WorldWideScience

Sample records for atmospheric trace gases

  1. Production, modification, and consumption of atmospheric trace gases by microorganisms

    OpenAIRE

    Schlegel, Prof. Dr. H. G.

    2011-01-01

    Some trace gases are contained in the atmosphere in appreciable amounts: methane, carbon monoxide, hydrogen, nitrous oxide. The bulk of these gases is of biological origin. Hydrogen is a primary product of microbial metabolism under anaerobic conditions. However, before reaching the atmosphere, it is converted by methane bacteria to methane, by nitrate reducing bacteria to nitrogen and to nitrous oxide and by sulfate reducing bacteria to hydrogen sulfide. Carbon monoxide is produced from cert...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Measurement of Trace Gases in the Atmosphere of Venus Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Southwest Sciences proposes to develop small, lightweight, low power instrumentation for the in situ balloon-borne measurement of several trace gases of importance...

  6. Trace gases in the atmosphere over Russian cities

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Spectroscopic Measurements of Atmospheric Trace Gases on Long-Distance Flights

    OpenAIRE

    Dix, Barbara

    2007-01-01

    In this thesis results of spectroscopic measurements of atmospheric trace gases on long-distance flights are presented. Nitrogen dioxide (NO2), bromine oxide (BrO), ozone (O3), formaldehyde (HCHO) and nitrous acid (HONO) are detected in scattered light spectra by means of Differential Optical Absorption Spectroscopy (DOAS). The underlying scientific scope is to gain information on global trace gas distributions, e.g. of BrO, which plays an important role in ozone chemistry or of HONO, which a...

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

    OpenAIRE

    Wittrock, F.; Oetjen, H.; Richter, A; Fietkau, S.; T. Medeke; Rozanov, A.(CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France); J. P. Burrows

    2003-01-01

    International audience 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 ...

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

    Directory of Open Access Journals (Sweden)

    C. E. Kolb

    2010-04-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Potential for the use of reconstructed IASI radiances in the detection of atmospheric trace gases

    Directory of Open Access Journals (Sweden)

    N. C. Atkinson

    2010-07-01

    Full Text Available Principal component (PC analysis has received considerable attention as a technique for the extraction of meteorological signals from hyperspectral infra-red sounders such as the Infrared Atmospheric Sounding Interferometer (IASI and the Atmospheric Infrared Sounder (AIRS. In addition to achieving substantial bit-volume reductions for dissemination purposes, the technique can also be used to generate reconstructed radiances in which random instrument noise has been reduced. Studies on PC analysis of hyperspectral infrared sounder data have been undertaken in the context of numerical weather prediction, instrument monitoring and geophysical variable retrieval, as well as data compression. This study examines the potential of PC analysis for chemistry applications.

    A major concern in the use of PC analysis for chemistry is that the spectral features associated with trace gases may not be well represented in the reconstructed spectra, either due to deficiencies in the training set or due to the limited number of PC scores used in the radiance reconstruction. In this paper we show examples of reconstructed IASI radiances for several trace gases: ammonia, sulphur dioxide, methane and carbon monoxide. It is shown that care must be taken in the selection of spectra for the initial training set: an iterative technique, in which outlier spectra are added to a base training set, gives the best results. For the four trace gases examined, key features of the chemical signatures are retained in the reconstructed radiances, whilst achieving a substantial reduction in instrument noise.

    A new regional re-transmission service for IASI is scheduled to start in 2010, as part of the EUMETSAT Advanced Retransmission Service (EARS. For this EARS-IASI service it is intended to include PC scores as part of the data stream. The paper describes the generation of the reference eigenvectors for this new service.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 (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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Burtis, M.D. [comp.] [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.R.; Stoss, F.W. [Oak Ridge National Lab., TN (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    B. Dix

    2009-11-01

    Full Text Available 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.

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

    OpenAIRE

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

    2004-01-01

    International audience 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 ...

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Synthesis of corrected multi-wavelength spectrometers for atmospheric trace gases

    Institute of Scientific and Technical Information of China (English)

    Hikmat H.Asadov; Islam M.Mirzabalayev; Davud Z.Aliyev; Javid A.Agayev; Sima R.Azimova; Nabi A.Nabiyev; Sevinj N.Abdullayeva

    2009-01-01

    The method for synthesis of corrected three-wavelengths spectrometers for trace gas components of atmo sphere on the basis of development of mathematical model has been suggested.The classification table for possible structures of corrected spectrometers is considered.The synthesis allows to reveal some new variants for development of three-wavelength spectrometers for trace gas components of atmosphere.For experimental checkup of achieved theoretical results,a laboratory pattern of three-wavelength spectrometer is developed and tested.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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 (CO2), 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Stoss, F.W. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center]|[Univ. of Tennessee, Knoxville, TN (United States). Energy, Environment, and Resources Center

    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.

  10. Atmospheric Chemistry and Greenhouse Gases

    Energy Technology Data Exchange (ETDEWEB)

    Ehhalt, D.; Prather, M.; Dentener, F.; Derwent, R.; Dlugokencky, Edward J.; Holland, E.; Isaksen, I.; Katima, J.; Kirchhoff, V.; Matson, P.; Midgley, P.; Wang, M.; Berntsen, T.; Bey, I.; Brasseur, G.; Buja, L.; Collins, W. J.; Daniel, J. S.; DeMore, W. B.; Derek, N.; Dickerson, R.; Etheridge, D.; Feichter, J.; Fraser, P.; Friedl, R.; Fuglestvedt, J.; Gauss, M.; Grenfell, L.; Grubler, Arnulf; Harris, N.; Hauglustaine, D.; Horowitz, L.; Jackman, C.; Jacob, D.; Jaegle, L.; Jain, Atul K.; Kanakidou, M.; Karlsdottir, S.; Ko, M.; Kurylo, M.; Lawrence, M.; Logan, J. A.; Manning, M.; Mauzerall, D.; McConnell, J.; Mickley, L. J.; Montzka, S.; Muller, J. F.; Olivier, J.; Pickering, K.; Pitari, G.; Roelofs, G.-J.; Rogers, H.; Rognerud, B.; Smith, Steven J.; Solomon, S.; Staehelin, J.; Steele, P.; Stevenson, D. S.; Sundet, J.; Thompson, A.; van Weele, M.; von Kuhlmann, R.; Wang, Y.; Weisenstein, D. K.; Wigley, T. M.; Wild, O.; Wuebbles, D.J.; Yantosca, R.; Joos, Fortunat; McFarland, M.

    2001-10-01

    Chapter 4 of the IPCC Third Assessment Report Climate Change 2001: The Scientific Basis. Sections include: Executive Summary 2414.1 Introduction 2434.2 Trace Gases: Current Observations, Trends and Budgets 2484.3 Projections of Future Emissions 2664.4 Projections of Atmospheric Composition for the 21st Century 2674.5 Open Questions 2774.6 Overall Impact of Global Atmospheric Chemistry Change 279

  11. Atmospheric transport and chemistry of trace gases in LMDz5B: evaluation and implications for inverse modelling

    Directory of Open Access Journals (Sweden)

    R. Locatelli

    2014-07-01

    Full Text Available Representation of atmospheric transport is a major source of error in the estimation of greenhouse gas sources and sinks by inverse modelling. Here we assess the impact on trace gas mole fractions of the new physical parameterisations recently implemented in the Atmospheric Global Climate Model LMDz to improve vertical diffusion, mesoscale mixing by thermal plumes in the planetary boundary layer (PBL, and deep convection in the troposphere. At the same time, the horizontal and vertical resolution of the model used in the inverse system has been increased. The aim of this paper is to evaluate the impact of these developments on the representation of trace gas transport and chemistry, and to anticipate the implications for inversions of greenhouse gas emissions using such an updated model. Comparison of a one-dimensional version of LMDz with large eddy simulations shows that the thermal scheme simulates shallow convective tracer transport in the PBL over land very efficiently, and much better than previous versions of the model. This result is confirmed in three dimensional simulations, by a much improved reproduction of the Radon-222 diurnal cycle. However, the enhanced dynamics of tracer concentrations induces a stronger sensitivity of the new LMDz configuration to external meteorological forcings. At larger scales, the inter-hemispheric exchange is slightly slower when using the new version of the model, bringing them closer to observations. The increase in the vertical resolution (from 19 to 39 layers significantly improves the representation of stratosphere/troposphere exchange. Furthermore, changes in atmospheric thermodynamic variables, such as temperature, due to changes in the PBL mixing, significantly modify chemical reaction rates and the equilibrium value of reactive trace gases. One implication of LMDz model developments for future inversions of greenhouse gas emissions is the ability of the updated system to assimilate a larger

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

    Science.gov (United States)

    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

  13. Application of the angular position of the visible horizon for atmospheric trace gases retrieval by MAX-DOAS method

    Science.gov (United States)

    Bruchkouski, Ilya; Krasovsky, Alexander; Demin, Victor

    2015-04-01

    Significant impact on the retrieval process of atmospheric trace gases by MAX-DOAS has accuracy of the elevation angle adjustment of the telescope unit. Additional information about the magnitude of the true elevation angles in MAX-DOAS system is very important because a slight change in elevation at angles 0 ° - 5 ° leads to a change in the geometry of the observation that has a strong influence on the measured value (slant column density). For monitoring the state of the atmosphere automated device based on the spectrograph ORIEL MS257 with a cooled CCD Andor Technology, spectral range 411-493 nm, FWHM = 0.5 nm has been constructed. This instrument records the spectrum of scattered sunlight in the range of elevation angles 0 ° - 90 ° within an aperture of 1.3 °. The number of registered spectra per day amounts to 4000. This device passed MAX-DOAS intercomparison campaign in the Max-Planck-Institute for Chemistry (Mainz) for the period 20.06.2013 - 10.09.2013. Procedures of the retrieval of nitrogen dioxide parallel measurements has been performed, the results of comparisons will be presented. Series of data about the angular position of the visible horizon line for two months of observation has been obtained. Using this pattern, corrections can be made in determining the elevation angle of the telescope unit, during the processing of the experimental data by MAX-DOAS.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. The impact of vibrational Raman scattering of air on DOAS measurements of atmospheric trace gases

    OpenAIRE

    J. Lampel; Frieß, U.; Platt, U.

    2015-01-01

    In remote sensing applications, such as differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered. After inelastic scattering on N2 and O2 molecules, the scattered photons occur as additional intensity at a different wavelength, effectively leading to "filling-in" of both solar Fraunhofer lines and absorptions of atmospheric constituents, if the inelastic scattering happens after the absorption. Measured spectra in p...

  18. The impact of vibrational Raman scattering of air on DOAS measurements of atmospheric trace gases

    OpenAIRE

    Lampel, J; Frieß, U.; U. Platt

    2015-01-01

    In remote sensing applications, such as differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered. After inelastic scattering on N2 and O2 molecules, the scattered photons occur as additional intensity at a different wavelength, effectively leading to filling-in of both solar Fraunhofer lines and absorptions of atmospheric constituents. Measured spectra in passive DOAS applications are typically corrected for rotationa...

  19. A broadband cavity ringdown spectrometer for in-situ measurements of atmospheric trace gases

    Directory of Open Access Journals (Sweden)

    M. Bitter

    2005-01-01

    Full Text Available This paper describes a broadband cavity ringdown spectrometer and its deployment during the 2002 North Atlantic Marine Boundary Layer Experiment (NAMBLEX to measure ambient concentrations of NO3, N2O5, I2 and OIO at the Mace Head Atmospheric Research Station, Co. Galway, Ireland. The effective absorption path lengths accessible with the spectrometer generally exceeded 10 km, enabling sensitive localised ``point' measurements of atmospheric absorbers to be made adjacent to the other instruments monitoring chemically related species at the same site. For the majority of observations, the spectrometer was used in an open path configuration thereby avoiding surface losses of reactive species. A subset of observations targeted the N2O5 molecule by detecting the additional NO3 formed by the thermal dissociation of N2O5. In all cases the concentrations of the atmospheric absorbers were retrieved by fitting the differential structure in the broadband cavity ringdown spectra using a methodology adapted from long path differential optical absorption spectroscopy. The uncertainty of the retrieval depends crucially on the correct treatment and fitting of the absorption bands due to water vapour, a topic that is discussed in the context of analysing broadband cavity ringdown spectra. The quality of the measurements and the retrieval method are illustrated with representative spectra acquired during NAMBLEX in spectral regions around 660 nm (NO3 and N2O5 and 570 nm (I2 and OIO. Typical detection limits were 1 pptv for NO3 in an integration time of 100 s, 4 pptv for OIO and 20 pptv for I2 in an integration time of 10 min. Additionally, the concentrations of atmospheric water vapour and the aerosol optical extinction were retrieved in both spectral regions. A companion paper in this issue presents the time series of the measurements and discusses their significance for understanding the variability of short lived nitrogen and iodine compounds in the marine

  20. The impact of vibrational Raman scattering of air on DOAS measurements of atmospheric trace gases

    Science.gov (United States)

    Lampel, J.; Frieß, U.; Platt, U.

    2015-09-01

    In remote sensing applications, such as differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered. After inelastic scattering on N2 and O2 molecules, the scattered photons occur as additional intensity at a different wavelength, effectively leading to "filling-in" of both solar Fraunhofer lines and absorptions of atmospheric constituents, if the inelastic scattering happens after the absorption. Measured spectra in passive DOAS applications are typically corrected for rotational Raman scattering (RRS), also called Ring effect, which represents the main contribution to inelastic scattering. Inelastic scattering can also occur in liquid water, and its influence on DOAS measurements has been observed over clear ocean water. In contrast to that, vibrational Raman scattering (VRS) of N2 and O2 has often been thought to be negligible, but it also contributes. Consequences of VRS are red-shifted Fraunhofer structures in scattered light spectra and filling-in of Fraunhofer lines, additional to RRS. At 393 nm, the spectral shift is 25 and 40 nm for VRS of O2 and N2, respectively. We describe how to calculate VRS correction spectra according to the Ring spectrum. We use the VRS correction spectra in the spectral range of 420-440 nm to determine the relative magnitude of the cross-sections of VRS of O2 and N2 and RRS of air. The effect of VRS is shown for the first time in spectral evaluations of Multi-Axis DOAS data from the SOPRAN M91 campaign and the MAD-CAT MAX-DOAS intercomparison campaign. The measurements yield in agreement with calculated scattering cross-sections that the observed VRS(N2) cross-section at 393 nm amounts to 2.3 ± 0.4 % of the cross-section of RRS at 433 nm under tropospheric conditions. The contribution of VRS(O2) is also found to be in agreement with calculated scattering cross-sections. It is concluded, that this phenomenon has to be included in the spectral evaluation of weak absorbers as it

  1. Year-round retrievals of trace gases in the Arctic using the Extended-range Atmospheric Emitted Radiance Interferometer

    Directory of Open Access Journals (Sweden)

    Z. Mariani

    2013-06-01

    Full Text Available The Extended-range Atmospheric Emitted Radiance Interferometer (E-AERI was installed at the Polar Environment Atmospheric Research Laboratory (PEARL at Eureka, Nunavut, Canada in October 2008. Spectra from the E-AERI provide information about the radiative balance and budgets of trace gases in the Canadian high Arctic. Measurements are taken every 7 min year-round, including polar night when the solar-viewing spectrometers at PEARL are not operated. This allows E-AERI measurements to fill the gap in the PEARL dataset during the four months of polar night. Measurements were taken year-round in 2008–2009 at the PEARL Ridge Lab, which is 610 m a.s.l. (above sea-level, and from 2011 onwards at the Zero-Altitude PEARL Auxiliary Lab (0PAL, which is at sea level 15 km from the Ridge Lab. Total columns of O3, CO, CH4, and N2O have been retrieved using a modified version of the SFIT2 retrieval algorithm adapted for emission spectra. This provides the first ground-based nighttime measurements of these species at Eureka. Changes in the total columns driven by photochemistry and dynamics are observed. Analyses of E-AERI retrievals indicate accurate spectral fits (root-mean-square residuals consistent with noise and a 10–15% uncertainty in the total column, depending on the trace gas. O3 comparisons between the E-AERI and a Bruker IFS 125HR Fourier transform infrared (FTIR spectrometer, three Brewer spectrophotometers, two UV-visible ground-based spectrometers, and a System D'Analyse par Observations Zenithales (SAOZ at PEARL are made from 2008–2009 and for 2011. 125HR CO, CH4, and N2O columns are also compared with the E-AERI measurements. Mean relative differences between the E-AERI and the other spectrometers are 1–10% (14% is for the un-smoothed profiles, which are less than the E-AERI's total column uncertainties. The E-AERI O3 and CO measurements are well correlated with the other spectrometers (r > 0.92 with the 125HR. The 24 h diurnal cycle

  2. Greenhouse Trace Gases in Deadwood

    Science.gov (United States)

    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.

  3. Polar night retrievals of trace gases in the Arctic using the Extended-range Atmospheric Emitted Radiance Interferometer

    Directory of Open Access Journals (Sweden)

    Z. Mariani

    2013-01-01

    Full Text Available The Extended-range Atmospheric Emitted Radiance Interferometer (E-AERI was installed at the Polar Environment Atmospheric Research Laboratory (PEARL at Eureka, Nunavut, Canada in October 2008. Spectra from the E-AERI provide information about the radiative balance and budgets of trace gases in the Canadian high Arctic. Measurements are taken every seven minutes year-round, including polar night when the solar-viewing spectrometers at PEARL are not operated. This allows E-AERI measurements to fill the gap in the PEARL dataset during the four months of polar night. Measurements were taken year-round in 2008–2009 at the PEARL Ridge Lab, which is 610 m above sea-level, and from 2011-onwards at the Zero-Altitude PEARL Auxiliary Lab (0PAL, which is 15 km from the Ridge Lab at sea level. Total columns of O3, CO, CH4, and N2O have been retrieved using a modified version of the SFIT2 retrieval algorithm adapted for emission spectra. This provides the first nighttime measurements of these species at Eureka. Changes in the total columns driven by photochemistry and dynamics are observed. Analyses of E-AERI retrievals indicate accurate spectral fits (root-mean-square residuals < 1.5% and a 10–15% uncertainty in the total column, depending on the trace gas. O3 comparisons between the E-AERI and a Bruker IFS 125HR Fourier transform infrared (FTIR spectrometer, three Brewer spectrophotometers, two UV-visible ground-based spectrometers, and a System D'Analyse par Observations Zenithales (SAOZ at PEARL are made from 2008–2009 and for 2011. 125HR CO, CH4, and N2O columns are also compared with the E-AERI measurements. Mean relative differences between the E-AERI and the other spectrometers are 1–14% (depending on the gas, which are less than the E-AERI's total column uncertainties. The E-AERI O3 and CO measurements are well correlated with the other spectrometers; the best

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

    Science.gov (United States)

    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.

  5. Basic characteristics of atmospheric particles, trace gases and meteorology in a relatively clean Southern African Savannah environment

    Directory of Open Access Journals (Sweden)

    L. Laakso

    2008-08-01

    Full Text Available We have analyzed one year (July 2006–July 2007 of measurement data from a relatively clean background site located in dry savannah in South Africa. The annual-median trace gas concentrations were equal to 0.7 ppb for SO2, 1.4 ppb for NOx, 36 ppb for O3 and 105 ppb for CO. The corresponding PM1, PM2.5 and PM10 concentrations were 9.0, 10.5 and 18.8 μg m−3, and the annual median total particle number concentration in the size range 10–840 nm was 2340 cm−3. During Easterly winds, influence of industrial sources approximately 150 km away from the measurement site was clearly visible, especially in SO2 and NOx concentrations. Of gases, NOx and CO had a clear annual, and SO2, NOx and O3 clear diurnal cycle. Atmospheric new-particle formation was observed to take place in more than 90% of the analyzed days. The days with no new particle formation were cloudy or rainy days. The formation rate of 10 nm particles varied in the range of 0.1–28 cm−3 s−1 (median 1.9 cm−3 s−1 and nucleation mode particle growth rates were in the range 3–21 nm h−1 (median 8.5 nm h−1. Due to high formation and growth rates, observed new particle formation gives a significant contribute to the number of cloud condensation nuclei budget, having a potential to affect the regional climate forcing patterns.

  6. Retrieval of trace gases vertical profile in the lower atmosphere combining. Differential Optical Absorption Spectroscopy with radiative transfer models

    OpenAIRE

    Palazzi, Elisa

    2008-01-01

    The motivation for the work presented in this thesis is to retrieve profile information for the atmospheric trace constituents nitrogen dioxide (NO2) and ozone (O3) in the lower troposphere from remote sensing measurements. The remote sensing technique used, referred to as Multiple AXis Differential Optical Absorption Spectroscopy (MAX-DOAS), is a recent technique that represents a significant advance on the well-established DOAS, especially for what it concerns the study of...

  7. A pre-processor of trace gases and aerosols emission fields for regional and global atmospheric chemistry models

    Directory of Open Access Journals (Sweden)

    S. R. Freitas

    2010-06-01

    Full Text Available The pre-processor PREP-CHEM-SRC presented in the paper is a comprehensive tool aiming at preparing emissions fields of trace gases and aerosols for use in regional or global transport models. The emissions considered are urban/industrial, biogenic, biomass burning, volcanic, biofuel use and burning from agricultural waste sources from most recent databases or from satellite fire detections for biomass burning. A plumerise model is used to derive the height of smoke emissions from satellite fire products. The pre-processor provides emission fields interpolated onto the transport model grid. Several map projections can be chosen. The way to include these emissions in transport models is also detailed. The pre-processor is coded using Fortran 90 and C and is driven by a namelist allowing the user to choose the type of emissions and the database.

  8. Off-axis measurements of atmospheric trace gases by use of an airborne ultraviolet-visible spectrometer

    Science.gov (United States)

    Petritoli, Andrea; Ravegnani, Fabrizio; Giovanelli, Giorgio; Bortoli, Daniele; Bonafè, Ubaldo; Kostadinov, Ivan; Oulanovsky, Alexey

    2002-09-01

    An airborne UV-visible spectrometer, the Gas Analyzer Spectrometer Correlating Optical Differences, airborne version (GASCOD/A4π) was successfully operated during the Airborne Polar Experiment, Geophysica Aircraft in Antarctica airborne campaign from Ushuaia (54°49'S, 68°18'W), Argentina in southern spring 1999. The instrument measured scattered solar radiation through three optical windows with a narrow field of view (FOV), one from the zenith, two from the horizontal, as well as actinic fluxes through 2π FOV radiometric heads. Only a few airborne measurements of scattered solar radiation at different angles from the zenith are available in the literature. With our configuration we attempted to obtain the average line-of-sight concentrations of detectable trace gases. The retrieval method, based on differential optical absorption spectroscopy, is described and results for ozone are shown and compared with measurements from an in situ instrument as the first method of validation.

  9. Human activities affecting trace gases and climate

    International Nuclear Information System (INIS)

    The Earth's climate has been in a constant state of change throughout geologic time due to natural perturbations in the global geobiosphere. However, various human activities have the potential to cause future global warming over a relatively short amount of time. These activities, which affect the Earth's climate by altering the concentrations of trace gases in the atmosphere, include energy consumption, particularly fossil-fuel consumption; industrial processes (production and use of chlorofluorocarbons, halons, and chlorocarbons, landfilling of wastes, and cement manufacture); changes in land use patterns, particularly deforestation and biomass burning; and agricultural practices (waste burning, fertilizer usage, rice production, and animal husbandry). Population growth is an important underlying factor affecting the level of growth in each activity. This paper describes how the human activities listed above contribute to atmospheric change, the current pattern of each activity, and how levels of each activity have changed since the early part of this century

  10. Absorption of Soluble Gases by Atmospheric Nanoaerosols

    CERN Document Server

    Elperin, Tov; Krasovitov, Boris; Lushnikov, Alexey

    2012-01-01

    We investigate mass transfer during absorption of atmospheric trace soluble gases by a single droplet whose size is comparable to the molecular mean free path in air at normal conditions. It is assumed that the trace reactant diffuses to the droplet surface and then reacts with the substances inside the droplet according to the first order rate law. Our analysis applies a flux-matching theory of transport processes in gases and assumes constant thermophysical properties of the gases and liquids. We derive an integral equation of Volterra type for the transient molecular flux density to a liquid droplet and solve it numerically. Numerical calculations are performed for absorption of sulfur dioxide (SO2), dinitrogen trioxide (N2O3) and chlorine (Cl2) by liquid nanoaerosols accompanied by chemical dissociation reaction. It is shown that during gas absorption by nanoaerosols the kinetic effects play significant role, and neglecting kinetic effects leads to significant overestimation of the soluble gas flux into a...

  11. Study of trace gases in the Martian atmosphere: Groundbased observation using SUBARU/IRCS and development of radiative transfer model for MEX/PFS limb observation

    Science.gov (United States)

    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.

  12. Greenhouse effect of trace gases, 1970-1980

    Science.gov (United States)

    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.

