring trace gases of atmospheric importance over the Pacific Ocean since 1995. The NIES Voluntary Observing Ships (NIES-VOS) program currently makes use of commercial cargo vessels because they operate regularly over fixed routes for long periods and sail over a wide area between various ports (e.g., between Japan and the United States, between Japan and Australia/New Zealand, and between Japan and southeast Asia). This program allows systematic and continuous measurements of non-CO2 greenhouse gases, providing long-term datasets for background air over the Pacific Ocean and regionally polluted air around east Asia. We observe both long-lived greenhouse gases (e.g., carbon dioxide) and short-lived air pollutants (e.g., tropospheric ozone, carbon monoxide) on a continuous basis. Flask samples are collected for later laboratory analysis of carbon dioxide, methane, nitrous oxide, and carbon monoxide by using gas chromatographic techniques. In addition, we recently installed cavity ringdown spectrometers for high-resolution measurement of methane and carbon dioxide to capture their highly variable features in regionally polluted air around southeast Asia (e.g., Hong Kong, Thailand, Singapore, Malaysia, Indonesia and Philippine), which is now thought to be a large source due to expanding socioeconomic activities as well as biomass burnings. Contrasting the Japan-Australia/New Zealand and Japan-southeast Asia cruises revealed regional characteristics of sources and sinks of these atmospherically important species, suggesting the existence of additional sources for methane, nitrous oxides, and carbon monoxide in this tropical Asian region.

  13. Plants Can't Do without Carbon Dioxide.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1992-01-01

    Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

  14. Abiotic uptake of gases by organic soils

    NASA Astrophysics Data System (ADS)

    Smagin, A. V.

    2007-12-01

    Methodological and experimental studies of the abiotic uptake of gaseous substances by organic soils were performed. The static adsorption method of closed vessels for assessing the interaction of gases with the solid and liquid soil phases and the dynamic method of determining the sorption isotherms of gases by soils were analyzed. The theoretical substantiation of the methods and their practical implementations on the basis of a PGA-7 portable gas analyzer (Russia) were considered. Good agreement between the equilibrium sorption isotherms of the gases and the Langmuir model was revealed; for the real ranges of natural gas concentrations, this model can be reduced to the linear Henry equation. The limit values of the gas sorption (Langmuir monolayer capacity) are typical for dry samples; they vary from 670 4000 g/m3 for methane and oxygen to 20 000 25 000 g/m3 for carbon dioxide. The linear distribution coefficients of gases between the solid and gas phases of organic soils (Henry constants) are 8 18 units for poorly sorbed gases (O2, CH4) and 40 60 units for CO2. The kinetics of the chemicophysical uptake of gases by the soil studied is linear in character and obeys the relaxation kinetic model of the first order with the corresponding relaxation constants, which vary from 1 h -1 in wet samples to 10 h -1 in dry samples.

  15. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, Santi

    1986-01-01

    The separation of polar gases from nonpolar gases may be effected by passing a mixture of 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 plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

  16. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, S.

    1986-08-19

    The separation of polar gases from nonpolar gases may be effected by passing a mixture of 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 plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

  17. Production of Greenhouse Gases in The Atmosphere of Early Mars

    NASA Technical Reports Server (NTRS)

    Kress, Monika E.; McKay, Christopher P.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Mars was much warmer and wetter 3.5 to 4 billion years ago than it is today, suggesting that its climate was able to support life in the distant past. Carbon dioxide and methane are greenhouse gases which may have kept Mars warm during this time. We explore the possibility that these gases were produced via grain-catalyzed reactions in the warm, dusty aftermath of large comet and/or asteroid impacts which delivered Mars, volatile inventory.

  18. Gases in Seawater

    NASA Astrophysics Data System (ADS)

    Nightingale, P. D.; Liss, P. S.