  13. Advanced Global Atmospheric Gases Experiment (AGAGE)

    Science.gov (United States)

    Prinn, Ronald G.; Kurylo, Michael (Technical Monitor)

    2004-01-01

    We seek funding from NASA for the third year (2005) of the four-year period January 1, 2003 - December 31, 2006 for continued support of the MIT contributions to the multi-national global atmospheric trace species measurement program entitled Advanced Global Atmospheric Gases Experiment (AGAGE). The case for real-time high-frequency measurement networks like AGAGE is very strong and the observations and their interpretation are widely recognized for their importance to ozone depletion and climate change studies and to verification issues arising from the Montreal Protocol (ozone) and Kyoto Protocol (climate). The proposed AGAGE program is distinguished by its capability to measure over the globe at high frequency almost all of the important species in the Montreal Protocol and almost all of the significant non-CO2 gases in the Kyoto Protocol.

  14. Miniature Tunable Laser Spectrometers for Quantifying Atmospheric Trace Gases, Water Resources, Earth Back-Contamination, and In Situ Resource Utilization

    Science.gov (United States)

    Webster, Chris; Blacksberg, Jordana; Flesch, Greg; Keymeulen, Didier; Christensen, Lance; Forouhar, Siamak

    2012-01-01

    The Tunable Laser Spectrometers (TLS) technique has seen wide applicability in gas measurement and analysis for atmospheric analysis, industrial, commercial and health monitoring and space applications. In Earth science using balloons and aircraft over 2 decades, several groups (JPL, NASA Langley & Ames, NOAA, Harvard U., etc) have demonstrated the technique for ozone hole studies, lab kinetics measurements, cloud physics and transport, climate change in the ice record. The recent availability of high-power (mW) room temperature lasers (TDL, IC, QC) has enabled miniaturized, high-sensitivity spectrometers for industry and space (1) Mars, Titan, Venus, Saturn, Moon (2) Commercial isotope ratio spectrometers are replacing bulkier, complex isotope ratio mass spectrometers.

  15. Spatial and Temporal Variability of Trace Gases during DISCOVER-AQ: Planning for Geostationary Observations of Atmospheric Composition

    Science.gov (United States)

    Follette-Cook, M. B.; Pickering, K. E.; Crawford, J. H.

    2015-12-01

    We quantify spatial and temporal variability of both in-situ mixing ratios and column integrated O3, NO2, CO, SO2, and HCHO during the four deployments of the NASA Earth Venture mission DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality). Using structure function analyses, we compare simulated variability of output from the regional chemical models WRF/Chem and CMAQ with variability observed during the campaigns. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument will be the first NASA mission to make atmospheric composition observations from geostationary orbit and partially fulfills the goals of the Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission. We compare both observed and simulated variability to the precision requirements defined by the science traceability matrices of these space-borne missions to explore how they relate to the science questions they are tasked to address.

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  17. Impacts of aerosols on the chemistry of atmospheric trace gases: a case study of peroxides and HO2 radicals

    Directory of Open Access Journals (Sweden)

    H. Liang

    2013-06-01

    Full Text Available Field measurements of atmospheric peroxides were obtained during the summer on two consecutive years over urban Beijing, and focused on the impacts of aerosols on the chemistry of peroxide compounds and hydroperoxyl radicals (HO2. The major peroxides were determined to be hydrogen peroxide (H2O2, methyl hydroperoxide (MHP, and peroxyacetic acid (PAA. A negative correlation was found between H2O2 and PAA in rainwater, providing evidence for a conversion between H2O2 and PAA in the aqueous phase. A standard gas phase chemistry model based on the NCAR Master Mechanism provided a good reproduction of the observed H2O2 profile on non-haze days but greatly overpredicted the H2O2 level on haze days. We attribute this overprediction to the reactive uptake of HO2 by the aerosols, since there was greatly enhanced aerosol loading and aerosol liquid water content on haze days. The discrepancy between the observed and modeled H2O2 can be diminished by adding to the model a newly proposed transition metal ion catalytic mechanism of HO2 in aqueous aerosols. This confirms the importance of the aerosol uptake of HO2 and the subsequent aqueous phase reactions in the reduction of H2O2. The closure of HO2 and H2O2 between the gas and aerosol phases suggests that the aerosols do not have a net reactive uptake of H2O2, because the conversion of HO2 to H2O2 on aerosols compensates for the H2O2 loss. Laboratory studies for the aerosol uptake of H2O2 in the presence of HO2 are urgently required to better understand the aerosol uptake of H2O2 in the real atmosphere.

  18. 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

    Science.gov (United States)

    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.

  19. LIDAR technology for measuring trace gases on Mars and Earth

    Directory of Open Access Journals (Sweden)

    H. Riris

    2010-11-01

    Full Text Available Trace gases and their isotopic ratios in planetary atmospheres offer important but subtle clues as to the origins of a planet's atmosphere, hydrology, geology, and potential for biology. Calculations show that an orbiting laser remote sensing instrument is capable of measuring trace gases on a global scale with unprecedented accuracy, and higher spatial resolution that can be obtained by passive instruments. Our proposed lidar uses Integrated Path Differential Absorption technique, Optical Parametric Amplifiers, and a receiver with high sensitivity detector at 1.65 μm to map methane concentrations, a strong greenhouse gas. For Mars we can use the same technique in the 3–4 μm spectral range to map various biogenic gas concentrations and search for the existence of life. Preliminary results demonstrating methane and water vapour detection using a laboratory prototype illustrate the viability of the technique.

  20. Greenhouse effect of chlorofluorocarbons and other trace gases

    OpenAIRE

    Hansen, James; Lacis, Andrew; Prather, Michael

    1989-01-01

    We compare the radiative (greenhouse) forcing of the climate system due to changes of atmospheric chlorofluorocarbons and other trace gases. We find that CFCs, defined to include chlorofluorocarbons, chlorocarbons, and fluorocarbons, now provide about one-quarter 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 du...

  1. Greenhouse effect of chlorofluorocarbons and other trace gases

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Method for detecting trace impurities in gases

    Science.gov (United States)

    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.

  4. Influence of orographically induced transport process on the structure of the atmospheric boundary layer and on the distribution of trace gases; Einfluss orographisch induzierter Transportprozesse auf die Struktur der atmosphaerischen Grenzschicht und die Verteilung von Spurengasen

    Energy Technology Data Exchange (ETDEWEB)

    Kossmann, M.

    1998-04-01

    The influence of terrain on the structure of the atmospheric boundary-layer and the distribution of trace gases during periods of high atmospheric pressure was studied by means of meteorological and air-chemical data collected in September 1992 during the TRACT experiment in the transition area between the upper Rhine valley and the northern Black Forest. The emphasis was on the investigation of the development of the convective boundary layer, the formation of thermally induced circulation systems, and the orographic exchange between the atmospheric boundary layer and the free troposphere. Thanks to the extensive measurements, phenomena not yet described in literature could be verified by case studies, and processes that had only been established qualitatively could be quantified. (orig.)

  5. 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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Stable isotope measurement techniques for atmospheric greenhouse gases

    International Nuclear Information System (INIS)

    The technical requirements to perform useful measurements of atmospheric greenhouse gas concentrations and of their isotope ratios are of direct relevance for all laboratories engaged in this field. A meaningful interpretation of isotopes in global models on sources and sinks of CO2 and other greenhouse gases depends on strict laboratory protocols and data quality control measures ensuring comparable data in time and space. Only with this precondition met, the isotope techniques can serve as a potentially powerful method for reducing uncertainties in the global CO2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. This publication provides four contributions describing methods for the determination of the isotopic composition of trace gases in atmospheric air and in ice cores. These contributions have been indexed separately

  9. Compilation and evaluation of gas-phase diffusion coefficients of reactive trace gases in the atmosphere: volume 2. Organic compounds and Knudsen numbers for gas uptake calculations

    Directory of Open Access Journals (Sweden)

    M. J. Tang

    2015-02-01

    Full Text Available Diffusion of organic vapours to the surface of aerosol or cloud particles is an important step for the formation and transformation of atmospheric particles. So far, however, a database of gas phase diffusion coefficients for organic compounds of atmospheric interest has not been available. In this work we have compiled and evaluated gas phase diffusivities (pressure-independent diffusion coefficients of organic compounds reported by previous experimental studies, and we compare the measurement data to estimates obtained with Fuller's semi-empirical method. The difference between measured and estimated diffusivities are mostly Kn although their gas phase diffusivities may vary over a wide range. Knudsen numbers of gases with unknown diffusivity can be approximated by a simple function of particle diameter and pressure and can be used to characterize the influence of diffusion on gas uptake by aerosol or cloud particles. We use a kinetic multi-layer model of gas-particle interaction to illustrate the effects of gas phase diffusion on the condensation of organic compounds with different volatilities. The results show that gas-phase diffusion can play a major role in determining the growth of secondary organic aerosol particles by condensation of low-volatility organic vapours.

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

    Science.gov (United States)

    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.

  11. Measurements and estimates of leaf wetness over agricultural grassland for dry deposition modeling of trace gases

    NARCIS (Netherlands)

    Wichink Kruit, R.J.; Jacobs, A.F.G.; Holtslag, A.A.M.

    2008-01-01

    Leaf wetness is an important and frequent phenomenon for the surface¿atmosphere exchange of some atmospheric trace gases that are well soluble in water, such as ammonia (NH3 and SO2), as well as for plant disease epidemiology. This study shows a comparison of two different techniques to measure leaf

  12. Escape of atmospheric gases from the Moon

    Indian Academy of Sciences (India)

    Da Dao-an; Yang Ya-tian

    2005-12-01

    The escape rate of atmospheric molecules on the Moon is calculated.Based on the assumption that the rates of emission and escape of gases attain equilibrium, the ratio of molecular number densities during day and night, 0/0, can be explained. The plausible emission rate of helium and radioactive elements present in the Moon has also been calculated.

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

    Science.gov (United States)

    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)

  14. Measurements of trace gases above the tropical forests....

    Science.gov (United States)

    Nicolas-Perea, V.; Monks, P. S.

    2009-04-01

    Measurements of trace gases above the tropical forests; A comparison between ozone levels in the forest and the oil palm plantation areas using the BAe -146 aircraft. The atmospheric composition of Sabah region (Borneo) was sampled using the FAAM BAE-146 instrumented aircraft during July 2008 as part of the OP3 (Oxidant particle photochemical processes above a South East Asia tropical rain forest) project. Tropical forests play an important role in the carbon and energy balance of the Earth (which determine global climate) and are themselves vulnerable to climate change. The tropical biosphere is one of the main sources of reactive trace gas emissions into the global atmosphere, and understanding the role of ozone in these areas is of major importance given the rapid changes in land-use in the tropics. This poster presents preliminary ozone concentrations results collected using the FAAM BAE 146 instrumented aircraft over some of Malaysia most extended oil palm plantations; comparing these with the results recorded when flying over forest areas. Oil palm is becoming one of the most widespread tropical crops; in Malaysia 13% of the land area (4.3Mha) is now oil palm plantations (MPOCP, 2008) compared with 1% in 1974 (FAO, 2005). This poster is expected to show very significant ozone concentrations over the two different landscapes. The set-up of the instruments, the specific sampling sites, as well as the land cover areas will be described.

  15. Ground-based Measurements of Vertical Profiles and Columns of Atmospheric Trace Gases Over Toronto Using a New High-Resolution Fourier Transform Infrared Spectrometer

    Science.gov (United States)

    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

  16. Use of satellite data to constrain the model-calculated atmospheric lifetime for N2O - Implications for other trace gases

    Science.gov (United States)

    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.

  17. The Global Atmosphere Watch reactive gases measurement network

    Directory of Open Access Journals (Sweden)

    Martin G. Schultz

    2015-10-01

    Full Text Available Abstract Long-term observations of reactive gases in the troposphere are important for understanding trace gas cycles and the oxidation capacity of the atmosphere, assessing impacts of emission changes, verifying numerical model simulations, and quantifying the interactions between short-lived compounds and climate change. The World Meteorological Organization’s (WMO Global Atmosphere Watch (GAW program coordinates a global network of surface stations some of which have measured reactive gases for more than 40 years. Gas species included under this umbrella are ozone, carbon monoxide, nitrogen oxides, and volatile organic compounds (VOCs. There are many challenges involved in setting-up and maintaining such a network over many decades and to ensure that data are of high quality, regularly updated and made easily accessible to users. This overview describes the GAW surface station network of reactive gases, its unique quality management framework, and discusses the data that are available from the central archive. Highlights of data use from the published literature are reviewed, and a brief outlook into the future of GAW is given. This manuscript constitutes the overview of a special feature on GAW reactive gases observations with individual papers reporting on research and data analysis of particular substances being covered by the program.

  18. Effects of land use on surface–atmosphere exchanges of trace gases and energy in Borneo: comparing fluxes over oil palm plantations and a rainforest

    OpenAIRE

    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

    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 ...

  19. On the impact of Vibrational Raman Scattering of N2/O2 on MAX-DOAS Measurements of atmospheric trace gases

    Science.gov (United States)

    Lampel, Johannes; Zielcke, Johannes; Frieß, Udo; Platt, Ulrich; Wagner, Thomas

    2015-04-01

    In remote sensing applications, such as the applications of differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered since they can modify the observed spectra. Inelastic scattering of photons by N2 and O2 molecules can be observed as additional intensity, effectively leading to filling-in of both, solar Fraunhofer lines and absorption bands of atmospheric constituents. The main contribution is due to rotational Raman scattering, which can lead to changes in observed optical densities of absorption lines up to several percent. Measured optical densities are typically corrected for this effect (also known as Ring Effect). In contrast to that Vibrational Raman scattering of N2 and O2 was often thought to be negligible, but also contributes to this effect. We present calculations of Vibrational Raman cross-sections for O2 and N2 for the application in passive DOAS measurements. Consequences of vibrational Raman scattering are red-shifted Fraunhofer structures, so called 'Fraunhofer Ghost' lines (FGL), in scattered light spectra and filling-in of Fraunhofer lines, additional to rotational Raman scattering. We also present first unequivocal observations of FGL at optical densities of up to several 104. From our measurements and calculations of the optical density of these FGL, we conclude, that this phenomenon has to be included in the spectral evaluation of weak absorbers. Its relevance is demonstrated in spectral evaluations of Multi-Axis (MAX)-DOAS data and an agreement with calculated scattering cross-sections is found. To exclude cross-sensitivities with other absorbers, such as water vapour, MAX-DOAS data from different latitudes and different instruments were analysed. We evaluate the influence of the additional intensities due to vibrational Raman scattering on the spectral retrieval of IO, Glyoxal, H2O and NO2 in the blue wavelength range. In the case of NO2 the column densities derived from certain wavelength

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

    Science.gov (United States)

    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.

  1. The CU Airborne MAX-DOAS instrument: vertical profiling of aerosol extinction and trace gases

    OpenAIRE

    S. Baidar; Oetjen, H.; S. Coburn; Dix, B.; I. Ortega; R. Sinreich; R. Volkamer

    2013-01-01

    The University of Colorado Airborne Multi-Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument uses solar stray light to detect and quantify multiple trace gases, including nitrogen dioxide (NO2), glyoxal (CHOCHO), formaldehyde (HCHO), water vapor (H2O), nitrous acid (HONO), iodine monoxide (IO), bromine monoxide (BrO), and oxygen dimers (O4) at multiple wavelengths (absorption bands at 360, 477, 577, 632 nm) simultaneously in the open atmosphere. The instrument is uniq...

  2. Mobile MAX-DOAS observations of tropospheric trace gases

    OpenAIRE

    Wagner, T; Ibrahim, O.; R. Shaiganfar; U. Platt

    2010-01-01

    From Multi-Axis- (MAX-) DOAS observations information on tropospheric trace gases close to the surface and up to the free troposphere can be obtained. Usually MAX-DOAS observations are performed at fixed locations, which allows to retrieve the diurnal variation of tropospheric species at that location. Alternatively, MAX-DOAS observations can also be made on mobile platforms like cars, ships or aircrafts. Then, in addition to the vertical (and temporal) distribution, also the horizontal ...

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

    Science.gov (United States)

    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.

  4. Volume 1 Chapter 2: Emissions and concentrations of radiatively active atmospheric trace constituents

    OpenAIRE

    W. Winiwarter

    2014-01-01

    Radiatively active atmospheric trace constituents consist of the following groups of compounds: long-lived greenhouse gases with residence times of years, subject to international conventions; short-lived gases formed in the atmosphere from precursor compounds, remaining in the atmosphere for hours or days: notably ozone; and aerosols, that is, airborne particles interacting with short-wave radiation with both direct and indirect effects. The "direct effect" covers scattering or absorption of...

  5. Mobile MAX-DOAS observations of tropospheric trace gases

    Science.gov (United States)

    Wagner, T.; Ibrahim, O.; Shaiganfar, R.; Platt, U.

    2010-02-01

    From Multi-Axis- (MAX-) DOAS observations, information on tropospheric trace gases close to the surface and up to the free troposphere can be obtained. Usually MAX-DOAS observations are performed at fixed locations, which allows to retrieve the diurnal variation of tropospheric species at that location. Alternatively, MAX-DOAS observations can also be made on mobile platforms like cars, ships or aircrafts. Then, in addition to the vertical (and temporal) distribution, also the horizontal variation of tropospheric trace gases can be measured. Such information is important for the quantitative comparison with model simulations, study of transport processes, and for the validation of tropospheric trace gas products from satellite observations. However, for MAX-DOAS observations from mobile platforms, the standard analysis techniques for MAX-DOAS observations can usually not be applied, because the probed airmasses can change rapidly between successive measurements. In this study we introduce a new technique which overcomes these problems and allows the exploitation of the full information content of mobile MAX-DOAS observations. Our method can also be applied to MAX-DOAS observations made at fixed locations in order to improve the accuracy especially in cases of strong winds. We apply the new technique to MAX-DOAS observations made during an automobile trip from Brussels to Heidelberg.

  6. Mobile MAX-DOAS observations of tropospheric trace gases

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2009-11-01

    Full Text Available From Multi-Axis- (MAX- DOAS observations information on tropospheric trace gases close to the surface and up to the free troposphere can be obtained. Usually MAX-DOAS observations are performed at fixed locations, which allows to retrieve the diurnal variation of tropospheric species at that location. Alternatively, MAX-DOAS observations can also be made on mobile platforms like cars, ships or aircrafts. Then, in addition to the vertical (and temporal distribution, also the horizontal variation of tropospheric trace gases can be measured. Such information is important for the quantitative comparison with model simulations, study of transport processes, and for the validation of tropospheric trace gas products from satellite observations. However, for MAX-DOAS observations from mobile platforms, the standard analysis techniques for MAX-DOAS observations can usually not be applied, because the probed airmasses can change rapidly between successive measurements. In this study we introduce a new technique which overcomes these problems and allows the exploitation of the full information content of mobile MAX-DOAS observations. Our method can also be applied to MAX-DOAS observations made at fixed locations in order to improve the accuracy especially in cases of strong winds. We apply the new technique to MAX-DOAS observations made during an automobile trip from Brussels to Heidelberg.

  7. Fuel characteristics and trace gases produced through biomass burning

    OpenAIRE

    BAMBANG HERO SAHARJO; SHIGETO SUDO; SEIICHIRO YONEMURA; HARUO TSURUTA

    2010-01-01

    Saharjo BH, Sudo S, Yonemura S, Tsuruta H (2010) Fuel characteristics and trace gases produced through biomass burning. Biodiversitas 11: 40-45. Indonesian 1997/1998 forest fires resulted in forest destruction totally 10 million ha with cost damaged about US$ 10 billion, where more than 1 Gt CO2 has been released during the fire episode and elevating Indonesia to one of the largest polluters of carbon in the world where 22% of world’s carbon dioxide produced. It has been found that 80-90% of ...

  8. 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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-07-01

    in June (Summer/Monsoon). For NO2, the highest concentrations are observed during Winter and the lowest concentrations are found in Summer/Monsoon. Like TOC, the HCHO showed seasonal maxima during summer and minima during winter. The expected sources are the crop residue burning, biomass/fossil fuel burning for heating purposes, urbanization, industrialization and meterological variations. Further focus is made on exploring the association of trace gases in atmosphere and their source identification.

  10. Isotope variations of carbon dioxide, methane and other trace gases in Cracow and Kasprowy, Poland

    International Nuclear Information System (INIS)

    Seasonal variations of concentration and isotopic composition of the atmospheric trace gases CO2, CH4 and SF6 are presented for a three years period in two stations in Poland. The station in Cracow represents a polluted urban area with strong contributions of anthropogenic local sources, while the other one is located 80 km away in the High Tatra mountains at Kasprowy Wierch representing a nearly undisturbed clean station. Trends of the concentration and isotopic signatures are discussed and a separation of the CO2 concentration in three components of anthropogenic, biogenic and background origin is presented. (author)

  11. 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

    Science.gov (United States)

    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.

  12. Measurements of Trace Gases in the Tropical Tropopause Layer

    Science.gov (United States)

    Marcy, T. P.; Popp, P. J.; Gao, R. S.; Fahey, D. W.; Ray, E. A.; Richard, E. C.; Thompson, T. L.; Atlas, E. L.; Lowenstein, M.; Wofsy, S. C.; Park, S.; Weinstock, E. M.; Swartz, W. H.; Mahoney, M. J.

    2008-01-01

    A unique dataset of airborne in situ observations of HCl, O3, HNO3, H2O, CO, CO2 and CH3Cl has been made in and near the tropical tropopause layer (TTL). A total of 16 profiles across the tropopause were obtained at latitudes between 10degN and 3degs from the NASA WB-57F high-altitude aircraft flying from Costa Rica. Few in situ measurements of these gases, particularly HCl and HNO3, have been reported for the TTL. The general features of the trace gas vertical profiles are consistent with the concept of the TTL as distinct from the lower troposphere and lower stratosphere. A combination of the tracer profiles and correlations with O3 is used to show that a measurable amount of stratospheric air is mixed into this region. The HCl measurements offer an important constraint on stratospheric mixing into the TTL because once the contribution from halocarbon decomposition is quantified, the remaining HCl (>60% in this study) must have a stratospheric source. Stratospheric HCl in the TTL brings with it a proportional amount of stratospheric O3. Quantifying the sources of O3 in the TTL is important because O3 is particularly effective as a greenhouse gas in the tropopause region.

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

    Science.gov (United States)

    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.

  14. Biosignature Gases in H2-Dominated Atmospheres on Rocky Exoplanets

    CERN Document Server

    Seager, S; Hu, R

    2013-01-01

    (Abridged) Super Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H2-dominated atmospheres. We study biosignature gases on exoplanets with thin H2 atmospheres and habitable surface temperatures, by using a model atmosphere with photochemistry, and biomass estimate framework for evaluating the plausibilty of a range of biosignature gas candidates. We find that photochemically produced H atoms are the most abundant reactive species in H2 atmospheres. In atmospheres with high CO2 levels, atomic O is the major destructive species for some molecules. In sun-Earth-like UV radiation environments, H (and in some cases O) will rapidly destroy nearly all biosignature gases of interest. The lower UV fluxes from UV quiet M stars would produce a lower concentration of H (or O) for the same scenario, enabling some biosignature gases to accumulate. The favorability of low-UV radiation environments to in an H2 atmosphere is closely analogous to the case of oxidized atmosp...

  15. Observations of halogenated trace gases in Taiwan and Malaysia

    Science.gov (United States)

    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.

  16. Isotope aided studies of atmospheric carbon dioxide and other greenhouse gases. Phase II

    International Nuclear Information System (INIS)

    The substantial increase in atmospheric greenhouse gas concentrations and their role in global warming have become major concerns of world governments. Application of isotope techniques to label sources and sinks of CO2 and other greenhouse gases has emerged as a potentially powerful method for reducing uncertainties in the global CO2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. As with CO2 concentration measurements, meaningful integration of isotopes in global models requires careful attention to quality assurance, quality control and inter-comparability of measurements made by a number of networks and laboratories. To support improvements in isotope measurement capabilities, the IAEA began implementing Co-ordinated Research Projects (CRPs) in 1992. The first project, entitled Isotope Variations of Carbon Dioxide and other Trace Gases in the Atmosphere, was implemented from 1992 to 1994. A significant contribution was made towards a better understanding of the global carbon cycle and especially of the sources and sinks of carbon with data on the 14C and 13C content of atmospheric CO2, pointing to a better understanding of the problem of the 'missing sink' in the global carbon cycle. Important methodological developments in the field of high precision stable isotope mass spectrometry and improved data acquisition procedures emerged from work carried out within the framework of this programme. The development of pressurized gas standards and planning for an associated interlaboratory calibration were initiated. Due to the good progress and long standing nature of the required work a second CRP was initiated and implemented from 1996 to 1999. It was entitled Isotope aided Studies of Atmospheric Carbon Dioxide and Other Trace Gases - Phase II, to document the close relationship of both programmes. This publication provides an overview of the scientific outcomes of the studies conducted within Phase II of

  17. Physics of Atmospheric Electric Discharges in Gases: An Informal Introduction

    CERN Document Server

    Treumann, R A; Parrot, M

    2007-01-01

    A short account of the physics of electrical discharges in gases is given in view of its historical evolution and application to planetary atmospheres. As such it serves as an introduction to the articles on particular aspects of electric discharges contained in this book, in particular in the chapters on lightning and the violent discharges which in the recent two decades have been observed to take place in Earth's upper atmosphere. In addition of briefly reviewing the early history of gas discharge physics we discuss the main parameters affecting violent atmospheric discharges like collision frequency, mean free path and critical electric field strength. Any discharge current in the atmosphere is clearly carried only by electrons. Above the lower bound of the mesosphere the electrons must be considered magnetized with the conductivity becoming a tensor. Moreover, the collisional mean free path in the upper atmosphere becomes relatively large which lowers the critical electric field there and more easily ena...