    2003-12-01

    The annual gross and net primary productivity of the surface oceans is similar in size to that on land (IPCC, 2001). Marine productivity drives the cycling of gases such as oxygen (O2), dimethyl sulfide (DMS), carbon monoxide (CO), carbon dioxide (CO2), and methyl iodide (CH3I) which are of fundamental importance in studies of marine productivity, biogeochemical cycles, atmospheric chemistry, climate, and human health, respectively. For example, ˜30% of the world's population (1,570 million) is thought to be at risk of iodine-deficiency disorders that impair mental development (WHO, 1996). The main source of iodine to land is the supply of volatile iodine compounds produced in the ocean and then transferred to the atmosphere via the air-surface interface. The flux of these marine iodine species to the atmosphere is also thought to be important in the oxidation capacity of the troposphere by the production of the iodine oxide radical ( Alicke et al., 1999). A further example is that the net flux of CO2 from the atmosphere to the ocean, ˜1.7±0.5 Gt C yr-1, represents ˜30% of the annual release of anthropogenic CO2 to the atmosphere (IPCC, 2001). This net flux is superimposed on a huge annual flux (90 Gt C yr-1) of CO2 that is cycled "naturally" between the ocean and the atmosphere. The long-term sink for anthropogenic CO2 is recognized as transfer to the ocean from the atmosphere. A final example is the emission of volatile sulfur, in the form of DMS, from the oceans. Not only is an oceanic flux from the oceans needed to balance the loss of sulfur (a bioessential element) from the land via weathering, it has also been proposed as having a major control on climate due to the formation of cloud condensation nuclei (Charlson et al., 1987). Indeed, the existence of DMS and CH3I has been used as evidence in support of the Gaia hypothesis (Lovelock, 1979).There are at least four main processes that affect the concentration of gases in the water column: biological

  19. Carbon Dioxide Removal via Passive Thermal Approaches

    NASA Technical Reports Server (NTRS)

    Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

    2011-01-01

    A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

  20. Noble gases in meteorites and terrestrial planets

    NASA Technical Reports Server (NTRS)

    Wacker, J. F.

    1985-01-01

    Terrestrial planets and chondrites have noble gas platforms that are sufficiently alike, especially Ne/Ar, that they may have acquired their noble gases by similar processes. Meteorites presumably obtained their noble gases during formation in the solar nebula. Adsorption onto C - the major gas carrier in chondrites - is the likely mechanism for trapping noble gases; recent laboratory simulations support this hypothesis. The story is more complex for planets. An attractive possibility is that the planets acquired their noble gases in a late accreting veneer of chondritic material. In chondrites, noble gases correlate with C, N, H, and volatile metals; by Occam's Razor, we would expect a similar coupling in planets. Indeed, the Earth's crust and mantle contain chondritic like trace volatiles and PL group metals, respectively and the Earth's oceans resemble C chondrites in their enrichment of D (8X vs 8-10X of the galactic D/H ratio). Models have been proposed to explain some of the specific noble gas patterns in planets. These include: (1) noble gases may have been directly trapped by preplanetary material instead of arriving in a veneer; (2) for Venus, irradiation of preplanetary material, followed by diffusive loss of Ne, could explain the high concentration of AR-36; (3) the Earth and Venus may have initially had similar abundances of noble gases, but the Earth lost its share during the Moon forming event; (4) noble gases could have been captured by planetestimals, possibly leading to gravitational fractionation, particularly of Xe isotopes and (5) noble gases may have been dissolved in the hot outer portion of the Earth during contact with a primordial atmosphere.

  1. Carbon Dioxide Information Analysis Center: FY 1991 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  2. Carbon Dioxide Information Analysis Center: FY 1991 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also described.

  3. Carbon Dioxide Information Analysis Center: FY 1992 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1993-03-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIACs staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1991 to September 30, 1992. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. As analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, fact sheets, specialty publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  4. Africa as a regional and global source of atmospheric gases and particulates

    NASA Astrophysics Data System (ADS)