  18. MAX-DOAS aerosol and trace gases measurements in megacities in China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xin [Institut fuer Energie- und Klimaforschung, Forschungszentrum Juelich (Germany); College of Environmental Science and Engineering Peking University, Beijing (China); Brauers, Theo [Institut fuer Energie- und Klimaforschung, Forschungszentrum Juelich (Germany); Shao, Min [College of Environmental Science and Engineering Peking University, Beijing (China)

    2011-07-01

    Multi Axis Differential Optical Absorption Spectroscopy (MAXDOAS) is a new remote sensing technique to measure atmospheric trace gases. Compared to other areas in the world, the atmospheric observations in megacities in China are rather limited. We present MAX-DOAS measurements at four sites in Beijing and Guangzhou in 2006 and 2008. At each site, the scattered sunlight was recorded at 7 elevation angles for about 1 months. Using the zenith spectrum as reference, the Differential Slant Column Densities (DSCDs) of HCHO, CHOCHO, O{sub 4} and NO{sub 2} at offaxis viewing geometries were derived from the DOAS fit. These DSCDs were simulated using a backward Monte Carlo radiative transfer model. The aerosol and trace gas profiles were defined by 3 parameters: the integrated quantities (T), the height of the surface layer (H), and the fraction of T below H. We fitted the modeled values to the measured values at the corresponding viewing geometries by varying the 3 parameters. The aerosol extinction and the boundary layer height were successfully retrieved from the measured O{sub 4} DSCDs as well as ground level concentrations of CHOCHO, HCHO, and NO{sub 2}, the latter being compared to simultaneous in-situ measurements.

  19. Sources and sinks of trace gases in Amazonia and the Cerrado

    Science.gov (United States)

    Bustamante, M. M. C.; Keller, M.; Silva, D. A.

    Data for trace gas fluxes (NOx, N2O, and CH4) from the Amazon and cerrado region are presented with focus on the processes of production and consumption of these trace gases in soils and how they may be changed because of land use changes in both regions. Fluxes are controlled by seasonality, soil moisture, soil texture, topography, and fine-root dynamics. Compared to Amazonian forests where the rapid cycling of nitrogen supports large emissions of N2O, nitrification rates and soil emissions of N oxide gases in the cerrado region are very low. Several studies report CH4 consumption during both wet and dry seasons in forest soils, but there is occasionally net production of CH4 during the wet season. A few studies suggest an unknown source of CH4 from upland forests. As with N oxide emissions, there are few data on CH4 emissions from cerrado soils, but CH4 consumption occurs during both wet and dry seasons. Clearing natural vegetation, burning, fertilization of agricultural lands, intensive cattle ranching, and increasing dominance by legume species in areas under secondary succession after land conversion have all been identified as causes of increasing N2O and NO emissions from tropical regions. Large uncertainties remain for regional estimates of trace gas fluxes. Improvement of models for the N oxides and CH4 fluxes for Amazonia and the cerrado still depends upon gathering more data from sites more widely distributed across two vast biomes and more importantly on basic theory about the controls of emissions from the ecosystem to the atmosphere.

  20. Satellite-derived Signatures of Trace Gases from US. Oil and Gas Operations

    Science.gov (United States)

    Kollonige, D. E.; Thompson, A. M.

    2013-12-01

    Since 2005, there has been an increase in shale gas production, which is expected to continue through 2035, leading to heightened environmental concerns regarding increased emissions of the greenhouse gas methane (CH4) and degradation of local air quality. Emissions of CH4 and VOCs may occur at any stage of exploration and production via venting, flashing, flaring, or fugitive/non-permitted emissions. The industrial equipment used to install and maintain a well is a potential emission source of CH4, VOCs, nitrogen oxides, and other gases. Emissions from these individual point sources can accumulate and represent a substantial area source of trace gases to the atmosphere. We have begun to characterize the trace gas signatures associated with oil and natural gas (O&NG) operations in the U.S. using satellite observations over two key regions: the Marcellus and Bakkan Shale Deposits. Current satellite products, including CH4 from the Tropospheric Emission Spectrometer (TES) and nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI) on Aura, are compared to aircraft and ground measurements. Preliminary analysis during June 2012 shows the potential for TES in the mid-troposphere to detect and track increases in CH4 due to a gas well leak in the Marcellus Shale Region. Trace gas trends from satellite observations are analyzed in the vicinity of O&NG sites. The TES CH4 representative tropospheric volume mixing ratio (RTVMR) product, particularly used for emission detection, displays evidence of increasing methane over PA from 2006 through 2012. This analysis begins to provide improved constraints on O&NG emissions and supply a template for future geo-missions, such as TEMPO, for continued observations of air quality.

  1. Determination of the Concentration of Atmospheric Gases By Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Haskin, Chris

    2013-09-01

    Full Text Available The study of common greenhouse gases such as Carbon Dioxide (CO2 and Methane (CH4 is important because the concentration can be linked to added absorption of emitted terrestrial radiation, leading to the warming of the atmosphere1. This research measures the concentrations of common greenhouse gases in the air surrounding Eastern Michigan University. The development of an auto-sampler system for long term use on the EMU campus will create a viable way to monitor greenhouse gas concentrations throughout the year. Samples were analyzed using an Agilent 6890 Gas Chromatograph and a Valco Industries Thermal Conductivity Detector fitted with a Restek 5A Molsieve column (part # 80440- 800 and a Varian poraPLOT column (part# CP7550 for proper molecular separation. Molecular data analysis is plotted using Peaksimple software by SRI Systems from Torrance, Ca. Although the experiment is ongoing, preliminary data suggest this methodology could be used to detect atmospheric methane.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  5. MASERATI: a new rocket-borne diode laser absorption spectrometer for in-situ measurement of trace gases in the middle and upper atmosphere; MASERATI: Ein neues raketengetragenes Diodenlaser-Absorptionsspektrometer zur in situ-Messung von Spurengasen in der mittleren und oberen Atmosphaere

    Energy Technology Data Exchange (ETDEWEB)

    Lucke, H. von

    1999-09-01

    MASERATI (middle atmosphere spectrometric experiment on Rockets for the analysis of trace gas influences) is the first rocket-borne tunable diode laser absorption spectrometer (TDLAS). It was developed to measure water vapor and carbon dioxide in the altitude range from 50 to 90 km and 120 km, respectively. Infrared absorption spectroscopy using two laser diodes is applied to measure both trace gases simultaneously. The laser beams are sent into an open multiple-pass absorption setup mounted on top of the sounding rocket. High sensitivity is achieved by means of frequency modulation and lock-in techniques. The results of several tests performed in the laboratory demonstrate that the instrument is capable of detecting relative absorbances down to 10{sup -4} - 10{sup -5} when integrating spectra for 1 s. Two almost identical MASERATI instruments have been built and launched on sounding rockets from the Andoeya rocket range (69 N, 16 E) in northern Norway during winter 1997/98. The results of these flights demonstrate that MASERATI is a new suitable tool for in situ studies of the mesosphere and lower thermosphere. (orig.)

  6. Greenhouse gases regional fluxes estimated from atmospheric measurements

    International Nuclear Information System (INIS)

    build up a new system to measure continuously CO2 (or CO), CH4, N2O and SF6 mixing ratios. It is based on a commercial gas chromatograph (Agilent 6890N) which have been modified to reach better precision. Reproducibility computed with a target gas on a 24 hours time step gives: 0.06 ppm for CO2, 1.4 ppb for CO, 0.7 ppb for CH4, 0.2 ppb for N2O and 0.05 ppt for SF6. The instrument's run is fully automated, an air sample analysis takes about 5 minutes. In July 2006, I install instrumentation on a telecommunication tall tower (200 m) situated near Orleans forest in Trainou, to monitor continuously greenhouse gases (CO2, CH4, N2O, SF6), atmospheric tracers (CO, Radon-222) and meteorological parameters. Intake lines were installed at 3 levels (50, 100 and 180 m) and allow us to sample air masses along the vertical. Continuous measurement started in January 2007. I used Mace Head (Ireland) and Gif-sur-Yvette continuous measurements to estimate major greenhouse gases emission fluxes at regional scale. To make the link between atmospheric measurements and surface fluxes, we need to quantify dilution due to atmospheric transport. I used Radon-222 as tracer (radon tracer method) and planetary boundary layer heights estimates from ECMWF model (boundary layer budget method) to parameterize atmospheric transport. In both cases I compared results to available emission inventories. (author)

  7. Ground-based imaging differential optical absorption spectroscopy of atmospheric gases.

    Science.gov (United States)

    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

  8. Retrieval of Atmospheric Aerosol and Trace Gas Vertical Profiles using Multi-Axis Differential Optical Absorption Spectroscopy

    OpenAIRE

    Yilmaz, Selami

    2012-01-01

    In this thesis, the vertical distribution of atmospheric trace gases and aerosols were retrieved using Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS). Various inversion methods were used to retrieve the profiles from the MAX-DOAS measurements. A new MAX-DOAS instrument optimized for the measurement of aerosol and trace gas profiles was developed. The retrieval methods were tested and advanced in the scope of the EUSAAR (European Supersites for Atmospheric Aerosol Research)...

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

    Science.gov (United States)

    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 Greenhouse gases Observational SATellite). The only network that currently measures CO2 and CH4 in the atmospheric column is TCCON (Total Carbon Column Observing Network), and only two of its 16 operational sites are in the United States. TCCON data is used for validation of GOSAT data, and will be used for OCO-2 validation. While these Fourier-transform spectrometers (FTS) can measure the largest range of trace gases, the network is severely limited

  10. Stratospheric trace gases from SCIAMACHY limb measurements using 3D full spherical Monte Carlo radiative transfer model Tracy-II

    Energy Technology Data Exchange (ETDEWEB)

    Pukite, Janis [Max- Planck-Institut fuer Chemie, Mainz (Germany); Institute of Atomic Physics and Spectroscopy, University of Latvia (Latvia); Kuehl, Sven; Wagner, Thomas [Max- Planck-Institut fuer Chemie, Mainz (Germany); Deutschmann, Tim; Platt, Ulrich [Institut fuer Umweltphysik, University of Heidelberg (Germany)

    2007-07-01

    A two step method for the retrieval of stratospheric trace gases (NO{sub 2}, BrO, OClO) from SCIAMACHY limb observations in the UV/VIS spectral region is presented: First, DOAS is applied on the spectra, yielding slant column densities (SCDs) of the respective trace gases. Second, the SCDs are converted into vertical concentration profiles applying radiative transfer modeling. The Monte Carlo method benefits from conceptual simplicity and allows realizing the concept of full spherical geometry of the atmosphere and also its 3D properties, which are important for a realistic description of the limb geometry. The implementation of a 3D box air mass factor concept allows accounting for horizontal gradients of trace gases. An important point is the effect of horizontal gradients on the profile inversion. This is of special interest in Polar Regions, where the Sun elevation is typically low and photochemistry can highly vary along the long absorption paths. We investigate the influence of horizontal gradients by applying 3-dimensional radiative transfer modelling.

  11. Climate aspects of radioactive trace gases, especially krypton-85

    International Nuclear Information System (INIS)

    The amount of krypton 85 currently present in the atmosphere is 3.300 Peta Bq. This atmospheric krypton contamination stems from atom bomb tests of the past and from nuclear power plants as well as spent fuel reprocessing plants. The paper investigates the air-electric and air-chemical impact of Kr-85 on the atmosphere and makes a forecast of the future Kr-85 contamination. (DG)

  12. Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) data processing and atmospheric temperature and trace gas retrieval

    Science.gov (United States)

    Riese, M.; Spang, R.; Preusse, P.; Ern, M.; Jarisch, M.; Offermann, D.; Grossmann, K. U.

    1999-07-01

    The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment aboard the Shuttle Pallet Satellite (SPAS) was successfully flown in early November 1994 (STS 66) and in August 1997 (STS 85). This paper focuses on the first flight of the instrument, which was part of the Atmospheric Laboratory for Application and Science 3 (ATLAS 3) mission of NASA. During a free flying period of 7 days, limb scan measurements of atmospheric infrared emissions were performed in the 4 to 71 μm wavelength region. For improved horizontal resolution, three telescopes (viewing directions) were used that sensed the atmosphere simultaneously. Atmospheric pressures, temperatures, and volume mixing ratios of various trace gases were retrieved from the radiance data by using a fast onion-peeling retrieval technique. This paper gives an overview of the data system including the raw data processing and the temperature and trace gas profile retrieval. Examples of version 1 limb radiance data (level 1 product) and version 1 mixing ratios (level 2 product) of ozone, ClONO2, and CFC-11 are given. A number of important atmospheric transport processes can already be identified in the level 1 limb radiance data. Radiance data of the lower stratosphere (18 km) indicate strong upwelling in some equatorial regions, centered around the Amazon, Congo, and Indonesia. Respective data at the date line are consistent with convection patterns associated with El Niño. Very low CFC-11 mixing ratios occur inside the South Polar vortex and cause low radiance values in a spectral region sensitive to CFC-11 emissions. These low values are a result of considerable downward transport of CFC-11 poor air that occurred during the winter months. Limb radiance profiles and retrieved mixing ratio profiles of CFC-11 indicate downward transport over ˜5 km. The accuracy of the retrieved version 1 mixing ratios is rather different for the various trace gases. In the middle atmosphere the estimated

  13. Knudsen cell: Investigations about the uptake of important traces gases on ambient airborne mineral dust

    Science.gov (United States)

    Horn, Sabrina; Herrmann, Hartmut

    2013-04-01

    Mineral dust constitutes one of the largest mass fractions of natural aerosol. Its emission is estimated between 800 - 2000 Tg/a]. The dust is emitted through sand and dust storms in the arid regions of our planet, in particular by the great desserts such as the Sahara. The complex chemical composition of mineral dust is similar to crust material, because the dust is produced by soil erosion. The main components of mineral dust are SiO2 and Al2O3, whereas the active oxides (Fe2O3, TiO2) show some variety in content due to the dust source region. Mineral dust particles can be transported over several 1000 km and during its transport the surface can be changed by the uptake of water vapor and trace gases. On such modified surfaces homo- and heterogeneous reactions can occur. Trace gas uptakes play an important role in atmospheric chemistry as sinks or sources for several gaseous species. Hence, it is necessary to study these reactions. Among several experimental setups, the Knudsen cell is one of the promising tools to study reactive uptakes from the gas phase and the release of products formed by dust surface-mediated reactions. The Knudsen cell, implemented by Golden et al. in 1975, is a high vacuum flow reactor operating under molecular flow conditions, i.e., gas-wall collisions are highly preferred over gas-gas collisions. Despite several Knudsen cell studies examining the reaction between different traces gases and model dust surfaces constituted of not more than a few components, no measurements utilizing collected ambient mineral dust are done so far. For a better understanding of the chemistry on mineral dust surfaces gas uptake measurements will be done with a Knudsen cell. The first measurements are done with isopropanol on TiO2. Afterwards there are studies with different substrates like, Al2O3 (α- and γ-phase), FeO2, Arizona test dust, air collected mineral dust from the Cap Verde islands. In the beginning SO2, NO2 and HNO3 will be used.

  14. The CU Airborne MAX-DOAS instrument: vertical profiling of aerosol extinction and trace gases

    Directory of Open Access Journals (Sweden)

    S. Baidar

    2013-03-01

    Full Text Available The University of Colorado Airborne Multi-Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS instrument uses solar stray light to detect and quantify multiple trace gases, including nitrogen dioxide (NO2, glyoxal (CHOCHO, formaldehyde (HCHO, water vapor (H2O, nitrous acid (HONO, iodine monoxide (IO, bromine monoxide (BrO, and oxygen dimers (O4 at multiple wavelengths (absorption bands at 360, 477, 577, 632 nm simultaneously in the open atmosphere. The instrument is unique as it (1 features a motion compensation system that decouples the telescope field of view from aircraft movements in real time ( The instrument is described, and data from flights over California during the CalNex (California Research at the Nexus of Air Quality and Climate Change and CARES (Carbonaceous Aerosols and Radiative Effects Study air quality field campaigns is presented. Horizontal distributions of NO2 VCD (below the aircraft maps are sampled with typically 1 km resolution, and show good agreement with two ground-based MAX-DOAS instruments (slope = 0.95 ± 0.09, R2 = 0.86. As a case study vertical profiles of NO2, CHOCHO, HCHO, and H2O concentrations and aerosol extinction coefficients, ε, at 477 nm calculated from O4 measurements from a low approach at Brackett airfield inside the South Coast Air Basin (SCAB are presented. These profiles contain ~12 degrees of freedom (DOF over a 3.5 km altitude range, an independent information approximately every 250 m. The boundary layer NO2 concentration, and the integral aerosol extinction over height (aerosol optical depth, AOD agrees well with nearby ground-based in situ NO2 measurement, and AERONET station. The detection limits of NO2, CHOCHO, HCHO, H2O442, ϵ360, ϵ477 for 30 s integration time spectra recorded forward of the plane are 5 ppt, 3 ppt, 100 ppt, 42 ppm, 0.004 km−1, 0.002 km−1 in the free troposphere (FT, and 30 ppt, 16 ppt, 540 ppt, 252 ppm, 0.012 km−1, 0.006 km−1

  15. The airborne mass spectrometer AIMS - Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

    Science.gov (United States)

    Jurkat, Tina; Kaufmann, Stefan; Voigt, Christiane; Schäuble, Dominik; Jeßberger, Philipp; Ziereis, Helmut

    2016-04-01

    Understanding the role of climate-sensitive trace gas variabilities in the upper troposphere and lower stratosphere region (UTLS) and their impact on its radiative budget requires accurate measurements. The composition of the UTLS is governed by transport and chemistry of stratospheric and tropospheric constituents, such as chlorine, nitrogen oxide and sulfur compounds. The Atmospheric chemical Ionization Mass Spectrometer AIMS has been developed to accurately measure a set of these constituents on aircraft by means of chemical ionization. Here we present a setup using SF5- reagent ions for the simultaneous measurement of trace gas concentrations of HCl, HNO3 and SO2 in the pptv to ppmv (10-12 to 10-6 mol mol-1) range with in-flight and online calibration called AIMS-TG (Atmospheric chemical Ionization Mass Spectrometer for measurements of trace gases). Part 1 of this paper (Kaufmann et al., 2016) reports on the UTLS water vapor measurements with the AIMS-H2O configuration. The instrument can be flexibly switched between two configurations depending on the scientific objective of the mission. For AIMS-TG, a custom-made gas discharge ion source has been developed for generation of reagent ions that selectively react with HCl, HNO3, SO2 and HONO. HNO3 and HCl are routinely calibrated in-flight using permeation devices; SO2 is continuously calibrated during flight adding an isotopically labeled 34SO2 standard. In addition, we report on trace gas measurements of HONO, which is sensitive to the reaction with SF5-. The detection limit for the various trace gases is in the low 10 pptv range at a 1 s time resolution with an overall uncertainty of the measurement of the order of 20 %. AIMS has been integrated and successfully operated on the DLR research aircraft Falcon and HALO (High Altitude LOng range research aircraft). As an example, measurements conducted during the TACTS/ESMVal (Transport and Composition of the LMS/UT and Earth System Model Validation) mission with

  16. Remote sensing of atmospheric greenhouse gases: bridging spatial scales

    Science.gov (United States)

    Humpage, N.; Boesch, H.; Parker, R.; Hewson, W.; Sembhi, H.; Somkuti, P.; Webb, A.; Palmer, P. I.; Feng, L.

    2015-12-01

    Observed atmospheric variations of greenhouse gases (GHG) are determined by surface-atmosphere exchange, and atmospheric chemistry and transport. These processes occur over a wide spectrum of spatial and temporal scales. Confronting atmospheric transport models and ultimately improving the fidelity of surface flux estimates demands an integrated observing system that captures these scales. We will discuss using data the role of GHG remote sensing instruments and argue that our ability to deploy them from the ground and to fly them on satellite, aircraft, and unmanned airborne vehicles (UAV) mean that they represent the ideal technology to bridge the observed scales of variability. We will discuss a five-year record of global-scale column observations of CO2 and CH4 from the Japanese GOSAT satellite instrument that is available from University of Leicester as part of the ESA Climate Change Initiative. We will showcase new CO2 and CH4 column data that was collected by our shortwave infrared spectrometer GHOST oboard the NASA Global Hak during a regional survey over the eastern Pacific during early spring 2015, which included coincident overpasses from GOSAT and the NASA OCO-2. These data are being used to test atmospheric transport models over remote regions and to help validate satellite observations over the oceans. We will also discuss GHOST data collected on the UK Dornier 226 research aircraft to measure local-scale measurements over Leicester city centre, a major power plant, and downwind of a controlled Cumbrian heathland fire. Finally, we will report preliminary results from a new ground-based Fourier transform spectrometer station at Harwell (80 km west of London). We anticipate that this site will eventually join the TCCON network, which has been used to validation of satellite observations.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, P.R.; Meeker, K. (New Mexico Institute of Mining and Technology, Socorro (USA)); Finnegan, D. (Los Alamos National Lab., NM (USA))

    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.

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

    Science.gov (United States)

    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.

  2. Measurements of organic gases during aerosol formation events in the boreal forest atmosphere during QUEST

    Directory of Open Access Journals (Sweden)

    K. Sellegri

    2004-08-01

    Full Text Available Biogenic VOCs are important in the growth and possibly also in the formation of atmospheric aerosol particles. In this work, we present 10 min-time resolution measurements of organic trace gases at Hyytiälä, Finland during March 2002. The measurements were part of the project QUEST (Quantification of Aerosol Nucleation in the European Boundary Layer and took place during a two-week period when nucleation events occurred with various intensities nearly every day. Using a ground-based Chemical Ionization Mass Spectrometer (CIMS instrument, the following trace gases were detected: acetone, TMA, DMA, mass 68 amu (candidate=isoprene, monoterpenes, Methyl Vinyl Ketone (MVK and Methacrolein (MaCR, cis-3-hexenyl acetate and MonoTerpene Oxidation Products (MTOP. For all of them except for the amines, we present daily variations during different classes of event days, and non-event days. Isoprene, monoterpenes, MVK+MaCR, cis-3-hexenyl acetate and MTOP are found to show significant correlations with the condensational sink (CS, which indicates that a fraction of these compounds are participating to the growth of the nucleated particles and generally secondary organic aerosol formation. Moreover, the terpene oxidation products (TOP (MVK, MaCR and MTOP show a higher ratio to the CS on event days compared to non-event days, indicating that their abundance relative to the surface of aerosol available is higher on nucleation days.

  3. Convective Transport of Trace Gases in the Maritime Continent

    Science.gov (United States)

    Harris, Neil

    2015-04-01

    Passage of air through the Tropical Tropopause Layer (TTL) is the major route for troposphere to stratosphere transport. The UK CAST (Co-ordinated Airborne Studies in the Tropics) campaign took place in the West Pacific in January/February 2014. The field campaign was based mainly in Guam (13.5oN, 144.8oE) and had three components: CAST with the NERC FAAM BAe-146 research aircraft; the NASA ATTREX project based around the Global Hawk; the NCAR-led CONTRAST campaign based around the Gulfstream V (HIAPER) aircraft. Together, these aircraft were able to make detailed measurements of atmospheric structure and composition from the ocean surface to 20 km. The CAST team also made ground-based and ozonesonde measurements at the ARM site on Manus Island in Papua New Guinea during February 2014, and halocarbon measurements were made at several West Pacific sites. I will present an overview of the CAST campaign along with the results of high resolution global Unified Model studies and NAME (Numerical Atmospheric-dispersion Modelling Environment) trajectory calculations to look at the transport of air into the TTL in convective systems over the Maritime continent and West Pacific. I will focus on the transport of air from in and around the boundary layer and will assess the possible importance of natural and anthropogenic emissions for TTL composition.

  4. A Nanoparticulate Photocatalytic Filter for Removal of Trace Contaminant Gases Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Maintaining a healthy atmosphere in closed life support systems is essential for crew well being and success of space missions. Current trace contaminant control...

  5. A Nanoparticulate Photocatalytic Filter for Removal of Trace Contaminant Gases Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Maintaining a healthy atmosphere in closed life support systems is necessary for the well being of the crew and success of a space mission. Current trace...

  6. Relationship between epiphytic lichens, trace elements and gaseous atmospheric pollutants

    NARCIS (Netherlands)

    Dobben, van H.F.; Wamelink, G.W.W.; Braak, ter C.J.F.

    2001-01-01

    A study was conducted to determine the joint effect of gaseous atmospheric pollutants and trace elements on epiphytic lichens. We used our data to test the hypothesis that lichens are generally insensitive to toxic effects of trace elements, and can therefore be used as accumulator organisms to esti

  7. Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes

    Science.gov (United States)

    Megonigal, J. P.; Hines, M. E.; Visscher, P. T.

    2003-12-01

    Life evolved and flourished in the absence of molecular oxygen (O2). As the O2 content of the atmosphere rose to the present level of 21% beginning about two billion years ago, anaerobic metabolism was gradually supplanted by aerobic metabolism. Anaerobic environments have persisted on Earth despite the transformation to an oxidized state because of the combined influence of water and organic matter. Molecular oxygen diffuses about 104 times more slowly through water than air, and organic matter supports a large biotic O2 demand that consumes the supply faster than it is replaced by diffusion. Such conditions exist in wetlands, rivers, estuaries, coastal marine sediments, aquifers, anoxic water columns, sewage digesters, landfills, the intestinal tracts of animals, and the rumen of herbivores. Anaerobic microsites are also embedded in oxic environments such as upland soils and marine water columns. Appreciable rates of aerobic respiration are restricted to areas that are in direct contact with air or those inhabited by organisms that produce O2.Rising atmospheric O2 reduced the global area of anaerobic habitat, but enhanced the overall rate of anaerobic metabolism (at least on an area basis) by increasing the supply of electron donors and acceptors. Organic carbon production increased dramatically, as did oxidized forms of nitrogen, manganese, iron, sulfur, and many other elements. In contemporary anaerobic ecosystems, nearly all of the reducing power is derived from photosynthesis, and most of it eventually returns to O2, the most electronegative electron acceptor that is abundant. This photosynthetically driven redox gradient has been thoroughly exploited by aerobic and anaerobic microorganisms for metabolism. The same is true of hydrothermal vents (Tunnicliffe, 1992) and some deep subsurface environments ( Chapelle et al., 2002), where thermal energy is the ultimate source of the reducing power.Although anaerobic habitats are currently a small fraction of Earth

  8. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    OpenAIRE

    E. J. Morgan; J. V. Lavrič; Seifert, T.; T. Chicoine; Day, A; J. Gomez; Logan, R. (Robert); Sack, J.; Shuuya, T.; E. G. Uushona; K. Vincent; Schultz, U.; E.-G. Brunke; C. Labuschagne; Thompson, R. L.

    2015-01-01

    A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g....

  9. The CU Airborne MAX-DOAS instrument: vertical profiling of aerosol extinction and trace gases

    Science.gov (United States)

    Baidar, S.; Oetjen, H.; Coburn, S.; Dix, B.; Ortega, I.; Sinreich, R.; Volkamer, R.

    2013-03-01

    The University of Colorado Airborne Multi-Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument uses solar stray light to detect and quantify multiple trace gases, including nitrogen dioxide (NO2), glyoxal (CHOCHO), formaldehyde (HCHO), water vapor (H2O), nitrous acid (HONO), iodine monoxide (IO), bromine monoxide (BrO), and oxygen dimers (O4) at multiple wavelengths (absorption bands at 360, 477, 577, 632 nm) simultaneously in the open atmosphere. The instrument is unique as it (1) features a motion compensation system that decouples the telescope field of view from aircraft movements in real time (detector system. Sets of solar stray light spectra collected from nadir to zenith scans provide some vertical profile information within 2 km above and below the aircraft altitude, and the vertical column density (VCD) below the aircraft is measured in nadir view. Maximum information about vertical profiles is derived simultaneously for trace gas concentrations and aerosol extinction coefficients over similar spatial scales and with a vertical resolution of typically 250 m during aircraft ascent/descent. The instrument is described, and data from flights over California during the CalNex (California Research at the Nexus of Air Quality and Climate Change) and CARES (Carbonaceous Aerosols and Radiative Effects Study) air quality field campaigns is presented. Horizontal distributions of NO2 VCD (below the aircraft) maps are sampled with typically 1 km resolution, and show good agreement with two ground-based MAX-DOAS instruments (slope = 0.95 ± 0.09, R2 = 0.86). As a case study vertical profiles of NO2, CHOCHO, HCHO, and H2O concentrations and aerosol extinction coefficients, ɛ, at 477 nm calculated from O4 measurements from a low approach at Brackett airfield inside the South Coast Air Basin (SCAB) are presented. These profiles contain ~12 degrees of freedom (DOF) over a 3.5 km altitude range, an independent information approximately every 250 m

  10. 1988 Pilot Institute on Global Change on trace gases and the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Remote Sensing of Stratospheric Trace Gases by TELIS

    Science.gov (United States)

    Xu, Jian; Schreier, Franz; Doicu, Adrian; Birk, Manfred; Wagner, Georg; Trautmann, Thomas

    2015-06-01

    TELIS (TErahertz and submillimeter LImb Sounder) is a balloon-borne cryogenic heterodyne spectrometer with two far infrared and submillimeter channels (1.8 THz and 480-650 GHz developed by DLR and SRON, respectively). The instrument was designed to investigate atmospheric chemistry and dynamics with a focus on the stratosphere. Between 2009 and 2011, TELIS participated in three winter campaigns in Kiruna, Sweden. The recent campaign took place in 2014 over Timmins, Canada. During previous campaigns, TELIS shared a stratospheric balloon gondola with the balloon version of MIPAS (MIPAS-B) and mini-DOAS. The primary scientific goal of these campaigns has been to monitor the time-dependent chemistry of chlorine and bromine, and to achieve the closure of chemical families inside the polar vortex. In this work, we present retrieved profiles of ozone (O3), hydrogen chlorine (HCl), carbon monoxide (CO), and hydroxyl radical (OH) obtained by the 1.8 THz channel from the polar winter flights during 2009-2011. Furthermore, the corresponding retrieval algorithm is briefly described. The quality of the retrieval products is analyzed in a quantitative manner including: error characterization, internal comparisons of the two different channels, and external comparisons with coincident spaceborne observations. The errors due to the instrument parameters and pressure dominate in the upper troposphere and lower stratosphere, while the errors at higher altitudes are mainly due to the spectroscopic parameters and the radiometric calibration. The comparisons with other limb sounders help us to assess the measurement capabilities and instrument characteristics of TELIS, thereby establishing the instrument as a valuable tool to study the chemical interactions in the stratosphere.

  12. Atmospheric trace gas measurements in the tropics

    OpenAIRE

    Petersen, Anna Katinka

    2009-01-01

    Fourier Transform Infrared (FTIR) spectrometry has been used for ground-based solar absorption, laboratory and flux measurements, to study the atmospheric composition, as well as physical and chemical processes in the atmosphere.The solar absorption FTIR measurements have been performed in Paramaribo, Suriname (5.8 N, 55.2 W) between September 2004 and November 2007 and represent the first remote sensing measurements in the inner tropics over severalyears. These measurements are of great impo...

  13. Azimuthal variability of trace gases and aerosols measured during the MADCAT campaign in summer 2013 in Mainz, Germany

    Science.gov (United States)

    Remmers, Julia; Wagner, Thomas

    2015-04-01

    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. MADCAT (Multi-Axis DOAS Comparison campaign for Aerosols and Trace gases) took place in summer 2013 in Mainz, a city in the Rhine-Main region close to Frankfurt, with high population density and many industrial complexes. The main focus of this campaign was on the comparison of the results from the different instruments. Therefore 16 MAX-DOAS instruments from 10 different institutes were operated on the roof of the MPI for Chemistry. In standard operation mode, vertical scans at one or several selected azimuth viewing direction were performed. In addition, 6 instruments scanned the sky also in azimuth direction every two hours. These scans were performed under a low elevation angle (2°) to capture the pollution close to the ground. A comparison of the trace gas columns derived from these instruments will be shown for NO2 and O4, the latter is used to retrieve information about aerosols. The observed variation for different azimuth angles does not only reflect a gradient in the trace gas, but also differences in the light path length, which is affected by sun and viewing geometry as well as aerosols. To distinguish between the different effects comparisons with radiative transfer models are performed. The results of the azimuth scans are also compared to car-DOAS measurements around Mainz, which were conducted at least twice a day.

  14. Quantum cascade laser-based spectrometer for high sensitive measurements of trace gases in air

    Institute of Scientific and Technical Information of China (English)

    Yuanyuan Tang; Wenqing Liu; Ruifeng Kan; Yujun Zhang; Dong Chen; Shuai Zhang; Jun Ruan

    2012-01-01

    A quantum cascade (QC) laser-based spectrometer is developed to measure trace gases in air.The proposed spectrometer is tested for N2O,and the results presented in this letter.This system takes advantage of recent technology in QC lasers by utilizing intra-pulse scan spectroscopy,which allows high sensitive measurement.Without calibration gases,the gas concentration can be calculated with scan integration and the corresponding values from the HITRAN04 database.By analyzing the Allan variance,a detection limit of 2 ppb is obtained.Continuous measurement of N2O sampled from ambient air shows the applicability of the proposed system for the field measurements of gases of environmental concern.

  15. Different wavelength evaluation ranges in the retrieval of trace gases with DOAS at the example of BrO

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Leif; Lampel, Johannes; Platt, Ulrich [Institut fuer Umweltphysik, Universitaet Heidelberg (Germany); Sihler, Holger [Institut fuer Umweltphysik, Universitaet Heidelberg (Germany); MPI fuer Chemie, Mainz (Germany); Wagner, Thomas [MPI fuer Chemie, Mainz (Germany)

    2010-07-01

    Optical remote sensing via scattered sunlight differential optical absorption Spectroscopy (DOAS) is routinely used to determine various trace gases in the atmosphere. Different applications and platforms (e.g. DOAS of volcanic plumes, Satellite measurements, Zenith DOAS or Max-DOAS) differ in measurement conditions, cross correlations of absorptions of different trace gases and their respective concentrations. Here, we present a method to determine the optimal evaluation range at the example of bromine oxide (BrO). With strongest absorption features of BrO between 315nm - 360nm, its retrieval results can depend on cross correlations with strong absorber like Ozone (O{sub 3}) or sulfur dioxide (SO{sub 2}). Whereas O{sub 3} influences especially Satellite and stratospheric measurements, SO{sub 2} cannot be neglected in the case of high volcanic gas emissions. Absorption features of both species are most pronounced at low wavelengths, but their diminished influence at higher wavelength ranges competes with a higher detection limit of BrO. The study is performed with artificial spectra and the results are compared with retrievals from real spectra of volcanic plumes, satellite and marine Max-DOAS measurements.

  16. 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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Tracing organic gaseous pollutants in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Rymen, T.A.A.

    1979-01-01

    Methods of tracing various air pollutants, including low molecular weight hydrocarbons, chlorinated hydrocarbons, and aromatics, are discussed. Gas chromatography and flame ionization, or electron capture detection were used to detect the pollutants in ambient air, depending on which method was more sensitive for the pollutant in question. Analysis, calibration procedures, and sampling techniques (both automatic field operation and discontinuous laboratory control), were studied for samples collected near a vinyl chloride plant, and in an area with intensive paint industry. The combination of gas-solid or gas-liquid chromatography with a highly sensitive detector offers a versatile analytic method of measuring organic air pollutants. (6 diagrams, 6 graphs, 16 references, 9 tables)

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

    Science.gov (United States)

    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

  1. Highly resolved observations of trace gases in the lowermost stratosphere and upper troposphere from the Spurt project: an overview

    Directory of Open Access Journals (Sweden)

    A. Engel

    2006-01-01

    Full Text Available During SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region we performed measurements of a wide range of trace gases with different lifetimes and sink/source characteristics in the northern hemispheric upper troposphere (UT and lowermost stratosphere (LMS. A large number of in-situ instruments were deployed on board a Learjet 35A, flying at altitudes up to 13.7 km, at times reaching to nearly 380 K potential temperature. Eight measurement campaigns (consisting of a total of 36 flights, distributed over all seasons and typically covering latitudes between 35° N and 75° N in the European longitude sector (10° W–20° E, were performed. Here we present an overview of the project, describing the instrumentation, the encountered meteorological situations during the campaigns and the data set available from SPURT. Measurements were obtained for N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O. We illustrate the strength of this new data set by showing mean distributions of the mixing ratios of selected trace gases, using a potential temperature-equivalent latitude coordinate system. The observations reveal that the LMS is most stratospheric in character during spring, with the highest mixing ratios of O3 and NOy and the lowest mixing ratios of N2O and SF6. The lowest mixing ratios of NOy and O3 are observed during autumn, together with the highest mixing ratios of N2O and SF6 indicating a strong tropospheric influence. For H2O, however, the maximum concentrations in the LMS are found during summer, suggesting unique (temperature- and convection-controlled conditions for this molecule during transport across the tropopause. The SPURT data set is presently the most accurate and complete data set for many trace species in the LMS, and its main value is the simultaneous measurement of a suite of trace gases having different lifetimes and physical-chemical histories. It is thus very well suited for

  2. Assessment of TRACE Condensation Model Against Reflux Condensation Tests with Noncondensable Gases

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Won; Cheong, Ae Ju; Shin, Andong; Suh, Nam Duk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    The TRACE is the latest in a series of advanced, best-estimated reactor systems code developed by U.S. Nuclear Regulatory Commission for analyzing transient and steady-state neutronic-thermal-hydraulic behavior in light water reactors. This special model is expected to replace the default model in a future code release after sufficient testing has been completed. This study assesses the special condensation model of TRACE 5.0-patch4 against the counter-current flow configuration. For this purpose, the predicted results of special model are compared to the experimental and to those of default model. The KAST reflux condensation test with NC gases are used in this assessment. We assessed the special model for film condensation of TRACE 5.0-patch4 against the data of the reflux condensation test in the presence of NC gases. The special condensation model of TRACE provides a reasonable estimate of HTC with good agreement at the low inlet steam flow rate.

  3. Vertical profiling of aerosol particles and trace gases over the central Arctic Ocean during summer

    Directory of Open Access Journals (Sweden)

    P. Kupiszewski

    2013-04-01

    Full Text Available Unique measurements of vertical size resolved aerosol particle concentrations, trace gas concentrations and meteorological data were obtained during the Arctic Summer Cloud Ocean Study (ASCOS, http://www.ascos.se, an International Polar Year project aimed at establishing the processes responsible for formation and evolution of low-level clouds over the high Arctic summer pack ice. The experiment was conducted from onboard the Swedish icebreaker Oden, and provided both ship- and helicopter-based measurements. This study focuses on the vertical helicopter profiles and onboard measurements obtained during a three-week period when Oden was anchored to a drifting ice floe, and sheds light on the characteristics of Arctic aerosol particles and their distribution throughout the lower atmosphere. Distinct differences in aerosol particle characteristics within defined atmospheric layers are identified. Near the surface (lowermost couple hundred meters, transport from the marginal ice zone (MIZ, if sufficiently short (less than ca. 2 days, condensational growth and cloud-processing develop the aerosol population. During two of the four representative periods defined in this study, such influence is shown. At altitudes above about 1 km, long-range transport occurs frequently. However, only infrequently does large-scale subsidence descend such air masses to become entrained into the mixed layer in the high Arctic, and therefore they are unlikely to directly influence low-level stratiform cloud formation. Nonetheless, long-range transport plumes can influence the radiative balance of the PBL by influencing formation and evolution of higher clouds, as well as through precipitation transport of particles downwards. New particle formation was occasionally observed, particularly in the near-surface layer. We hypothesize that the origin of these ultrafine particles can be from biological processes, both primary and secondary, within the open leads between the

  4. One year observations of atmospheric reactive gases (O3, CO, NOx, SO2) at Jang Bogo base in Terra Nova Bay, Antarctica

    Science.gov (United States)

    Siek Rhee, Tae; Seo, Sora

    2016-04-01

    Antarctica is a remote area surrounded by the Southern Ocean and far from the influence of human activities, giving us unique opportunity to investigate the background variation of trace gases which are sensitive to the human activities. Korean Antarctic base, Jang Bogo, was established as a unique permanent overwintering base in Terra Nova Bay in February, 2014. One year later, we installed a package of instruments to monitor atmospheric trace gases at the base, which includes long-lived greenhouse gases, CO2, CH4, and N2O, and reactive gases, O3, CO, NOx, and SO2. The atmospheric chemistry observatory, where these scientific instruments were installed, is located ca. 1 km far from the main building and power plant, minimizing the influence of pollution that may come from the operation of the base. Here we focus on the reactive gases measured in-situ at the base; O3 displays a typical seasonal variation with high in winter and low in summer with seasonal amplitude of ~18 ppb, CO was high in September at ~56 ppb, probably implying the invasion of lower latitude air mass with biomass burning, and low in late summer due to photochemical oxidation. NO did not show clear seasonal variation, but SO2 reveals larger values in summer than in winter. We will discuss potential atmospheric processes behind these first observations of reactive gases in Terra Nova Bay, Antarctica.

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

    Science.gov (United States)

    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.

  6. The star reference system of MIPAS-B2. Line of sight determination of a balloonborne spectrometer for remote sensing of atmospheric trace gases; Das Sternreferenzsystem von MIPAS-B2. Sichtlinien-Bestimmung fuer ein ballongetragenes Spektrometer zur Fernerkundung atmosphaerischer Spurengase

    Energy Technology Data Exchange (ETDEWEB)

    Maucher, G.

    1999-07-01

    The spectrometer MIPAS-B (Michelson Interferometer for Passive Atmospheric Sounding - Balloonborne Version) is a limb emission sounder in the mid infrared spectral range, adapted to a stratospheric balloon gondola. Its task is remote sensing of vertical profiles of several trace gases in the context of environmental research. The thesis discusses the effects of errors in the stabilisation and knowledge of the line of sight on the measurements. A variation in the line of sight affects the instrumental line shape of recorded spectra and broadens - through the coaddition of spectra - the resulting field of view. An insufficient knowledge reduces the accuracy of the retrieved vertical profiles. The new pointing system is described. The hard- and software components needed for the star reference system are shown in detail. The central component is a CCD-camera taking pictures of a part of the night sky for every interferogram. The light of the stars is superimposed onto the light of marks representing the optical axies without masking the infrared beam. Through this, the thermal warping of the optics due to the changes in temperature during flight can be determined. After data reduction star images are sent to ground by telemetry. Algorithms for subpixel resolution, calculation of star positions and star pattern recognition have been developed. The results derived with the star reference system and the performance of the pointing system are analysed. The error sources are discussed. (orig./SR) [German] Das Fourierspektrometer MIPAS-B (Michelson Interferometer fuer passive atmosphaerische Sondierung - Ballonversion) erfasst von einem Stratosphaerenballon aus Emissionsspektren im infraroten Spektralbereich mit der Methode der Horizontsondierung. Daraus werden Hoehenprofile einer groesseren Anzahl umweltrelevanter Spurengase im selben Luftvolumen gewonnen. Im ersten Teil der Arbeit werden die Auswirkungen von Stabilisierungsfehlern diskutiert, die sowohl das Apparateprofil

  7. Atmospheric trace chemistry in the American humid tropics

    OpenAIRE

    Lodge Jr., James P.; Machado, P. A.; Pate, J. B.; Sheesley, D. C.; Wartburg, A. F.

    2011-01-01

    Numerous attempts have been made to define global mean concentrations of trace substances and to incorporate these into global models of net source and sink strengths of the various natural and anthropogenic atmospheric contaminants.DOI: 10.1111/j.2153-3490.1974.tb01973.x

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

    Science.gov (United States)

    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.

  9. The ray-tracing mapping operator in an asymmetric atmosphere

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In a spherically symmetric atmosphere, the refractive index profile is retrieved from bending angle measurements through Abel integral transform. As horizontal refractivity inhomogeneity becomes significant in the moist low atmosphere, the error in refractivity profile obtained from Abel inversion reaches about 10%. One way to avoid this error is to directly assimilate bending angle profile into numerical weather models. This paper discusses the 2D ray-tracing mapping operator for bending angle in an asymmetric atmosphere. Through simulating computations, the retrieval error of the refractivity in horizontal inhomogeneity is assessed. The step length of 4 rank Runge-Kutta method is also tested.

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

    Science.gov (United States)

    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

  11. Measurements of reactive trace gases in the marine boundary layer using novel DOAS methods

    OpenAIRE

    Lampel, Johannes

    2014-01-01

    Reactive Halogen Species (RHS) can have a large impact on tropospheric chemistry. Already small concentrations in the marine boundary layer (MBL) can have a significant impact on the global budget of ozone and other trace-gases. Shipborne measurements of BrO and IO were conducted in the MBL from 70°S to 90°N to obtain a global picture of their distribution over several years. A focus were upwelling regions, which can provide large amounts of precursor substances for RHS in the MBL, of which s...

  12. The role of atmospheric gases in global warming

    OpenAIRE

    Tuckett, R. P.

    2009-01-01

    The purpose of this opening chapter of this book is to explain in simple terms what the greenhouse effect is, what its origins are, and what the properties of greenhouse gases are. I will restrict this chapter to an explanation of the physical chemistry of greenhouse gases and the greenhouse effect, and not delve too much into the politics of ‘what should or should not be done’. However, one simple message to convey at the onset is that the greenhouse effect is not just about concentration le...

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

    Directory of Open Access Journals (Sweden)

    S. K. Akagi

    2011-08-01

    Full Text Available 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

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

    Directory of Open Access Journals (Sweden)

    C. E. Wold

    2012-02-01

    Full Text Available 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

  15. Atmospheric contamination: A possible source for heavy noble gases in basalts from Loihi Seamount, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, D.B.; Honda, M.; McDougall, I. (Australian National Univ., Canberra (Australia))

    1990-05-01

    Re-evaluation of available noble gas data obtained from the glassy rims of basalts from Loihi Seamount, Hawaii, shows that contamination of magmas prior to eruption, by addition of a significant component of atmosphere-derived heavy noble gases, is a plausible explanation for the observed atmosphere-like isotopic compositions of Ne, Ar, Kr, and Xe. The most likely source for the atmospheric component is interaction of the magma with seawater carrying dissolved atmosphere-derived noble gases. The possibility of a significant atmospheric component in Loihi samples suggests that the observed heavy noble gas compositions may not be representative of the mantle source of Loihi magmas. While leaving open the question of the noble gas composition in the source region, atmospheric contamination provides a valid alternative to the interpretation that the mantle source region of Loihi magmas has an atmosphere-like noble gas composition.

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

    Science.gov (United States)

    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.

  17. Removal of Titan's Atmospheric Noble Gases by their Sequestration in Surface Clathrates

    CERN Document Server

    Mousis, Olivier; Picaud, Sylvain; Cordier, Daniel; Waite, J Hunter; Jr.,; Mandt, Kathleen E

    2011-01-01

    A striking feature of the atmosphere of Titan is that no heavy noble gases other than argon were detected by the Gas Chromatograph Mass Spectrometer (GCMS) aboard the Huygens probe during its descent to Titan's surface in January 2005. Here we provide an explanation of the mysterious absence or rarity of these noble gases in Titan's atmosphere: the thermodynamic conditions prevailing at the surface-atmosphere interface of the satellite allow the formation of multiple guest clathrates that preferentially store some species, including all heavy noble gases, over others. The clean water ice needed for formation of these clathrates could be delivered by successive episodes of cryovolcanic lavas that have been hypothesized to regularly cover the surface of Titan. The formation of clathrates in the porous lavas and their propensity for trapping Ar, Kr and Xe would progressively remove these species from the atmosphere of Titan over its history. In some circumstances, a global clathrate crust with an average thickne...

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

    Science.gov (United States)

    Cess, R.; Owen, T.

    1973-01-01

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

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

    Science.gov (United States)

    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.

  20. Sorption of atmospheric gases by bulk lithium metal

    Science.gov (United States)

    Hart, C. A.; Skinner, C. H.; Capece, A. M.; Koel, B. E.

    2016-01-01

    Lithium conditioning of plasma facing components has enhanced the performance of several fusion devices. Elemental lithium will react with air during maintenance activities and with residual gases (H2O, CO, CO2) in the vacuum vessel during operations. We have used a mass balance (microgram sensitivity) to measure the mass gain of lithium samples during exposure of a ˜1 cm2 surface to ambient and dry synthetic air. For ambient air, we found an initial mass gain of several mg/h declining to less than 1 mg/h after an hour and decreasing by an order of magnitude after 24 h. A 9 mg sample achieved a final mass gain corresponding to complete conversion to Li2CO3 after 5 days. Exposure to dry air resulted in a 30 times lower initial rate of mass gain. The results have implications for the chemical state of lithium plasma facing surfaces and for safe handling of lithium coated components.

  1. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    Directory of Open Access Journals (Sweden)

    E. J. Morgan

    2015-02-01

    Full Text Available A new coastal background site has been established for observations of greenhouse gases (GHGs in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA. Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS; nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS. Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a working tank.

  2. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    Science.gov (United States)

    Morgan, E. J.; Lavrič, J. V.; Seifert, T.; Chicoine, T.; Day, A.; Gomez, J.; Logan, R.; Sack, J.; Shuuya, T.; Uushona, E. G.; Vincent, K.; Schultz, U.; Brunke, E.-G.; Labuschagne, C.; Thompson, R. L.; Schmidt, S.; Manning, A. C.; Heimann, M.