    Mtetwa, Lawrence

    The role of the continent of Africa as a source of gaseous and particulate emissions to the atmosphere is investigated in this study. Sources of gases and particulates from Africa include fossil fuel combustion, biomass burning, and biogenic soil emissions of nitric oxide. This study represents the first comprehensive database of gaseous and particulate emissions developed for the continent of Africa on a country by country basis and establishes the framework for country-by-country, assessment of greenhouse gases emissions as required by the Kyoto Conference on Global Warming, which was attended by representatives from more than 100 countries. Calculations of gases and particulates resulting from fossil fuel combustion were based on the Intergovernmental Panel on Climate Change (IPCC) guidelines. Calculations of gases and particulates resulting from biomass burning were based on fire counts obtained from the Defense Meteorological Satellite Program (DMSP). Block 5 satellites and emission ratios for various gaseous and particulate fire products obtained during the recent Southern African Fire- Atmosphere Research Initiative (SAFARI), an activity of the international Global Atmospheric Chemistry (IGAC) Project, part of the international Geosphere-Biosphere Program (IGBP). The calculations of biogenic soil emissions of nitric oxide were obtained with the NOAA Geophysical Fluid Dynamics Laboratory (GFDL) Biogenic Soil NOx Model. Africa was found to be a significant global source of the following gases: carbon dioxide (CO2), carbon monoxide (CO), methyl chloride (CH3Cl), oxides of nitrogen (NOx), and carbon particulates. The results indicate that Africa is the world's single largest continental source of emissions due to biomass burning and that these emissions are likely to increase with time. The study established that on a global scale, Africa was the largest source of soil biogenic NOx. The importance of Africa as a key global source of trace gases and aerosols has

  5. 40 CFR 60.173 - Standard for sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for sulfur dioxide. 60.173... Smelters § 60.173 Standard for sulfur dioxide. (a) On and after the date on which the performance test... subpart shall cause to be discharged into the atmosphere from any roaster any gases which contain...

  6. Synthetic greenhouse gases to decline if Montreal Protocol amended

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-07-01

    The Montreal Protocol, an international treaty designed to reduce the release into the atmosphere of ozone-depleting gases such as hydrochlorofluorocarbons and chlorofluorocarbons, has been successful since its implementation in the late 1980s. However, related greenhouse gases, such as hydrofluorocarbons (HFCs), have increased in concentration in the atmosphere since then. HFCs, along with other synthetic greenhouse gases (SGHGs), account for a radiative forcing almost 20% as large as that due to the increase in carbon dioxide (CO2) since the preindustrial era.

  7. Methods and compositions for removing carbon dioxide from a gaseous mixture

    SciTech Connect

    Li, Jing; Wu, Haohan

    2014-06-24

    Provided is a method for adsorbing or separating carbon dioxide from a mixture of gases by passing the gas mixture through a porous three-dimensional polymeric coordination compound having a plurality of layers of two-dimensional arrays of repeating structural units, which results in a lower carbon dioxide content in the gas mixture. Thus, this invention provides useful compositions and methods for removal of greenhouse gases, in particular CO.sub.2, from industrial flue gases or from the atmosphere.

  8. Trace-gas measurements with an infrared sun photometer

    SciTech Connect

    Allen, J.E. Jr.; Glenar, D.A.; Markham, B.L.

    1994-12-31

    Accurate assessment of the potential impact of greenhouse gases and aerosols on the Earth system can be enhanced by a global monitoring network and can be facilitated by the development of compact, portable optical instruments for field use. The more important of these gases, e.g., methane (CH{sub 4}), carbon dioxide (CO{sub 2}), and nitrous oxide (N{sub 2}O), have strong absorptions at wavelengths between 2 and 5 {micro}m; however, this spectral region is heavily dominated by absorption by water (H{sub 2}O) which is itself an important contributor to radiative transfer at these wavelengths. To achieve the desired reduction in instrument size, it is often necessary to relax wavelength resolution requirements which in turn affects the accuracy and precision of the retrieved column abundances. To address these measurement problems, an infrared sun photometer has been constructed for application to trace-gas detection and analysis techniques are being developed to extract column abundances from the spectrally congested data. The current instrument design is based on a circular variable filter (CVF) with wavelength coverage from 1.2 to 5 {micro}m. Preliminary measurements with this instrument will be presented and electro-optical alternatives to the CVF as the tuning element will be discussed.

  9. Unknown Gases: Student-Designed Experiments in the Introductory Laboratory.

    ERIC Educational Resources Information Center

    Hanson, John; Hoyt, Tim

    2002-01-01

    Introductory students design and carry-out experimental procedures to determine the identity of three unknown gases from a list of eight possibilities: air, nitrogen, oxygen, argon, carbon dioxide, helium, methane, and hydrogen. Students are excited and motivated by the opportunity to come up with their own experimental approach to solving a…

  10. Iatrogenic greenhouse gases: the role of anaesthetic agents.

    PubMed

    Uzoigwe, Chika E; Sanchez Franco, Luis C; Forrest, Michael D

    2016-01-01

    The contribution of health-care activity to climate change is not negligible and is increasing. Anaesthetic greenhouse gases, in particular the fluranes, have a much more potent global warming capacity, volume for volume, than carbon dioxide, but their emissions remain completely unregulated.

  11. Iatrogenic greenhouse gases: the role of anaesthetic agents.

    PubMed

    Uzoigwe, Chika E; Sanchez Franco, Luis C; Forrest, Michael D

    2016-01-01

    The contribution of health-care activity to climate change is not negligible and is increasing. Anaesthetic greenhouse gases, in particular the fluranes, have a much more potent global warming capacity, volume for volume, than carbon dioxide, but their emissions remain completely unregulated. PMID:26903451

  12. Long-term measurements of atmospheric trace gases (CO2, CH4, N2O, SF6, CO, H2), O2, and δ13CH4 isotopes at Weybourne Atmospheric Observatory, UK: past, present and future

    NASA Astrophysics Data System (ADS)

    Manning, Andrew C.; Forster, Grant L.; Oram, David E.; Reeves, Claire E.; Pickers, Penelope A.; Barningham, S. Thomas; Sturges, William T.; Bandy, Brian; Nisbet, Euan G.; Lowry, David; Fisher, Rebecca; Fleming, Zoe

    2016-04-01

    The Weybourne Atmospheric Observatory (WAO) is situated on the north Norfolk Coast (52.95°N, 1.13°E) in the United Kingdom and is run by the University of East Anglia (UEA), with support from the UK National Centre for Atmospheric Science (NCAS). In 2016, the WAO became a UK-ICOS (Integrated Carbon Observing System) monitoring station. Since 2008, we have been collecting high-precision long-term in situ measurements of atmospheric carbon dioxide (CO2), oxygen (O2), carbon monoxide (CO) and molecular hydrogen (H2), as well as regular bag sampling for δ13CH4. In early 2013, the measurement of atmospheric methane (CH4) commenced, and nitrous oxide (N2O) and sulphur hexafluoride (SF6) began in 2014. We summarise the CO2, O2, CH4, N2O, SF6, CO, H2 and δ13CH4 measurements made to date and highlight some key features observed (e.g. seasonal cycles, long-term trends, pollution events and deposition events). We summarise how the long-term measurements fit into other broader projects which have helped to support the long term time-series at WAO over the years, and highlight how we contribute to broader global atmospheric observation networks.

  13. Variations in trace metal and halogen ratios in magmatic gases through an eruptive cycle of the Pu'u O'o vent, Kilauea, Hawaii: July-August 1985

    SciTech Connect

    Miller, T.L.; Zoller, W.H. ); Crowe, B.M.; Finnegan, D.L. )

    1990-08-10

    Particle and gas samples were obtained before and after eruptive episode 35 in July and August 1985 at the fuming Pu'u O'o vent, Kilauea volcano, Hawaii. The sampling system employed consisted of a particle filter followed by four {sup 7}LiOH treated filters to collect acidic gases. The filters were analyzed using instrumental neutron activation analysis (INAA). The results indicate that Br/Cl and Re/Cl ratios do not fluctuate through an eruption cycle but the F/Cl, F/Br and metal/Cl ratios (In and Cd) do change through the cycle. An inverse relationship between F/Cl and metal/Cl was observed. The changes are probably due to influxes of relatively undegassed magma during the repose period releasing fume with lower F/Cl, F/BR and higher metal/Cl ratios. As the magma in the Pu'u O'o conduit gradually degasses either before or several days after an eruptive episode, F/Cl and F/Br ratios increase and the metal/Cl ratios decrease. One sample collected on July 24, two days before eruptive episode 35, did not follow this general trend. This can be explained by a gas pulse from a deeper, less degassed portion of magma making its way to the top of the conduit.