    2015-02-01

    A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a working tank.

  3. Miniaturized Hollow-Waveguide Gas Correlation Radiometer (GCR) for Trace Gas Detection in the Martian Atmosphere

    Science.gov (United States)

    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.

  4. Trace elements in the atmosphere over South Africa

    International Nuclear Information System (INIS)

    Natural sources of trace elements in the atmosphere are suspended soil particles, the evaporation of sea spray and smoke from veld fires. In urban and industrialised areas the main sources are fossil-fuel power plants, metallurgical smelters, blast furnaces, incinerators, automobiles, fossil-fueled locomotives and open fires in the Black townships. Often a source can be recognised by the relative concentrations of particular trace elements. A monitoring programme was established in 1974 by the Air Pollution Research Group of the CSIR and the Isotope and Radiation Division of the Atomic Energy Board in order to study the levels of trace elements in urban areas such as Johannesburg, Cape Town, and Durban, to measure the effects of industrialisation on trace elements levels in developing areas such as Richards Bay and Saldanha Bay and also to determine baseline values in rural areas. Extremely sensitive analytical techniques, e.g. neutron activation and atomic absorption were used for the analyses of filter samples. Methods of sampling and analysis are discussed and the preliminary results of this programme are presented

  5. Possible cometary origin of heavy noble gases in the atmospheres of Venus, earth, and Mars

    Science.gov (United States)

    Owen, Tobias; Bar-Nun, Akiva; Kleinfeld, Idit

    1992-01-01

    Due consideration of the probable history of the Martian atmosphere, as well as noble-gas data from the Mars-derived SNC meteorites and from laboratory tests on the trapping of noble gases in ice, are the bases of the presently hypothesized domination of noble gases in the atmospheres of all terrestrial planets by a mixture of internal components and a contribution from comets. If verified, this hypothesis would underscore the significance of impacts for these planets' volatile inventories. The sizes of the hypothesized comets are of the order of 120 km for Venus and only 80 km for that which struck the earth.

  6. Sorption of atmospheric gases by bulk lithium metal

    Energy Technology Data Exchange (ETDEWEB)

    Hart, C. A. [Univ. of Maryland, College Park, MD (United States). Dept. of Physics; Skinner, C. H. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Capece, A. M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Koel, B. E. [Princeton Univ., NJ (United States). Dept. of Chemical and Biological Engineering

    2016-01-01

    Lithium conditioning of plasma facing components has enhanced the performance of several fusion devices. Elemental lithium will react with air during maintenance activities and with residual gases (H2O, CO, CO2) in the vacuum vessel during operations. We have used a mass balance (microgram sensitivity) to measure the mass gain of lithium samples during exposure of a similar to 1 cm(2) surface to ambient and dry synthetic air. For ambient air, we found an initial mass gain of several mg/h declining to less than 1 mg/h after an hour and decreasing by an order of magnitude after 24 h. A 9 mg sample achieved a final mass gain corresponding to complete conversion to Li2CO3 after 5 days. Exposure to dry air resulted in a 30 times lower initial rate of mass gain. The results have implications for the chemical state of lithium plasma facing surfaces and for safe handling of lithium coated components. (C) 2015 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  8. The CU Airborne MAX-DOAS instrument: ground based validation, and vertical profiling of aerosol extinction and trace gases

    Directory of Open Access Journals (Sweden)

    S. Baidar

    2012-09-01

    Full Text Available The University of Colorado Airborne Multi Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS instrument uses solar stray light remote sensing to detect and quantify multiple trace gases, including nitrogen dioxide (NO2, glyoxal (CHOCHO, formaldehyde (HCHO, water vapor (H2O, nitrous acid (HONO, iodine monoxide (IO, bromine monoxide (BrO, and oxygen dimers (O4 at multiple wavelengths (360 nm, 477 nm, 577 nm and 632 nm simultaneously, and sensitively in the open atmosphere. The instrument is unique, in that it presents the first systematic implementation of MAX-DOAS on research aircraft, i.e. (1 includes measurements of solar stray light photons from nadir, zenith, and multiple elevation angles forward and below the plane by the same spectrometer/detector system, and (2 features a motion compensation system that decouples the telescope field of view (FOV from aircraft movements in real-time (< 0.35° accuracy. Sets of solar stray light spectra collected from nadir to zenith scans provide some vertical profile information within 2 km above and below the aircraft altitude, and the vertical column density (VCD below the aircraft is measured in nadir view. Maximum information about vertical profiles is derived simultaneously for trace gas concentrations and aerosol extinction coefficients over similar spatial scales and with a vertical resolution of typically 250 m during aircraft ascent/descent.

    The instrument is described, and data from flights over California during the CalNex and CARES air quality field campaigns is presented. Horizontal distributions of NO2 VCDs (below the aircraft maps are sampled with typically 1 km resolution, and show good agreement with two ground based CU MAX-DOAS instruments (slope 0.95 ± 0.09, R2 = 0.86. As a case study vertical profiles of NO2, CHOCHO, HCHO, and H2O mixing ratios and aerosol extinction coefficients

  9. Soil greenhouse gases emissions reduce the benefit of mangrove plant to mitigating atmospheric warming effect

    OpenAIRE

    Chen, Guangcheng; Chen, Bin; Yu, Dan; Ye, Yong; Tam, Nora F. Y.; Chen, Shunyang

    2016-01-01

    Mangrove soils have been recognized as sources of atmospheric greenhouse gases but the atmospheric fluxes are poorly characterized, and their adverse warming effect has scarcely been considered with respect to the role of mangrove wetlands in mitigating global warming. The present study balanced the warming effect of soil greenhouse gas emissions with plant carbon dioxide (CO2) sequestration rate in a highly productive mangrove wetland in South China to assess the role of mangrove wetland in ...

  10. Continuous Measurements of Greenhouse Gases and Atmospheric Oxygen in the Namib Desert

    OpenAIRE

    Morgan, Eric James

    2015-01-01

    A new, near-coastal background site was established for observations of greenhouse gases (GHGs) and atmospheric oxygen in the central Namib Desert near Gobabeb, Namibia. The location of the site was chosen to provide observations in a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from...

  11. Separation and Conditioning of Mars Atmospheric Gases via TSA

    Science.gov (United States)

    Finn, John E.; Luna, Bernadette (Technical Monitor)

    2000-01-01

    Space and planetary exploration almost always presents interesting and unusual engineering challenges. Separations engineering for chemical processes that are critical to humans working in space is no exception. The challenges are becoming clearer as we make the transition from concepts and planning to hardware development, and as we understand better the constraints and environments in which the processes must perform. The coming decade will see a robotic Mars exploration program that has recovered from recent setbacks and is building a knowledge and technology base for human exploration. One of the missions will carry a small chemical pilot plant for demonstrating the manufacture of rocket propellants and life support consumables from the low-pressure (0.01 atm) Martian atmosphere. By manufacturing and storing the fuel and consumables needed for human-return missions in situ, launch mass and landed mass are reduced by tons and missions become far less expensive. The front-end to the pilot plant is a solid-state atmosphere acquisition and separation unit based on temperature-swing adsorption (TSA). The unit produces purified and pressurized (to 1.0 atm) carbon dioxide to downstream reactors that will make methane and oxygen. The unit also produces a nitrogen-argon mixture as a valuable by-product for life support, inflatable structures, and propellant pressurization. With nighttime temperatures falling to -100 degrees C, power availability restricted to a few watts, and flawless operation critical to success, the dusty Martian surface is a difficult place to operate a remote plant. This talk will focus on how this TSA separation process is designed and implemented for this application, and how it might be used in the more distant future for human exploration.

  12. THE INTEGRITY OF THE ICE RECORD OF GREENHOUSE GASES WITH A SPECIAL FOCUS ON ATMOSPHERIC CO2

    Directory of Open Access Journals (Sweden)

    Dominique Raynaud

    2012-01-01

    Full Text Available Over the last 25 years, the ice core record has provided a unique and precious archive of past changes in three important greenhouse gases: carbon dioxide CO2, methane CH4 and nitrous oxide N2O. Recovering the Vostok ice core has played a major role, being the first ice record showing the variations of CO2 and CH4 during a full glacial-interglacial cycle, and a few years later being extended to three more cycles. This information, by revealing the tight coupling between climate and carbon cycle during the last glacial-interglacial cycles, has become a benchmark against which climate and carbon cycle models can be tested. The purpose of the present work is to discuss the degree of integrity of the ice core record of greenhouse gases and to assess to which degree it provides an accurate reconstruction of the past atmospheric changes. The various processes potentially affecting the integrity of the record are discussed. They include the interactions of trace gases with precipitation or firn grains, the effect of summer-melting at the surface of the ice sheet, the diffusion and the gravitational setting of gases in the open spaces of the firn, the physical, chemical and biological interactions between the air trapped and the ice matrix, the role of the transformation of air bubbles into air hydrates with depth in the ice column. Providing to select an appropriate sampling site, to take specific precautions during storage and transportation of the ice cores, and to select ice of good quality, the ice core record of initial atmospheric gases is hardly affected by the processes listed above. Such conclusion is strongly supported by the remarkable agreement of global signals like CO2 or CH4 measured in different cores taken at different locations. Finally, I bring back here the history of how the ice core record of atmospheric CO2 has been obtained, from the pioneering times to today, and summarize the main conclusions reached in terms of climate

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

    Energy Technology Data Exchange (ETDEWEB)

    Davidovits, P. (Boston Coll., Chestnut Hill, MA (United States). Dept. of Chemistry); Worsnop, D.W.; Zahniser, M.S.; Kolb, C.E. (Aerodyne Research, Inc., Billerica, MA (United States). 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.

  14. Incorporation of Solar Noble Gases from a Nebula-Derived Atmosphere During Magma Ocean Cooling

    Science.gov (United States)

    Woolum, D. S.; Cassen, P.; Wasserburg, G. J.; Porcelli, D.; DeVincenzi, Donald (Technical Monitor)

    1998-01-01

    The presence of solar noble gases in the deep interior of the Earth is inferred from the Ne isotopic compositions of MORB (Mid-ocean Ridge Basalts) and OIB (Oceanic Island Basalt); Ar data may also consistent with a solar component in the deep mantle. Models of the transport and distribution of noble gases in the earth's mantle allow for the presence of solar Ar/Ne and Xe/Ne ratios and permit the calculation of lower mantle noble gas concentrations. These mantle data and models also indicate that the Earth suffered early (0.7 to 2 x 10(exp 8) yr) and large (greater than 99 percent) losses of noble gases from the interior, a result previously concluded for atmospheric Xe. We have pursued the suggestion that solar noble gases were incorporated in the forming Earth from a massive, nebula-derived atmosphere which promoted large-scale melting, so that gases from this atmosphere dissolved in the magma ocean and were mixed downward. Models of a primitive atmosphere captured from the solar nebula and supported by accretion luminosity indicate that pressures at the Earth's surface were adequate (and largely more than the required 100 Atm) to dissolve sufficient gases. We have calculated the coupled evolution of the magma ocean and the overlying atmosphere under conditions corresponding to the cessation (or severe attenuation) of the sustaining accretion luminosity, prior to the complete removal of the solar nebula. Such a condition was likely to obtain, for instance, when most of the unaccumulated mass resided in large bodies which were only sporadically accreted. The luminosity supporting the atmosphere is then that provided by the cooling Earth, consideration of which sets a lower limit to the time required to solidify the mantle and terminate the incorporation of atmospheric gases within it. In our initial calculations, we have fixed the nebula temperature at To = 300K, a value likely to be appropriate for nebular temperatures at lAU in the early planet-building epoch

  15. A Fourier transform infrared trace gas and isotope analyser for atmospheric applications

    Directory of Open Access Journals (Sweden)

    D. W. T. Griffith

    2012-10-01

    Full Text Available Concern in recent decades about human impacts on Earth's climate has led to the need for improved and expanded measurement capabilities of greenhouse gases in the atmosphere. In this paper we describe in detail an in situ trace gas analyser based on Fourier Transform Infrared (FTIR spectroscopy that is capable of simultaneous and continuous measurements of carbon dioxide (CO2, methane (CH4, carbon monoxide (CO, nitrous oxide (N2O and 13C in CO2 in air with high precision. High accuracy is established by reference to measurements of standard reference gases. Stable water isotopes can also be measured in undried airstreams. The analyser is automated and allows unattended operation with minimal operator intervention. Precision and accuracy meet and exceed the compatibility targets set by the World Meteorological Organisation – Global Atmosphere Watch for baseline measurements in the unpolluted troposphere for all species except 13C in CO2.

    The analyser is mobile and well suited to fixed sites, tower measurements, mobile platforms and campaign-based measurements. The isotopic specificity of the optically-based technique and analysis allows its application in isotopic tracer experiments, for example in tracing variations of 13C in CO2 and 15N in N2O. We review a number of applications illustrating use of the analyser in clean air monitoring, micrometeorological flux and tower measurements, mobile measurements on a train, and soil flux chamber measurements.

  16. A New Laser Based Approach for Measuring Atmospheric Greenhouse Gases

    Directory of Open Access Journals (Sweden)

    Jeremy Dobler

    2013-11-01

    Full Text Available In 2012, we developed a proof-of-concept system for a new open-path laser absorption spectrometer concept for measuring atmospheric CO2. The measurement approach utilizes high-reliability all-fiber-based, continuous-wave laser technology, along with a unique all-digital lock-in amplifier method that, together, enables simultaneous transmission and reception of multiple fixed wavelengths of light. This new technique, which utilizes very little transmitted energy relative to conventional lidar systems, provides high signal-to-noise (SNR measurements, even in the presence of a large background signal. This proof-of-concept system, tested in both a laboratory environment and a limited number of field experiments over path lengths of 680 m and 1,600 m, demonstrated SNR values >1,000 for received signals of ~18 picoWatts averaged over 60 s. A SNR of 1,000 is equivalent to a measurement precision of ±0.001 or ~0.4 ppmv. The measurement method is expected to provide new capability for automated monitoring of greenhouse gas at fixed sites, such as carbon sequestration facilities, volcanoes, the short- and long-term assessment of urban plumes, and other similar applications. In addition, this concept enables active measurements of column amounts from a geosynchronous orbit for a network of ground-based receivers/stations that would complement other current and planned space-based measurement capabilities.

  17. Measurement of fossil fuel derived carbon dioxide and other anthropogenic trace gases above Sacramento, California in Spring 2009

    Directory of Open Access Journals (Sweden)

    J. C. Turnbull

    2010-09-01

    Full Text Available Direct quantification of fossil fuel CO2 (CO2ff in atmospheric samples can be used to examine several carbon cycle and air quality questions. We collected in-situ CO2, CO, and CH4 measurements and flask samples in the boundary layer and free troposphere over Sacramento, California, USA, during two aircraft flights over and downwind of this urban area during spring of 2009. The flask samples were analyzed for Δ14CO2 and CO2 to determine the recently added CO2ff mole fraction. A suite of additional greenhouse gases including hydrocarbons and halocarbons were measured in the same samples. Strong correlations were observed between CO2ff and numerous trace gases associated with urban emissions. From these correlations we estimate emission ratios between CO2ff and these species, and compare these with bottom-up inventory-derived estimates. Recent county level inventory estimates for carbon monoxide (CO and benzene from the California Air Resources Board CEPAM database are in good agreement with our measured emission ratios, whereas older emissions inventories appear to overestimate emissions of these gases. For most other trace species, there are substantial differences between our measured emission ratios and those derived from available emission inventories. For the first flight, we combine in situ CO measurements with the measured CO:CO2ff emission ratio of 14±2 ppbCO/ppmCO2 to derive an estimate of CO2ff mole fraction throughout this flight, and also estimate the biospheric CO2 mixing ratio (CO2bio from the difference of total and fossil CO2. The resulting CO2bio varies substantially between air in the urban plume and the surrounding boundary layer air. Finally, we use the in situ estimates of CO2ff mole fraction to infer total fossil fuel CO2

  18. European emissions of halogenated greenhouse gases inferred from atmospheric measurements.

    Science.gov (United States)

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

    2012-01-01

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

  19. On the detectability of trace chemical species in the martian atmosphere using gas correlation filter radiometry

    Science.gov (United States)

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

    2015-11-01

    The martian atmosphere is host to many trace gases including water (H2O) and its isotopologues, methane (CH4) and potentially sulphur dioxide (SO2), nitrous oxide (N2O) and further organic compounds, which would serve as indirect tracers of geological, chemical and biological processes on Mars. With exception of the recent detection of CH4 by Curiosity, previous detections of these species have been unsuccessful or considered tentative due to the low concentrations of these species in the atmosphere (∼10-9 partial pressures), limited spectral resolving power and/or signal-to-noise and the challenge of discriminating between telluric and martian features when observing from the Earth. In this study, we present radiative transfer simulations of an alternative method for detection of trace gas species - the gas correlation radiometry method. Two potential observing scenarios were explored where a gas correlation filter radiometer (GCFR) instrument: (1) performs nadir and/or limb sounding of the martian atmosphere in the thermal infrared (200-2000 cm-1 from an orbiting spacecraft or (2) performs solar occultation measurements in the near-infrared (2000-5000 cm-1) from a lander on the martian surface. In both scenarios, simulations of a narrowband filter radiometer (without gas correlation) were also generated to serve as a comparison. From a spacecraft, we find that a gas correlation filter radiometer, in comparison to a filter radiometer (FR), offers a greater discrimination between temperature and dust, a greater discrimination between H2O and HDO, and would allow detection of N2O and CH3OH at concentrations of ∼10 ppbv and ∼2 ppbv, respectively, which are lower than previously-derived upper limits. However, the lowest retrievable concentration of SO2 (approximately 2 ppbv) is comparable with previous upper limits and CH4 is only detectable at concentrations of approximately 10 ppbv, which is an order of magnitude higher than the concentration recently measured

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

    Science.gov (United States)

    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. Limitations of wind extraction from 4-D-Var assimilation of trace gases

    Directory of Open Access Journals (Sweden)

    D. R. Allen

    2012-12-01

    Full Text Available Time-dependent variational data assimilation allows the possibility of extracting wind information from observations of long-lived trace gases. Since trace gas observations are not available at sufficient resolution for deriving feature-track winds, they must be combined with model background information to produce an analysis. If done with time-dependent variational assimilation, wind information may be extracted via the adjoint of the linearized tracer continuity equation. This paper presents idealized experiments that illustrate the mechanics of tracer-wind extraction and demonstrate some of the limitations of this procedure. We first examine tracer-wind extraction using a simple one-dimensional advection equation. The analytic solution for a single trace gas observation is discussed along with numerical solutions for multiple observations. The limitations of tracer-wind extraction are then explored using highly idealized ozone experiments performed with a development version of the Navy Global Environmental Model (NAVGEM in which stratospheric globally-distributed hourly stratospheric ozone profiles are assimilated in a single 6-h update cycle in January 2009. Starting with perfect background ozone conditions, but imperfect dynamical conditions, ozone errors develop over the 6-h background window. Wind increments are introduced in the analysis in order to reduce the differences between background ozone and ozone observations. For "perfect" observations (unbiased and no random error, this results in root mean square (RMS vector wind error reductions of up to ∼ 3 m s−1 in the winter hemisphere and tropics. Wind extraction is more difficult in the summer hemisphere due to weak ozone gradients and smaller background wind errors. The limitations of wind extraction are also explored for observations with imposed random errors and for limited sampling patterns. As expected, the amount of wind information extracted degrades as

  2. Coherent structures and trace gases fluxes and concentrations in and above a heterogeneous spruce forest (Invited)

    Science.gov (United States)

    Foken, T.

    2013-12-01

    Near the FLUXNET site DE-Bay (Waldstein-Weidenbrunnen) three intensive measuring periods took place in 2007, 2008, and 2011 within the EGER project (ExchanGE processes in mountainous Regions). The main focus of all three experiments was the investigation of turbulent structures and their influence on the energy exchange and trace gas fluxes as well as trace gas reactions. Due to a tornado-like storm event an approximately 300 m long forest edge between a 25 m high spruce forest and a clearing was generated about 150 m south of the DE-Bay site. The investigation of processes at these forest edge was the main issue of the 2011 experiment. A main topic of all experiments was the investigation of the coupling between the atmosphere, the crowns and the trunk space as well as the horizontal coupling. This coupling algorithm is based on the analysis of coherent structures at three levels. While a complete coupling was only observed during daytime, at night well-coupled events were found in connection with low-level jets. The change of inert (CO2) or reactive (O3, NO, NO2, HONO) trace gas concentration could be explained with the coupling situation. It was also found that at the forest edge, coherent structures contribute less to total turbulent flux than within the forest. Accordingly, these coherent motions do not ensure that there is better vertical coupling between the forest stand and the overlying atmosphere at the forest edge. The relative contributions of sweeps and ejections to coherent flux reveal that there might be even larger circulations that cause better ventilation at the forest edge. Ejections dominate during the daytime, whereas sweeps contribute more during nighttime. Thus, there is systematic outflow during the daytime and inflow of fresh air directly at the forest edge during the nighttime. To underline these findings perpendicular to the edge, a mobile measuring system investigated the horizontal gradients of temperature, moisture, radiation, carbon

  3. Integrated method for the measurement of trace nitrogenous atmospheric bases

    Science.gov (United States)

    Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.

    2011-12-01

    Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace, atmospheric, gaseous nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications (e.g., methylamine, 1 pptv; ethylamine, 2 pptv; morpholine, 1 pptv; aniline, 1 pptv; hydrazine, 0.1 pptv; methylhydrazine, 2 pptv), as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  4. Integrated method for the measurement of trace atmospheric bases

    Science.gov (United States)

    Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.

    2011-09-01

    Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  5. Integrated method for the measurement of trace atmospheric bases

    Directory of Open Access Journals (Sweden)

    D. Key

    2011-09-01

    Full Text Available Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  6. Computerized atmospheric trace contaminant control simulation for manned spacecraft

    Science.gov (United States)

    Perry, J. L.

    1993-01-01

    Buildup of atmospheric trace contaminants in enclosed volumes such as a spacecraft may lead to potentially serious health problems for the crew members. For this reason, active control methods must be implemented to minimize the concentration of atmospheric contaminants to levels that are considered safe for prolonged, continuous exposure. Designing hardware to accomplish this has traditionally required extensive testing to characterize and select appropriate control technologies. Data collected since the Apollo project can now be used in a computerized performance simulation to predict the performance and life of contamination control hardware to allow for initial technology screening, performance prediction, and operations and contingency studies to determine the most suitable hardware approach before specific design and testing activities begin. The program, written in FORTRAN 77, provides contaminant removal rate, total mass removed, and per pass efficiency for each control device for discrete time intervals. In addition, projected cabin concentration is provided. Input and output data are manipulated using commercial spreadsheet and data graphing software. These results can then be used in analyzing hardware design parameters such as sizing and flow rate, overall process performance and program economics. Test performance may also be predicted to aid test design.

  7. Adsorption and reaction of trace gas-phase organic compounds on atmospheric water film surfaces: a critical review.

    Science.gov (United States)

    Donaldson, D J; Valsaraj, Kalliat T

    2010-02-01

    The air-water interface in atmospheric water films of aerosols and hydrometeors (fog, mist, ice, rain, and snow) presents an important surface for the adsorption and reaction of many organic trace gases and gaseous reactive oxidants (hydroxyl radical (OH(.)), ozone (O(3)), singlet oxygen (O(2)((1)Delta(g))), nitrate radicals (NO(3)(.)), and peroxy radicals (RO(2)(.)). Knowledge of the air-water interface partition constant of hydrophobic organic species is necessary for elucidating the significance of the interface in atmospheric fate and transport. Various methods of assessing both experimental and theoretical values of the thermodynamic partition constant and adsorption isotherm are described in this review. Further, the reactivity of trace gases with gas-phase oxidants (ozone and singlet oxygen) at the interface is summarized. Oxidation products are likely to be more water-soluble and precursors for secondary organic aerosols in hydrometeors. Estimation of characteristic times shows that heterogeneous photooxidation in water films can compete effectively with homogeneous gas-phase reactions for molecules in the atmosphere. This provides further support to the existing thesis that reactions of organic compounds at the air-water interface should be considered in gas-phase tropospheric chemistry. PMID:20058916

  8. Adsorption and reaction of trace gas-phase organic compounds on atmospheric water film surfaces: a critical review.

    Science.gov (United States)

    Donaldson, D J; Valsaraj, Kalliat T

    2010-02-01

    The air-water interface in atmospheric water films of aerosols and hydrometeors (fog, mist, ice, rain, and snow) presents an important surface for the adsorption and reaction of many organic trace gases and gaseous reactive oxidants (hydroxyl radical (OH(.)), ozone (O(3)), singlet oxygen (O(2)((1)Delta(g))), nitrate radicals (NO(3)(.)), and peroxy radicals (RO(2)(.)). Knowledge of the air-water interface partition constant of hydrophobic organic species is necessary for elucidating the significance of the interface in atmospheric fate and transport. Various methods of assessing both experimental and theoretical values of the thermodynamic partition constant and adsorption isotherm are described in this review. Further, the reactivity of trace gases with gas-phase oxidants (ozone and singlet oxygen) at the interface is summarized. Oxidation products are likely to be more water-soluble and precursors for secondary organic aerosols in hydrometeors. Estimation of characteristic times shows that heterogeneous photooxidation in water films can compete effectively with homogeneous gas-phase reactions for molecules in the atmosphere. This provides further support to the existing thesis that reactions of organic compounds at the air-water interface should be considered in gas-phase tropospheric chemistry.