  14. Molecular and isotopic composition of hydrate-bound and dissolved gases in the southern basin of Lake Baikal, based on an improved headspace gas method

    NASA Astrophysics Data System (ADS)

    Sakagami, Hirotoshi; Takahashi, Nobuo; Hachikubo, Akihiro; Minami, Hirotsugu; Yamashita, Satoshi; Shoji, Hitoshi; Khlystov, Oleg; Kalmychkov, Gennadiy; Grachev, Mikhail; De Batist, Marc

    2012-12-01

    Assessments of the molecular and isotopic composition of hydrate-bound and dissolved gases in pore water were conducted during the multi-phase gas hydrate project (MHP-09) cruise VER09-03 to the southern basin of Lake Baikal in September 2009. To avoid changes in gas composition during core sampling and transport, various headspace methods were investigated aimed at preserving the dissolved gases in pore water. When distilled water was added to the sediment samples, the concentrations of carbon dioxide and oxygen decreased because of dissolution into the water and/or microbial consumption. When the headspace was not flushed with inert gases, trace levels of hydrogen and ethylene were detected. The findings suggest that best preparation is achieved by flushing the headspace with helium, and adding a saturated aqueous solution of sodium chloride. This improved headspace method served to examine the molecular and isotopic compositions of gas samples retrieved at several new sites in the southern basin. Methane was the major component, and the proportion of ethane ranged widely from 0.0009 to 1.67 mol% of the total hydrocarbon gases. The proportions of propane and higher hydrocarbons were small or less than their detection limits. The carbon isotope signatures suggest that microbial-sourced methane and ethane were dominant in the Peschanka study area, whereas ethane was of thermogenic origin at all other study sites in the southern basin of Lake Baikal.

  15. The search for active release of volcanic gases on Mars

    NASA Astrophysics Data System (ADS)

    Khayat, Alain; Villanueva, Geronimo; Mumma, Michael; Tokunaga, Alan

    2015-11-01

    The study of planetary atmospheres by means of spectroscopy is important for understanding their origin and evolution. The presence of short-lived trace gases in the martian atmosphere would imply recent production, for example, by ongoing geologic activity. On Earth, sulfur dioxide (SO2), sulfur monoxide (SO) and hydrogen sulfide (H2S) are the main sulfur-bearing gases released during volcanic outgassing. Carbonyl sulfide (OCS), also released from some volcanoes on Earth (e.g., Erebus and Nyiragongo), could be formed by reactions involving SO2 or H2S inside magma chambers. We carried out the first ground-based, semi-simultaneous, multi-band and multi-species search for such gases above the Tharsis and Syrtis volcanic regions on Mars. The submillimeter search extended between 23 November 2011 and 13 May 2012 which corresponded to Mars’ mid Northern Spring and early Northern Summer seasons (Ls = 34-110°). The strong submillimeter rotational transitions of SO2, SO and H2S were targeted using the high-resolution heterodyne receiver (aka Barney) on the Caltech Submillimeter Observatory. We reached sensitivities sufficient to detect a volcanic release on Mars that is 4% of the SO2 released continuously from Kilauea volcano in Hawaii, or 5% that of the Masaya volcano in Nicaragua. The infrared search covered OCS in its combination band (ν2+ν3) at 3.42 μm at two successive Mars years, during Mars’ late Northern Spring and mid Northern Summer seasons, spanning Ls= 43º and Ls= 147º. The targeted volcanic districts were observed during the two intervals, 14 Dec. 2011 to 6 Jan. 2012 in the first year, and 30 May 2014 to 16 June 2014 in the second year, using the high resolution infrared spectrometer (CSHELL) on NASA’s Infrared Telescope Facility (NASA/IRTF). We will present our results and discuss their implications for current volcanic outgassing activity on the red planet. We gratefully acknowledge support from the NASA Planetary Astronomy Program under NASA

  16. Control of Effluent Gases from Solid Waste Processing using Impregnated Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Li, Jing; Fisher, John; Wignarajah, Kanapathipillai

    2005-01-01

    One of the major problems associated with solid waste processing technologies is effluent contaminants that are released in gaseous forms from the processes. This is a concern in both biological as well as physicochemical solid waste processing. Carbon dioxide (CO2), the major gas released, does not present a serious problem and there are currently in place a number of flight-qualified technologies for CO2 removal. However, a number of other gases, in particular NOx, SO2, NH3, and various hydrocarbons (e.g. CH4) do present health hazards to the crew members in space habitats. In the present configuration of solid waste processing in the International Space Station (ISS), some of these gases are removed by the Trace Contaminant Control System (TCCS), demands a major resupply. Reduction of the resupply can be effective by using catalyst impregnated carbon nanotubes. For example, NO decomposition to N2 and O2 is thermodynamically favored. Data showing decomposition of NO on metal impregnated carbon nanotubes is presented. Comparisons are made of the existing TCCS systems with the carbon nanotube based technology for removing NOx based on mass/energy penalties.

  17. Standard test method for sulfur in liquefied petroleum gases (oxyhydrogen burner or lamp)

    SciTech Connect

    Not Available

    1980-01-01

    This method covers the determination of total sulfur in LP-gases containing more than 1 ppM. Samples should not contain more than 100 ppM of halogens. The sample is burned in an oxy-hydrogen burner, or in a lamp in a closed system in a carbon dioxide-oxygen atmosphere. The latter is not recommended for trace quantities of sulfur due to the inordinately long combustion times needed. The oxides of sulfur are absorbed and oxidized to sulfuric acid in a hydrogen peroxide solution. The sulfate ions are then determined by either of the following finishes: barium perchlorate titration - the sulfate is titrated with barium perchlorate using a thorin-methylene blue mixed indicator; turbidimetric - the sulfate is precipitated as barium sulfate and the turbidity of a suspension of the precipitate is measured with a photometer. It is important to have the sulfur content of liquefied petroleum gases at low enough concentration to meet government regulations. The presence of sulfur may result in corrosion of metal surfaces. Sulfur may be poisonous to catalysts in subsequent processing.

  18. MERCURY SPECIATION IN COMBUSTION SYSTEMS: STUDIES WITH SIMULATED FLUE GASES AND MODEL FLY ASHES

    EPA Science Inventory

    The paper gives results of a bench-scale study of the effects of flue gas and fly ash parameters on the oxidation of elemental mercury in simulated flue gases containing hydrogen chloride (HCl), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and water vapor (H2O...

  19. Nitrogen dioxide

    Integrated Risk Information System (IRIS)

    Nitrogen dioxide ; CASRN 10102 - 44 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  20. Chlorine dioxide

    Integrated Risk Information System (IRIS)

    Chlorine dioxide ; CASRN 10049 - 04 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  1. Trace Contaminant Testing with the Orion Atmosphere Revitalization Technology

    NASA Technical Reports Server (NTRS)

    Button, Amy B.; Sweterlitsch, Jeffrey J.; Broerman, Craig D.; Campbell, Melissa L.

    2010-01-01

    Every spacecraft atmosphere contains trace contaminants resulting from offgassing by cabin materials and human passengers. An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). Part of the risk mitigation effort for this new technology is the study of how atmospheric trace contaminants will affect and be affected by the technology. One particular area of concern is ammonia, which, in addition to the normal spacecraft sources, can also be offgassed by the amine-based sorbent. In the spring of 2009, tests were performed at Johnson Space Center (JSC) with typical cabin atmosphere levels of five of the most common trace gases, most of which had not yet been tested with this technology. A subscale sample of the sorbent was exposed to each of the chemicals mixed into a stream of moist, CO2-laden air, and the CO2 adsorption capacity of the sorbent was compared before and after the exposure. After these typical-concentration chemicals were proven to have negligible effect on the subscale sample, tests proceeded on a full-scale test article in a sealed chamber with a suite of eleven contaminants. To isolate the effects of various test rig components, several extended-duration tests were run: without injection or scrubbing, with injection and without scrubbing, with injection of both contaminants and metabolic CO2 and water vapor loads and scrubbing by both the test article and dedicated trace contaminant filters, and with the same injections and scrubbing by only the test article. The high-level results of both the subscale and full-scale tests are examined in this paper.