  9. A simple method to estimate entropy of atmospheric gases from their action

    CERN Document Server

    Kennedy, Ivan R; Rose, Michael T; Crossan, Angus N

    2015-01-01

    A convenient model for estimating the total entropy ({\\Sigma}Si) of atmospheric gases based on physical action is proposed. This realistic approach is fully consistent with statistical mechanics, but uses the properties of translational, rotational and vibrational action to partition the entropy. When all sources of action are computed as appropriate non-linear functions, the total input of thermal energy ({\\Sigma}SiT) required to sustain a chemical system at specific temperatures (T) and pressures (p) can be estimated, yielding results in close agreement with published experimental third law values. Thermodynamic properties of gases including enthalpy, Gibbs energy and Helmholtz energy can be easily calculated from simple molecular and physical properties. We propose that these values for entropy are employed both chemically for reactions and physically for computing atmospheric profiles, the latter based on steady state heat flow equilibrating thermodynamics with gravity. We also predict that this applicati...

  10. Tooth Whitening Effects by Atmospheric Pressure Cold Plasmas with Different Gases

    Science.gov (United States)

    Choi, Hye-sook; Kim, Kyoung-Nam; You, Eun-Mi; Choi, Eun-Ha; Kim, Yong-Hee; Kim, Kwang-Mahn

    2013-11-01

    The aim of the present study was to investigate the effects of atmospheric pressure cold plasma with different gases on external tooth bleaching. After 10 min treatment, the air (50%) + oxygen (50%) group shows a remarkable color change (ΔE*), and nitrogen and air groups indicate some color change, although not as much as that shown by the air + oxygen group. Also, the argon group shows the least amount of color change among the various gases in this experiment. Atomic oxygen species exists during this tooth bleaching as determined by optical emission spectroscopy. Hence, atmospheric pressure cold plasma treatment could significantly accelerate the tooth bleaching process owing to this atomic oxygen species, and the intensity of tooth bleaching depends on the type of gas in the cold plasma.

  11. Iterative maximum a posteriori (IMAP)-DOAS for retrieval of strongly absorbing trace gases: Model studies for CH_4 and CO_2 retrieval from near infrared spectra of SCIAMACHY onboard ENVISAT

    OpenAIRE

    Frankenberg, C.; U. Platt; Wagner, T

    2005-01-01

    In the past, differential optical absorption spectroscopy (DOAS) has mostly been employed for atmospheric trace gas retrieval in the UV/Vis spectral region. New spectrometers such as SCIAMACHY onboard ENVISAT also provide near infrared channels and thus allow for the detection of greenhouse gases like CH4, CO2, or N2O. However, modifications of the classical DOAS algorithm are necessary to account for the idiosyncrasies of this spectral region, i.e. the temperature and...

  12. Airborne observations of trace gases over boreal Canada during BORTAS: campaign climatology, airmass analysis and enhancement ratios

    Directory of Open Access Journals (Sweden)

    S. J. O'Shea

    2013-05-01

    Full Text Available In situ airborne measurements were made over Eastern Canada in summer 2011 as part of the BORTAS experiment (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and~Satellites. In this paper we present observations of greenhouse gases (CO2 and CH4 and other biomass burning tracers and related trace gases, both climatologically and through case studies, as recorded on board the FAAM BAe-146 research aircraft. Vertical profiles of CO2 were generally characterised by depleted boundary layer concentrations relative to the free troposphere, consistent with terrestrial biospheric uptake. In contrast, CH4 concentrations were found to rise with decreasing altitude due to strong local and regional surface sources. We use coincident tracer-tracer correlations and a Lagrangian trajectory model to characterise and differentiate air mass history of intercepted plumes. In particular, CO, HCN and CH3CN were used to identify air masses that have been recently influenced by biomass burning. Concentrations of CO2 were found to have a mean tropospheric, campaign-average concentration of 384.8 ppm (ranging between 371.5 and 397.1 ppm, whilst CH4 concentrations had a mean value of 1859 ppb (ranging between 1797 and 1968 ppb, representing the episodic sampling of local fire plumes. CH4 and CO2 concentrations during BORTAS were found to be broadly comparable to previous measurements in the region during the regional burning season and with reanalysed composition fields from the EU Monitoring Atmospheric Composition and Change (MACC project. By examining individual case studies we were able to quantify emissions from biomass burning. Using both near-field (1 day sampling, boreal forest fire plumes were identified throughout the troposphere. Fresh plumes from fires in Northwest Ontario yield emission factors for CH4 and CO2 of 8.5 ± 0.9 g (kg dry matter−1 and 1512 g ± 185 g (kg dry matter−1, respectively. We have

  13. The CU Airborne MAX-DOAS instrument: ground based validation, and vertical profiling of aerosol extinction and trace gases

    OpenAIRE

    S. Baidar; Oetjen, H.; S. Coburn; Dix, B.; I. Ortega; R. Sinreich; R. Volkamer

    2012-01-01

    The University of Colorado Airborne Multi Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument uses solar stray light remote sensing to detect and quantify multiple trace gases, including nitrogen dioxide (NO2), glyoxal (CHOCHO), formaldehyde (HCHO), water vapor (H2O), nitrous acid (HONO), iodine monoxide (IO), bromine monoxide (BrO), and oxygen dimers (O4) at multiple wavelengths (360 nm, 477 nm, 5...

  14. Long term measurements of submicrometer urban aerosols: statistical analysis for correlations with meteorological conditions and trace gases

    Directory of Open Access Journals (Sweden)

    B. Wehner

    2003-01-01

    Full Text Available Long-term measurements (over 4 years of particle number size distributions (submicrometer particles, 3-800 nm in diameter, trace gases (NO, NO2, and O3, and meteorological parameters (global radiation, wind speed and direction, atmospheric pressure, etc. were taken in a moderately polluted site in the city of Leipzig (Germany. The resulting complex data set was analyzed with respect to seasonal, weekly, and diurnal variation of the submicrometer aerosol. Car traffic produced a peak in the number size distribution at around 20 nm particle diameter during morning rush hour on weekdays. A second peak at 10-15 nm particle diameter occurred around noon during summer, confirmed by high correlation between concentration of particles less than 20 nm and the global radiation. This new-particle formation at noon was correlated with the amount of global radiation. A high concentration of accumulation mode particles (between 100 and 800 nm, which are associated with large particle-surface area, might prevent this formation. Such high particle concentration in the ultrafine region (particles smaller than 20 nm in diameter was not detected in the particle mass, and thus, particle mass concentration is not suitable for determining the diurnal patterns of particles. In summer, statistical time series analysis showed a cyclic pattern of ultrafine particles with a period of one day and confirmed the correlation with global radiation. Principal component analysis (PCA revealed a strong correlation between the particle concentration for 20-800 nm particles and the NO- and NO2-concentrations, indicating the influence of combustion processes on this broad size range, in particular during winter. In addition, PCA also revealed that particle concentration depended on meteorological conditions such as wind speed and wind direction, although the dependence differed with particle size class.

  15. The airborne mass spectrometer AIMS – Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

    Directory of Open Access Journals (Sweden)

    T. Jurkat

    2016-04-01

    an isotopically labeled 34SO2 standard. In addition, we report on trace gas measurements of HONO, which is sensitive to the reaction with SF5−. The detection limit for the various trace gases is in the low 10 pptv range at a 1 s time resolution with an overall uncertainty of the measurement of the order of 20 %. AIMS has been integrated and successfully operated on the DLR research aircraft Falcon and HALO (High Altitude LOng range research aircraft. As an example, measurements conducted during the TACTS/ESMVal (Transport and Composition of the LMS/UT and Earth System Model Validation mission with HALO in 2012 are presented, focusing on a classification of tropospheric and stratospheric influences in the UTLS region. The combination of AIMS measurements with other measurement techniques yields a comprehensive picture of the sulfur, chlorine and reactive nitrogen oxide budget in the UTLS. The different trace gases measured with AIMS exhibit the potential to gain a better understanding of the trace gas origin and variability at and near the tropopause.

  16. An approach to noble-gas isotopic compositions in natural gases and gas-source tracing in the Ordos Basin, China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Isotopic compositions of noble gases, i.e. He Ar Kr and Xe, are measured in natural gases from the Zhongbu gasfield in the Ordos Basin. And heavy noble-gas isotopes (Kr, Xe) are here first used in geochemically studying natural gases and gas-source correlation. Isotopic compositions of heavy noble gases in natural gases, especially Xe, show two-source mixing in the Zhongbu gasfield. Gas sources are somewhat different in the northeast and the southwest of the gasfield. Generally, the gas source of the Lower Paleozoic makes a greater contribution in the southwest than in the northeast in the field. Two kinds of gases can be differentiated from isotopic compositions of heavy noble gases and from their relation with the Ar isotopic composition, Therefore, the comprehensive study on isotopic compositions of light and heavy noble gases can supply more useful information on gas-source correlation and tracing.

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

    Science.gov (United States)

    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 (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/Vis including BrO, OClO, IO, I2, OIO, ozone, NO2, H2O, O4, and SO2 simultaneously at a temporal resolution of 1

  18. The 1997 El Niño impact on clouds, water vapour, aerosols and reactive trace gases in the troposphere, as measured by the Global Ozone Monitoring Experiment

    Directory of Open Access Journals (Sweden)

    D. Loyola

    2006-01-01

    Full Text Available The El Niño event of 1997/1998 caused dry conditions over the Indonesian area that were followed by large scale forest and savannah fires over Kalimantan, Sumatra, Java, and parts of Irian Jaya. Biomass burning was most intense between August and October 1997, and large amounts of ozone precursors, such as nitrogen oxides, carbon monoxide and hydrocarbons were emitted into the atmosphere. In this work, we use satellite measurements from the Global Ozone Monitoring Experiment (GOME sensor to study the teleconnections between the El Niño event of 1997 and the Indonesian fires, clouds, water vapour, aerosols and reactive trace gases (nitrogen dioxide, formaldehyde and ozone in the troposphere.

  19. Atmospheric composition change: Ecosystems-Atmosphere interactions

    NARCIS (Netherlands)

    Fowler, D.; Pilegaard, K.; Sutton, M.A.; Ambus, P.; Raivonen, M.; Duyzer, J.; Simpson, D.; Fagerli, H.; Fuzzi, S.; Schjoerring, J.K.; Granier, C.; Neftel, A.; Isaksen, I.S.A.; Laj, P.; Maione, M.; Monks, P.S.; Burkhardt, J.; Daemmgen, U.; Neirynck, J.; Personne, E.; Wichink Kruit, R.J.; Butterbach-Bahl, K.; Flechard, C.; Tuovinen, J.P.; Coyle, M.; Gerosa, G.; Loubet, B.; Altimir, N.; Gruenhage, L.; Ammann, C.; Cieslik, S.; Paoletti, E.; Mikkelsen, T.N.; Ro-Poulsen, H.; Cellier, P.; Cape, J.N.; Horvath, L.; Loreto, F.; Niinemets, U.; Palmer, P.I.; Rinne, J.; Misztal, P.; Nemitz, E.; Nilsson, D.; Pryor, S.; Gallagher, M.W.; Vesala, T.; Skiba, U.; Brueggemann, N.; Zechmeister-Boltenstern, S.; Williams, J.; O'Dowd, C.; Facchini, M.C.; Leeuw, de G.; Flossman, A.; Chaumerliac, N.; Erisman, J.W.

    2009-01-01

    Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O-3, CH4, N2O and particles i

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

    Science.gov (United States)

    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

  1. Massive impact-induced release of carbon and sulfur gases in the early Earth's atmosphere

    Science.gov (United States)

    Marchi, S.; Black, B. A.; Elkins-Tanton, L. T.; Bottke, W. F.

    2016-09-01

    Recent revisions to our understanding of the collisional history of the Hadean and early-Archean Earth indicate that large collisions may have been an important geophysical process. In this work we show that the early bombardment flux of large impactors (>100 km) facilitated the atmospheric release of greenhouse gases (particularly CO2) from Earth's mantle. Depending on the timescale for the drawdown of atmospheric CO2, the Earth's surface could have been subject to prolonged clement surface conditions or multiple freeze-thaw cycles. The bombardment also delivered and redistributed to the surface large quantities of sulfur, one of the most important elements for life. The stochastic occurrence of large collisions could provide insights on why the Earth and Venus, considered Earth's twin planet, exhibit radically different atmospheres.

  2. A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, Sangeeta B. [Electrical Engineering Department, V. J.T.I, Matunga, Mumbai 400019 (India); Department of Physics, University of Mumbai, Kalina, Santacruz(E) 400098 (India); Joshi, N. K. [Faculty of Engineering and technology, MITS, lakshmangarh, (Sikar), Rajasthan 332311 (India); Mangalvedekar, H. A.; Lande, B. K. [Electrical Engineering Department, V. J.T.I, Matunga, Mumbai 400019 (India); Das, A. K. [Laser and Plasma Technology Division, BARC, Mumbai 400085 (India); Kothari, D. C. [Department of Physics, University of Mumbai, Kalina, Santacruz(E) 400098 (India)

    2012-01-15

    A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software fluent{sup (c)}. The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications.

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

    Science.gov (United States)

    Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Ed

    2016-04-01

    We present results from the eleventh annual Greenhouse Gas Bulletin (http://www.wmo.int/pages/prog/arep/gaw/ghg/GHGbulletin.html) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (www.wmo.int/gaw). The Bulletin presents results of global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG). Bulletins are prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in collaboration with WDCGG. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of CO2, CH4 and N2O derived from this network reached new highs in 2014, at 397.7±0.1 ppm, 1833±1 ppb and 327.1±0.1 ppb respectively. These values constitute 143%, 254% and 121% of pre-industrial (before 1750) levels. The atmospheric increase of CO2 from 2013 to 2014 was 1.9 ppm, which is smaller than the increase from 2012 to 2013 and the average growth rate for the past decade (˜2.06 ppm per year), but larger than the average growth rate for the 1990s (˜1.5 ppm per year). Smaller growth in 2014 compared with other recent years is most likely related to a relatively small net change in large fluxes between the atmosphere and terrestrial biosphere. The rise of atmospheric CO2 has been only about a half of what is expected if all excess CO2 from burning fossil-fuels stayed in the air. The other half has been absorbed by the land biosphere and the oceans, leading to ocean acidification. For both CH4 and N2O the increases from 2013 to 2014 were larger than those observed from 2012 to 2013 and the mean rates over the past 10 years. The National

  4. Condition of Retrieving Vertical Column Density of Atmospheric Pollution Gases by Using Scattered Solar Radiation

    Institute of Scientific and Technical Information of China (English)

    ZUO Sao-Yi

    2009-01-01

    We present a method to monitor the vertical column density (VCD) of atmospheric pollution gases by using the scattered solar radiation. The necessary condition of capturing the useful scattered solar radiation is achieved. The condition is only dependent on the solar elevation angle, while independent of the solar azimuth angle, which could greatly simply the capturing equipment and procedure. Under the condition, the VCD of tropospheric NO2 in Chengdu, China is retrieved from the scattered solar radiation, which is dose to that from the direct solar radiation.

  5. Technical Note: A new global database of trace gases and aerosols from multiple sources of high vertical resolution measurements

    Directory of Open Access Journals (Sweden)

    G. E. Bodeker

    2008-09-01

    Full Text Available A new database of trace gases and aerosols with global coverage, derived from high vertical resolution profile measurements, has been assembled as a collection of binary data files; hereafter referred to as the "Binary DataBase of Profiles" (BDBP. Version 1.0 of the BDBP, described here, includes measurements from different satellite- (HALOE, POAM II and III, SAGE I and II and ground-based measurement systems (ozonesondes. In addition to the primary product of ozone, secondary measurements of other trace gases, aerosol extinction, and temperature are included. All data are subjected to very strict quality control and for every measurement a percentage error on the measurement is included. To facilitate analyses, each measurement is added to 3 different instances (3 different grids of the database where measurements are indexed by: (1 geographic latitude, longitude, altitude (in 1 km steps and time, (2 geographic latitude, longitude, pressure (at levels ~1 km apart and time, (3 equivalent latitude, potential temperature (8 levels from 300 K to 650 K and time.

    In contrast to existing zonal mean databases, by including a wider range of measurement sources (both satellite and ozonesondes, the BDBP is sufficiently dense to permit calculation of changes in ozone by latitude, longitude and altitude. In addition, by including other trace gases such as water vapour, this database can be used for comprehensive radiative transfer calculations. By providing the original measurements rather than derived monthly means, the BDBP is applicable to a wider range of applications than databases containing only monthly mean data. Monthly mean zonal mean ozone concentrations calculated from the BDBP are compared with the database of Randel and Wu, which has been used in many earlier analyses. As opposed to that database which is generated from regression model fits, the BDBP uses the original (quality controlled measurements with no smoothing applied in any

  6. Biogenic feedbacks on the atmospheric concentrations of greenhouse gases: overview of the GREENCYCLES network

    International Nuclear Information System (INIS)

    Full text: GREENCYCLES is a Marie Curie research training network focussed on the roles of global biogeochemistry for climate change. The project aims to reduce uncertainties associated with biogenic feedbacks on global environmental change and foster the education of the next generation of Earth system scientists. GREENCYCLES young scientists are offered a unique environment bringing together key European research modelling teams with complementary expertise in coupled earth system, oceans, field-based understanding of the terrestrial and oceanic processes, and space based observations. To improve the understanding of the important biogeochemical processes that control the concentrations of anthropogenic greenhouse gases, the network is spread across six key science objectives, each involving different individual research projects undertaken by Early-Stage Researchers (ESRs) and Experienced Researchers (ERs): quantify feedbacks in the global carbon cycle; determine the effects of changing land use on climate; improve understanding of natural sources of CH4 and their responses to human activities; quantify impacts of climate change and climate variability on fire-induced emissions of greenhouse gases; quantify impacts of climate change on terrestrial and oceanic biogenic emissions of aerosols and chemically active gases, and their effects on tropospheric chemistry; quantify impacts of vegetation and climate changes on atmospheric dust, and its feedbacks on CO2 and climate. An overview of the research and training progress to date will be presented. (author)

  7. Combining stable isotope (δ13C) of trace gases and aerobiological data to monitor the entry and dispersion of microorganisms in caves.

    Science.gov (United States)

    Garcia-Anton, E; Cuezva, S; Jurado, V; Porca, E; Miller, A Z; Fernandez-Cortes, A; Saiz-Jimenez, C; Sanchez-Moral, S

    2014-01-01

    Altamira Cave (north of Spain) contains one of the world's most prominent Paleolithic rock art paintings, which are threatened by a massive microbial colonization of ceiling and walls. Previous studies revealed that exchange rates between the cave and the external atmosphere through the entrance door play a decisive role in the entry and transport of microorganisms (bacteria and fungi) and nutrients to the interior of the cave. A spatial-distributed sampling and measurement of carrier (CO2) and trace (CH4) gases and isotopic signal of CO2 (δ(13)C) inside the cave supports the existence of a second connection (active gas exchange processes) with the external atmosphere at or near the Well Hall, the innermost and deepest area of the cave. A parallel aerobiological study also showed that, in addition to the entrance door, there is another connection with the external atmosphere, which favors the transport and increases microorganism concentrations in the Well Hall. This double approach provides a more complete knowledge on cave ventilation and revealed the existence of unknown passageways in the cave, a fact that should be taken into account in future cave management. PMID:23807558

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

    Science.gov (United States)

    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.

  9. New SI-traceable reference gas mixtures for fluorinated gases at atmospheric concentration

    Science.gov (United States)

    Guillevic, Myriam; Wyss, Simon A.; Pascale, Céline; Vollmer, Martin K.; Niederhauser, Bernhard; Reimann, Stefan

    2016-04-01

    In order to better support the monitoring of greenhouse gases in the atmosphere, we develop a method to produce reference gas mixtures for fluorinated gases (F-gases, i.e. gases containing fluorine atoms) in a SI-traceable way, meaning that the amount of substance fraction in mole per mole is traceable to SI-units. These research activities are conducted in the framework of the HIGHGAS and AtmoChem-ECV projects. First, single-component mixtures in synthetic air at ~85 nmol/mol (ppb) are generated for HFC-125 (pentafluoroethane, a widely used HFC) and HFC-1234yf (2,3,3,3-tetrafluoropropene, a car air conditioner fluid of growing importance). These mixtures are first dynamically produced by permeation: a permeator containing the pure substance loses mass linearly over time under a constant gas flow, in the permeation chamber of a magnetic suspension balance, which is regularly calibrated. This primary mixture is then pressurised into Silconert2000-coated stainless steel cylinders by cryo-filling. In a second step these mixtures are dynamically diluted using 2 subsequent dilution steps piloted by mass flow controllers (MFC) and pressure controllers. The assigned mixture concentration is calculated mostly based on the permeator mass loss, on the carrier gas purity and on the MFCs flows. An uncertainty budget is presented, resulting in an expanded uncertainty of 2% for the HFC-125 reference mixture and of 2.5% for the HFC-1234yf mixture (95% confidence interval). The final gas, with near-atmospheric concentration (17.11 pmol/mol for HFC-125, 2.14 pmol/mol for HFC-1234yf) is then measured with Medusa-GC/MS technology against standards calibrated on existing reference scales. The assigned values of the dynamic standards are in excellent agreement with measurements vs the existing reference scales, SIO-14 from the Scripps Institution of Oceanography for HFC-125 and Empa-2013 for HFC-1234yf. Moreover, the Medusa-GC/MS measurements show the excellent purity of the SI

  10. Biomass Burning: The Cycling of Gases and Particulates from the Biosphere to the Atmosphere

    Science.gov (United States)

    Levine, J. S.

    2003-12-01

    Biomass burning is both a process of geochemical cycling of gases and particulates from the biosphere to the atmosphere and a process of global change. In the preface to the book, One Earth, One Future: Our Changing Global Environment (National Academy of Sciences, 1990), Dr. Frank Press, the President of the National Academy of Sciences, writes: "Human activities are transforming the global environment, and these global changes have many faces: ozone depletion, tropical deforestation, acid deposition, and increased atmospheric concentrations of gases that trap heat and may warm the global climate."It is interesting to note that all four global change "faces" identified by Dr. Press have a common thread - they are all caused by biomass burning.Biomass burning or vegetation burning is the burning of living and dead vegetation and includes human-initiated burning and natural lightning-induced burning. The bulk of the world's biomass burning occurs in the tropics - in the tropical forests of South America and Southeast Asia and in the savannasof Africa and South America. The majority of the biomass burning, primarily in the tropics (perhaps as much as 90%), is believed to be human initiated for land clearing and land-use change. Natural fires triggered by atmospheric lightning only accounts for ˜10% of all fires (Andreae, 1991). As will be discussed, a significant amount of biomass burning occurs in the boreal forests of Russia, Canada, and Alaska.Biomass burning is a significant source of gases and particulates to the regional and global atmosphere (Crutzen et al., 1979; Seiler and Crutzen, 1980; Crutzen and Andreae, 1990; Levine et al., 1995). Its burning is truly a multidiscipline subject, encompassing the following areas: fire ecology, fire measurements, fire modeling, fire combustion, remote sensing, fire combustion gaseous and particulate emissions, the atmospheric transport of these emissions, and the chemical and climatic impacts of these emissions. Recently

  11. Gas chromatographic instrumentation for the analysis of aerosols and gases in Titan's atmosphere

    Science.gov (United States)

    Scattergood, T. W.; Valentin, J. R.; Ohara, B. J.; Kojiro, D. R.; Carle, G. C.

    1987-01-01

    Instrumentation presently being developed by NASA for the collection and analysis of organic gases and aerosols in Titan's atmosphere is described together with the results of the preliminary experiments. For the aerosols, stepwise pyrolysis was shown to be a suitable method for preparing complex organic material for gas chromatography (GC), and a pyrolysis-gas chromatograph was developed and successfully used to analyze a simulated Titan aerosol. Atmospheric gases will be collected by a low-pressure gas sampling system using large-volume sample loops and analyzed by GC. The results of preliminary studies using a 20 cu cm sampling system and a very sensitive metastable ionization detector showed that hydrocarbon components at the 10 ppb level can be detected. Studies are in progress on shortening the overall analysis time by improving the pyrolysis system, the gas sampling system, and the associated gas chromatograph. Further development of the gas sampling system is planned to ensure rapid collection of samples adequate for analysis by GC over the entire range of pressures to be encountered during the probe's descent.

  12. Organic Nitrates: A Complex Family of Atmospheric Trace Constituents

    Science.gov (United States)

    Ballschmiter, K.; Fischer, R. G.; Grünert, A.; Kastler, J.; Schneider, M.; Woidich, S.