  2. Trace Contaminant Testing with the Orion Atmosphere Revitalization Technology

    NASA Technical Reports Server (NTRS)

    Button, Amy Lin; Sweterlitsch, Jeffrey; Broerman, Craig

    2009-01-01

    Every spacecraft atmosphere contains trace contaminants resulting from offgassing by cabin materials and human passengers. An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). Part of the risk mitigation effort for this new technology is the study of how atmospheric trace contaminants will affect and be affected by the technology. One particular area of concern is ammonia, which, in addition to the normal spacecraft sources, can also be off-gassed by the amine-based sorbent. In the first half of 2009, tests were performed with typical cabin atmosphere levels of five of the most common trace gases, most of which had not yet been tested with this technology. A subscale sample of the sorbent was exposed to each of the chemicals mixed into a stream of moist, CO2-laden air, and the CO2 adsorption capacity of the sorbent was compared before and after the exposure. After these typical-concentration chemicals were proven to have negligible effect on the subscale sample, tests proceeded on a full-scale test article in a sealed chamber with a suite of eleven contaminants. To isolate the effects of various test rig components, several extended-duration tests were run: without injection or scrubbing, with injection and without scrubbing, with injection and scrubbing by both the test article and dedicated trace contaminant filters, and with injection and scrubbing by only the test article. The high-level results of both the subscale and full-scale tests are examined in this paper.

  3. Aircraft measurements of nitrogen dioxide and peroxyacyl nitrates using luminol chemiluminescence with fast capillary gas chromatography

    SciTech Connect

    Gaffney, J.S.; Marley, N.A.; Drayton, P.J.

    1997-09-01

    Peroxyacyl nitrates (PANs) and nitrogen dioxide (NO{sub 2}) are important trace gas species associated with photochemical air pollution. The PANs are in thermal equilibrium with the peroxyacetyl radical and NO{sub 2}. Because PANs are trapped peroxy radicals, they are an important indicator species of the photochemical age of an air parcel, as well as being a means of long-range transporting of NO{sub 2}, leading to the formation of regional ozone and other oxidants. Typically, PANs are measured by using a gas chromatograph with electron-capture detection (ECD). Once automated, this method has been shown to be reliable and quite sensitive, allowing the levels of PANs to be measured at low parts per trillion in the troposphere. Unfortunately, a number of other atmospheric gases also have strong ECD signals or act as inferences and limit the speed in which the analysis can be completed. Currently, the shortest analysis time for PAN is approx. 5 minutes with ECD. The authors recent examined the luminol detection of NO{sub 2} and PANs using gas capillary chromatography for rapid monitoring of these important trace gases. Analysis of the PANs (PAN, PPN, and PBN) and NO{sub 2} in one minute has been demonstrated in laboratory studies by using this approach. Reported here are modifications of this instrument for aircraft operation and preliminary results from test flights taken near Pasco, Washington in August of 1997.

  4. Carbon dioxide and climate

    SciTech Connect

    Not Available

    1990-10-01

    Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

  5. Inerting Aircraft Fuel Systems Using Exhaust Gases

    NASA Technical Reports Server (NTRS)

    Hehemann, David G.

    2002-01-01

    Our purpose in this proposal was to determine the feasibility of using carbon dioxide, possibly obtained from aircraft exhaust gases as a substance to inert the fuel contained in fuel tanks aboard aircraft. To do this, we decided to look at the effects carbon dioxide has upon commercial Jet-A aircraft fuel. In particular, we looked at the solubility of CO2 in Jet-A fuel, the pumpability of CO2-saturated Jet-A fuel, the flashpoint of Jet-A fuel under various mixtures of air and CO2, the static outgassing of CO2-Saturated Jet-A fuel and the dynamic outgassing of Jet-A fuel during pumping of Jet-A fuel.

  6. Carbon dioxide conversion over carbon-based nanocatalysts.

    PubMed

    Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

    2013-07-01

    The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity.

  7. Electron beam treatment of stack gases

    NASA Astrophysics Data System (ADS)

    Frank, N.; Kawamura, K.; Miller, G.

    A method of simultaneously removing sulfur dioxide and nitrogen oxides from high sulfur, coal-fired utility boiler combustion gases is discussed. Process development history is briefly presented and salient details of a commercial demonstration unit currently under construction at an electric utility power plant in Indiana are given. Detailed discussion on the design details and performance requirements of a cable connected set of 80 kW electron beam sources precedes a discussion of the projected economics of the process. Requirements for future electron beam machine configurations and capacities as well as impact on the radiation machine manufacturing industry, assuming acceptance of the process by the electric utilities, are presented.