    2003-04-01

    Biogenic and geogenic hydrocarbons are the precursors of organic nitrates that are formed as tropospheric photo-oxidation products in the presence of NOx. Air chemistry leads to a very complex pattern of nitric acid esters: alkyl nitrates, aryl-alkyl nitrates, and bifunctional nitrates like alkyl dinitrates, hydroxy alkyl nitrates and carbonyl alkyl nitrates. We have analyzed the pattern of organic nitrates in air samples after adsorption/thermal desorption (low volume sampling-LVS) or adsorption/solvent desorption (high volume sampling-HVS) by capillary gas chromatography with electron capture (ECD) and mass spectrometric detection (MSD) using air aliquotes of 100 up to 3000 liters on column. The complexity of the organic nitrates found in air requires a group pre-separation by normal phase liquid chromatography. A detection limit per compound of 0.005 ppt(v) is achieved by our approach. We have synthesized a broad spectrum of organic nitrates as reference compounds. Air samples were taken from central Europe, the US West (Utah, Nevada, California), and the North- and South Atlantic including Antarctica. Levels and patterns of the regional and global occurrence of the various groups of C1-C12 organic nitrates including dinitrates and hydroxy nitrates and nitrates of isoprene (2-methylbutadiene) are presented. Werner G., J. Kastler, R. Looser, K. Ballschmiter: "Organic nitrates of isoprene as atmospheric trace compounds" Angewandte Chemie - International Edition (1999) 38: 1634-1637. Woidich S., O. Froescheis, O. Luxenhofer, K. Ballschmiter: "EI- and NCI-mass spectrometry of arylalkyl nitrates and their occurrence in urban air" Fresenius J. Anal. Chem. (1999) 364 : 91-99. Kastler, J; Jarman, W; Ballschmiter, K.: "Multifunctional organic nitrates as constituents in European and US urban photo-smog" Fresenius J. Anal. Chem. (2000) 368:244-249. Schneider M., K. Ballschmiter: "C3-C14 alkyl nitrates in remote South Atlantic air" Chemosphere (1999) 38: 233-244. Fischer

  13. Noble gases in planetary atmospheres - Implications for the origin and evolution of atmospheres

    Science.gov (United States)

    Pollack, J. B.; Black, D. C.

    1982-01-01

    The radiogenic and primordial noble gas contents of the Venus, earth, and Mars atmospheres are compared with one another and with the noble gas content of other extraterrestrial samples, particularly meteorites. Key trends in the primordial noble gas content of terrestrial planetary atmospheres are shown to include: (1) a several-orders-of-magnitude decrease in Ne-20 and Ar-36 from Venus to earth to Mars; (2) a nearly constant Ne-20/Ar-36 ratio, which is comparable to that found in the more primitive carbonaceous chondrites and which is two orders of magnitude smaller than the solar ratio; (3) a sizable fractionation of Ar, Kr, and Xe from their solar ratios, though the degree of fractionation (especially for Ar-36/Xe-132) appears to decrease systematically from carbonaceous chondrites to Mars to earth to Venus; and (4) large differences in Ne and Xe isotopic ratios among earth, meteorites, and the sun. It is suggested that the grain-accretion hypothesis can explain all four trends, though the assumptions needed to achieve this agreement are far from proven.

  14. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere

    Science.gov (United States)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M.; Canadell, Josep G.; Saikawa, Eri; Huntzinger, Deborah N.; Gurney, Kevin R.; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R.; Wofsy, Steven C.

    2016-03-01

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

  15. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

    Science.gov (United States)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

    2016-03-10

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change. PMID:26961656

  16. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

    Science.gov (United States)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

    2016-03-10

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

  17. Production of stable, non-thermal atmospheric pressure rf capacitive plasmas using gases other than helium or neon

    Science.gov (United States)

    Park, Jaeyoung; Henins, Ivars

    2005-06-21

    The present invention enables the production of stable, steady state, non-thermal atmospheric pressure rf capacitive .alpha.-mode plasmas using gases other than helium and neon. In particular, the current invention generates and maintains stable, steady-state, non-thermal atmospheric pressure rf .alpha.-mode plasmas using pure argon or argon with reactive gas mixtures, pure oxygen or air. By replacing rare and expensive helium with more readily available gases, this invention makes it more economical to use atmospheric pressure rf .alpha.-mode plasmas for various materials processing applications.

  18. Effect of ''outer'' sources and dissipative processes on abundance of inert gases in atmospheres of the Earth group planets

    International Nuclear Information System (INIS)

    The problem of abundance of inert gases in atmospheres of the Earth group planets is discussed. It is shown that introduction of He, Ne and 36Ar into the Mars and Mercury atmospheres with interplanetary dust and from other external sources require the presence of special mechanisms of losses for these gases. For the Mars atmosphere dissipation on atmosphere interaction with solar wind during the periods of anomalously low temperatures is a probable mechanisms of Ne and 36Ar losses. For the Mercury thermal dissipation for He and polar wind for other inert gases are possible. For all the planets of the Earth group dissipation on interaction with solar wind and introduction with interplanetary dust could play an important role at the early stages of evolution of planets

  19. Atmospheric observations for quantifying emissions of point-source synthetic greenhouse gases (CF4, NF3 and HFC-23)

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair J.; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Fraser, Paul J.; Mitrevski, Blagoj; Steele, L. Paul; Krummel, Paul B.; Mühle, Jens; Weiss, Ray F.

    2016-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacement compounds that are emitted from fugitive and mobile emission sources, these gases are largely emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane factories (HFC-23). In this work we show the potential for atmospheric measurements to understand regional sources of these gases and to highlight emission 'hotspots'. We target our analysis on measurements from two Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites that are particularly sensitive to regional emissions of these gases: Gosan on Jeju Island in the Republic of Korea and Cape Grim on Tasmania in Australia. These sites measure CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over a decade (2005-2015) at high spatial resolution. At present these gases make a small contribution to global radiative forcing, however, given that their impact could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

  20. WAVELENGTH-RESOLVED REMPI MASS SPECTROMETRY FOR THE MONITORING OF TOXIC INCINERATION TRACE GASES

    Science.gov (United States)

    Structure-selective measurement techniques are needed for the assessment of the toxic loading of incinerator gases. This review article shows that wavelength-resolved, resonance-enhanced, multiphoton- ionization (REMPY) mass spectrometry can be used to this end. In this case, how...

  1. A rapid method to derive horizontal distributions of trace gases and aerosols near the surface using multi-axis differential optical absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2013-09-01

    Full Text Available We apply a novel experimental procedure for the rapid measurement of the average volume mixing ratios (VMRs and horizontal distributions of trace gases such as NO2, SO2, and HCHO in the boundary layer, which was recently suggested by Sinreich et al. (2013. The method is based on two-dimensional scanning multi-axis differential optical absorption spectroscopy (MAX-DOAS. It makes use of two facts (Sinreich et al. 2013: First, the light path for observations at 1° elevation angle traverses mainly air masses located close to the ground (typically 4. Thus, the average value of the trace gas VMR in the atmospheric layer between the surface and the altitude, for which this observation was sensitive, can be calculated. Compared to the originally proposed method, we introduce several important modifications and improvements: We apply the method only to measurements at 1° elevation angles, for which the uncertainties are especially small. Using only 1 elevation angle also allows an increased temporal resolution. We apply correction factors (and their uncertainties as function of the simultaneously modelled O4 absorption. In this way the correction factors can be directly determined according to the measured O4 dAMF. Finally, the method is extended to trace gases analysed at other wavelengths and also to the retrieval of the aerosol extinction. Depending on the atmospheric visibility, the typical uncertainty of the results ranges from about 15 to 30%. We apply the rapid method to observations of a newly developed ground-based multifunctional passive differential optical absorption spectroscopy (GM-DOAS instrument in the north-west outskirt near Hefei City in China. We report NO2, SO2, and HCHO VMRs and aerosol extinction for four azimuth angles and compare these results with those from simultaneous long-path DOAS observations. Good agreement is found (squares of the correlation coefficients for NO2, SO2, and HCHO were 0.92, 0.84, and 0.59, respectively

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Possible future scenarios for atmospheric concentration of greenhouse gases. A simplified thermodynamic approach

    Energy Technology Data Exchange (ETDEWEB)

    Angulo-Brown, F.; Sanchez-Salas, N. [Departamento de Fisica, Escuela Superior de Fisica y Matematicas, del IPN Edif. 9, U.P. Zacatenco, 07738 Mexico, D.F. (Mexico); Barranco-Jimenez, M.A. [Departamento de Ciencias Basicas, Escuela Superior de Computo, del IPN Av., Miguel Bernard s/n., Esq. Juan de Dios Batiz, U.P. Zacatenco, 07738 Mexico, D.F. (Mexico); Rosales, M.A. [Departamento de Fisica y Matematicas, Universidad de las Americas Puebla, Exhacienda Sta., Catarina Martir, Cholula 72820, Puebla (Mexico)

    2009-11-15

    Most of the increase in concentrations of greenhouse gases in the Earth's atmosphere is mainly due to anthropogenic activities. This is particularly significant in the case of CO{sub 2}. The atmospheric concentration of CO{sub 2} has systematically increased since the Industrial Revolution (260 ppm), with a remarkable raise after the 1970s until the present day (380 ppm). If this increasing tendency is maintained, the last report of the Intergovernmental Panel on Climate Change (IPCC) estimates that, for the year 2100, the CO{sub 2} concentration can augment up to approximately 675 ppm. In this work it is assumed that the quantity of anthropogenic greenhouse gases emitted to the Earth's atmosphere is proportional to the quantity of heat rejected to the environment by internal combustion heat engines. It is also assumed that this increasing tendency of CO{sub 2} due to men's activity stems from a mode of energy production mainly based on a maximum-power output paradigm. With these hypotheses, a thermoeconomic optimization of a thermal engine model under two regimes of performance: the maximum-power regime and the so-called ecological function criterion is presented. This last regime consists in maximizing a function that represents a good compromise between high power output and low entropy production. It is showed that, under maximum ecological conditions, the emissions of thermal energy to the environment are reduced approximately up to 50%. Thus working under this mode of performance the slope of the curves of CO{sub 2} concentration, for instance, drastically diminishes. A simple qualitative criterion to design ecological taxes is also suggested. (author)

  4. Possible future scenarios for atmospheric concentration of greenhouse gases. A simplified thermodynamic approach

    International Nuclear Information System (INIS)

    Most of the increase in concentrations of greenhouse gases in the Earth's atmosphere is mainly due to anthropogenic activities. This is particularly significant in the case of CO2. The atmospheric concentration of CO2 has systematically increased since the Industrial Revolution (260 ppm), with a remarkable raise after the 1970s until the present day (380 ppm). If this increasing tendency is maintained, the last report of the Intergovernmental Panel on Climate Change (IPCC) estimates that, for the year 2100, the CO2 concentration can augment up to approximately 675 ppm. In this work it is assumed that the quantity of anthropogenic greenhouse gases emitted to the Earth's atmosphere is proportional to the quantity of heat rejected to the environment by internal combustion heat engines. It is also assumed that this increasing tendency of CO2 due to men's activity stems from a mode of energy production mainly based on a maximum-power output paradigm. With these hypotheses, a thermoeconomic optimization of a thermal engine model under two regimes of performance: the maximum-power regime and the so-called ecological function criterion is presented. This last regime consists in maximizing a function that represents a good compromise between high power output and low entropy production. It is showed that, under maximum ecological conditions, the emissions of thermal energy to the environment are reduced approximately up to 50%. Thus working under this mode of performance the slope of the curves of CO2 concentration, for instance, drastically diminishes. A simple qualitative criterion to design ecological taxes is also suggested. (author)

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

    Science.gov (United States)

    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

  6. Potential Trace Metal–Organic Complexation in the Atmosphere

    OpenAIRE

    Hiroshi Okochi; Peter Brimblecombe

    2002-01-01

    It is possible that metal–organic complexation enhances the uptake of gaseous organic compounds and the solubility of metals in aerosols and atmospheric water. We investigated potential atmospheric organic ligands and the enhanced uptake of hydroxy-, oxo-, and dicarboxylic acids as well as dicarbonyls into atmospheric aqueous aerosol. We examined complexation with transition metals (iron, manganese, nickel, copper, zinc) and lead on the basis of available references and our experimental data....

  7. Increased soil emissions of potent greenhouse gases under increased atmospheric CO2.

    Science.gov (United States)

    van Groenigen, Kees Jan; Osenberg, Craig W; Hungate, Bruce A

    2011-07-13

    Increasing concentrations of atmospheric carbon dioxide (CO(2)) can affect biotic and abiotic conditions in soil, such as microbial activity and water content. In turn, these changes might be expected to alter the production and consumption of the important greenhouse gases nitrous oxide (N(2)O) and methane (CH(4)) (refs 2, 3). However, studies on fluxes of N(2)O and CH(4) from soil under increased atmospheric CO(2) have not been quantitatively synthesized. Here we show, using meta-analysis, that increased CO(2) (ranging from 463 to 780 parts per million by volume) stimulates both N(2)O emissions from upland soils and CH(4) emissions from rice paddies and natural wetlands. Because enhanced greenhouse-gas emissions add to the radiative forcing of terrestrial ecosystems, these emissions are expected to negate at least 16.6 per cent of the climate change mitigation potential previously predicted from an increase in the terrestrial carbon sink under increased atmospheric CO(2) concentrations. Our results therefore suggest that the capacity of land ecosystems to slow climate warming has been overestimated.

  8. Satellite Observations of Trace Gases and Their Application for Studying Air Quality Near Oil and Gas Operations

    Science.gov (United States)

    Kollonige, D. E.; Thompson, A. M.; Nichols, M.; Fasnacht, Z.; Martins, D. K.; Dickerson, R. R.

    2014-12-01

    The increase in the natural gas component of the energy sector has led many state and local municipalities to begin regulation of emissions from the oil and natural gas operators with air quality (AQ) as a concern. "Top-down" measurements of trace gases in the air above wells complement "bottom-up" inventories, used by EPA and AQ stakeholders, through a more accurate depiction of regional variability of methane and other species near and downwind of oil and gas operations. Satellite observations of methane, nitrogen dioxide, formaldehyde, ozone, and other carbon gases enhance the spatial and temporal coverage of the data needed to demonstrate any long-term impacts from shale gas development. As part of a NASA AQAST (Air Quality Applied Sciences Team) project, we are evaluating satellite measurements of trace gases in regions with oil and gas operations for their application as a "top-down" constraint. For validation of the satellite instruments' sensitivities to emitted gases, we focus on regions where the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) campaign deployed with ground and aircraft measurements, including, Maryland (2011), California and Texas (2013), and Colorado (2014). We compare vertical distributions of methane and volatile organic compounds (VOCs) nearby and downwind of oil and gas wells to locate any regional differences during the campaign time periods. This allows for better characterization of the satellite observations and their limitations for application in air quality studies in similar environments. Taking advantage of current EOS-era satellites' data records, we also analyze methane anomalies and gas correlations in the free troposphere from 2005 to present to identify trends for basins with oil and gas extraction sites and their influence on background concentrations downwind of wells. In most regions with oil and gas activity, we see continually

  9. Real-time measurements of ammonia, acidic trace gases and water-soluble inorganic aerosol species at a rural site in the Amazon Basin

    Directory of Open Access Journals (Sweden)

    I. Trebs

    2004-01-01

    Full Text Available We measured the mixing ratios of ammonia (NH3, nitric acid (HNO3, nitrous acid (HONO, hydrochloric acid (HCl, sulfur dioxide (SO2 and the corresponding water-soluble inorganic aerosol species, ammonium (NH4+, nitrate (NO3-, nitrite (NO2-, chloride (Cl- and sulfate (SO42-, and their diel and seasonal variations at a pasture site in the Amazon Basin (Rondônia, Brazil. This study was conducted within the framework of LBA-SMOCC (Large Scale Biosphere Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate. Sampling was performed from 12 September to 14 November 2002, extending from the dry season (extensive biomass burning activity, through the transition period to the wet season (background conditions. Measurements were made continuously using a wet-annular denuder (WAD in combination with a Steam-Jet Aerosol Collector (SJAC followed by suitable on-line analysis. A detailed description and verification of the inlet system for simultaneous sampling of soluble gases and aerosol compounds is presented. Overall measurement uncertainties of the ambient mixing ratios usually remained below 15%. The limit of detection (LOD was determined for each single data point measured during the field experiment. Median LOD values (3σ-definition were ≤0.015ppb for acidic trace gases and aerosol anions and ≤0.118ppb for NH3 and aerosol NH4+. Mixing ratios of acidic trace gases remained below 1ppb throughout the measurement period, while NH3 levels were an order of magnitude higher. Accordingly, mixing ratios of NH4+ exceeded those of other inorganic aerosol contributors by a factor of 4 to 10. During the wet season, mixing ratios decreased by nearly a factor of 3 for all compounds compared to those observed when intensive biomass burning took place. Additionally, N-containing gas and aerosol species featured pronounced diel variations. This is attributed to strong

  10. Real-time measurements of ammonia, acidic trace gases and water-soluble inorganic aerosol species at a rural site in the Amazon Basin

    Directory of Open Access Journals (Sweden)

    I. Trebs

    2004-02-01

    Full Text Available We measured the mixing ratios of ammonia (NH3, nitric acid (HNO3, nitrous acid (HONO, hydrochloric acid (HCl, sulfur dioxide (SO2 and the corresponding water-soluble inorganic aerosol species, ammonium (NH4+, nitrate (NO3, nitrite (NO2, chloride (Cl and sulfate (SO42−, and their diel and seasonal variations at a pasture site in the Amazon Basin (Rondônia, Brazil. This study was conducted within the framework of LBA-SMOCC (Large Scale Biosphere Atmosphere Experiment in Amazonia Smoke Aerosols, Clouds, Rainfall and Climate. Sampling was performed from 12 September to 14 November 2002, extending from the dry season (extensive biomass burning activity, through the transition period to the wet season (background conditions. Measurements were made continuously using a wet-annular denuder in combination with a Steam-Jet Aerosol Collector (SJAC followed by suitable on-line analysis. A detailed description and verification of the inlet system for simultaneous sampling of soluble gases and aerosol compounds is presented. Overall measurement uncertainties of the ambient mixing ratios usually remained below 15%. The limit of detection (LOD was determined for each single data point measured during the field experiment. Median LOD values (3σ-definition were ≤0.015 ppb for acidic trace gases and aerosol anions and ≤0.118 ppb for NH3 and aerosol NH4+. Mixing ratios of acidic trace gases remained below 1ppb throughout the measurement period, while NH3 levels were an order of magnitude higher. Accordingly, mixing ratios of NH4+ exceeded those of other inorganic aerosol contributors by a factor of 4 to 10. During the wet season, mixing ratios decreased by nearly a factor of 3 for all compounds compared to those observed when intensive biomass burning

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

    Science.gov (United States)

    Molto, Carlos; Mas, Miquel

    2010-05-01

    The project presented here was developed by fifteen year old students of the Institut Sabadell (Sabadell Secondary School. Spain). The objective of this project was to raise the students awareness' about the problem of climate change, mainly caused by the accumulation of greenhouse gases in the atmosphere. It is also intended that students use the scientific method as an effective system of troubleshooting and that they use the ICTs (Information and Communication Technologies) to elicit data and process information. To develop this project, four lessons of sixty minutes each were needed. The first lesson sets out the role of the atmosphere as an Earth's temperature regulator, highlighting the importance of keeping the levels of carbon dioxide, methane and water steam in balance. The second lesson is focused on the experimental activity that students will develop in the following lesson. In lesson two, students will present and justify their hypothesis about the experiment. Some theoretical concepts, necessary to carry out the experiment, will also be explained. The third lesson involves the core of the project, that is the experiment in the laboratory. The experiment consists on performing the atmosphere heating on a little scale. Four different atmospheres are created inside four plastic boxes heated by an infrared lamp. Students work in groups (one group for each atmosphere) and have to monitor the evolution of temperature by means of a temperature sensor (Multilog software). The first group has to observe the relationship between temperature and carbon dioxide levels increase, mainly caused by the widespread practice of burning fossil fuels by growing human populations. The task of this group is to measure simultaneously the temperature of an empty box (without CO2) and the temperature of a box with high carbon dioxide concentration. The carbon dioxide concentration is the result of the chemical reaction when sodium carbonate mixes with hydrochloric acid. The

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

    Science.gov (United States)

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

    2015-04-01

    We present results from the tenth annual Greenhouse Gas Bulletin (http://www.wmo.int/pages/prog/arep/gaw/ ghg/GHGbulletin.html) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (www.wmo.int/gaw). The Bulletin presents results of global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG), and for the first time, it includes a summary of ocean acidification. Bulletins are prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in collaboration with WDCGG. The summary of ocean acidification and trends in ocean pCO2 was jointly produced by the International Ocean Carbon Coordination Project (IOCCP) of the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO), the Scientific Committee on Oceanic Research (SCOR), and the Ocean Acidification International Coordination Centre (OA-ICC) of the International Atomic Energy Agency (IAEA). The tenth Bulletin included a special edition published prior to the United Nations Climate Summit in September 2014. The scope of this edition was to demonstrate the level of emission reduction necessary to stabilize radiative forcing by long-lived greenhouse gases. It shows in particular that a reduction in radiative forcing from its current level (2.92 W m-2 in 2013) requires significant reductions in anthropogenic emissions of all major greenhouse gases. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide, methane and nitrous oxide derived from this network reached new highs in 2013, with CO2 at 396.0 ± 0.1 ppm, CH4 at

  13. Atmospheric wet and dry deposition of trace elements at 10 sites in Northern China

    OpenAIRE

    Pan, Y. P.; Y. S. Wang

    2015-01-01

    Atmospheric deposition is considered to be a major process that removes pollutants from the atmosphere and an important source of nutrients and contaminants for ecosystems. Trace elements (TEs), especially toxic metals deposited on plants and into soil or water, can cause substantial damage to the environment and human health due to their transfer and accumulation in food chains. Despite public concerns, quantitative knowledge of metal deposition from the atmosphere to ecosy...

  14. Potential Trace Metal–Organic Complexation in the Atmosphere

    Directory of Open Access Journals (Sweden)

    Hiroshi Okochi

    2002-01-01

    Full Text Available It is possible that metal–organic complexation enhances the uptake of gaseous organic compounds and the solubility of metals in aerosols and atmospheric water. We investigated potential atmospheric organic ligands and the enhanced uptake of hydroxy-, oxo-, and dicarboxylic acids as well as dicarbonyls into atmospheric aqueous aerosol. We examined complexation with transition metals (iron, manganese, nickel, copper, zinc and lead on the basis of available references and our experimental data. Humic-like substances are most likely ligands in the atmosphere, although this is a poorly characterized material. A number of polycarboxylic acids and hydroxy forms (e.g., citric and tartronic acids effectively complex metals such as copper in atmospheric aerosols. The simple equilibrium model calculations show that the effect of the complexation on the gas–aqueous phase partition of gaseous atmospheric ligands is quite small for the ligands with the high physical Henry’s law constants, e.g., dicarboxylic acids represented by oxalic acid, even if they have high affinity with metal ions. The lower Henry’s law constants of the α-dicarbonyls, such as glyoxal and methylglyoxal, mean that the complexation could lead to profound increases in their partition into the aqueous phase. Despite quantum mechanical arguments for copper–glyoxal complexes, experiments showed no evidence of complexation between either hydrated or unhydrated α-dicarbonyls and the cupric ion. By contrast the β-dicarbonyl, malondialdehyde, has properties that would allow it to partition into atmospheric water via the complexation with metal ions under some conditions.

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

    Science.gov (United States)

    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

  16. DEVELOPMENT OF LIGHTWEIGHT INSTRUMENTATION FOR MEASUREMENT OF LONG-LIVED TRACE GASES

    Science.gov (United States)

    The ozone budget of the upper troposphere is highly uncertain with respect to both chemistry and dynamical effects. Extensive data in the 6 to 12 km region of the atmosphere is needed to constrain the relative roles of various dynamical processes, such as convection and int...

  17. Measurements of aerosol and trace gases at Agra in Indo-Gangetic plain during special aerosol land campaign II

    Science.gov (United States)

    Kumar, Ranjit; Maharaj Kumari, K.