  8. Handbook of infrared radiation from combustion gases

    NASA Technical Reports Server (NTRS)

    Ludwig, C. B.; Malkmus, W.; Reardon, J. E.; Thomson, J. A. L.; Goulard, R. (Editor)

    1973-01-01

    The treatment of radiant emission and absorption by combustion gases are discussed. Typical applications include: (1) rocket combustion chambers and exhausts, (2) turbojet engines and exhausts, and (3) industrial furnaces. Some mention is made of radiant heat transfer problems in planetary atmospheres, in stellar atmospheres, and in reentry plasmas. Particular consideration is given to the temperature range from 500K to 3000K and the pressure range from 0.001 atmosphere to 30 atmospheres. Strong emphasis is given to the combustion products of hydrocarbon fuels with oxygen, specifically to carbon dioxide, water vapor, and carbon monoxide. In addition, species such as HF, HC1, CN, OH, and NO are treated.

  9. Catalytic Generation of Lift Gases for Balloons

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert; Berggren, Mark

    2011-01-01

    A lift-gas cracker (LGC) is an apparatus that generates a low-molecular-weight gas (mostly hydrogen with smaller amounts of carbon monoxide and/or carbon dioxide) at low gauge pressure by methanol reforming. LGCs are undergoing development for use as sources of buoyant gases for filling zero-gauge-pressure meteorological and scientific balloons in remote locations where heavy, high-pressure helium cylinders are not readily available. LGCs could also be used aboard large, zero-gauge-pressure, stratospheric research balloons to extend the duration of flight.

  10. Nitrogen dioxide monitoring with an automatic DOAS station at Terra Nova Bay, Antarctica

    NASA Astrophysics Data System (ADS)

    Ravegnani, Fabrizio; Kostadinov, Ivan K.; Giovanelli, Giorgio

    1998-08-01

    During the last few years UV-Vis spectrometers were developed at the FISBAT Institute and are used for application of differential optical absorption spectroscopy method to detect many atmospheric trace gases playing important roles in the stratospheric chemistry. After several test both in laboratory and in Antarctic region, one of the spectrometers, called GASCOD2/2, was modified in collaboration with ENEA for unattended and automatic measurement in extreme high-latitude environment. The instrument was installed in December 1995 in the Italian Station at Terra Nova Bay. The aim of this research is to study the dentrification processes during the formation of the so-called ozone hole over the Antarctic region. The preliminary results for the first year of nitrogen dioxide measurement are presented and discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  12. The NOMAD Spectrometer Suite on ExoMars Trace Gas Orbiter

    NASA Astrophysics Data System (ADS)

    Thomas, I. R.; Vandaele, A. C.; Daerden, F.; Drummond, R.; Neefs, E.; Patel, M. R.; López-Moreno, J.-J.; Rodriguez Gomez, J.; Bellucci, G.; NOMAD Team

    2014-07-01

    NOMAD, due to launch in 2016 onboard ExoMars Trace Gas Orbiter, consists of one ultraviolet/visible and two infrared spectrometers. Through solar occultation, limb and nadir observations, it will measure a wide range of trace atmospheric gases.

  13. Biomass burning and the production of greenhouse gases

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1991-01-01

    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.

  14. Greenhouse gases: What is their role in climate change

    SciTech Connect

    Edmonds, J.A.; Chandler, W.U. ); Wuebbles, D. )

    1990-12-01

    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.

  15. Preparation of perlite-based carbon dioxide absorbent.

    PubMed

    He, H; Wu, L; Zhu, J; Yu, B

    1994-02-01

    A new highly efficient carbon dioxide absorbent consisting of sodium hydroxide, expanded perlite and acid-base indicator was prepared. The absorption efficiency, absorption capacity, flow resistance and color indication for the absorbent were tested and compared with some commercial products. The absorbent can reduce the carbon dioxide content in gases to 3.3 ppb (v/v) and absorbs not less than 35% of its weight of carbon dioxide. Besides its large capacity and sharp color indication, the absorbent has an outstanding advantage of small flow resistance in comparison with other commercial carbon dioxide absorbents. Applications in gas analysis and purification were also investigated.

  16. Encapsulated liquid sorbents for carbon