    2010-05-01

    This paper deals with measurements of aerosol, their chemical properties and precursor trace gases at Agra in the Indo-Gangetic plain during ISRO-GBP special aerosol land campaign II. Aerosol and trace gas sampling as well a meteorological parameters monitoring were carried out at Dayalbagh, a suburban site of Agra during campaign in December 2004 along with seven other stations in India. The average TSPM level was 441.2 µg m-3 and ranges between 60.8 µg m-3 and 1004.6 µg m-3 and was higher than National Ambient Air Quality Standard values of India. The high load SPM in this region may be probably due to industrial-vehicular emissions of sulphur and nitrogen oxides, transport of soil-sand dust from local agricultural field and Thar Desert of Rajasthan and long range transported pollutants. Meteorological study revealed that high wind speed and wind from North West direction influences the aerosol load as it may be long range transported. TSP load was higher during initial foggy and foggy days and lower during post foggy days. NH4+ concentration is highest followed by NO3-, SO42-, Cl-, K+, Ca2+, Na+, Mg2+ and F-. The high concentration of NH4+ may be probably due to nearby cattle yard, use of fertilizers and biogenic emissions. The concentration of trace gases SO2, NO2, HNO3 and NH3 are 20.8 µg m-3, 26.3 µg m-3, 1.6 µg m-3, 18.6 µg m-3, respectively. The transportation of urban plumes may be responsible for high concentration of SO2 and NO2. HNO3/NO3- ratio is less than unity. NO3- and NO2 (r=0.4) suggests formation of particulate NO3- from NO2. Ratio of NH3/NH4+ is less than unity. SO42-/SO2 ratio is 0.84. The lack of correlation between SO42- and SO2 (r = 0.14) indicates only a small fraction of SO42- is contributed by SO2 while the major fraction is contributed by soil and other sources probably long range transported sulphate.

  18. Retrieval and monitoring of atmospheric trace gas concentrations in nadir and limb geometry using the space-borne SCIAMACHY instrument.

    Science.gov (United States)

    Sierk, B; Richter, A; Rozanov, A; Von Savigny, Ch; Schmoltner, A M; Buchwitz, M; Bovensmann, H; Burrows, J P

    2006-09-01

    The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) onboard the European Envisat spacecraft performs continuous spectral observations of reflected, scattered and transmitted sunlight in various observation geometries. A unique feature of SCIAMACHY is the capability of probing the atmosphere in three different observation geometries:The nadir, limb, and occultation measurement modes. In nadir mode, column densities of trace gases are retrieved with a spatial resolution of typically 30 x 60 km using the Differential Optical Absorption Spectroscopy (DOAS) technique (Platt and Perner, 1983). Alternating with the nadir measurement, vertical profiles of absorber concentration in the stratosphere are derived in limb and occultation. In this paper we present an overview over some applications of SCIAMACHY data in space-based monitoring of atmospheric pollution. The DOAS algorithms for the retrieval of total column amounts from nadir spectra are briefly described and case studies of pollution events are presented. We also illustrate the technique used to derive stratospheric concentration profiles from limb observations and show comparisons with other remote sensing systems. Special emphasis will be given to techniques, which take advantage of SCIAMACHY's different viewing geometries. In particular, we will discuss the potential and limits of strategies to infer tropospheric abundances of O3 and NO2. PMID:16715354

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

    Science.gov (United States)

    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

  20. Osmium isotopic tracing of atmospheric emissions from an aluminum smelter

    Science.gov (United States)

    Gogot, Julien; Poirier, André; Boullemant, Amiel

    2015-09-01

    We present for the first time the use of osmium isotopic composition as a tracer of atmospheric emissions from an aluminum smelter, where alumina (extracted from bauxite) is reduced through electrolysis into metallic aluminum using carbonaceous anodes. These anodes are consumed in the process; they are made of petroleum coke and pitch and have high Re/Os elementary ratio. Due to the relatively large geological age of their source material, their osmium shows a high content of radiogenic 187Os produced from in situ187Re radioactive decay. The radiogenic isotopic composition (187Os/188Os ∼ 2.5) of atmospheric particulate emissions from this smelter is different from that of other typical anthropogenic osmium sources (that come from ultramafic geological contexts with unradiogenic Os isotopes, e.g., 187Os/188Os < 0.2) and also different from average eroding continental crust 187Os/188Os ratios (ca. 1.2). This study demonstrates the capacity of osmium measurements to monitor particulate matter emissions from the Al-producing industry.

  1. Atmospheric Deposition of Trace Elements in Ombrotrophic Peat as a Result of Anthropic Activities

    Science.gov (United States)

    Fabio Lourençato, Lucio; Cabral Teixeira, Daniel; Vieira Silva-Filho, Emmanoel

    2014-05-01

    Ombrotrophic peat can be defined as a soil rich in organic matter, formed from the partial decomposition of vegetable organic material in a humid and anoxic environment, where the accumulation of material is necessarily faster than the decomposition. From the physical-chemical point of view, it is a porous and highly polar material with high adsorption capacity and cation exchange. The high ability of trace elements to undergo complexation by humic substances happens due to the presence of large amounts of oxygenated functional groups in these substances. Since the beginning of industrialization human activities have scattered a large amount of trace elements in the environment. Soil contamination by atmospheric deposition can be expressed as a sum of site contamination by past/present human activities and atmospheric long-range transport of trace elements. Ombrotrophic peat records can provide valuable information about the entries of trace metals into the atmosphere and that are subsequently deposited on the soil. These trace elements are toxic, non-biodegradable and accumulate in the food chain, even in relatively low quantities. Thus studies on the increase of trace elements in the environment due to human activities are necessary, particularly in the southern hemisphere, where these data are scarce. The aims of this study is to evaluate the concentrations of mercury in ombrotrophic peat altomontanas coming from atmospheric deposition. The study is conducted in the Itatiaia National Park, Brazilian conservation unit, situated between the southeastern state of Rio de Janeiro, São Paulo and Minas Gerais. An ombrotrophic peat core is being sampled in altitude (1980m), to measure the trace elements concentrations of this material. As it is conservation area, the trace elements found in the samples is mainly from atmospheric deposition, since in Brazil don't exist significant lithology of trace elements. The samples are characterized by organic matter content which

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

    Directory of Open Access Journals (Sweden)

    J. P. Veefkind

    2010-08-01

    Full Text Available 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, sulfur dioxide, and formaldehyde 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 suggests that 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 (local efficiency 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 differences, providing some confidence in our understanding of aerosol sources, formation mechanisms, and sinks. Wintertime

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

    Science.gov (United States)

    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. Bifunctional alkyl nitrates - trace constituents of the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Kastler, J. [Department of Analytical and Environmental Chemistry, University of Ulm (Germany); Ballschmiter, K. [Center of Technology Assessment in Baden-Wuerttemberg, Stuttgart (Germany)

    1998-04-01

    Mono- and multifunctional esters of nitric acid (alkyl nitrates or organonitrates) form very complex mixtures of organic trace constituents in air. An analytical method was developed which combines selectivity in separation and detection in order to simplify this complexity in analytical terms. Mononitrates, dinitrates, keto nitrates, hydroxy nitrates of alkanes and alkenes, respecitvely, and bifunctional terpene nitrates were synthesized as reference substances. A specially developed new HPLC stationary phase (organonitrate phase) allows a group separation of mono-, di-, and hydroxy nitrates. After the HPLC preseparation the single components were finally separated by capillary HRGC-ECD and HRGC-MSD on polar and non-polar stationary phases. Mass spectrometric detection in the selected-ion-mode using the highly selective NO{sub 2}{sup +} fragment (m/z = 46 amu) led to very good selectivities for the nitric acid ester moiety. The analysis of a 100 m{sup 3} ambient air sample using this new analytical protocol allowed the identification of seven hydroxy nitrates and 24 dinitrates ranging from C2 to C7, 22 of them for the first time ever. (orig.) With 3 figs., 3 tabs., 20 refs.

  5. Millimeter wavelength spectroscopy of trace atmospheric constituents from the Five College Radio Astronomy Observatory

    Science.gov (United States)

    Huguenin, G. R.; Irvine, W. M.

    1978-01-01

    The Five College Radio Astronomy Observatory system, located in western Massachusetts, is described. It is suggested that high sensitivity in the three-millimeter wavelength band facilitates detection and monitoring of a number of trace molecules in the earth's atmosphere as well as astonomical observation at radio wavelengths. Line formation and radiative transfer in the earth's atmosphere are discussed, and the receiver sensitivity is considered.

  6. Atmospheric wet and dry deposition of trace elements at ten sites in Northern China

    OpenAIRE

    Pan, Y. P.; Y. S. Wang

    2014-01-01

    Atmospheric deposition is considered to be a major process that removes pollutants from the atmosphere and an important source of nutrients and contaminants for ecosystems. Trace elements (TEs), especially toxic metals deposited on plants and into soil and water, can cause substantial damage to the environment and human health due to their transfer and accumulation in food chains. Despite public concerns, quantitative knowledge of metal deposition from the a...

  7. Biomonitoring trace element atmospheric deposition using lichens in China

    International Nuclear Information System (INIS)

    Concentrations of 34 elements, Ag, As, Au, Ba, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mo, Na, Nd, Ni, Rb, Ru, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Tm, U, W, Yb, and Zn were determined by instrumental neutron activation analysis (INAA) in the early preserved epiphytic lichens (Parmotrema recticulata) from the remote Southwestern China area in 1960s, 1980s, and 1990s. The concentrations of Ag, As, Ce, Cr, Cs, Eu, Fe, Hf, La, Nd, Ni, Sc, Se, Sm, Tb, U, Yb, and Zn were dropped down by the temporal prolonation. The elemental concentration levels obtained from the organisms indicate that the extent of heavy metal atmospheric deposition among the sampling sites was declining during the past decades. (author)

  8. Observing Trace Gases Of The Arctic And Subarctic Stratosphere By TELIS

    Science.gov (United States)

    Xu, Jian; Schreier, Franz; Doicu, Adrian; Vogt, Peter; Birk, Manfred; Wagner, Georg; Trautmann, Thomas

    2013-12-01

    The Terahertz and submillimeter Limb Sounder (TELIS) is a balloon-borne cryogenic heterodyne spectrometer developed by a consortium of European institutes, which was mounted together with the Michelson Interferometer for Passive Atmospheric Sounding - Balloon (MIPAS- B) and the mini- Differential Optical Absorption Spectroscopy (mini-DOAS) instruments on a stratospheric gondola. The TELIS instrument is designed to monitor the vertical distribution of stratospheric state parameters associated with ozone destruction and climate change in Arctic and subarctic areas. The broad spectral coverage of TELIS is achieved by utilizing three frequency channels: a tunable 1.8THz channel based on a solid state local oscillator and a hot electron bolometer as mixer, a 480-650GHz channel with the Superconducting Integrated Receiver (SIR) technology, and a highly compact 500 GHz channel developed by the German Aerospace Center (DLR), the Netherlands Institute for Space Research (SRON), and the Rutherford Apple- ton Laboratory (RAL), respectively. Furthermore, an ex- tended spectral range is observed by the combination of TELIS and MIPAS-B, which can be employed for cross validation of several gas concentrations. Between 2009 and 2011 three successful scientific flights have been launched in Kiruna, Sweden and all relevant atmospheric gas species were seen by TELIS over an altitude range of 10-32.5 km. For estimation of concentration profiles from TELIS measurements, a constrained nonlinear least squares fitting framework along with var- ious Tikhonov-type regularization methods has been developed. In this work we present recent retrieval results from latest calibrated spectra during the 2010 flight. Emphasis is placed on ozone (O3) and hydrogen chloride (HCl), and error issues pertaining to the main instrumental uncertainty terms including nonlinearity in the calibration procedure, sideband ratio and pointing offset are investigated. The retrieved profiles are validated against

  9. Trans-Pacific transport and evolution of aerosols and trace gases from Asia during the INTEX-B field campaign

    Directory of Open Access Journals (Sweden)

    B. Adhikary

    2009-08-01

    Full Text Available The Sulfur Transport and dEposition Model (STEM developed at the University of Iowa is applied to the analysis of observations obtained during the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B, conducted over the Pacific Ocean during the 2006 North American spring season. This paper reports on the model performance of meteorological parameters, trace gases, aerosols and photolysis rate (J-values predictions with the NASA DC-8 and NSF/NCAR C-130 airborne measurements along with observations from three surface sites Mt. Bachelor, Trinidad Head and Kathmandu, Nepal. In general the model shows appreciable skill in predicting many of the important aspects of the observed distributions. The major meteorological parameters driving long range transport are accurately predicted by the WRF simulations used in this study. Furthermore, the STEM model predicts aerosols and trace gases concentrations within a standard deviation of most of the observed mean values. The results also point towards areas where model improvements are needed; e.g., the STEM model underestimates CO (15% for the DC8 and 6% for the C-130, whereas it overpredicts PAN (by a factor of two for both aircraft. The errors in the model calculations are attributed to uncertainty in emissions estimates and uncertainty in the top and lateral boundary conditions. Results from a series of sensitivity simulations examining the impact of the growth of emissions in Asia from 2000 to 2006, the importance of biomass burning, the effect of using boundary conditions from different global models, and the role of heterogeneous chemistry on the predictions are also presented. The impacts of heterogeneous reactions at specific times during dust transport episodes can be significant, and in the presence of dust both sulfate and nitrate aerosol production is increased and gas phase nitric acid levels are reduced appreciably (~50%. The aging of the air masses during the long range

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

    Science.gov (United States)

    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

  11. Refraction in planetary atmospheres: improved analytical expressions and comparison with a new ray-tracing algorithm

    CERN Document Server

    Betremieux, Yan

    2015-01-01

    Atmospheric refraction affects to various degrees exoplanet transit, lunar eclipse, as well as stellar occultation observations. Exoplanet retrieval algorithms often use analytical expressions for the column abundance along a ray traversing the atmosphere as well as for the deflection of that ray, which are first order approximations valid for low densities in a spherically symmetric homogeneous isothermal atmosphere. We derive new analytical formulae for both of these quantities, which are valid for higher densities, and use them to refine and validate a new ray tracing algorithm which can be used for arbitrary atmospheric temperature-pressure profiles. We illustrate with simple isothermal atmospheric profiles the consequences of our model for different planets: temperate Earth-like and Jovian-like planets, as well as HD189733b, and GJ1214b. We find that, for both hot exoplanets, our treatment of refraction does not make much of a difference to pressures as high as 10 atmosphere, but that it is important to ...

  12. Ray-Tracing studies in a perturbed atmosphere I- The initial value problem

    CERN Document Server

    Tannous, C

    2001-01-01

    We report the development of a new ray-tracing simulation tool having the potential of the full characterization of a radio link through the accurate study of the propagation path of the signal from the transmitting to the receiving antennas across a perturbed atmosphere. The ray-tracing equations are solved, with controlled accuracy, in three dimensions (3D) and the propagation characteristics are obtained using various refractive index models. The launching of the rays, the atmospheric medium and its disturbances are characterized in 3D. The novelty in the approach stems from the use of special numerical techniques dealing with so called stiff differential equations without which no solution of the ray-tracing equations is possible. Starting with a given launching angle, the solution consists of the ray trajectory, the propagation time information at each point of the path, the beam spreading, the transmitted (resp. received) power taking account of the radiation pattern and orientation of the antennas and ...

  13. Atmospherically deposited trace metals from bulk mineral concentrate port operations.

    Science.gov (United States)

    Taylor, Mark Patrick

    2015-05-15

    Although metal exposures in the environment have declined over the last two decades, certain activities and locations still present a risk of harm to human health. This study examines environmental dust metal and metalloid hazards (arsenic, cadmium, lead and nickel) associated with bulk mineral transport, loading and unloading port operations in public locations and children's playgrounds in the inner city of Townsville, northern Queensland. The mean increase in lead on post-play hand wipes (965 μg/m(2)/day) across all sites was more than 10-times the mean pre-play loadings (95 μg/m(2)/day). Maximum loading values after a 10-minute play period were 3012 μg/m(2), more than seven times the goal of 400 μg/m(2) used by the Government of Western Australia (2011). Maximum daily nickel post-play hand loadings (404 μg/m(2)) were more than 26 times above the German Federal Immission Control Act 2002 annual benchmark of 15 μg/m(2)/day. Repeat sampling over the 5-day study period showed that hands and surfaces were re-contaminated daily from the deposition of metal-rich atmospheric dusts. Lead isotopic composition analysis of dust wipes ((208)Pb/(207)Pb and (206)Pb/(207)Pb) showed that surface dust lead was similar to Mount Isa type ores, which are exported through the Port of Townsville. While dust metal contaminant loadings are lower than other mining and smelting towns in Australia, they exceeded national and international benchmarks for environmental quality. The lessons from this study are clear - even where operations are considered acceptable by managing authorities, targeted assessment and monitoring can be used to evaluate whether current management practices are truly best practice. Reassessment can identify opportunities for improvement and maximum environmental and human health protection.

  14. Internationally harmonised approach to biomonitoring trace element atmospheric deposition

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has been supporting work on airborne particulate matter since 1992 through various co-ordinated research and technical co-operation projects. In 1997, biomonitoring air pollution using plants, became officially a part of the IAEA project on environmental pollution monitoring and research. Based on: (1) positive experience in using biomonitors, especially lower plants such as mosses and lichens in several developed countries; (2) the continuous use of biomonitors in several Member States; and (3) the fact that nuclear and related analytical techniques have been shown to be particularly appropriate for the analysis of air pollution biomonitors, such studies are now being supported by the IAEA in 14 countries within a co-ordinated research project. The main emphasis of this project is on (1) identification of suitable biomonitors of atmospheric pollution for local and/or regional application, and (2) their validation for general environmental monitoring, whenever possible. Although the participants are using different plants as biomonitors in their research in geographically and climatically diverse parts of the world, they are harmonising sampling approaches and analytical procedures. In this paper, an overview of these activities is given, along with the details, where possible. In all of these activities, proficiency testing and analytical quality assurance are important issue, which merits special attention. To this end, a variety of analytical quality control materials have been used in intercomparison exercises and proficiency testing. Within the scope of the NAT-5 intercomparison exercise, two lichen materials were distributed among 15 participating laboratories and a proficiency test was organised. The results obtained proved satisfactory performance for most participating laboratories. (author)

  15. Laser Atmospheric Transmitter Receiver-Network (LAnTeRN): A new approach for active measurement of atmospheric greenhouse gases

    Science.gov (United States)

    Dobler, J. T.; Braun, M.; Zaccheo, T.

    2012-12-01

    The Laser Atmospheric Transmitter Receiver-Network (LAnTeRN) is a new measurement concept that will enable local, regional and continental determination of key greenhouse gases, with unparalleled accuracy and precision. This new approach will offer the ability to make low bias, high precision, quasi-continuous, measurements to the accuracies required for separating anthropogenic and biogenic sources and sinks. In 2004 ITT Exelis developed an airborne demonstration unit, based on an intensity modulated continuous wave (IM-CW) lidar approach, for actively measuring atmospheric CO2 and O2. The multi-functional fiber laser lidar (MFLL) system relies on low peak power, high reliability, and efficient telecom laser components to implement this unique measurement approach. While evaluating methods for discriminating against thin clouds for the MFLL instrument, a new measurement concept was conceived. LAnTeRN has several fundamental characteristics in common with the MFLL instrument, but is a fundamentally different implementation and capability. The key difference is that LAnTeRN operates in transmission rather than in the traditional backscatter lidar configuration, which has several distinct advantages. Operating as a forward scatter, bistatic lidar system, LAnTeRN enables consideration of continuous monitoring from a geostationary orbit to multiple locations on the ground. Having the receivers on the ground significantly lowers cost and risk compared to an all space based mission, and allows the transmitter subsystem to be implemented, near term, as a hosted payload. Furthermore, the LAnTeRN measurement approach is also applicable for ground to ground measurements where high precision measurements over a long open path is required, such as facilities monitoring, or monitoring of passive volcanoes and fault lines. Using narrow linewidth laser sources allows flexibility to select the position on the absorption feature being probed. This feature allows for weighting the

  16. Russian contribution to ExoMars Trace Gas Orbiter: Atmospheric Chemistry Suite (ACS)

    Science.gov (United States)

    Shakun, Alexey; Korablev, Oleg; Trokhimovskiy, Alexander; Grigoriev, Alexey; Anufreychik, Konstantin; Fedorova, Anna; Ignatiev, Nikolay; Ivanov, Yuriy; Moshkin, Boris; Kalinnikov, Yuriy; Montmessin, Franck

    2016-04-01

    . The MIR channel is a novel, high-aperture cross-dispersion spectrometer working in 2.3-4.2 μm spectral range, with resolving power of 50000, and covering simultaneously up to 300 nm per measurement. Targeting very high spectral resolution the MIR channel will operate in solar occultation only with a narrow FOV. MCT detector array with cryo-cooler is applied. The main science goal of MIR channel is to do record-breaking measurements and detections of minor gaseous species (CH4, C2H2, H2S, HCl and others), some yet undetected, some possibly related to volcanic or biologic activity. For the methane we predicting ~20 ppt sensitivity. The spectral range of MIR includes several CO2 absorption bands allowing doing measurements of density and temperature. D/H and its vertical profile in the Martian atmosphere will be measured for the first time. The short-wavelength side of MIR's spectral range is extended to cover almost the whole carbon monoxide band. TIRVIM is a 2-inch double pendulum Fourier-transform spectrometer covering in one interferometric channel the spectral range of 2-17 μm. Instrument has maximal optical path difference of 6 cm so its apodized spectral resolution is 0.2 cm-1. Single element PV-MCT detector with Stirling cooler is applied. To calibrate TIRVIM data onboard, internal black body and one-coordinate scanner are implemented. Scanning mirror provides possibility of observation in both nadir and solar occultation modes. FOV of the TIRVIM is 2.5deg. Main science goals of TIRVIM are detection of trace gases (solar occultation) and measurement of thermal profiles using 15μm-CO2 band (nadir). Martian aerosol properties and profiles can be also retrieved. Trace gases NO and N2O can be detected.

  17. Regional Modeling Support for Planning Airborne Campaigns to Observe CO2 and Other Trace Gases

    Science.gov (United States)

    Uliasz, M.; Schuh, A. E.; Denning, A.

    2010-12-01

    Lagrangian particle models (e.g., CSU LPDM, STILT) driven by regional meteorological models (e.g., WRF, SiB-RAMS) are useful tools in regional CO2 research including inversion studies, design of tower network, or testing and supporting flight scenarios. They are typically used in backward in time mode as an adjoint transport model providing, for each data point, influence functions (footprints) for surface fluxes and inflow fluxes across a domain perimeter. The following modeling framework is proposed to support a design of observational networks and field campaigns for measurement of CO2 concentrations in regional and continental scales: (1) atmospheric transport climatology covering several months for selected towers or flight transects, (2) testing specific flight scenarios (shorter time periods, but higher resolution), and (3) using model generated pseudo-data and inversion techniques to optimize observational strategies for specific objectives in terms of uncertainty reduction in estimated CO2 surface fluxes. This framework will be presented using examples from previous regional CO2 studies over North America with the aid of CSU SiB-RAMS and LPDM models. Then, it will be used to explore how column integrated measurements of CO2 from aircraft (active laser sounding) together with airborne sampling can complement the NOAA tall tower network of continuous CO2 measurements for inversion studies. Hypothetical flight scenarios are designed to collect information on both surface fluxes and boundary conditions around US domain perimeter using model simulations for the entire year of 2007. Example of three concentration sampling strategies (WBI tower continuous, and two flights during 4 afternoon hours every day), one month average (July, 2007) for a passive tracer (top), CO2 respiration flux (middle) and CO2 assimilation flux (bottom)

  18. Online technique for isotope and mixing ratios of CH4, N2O, Xe and mixing ratios of organic trace gases on a single ice core sample

    Science.gov (United States)

    Schmitt, J.; Seth, B.; Bock, M.; Fischer, H.

    2014-08-01

    Firn and polar ice cores enclosing trace gas species offer a unique archive to study changes in the past atmosphere and in terrestrial/marine source regions. Here we present a new online technique for ice core and air samples to measure a suite of isotope ratios and mixing ratios of trace gas species on a single sample. Isotope ratios are determined on methane, nitrous oxide and xenon with reproducibilities for ice core samples of 0.15‰ for δ13C-CH4, 0.22‰ for δ15N-N2O, 0.34‰ for δ18O-N2O, and 0.05‰ per mass difference for δ136Xe for typical concentrations of glacial ice. Mixing ratios are determined on methane, nitrous oxide, xenon, ethane, propane, methyl chloride and dichlorodifluoromethane with reproducibilities of 7 ppb for CH4, 3 ppb for N2O, 70 ppt for C2H6, 70 ppt for C3H8, 20 ppt for CH3Cl, and 2 ppt for CCl2F2. However, the blank contribution for C2H6 and C3H8 is large in view of the measured values for Antarctic ice samples. The system consists of a vacuum extraction device, a preconcentration unit and a gas chromatograph coupled to an isotope ratio mass spectrometer. CH4 is combusted to CO2 prior to detection while we bypass the oven for all other species. The highly automated system uses only ~ 160 g of ice, equivalent to ~ 16 mL air, which is less than previous methods. The measurement of this large suite of parameters on a single ice sample is new and key to understanding phase relationships of parameters which are usually not measured together. A multi-parameter data set is also key to understand in situ production processes of organic species in the ice, a critical issue observed in many organic trace gases. Novel is the determination of xenon isotope ratios using doubly charged Xe ions. The attained precision for δ136Xe is suitable to correct the isotopic ratios and mixing ratios for gravitational firn diffusion effects, with the benefit that this information is derived from the same sample. Lastly, anomalies in the Xe mixing ratio,

  19. Atmospherically deposited trace metals from bulk mineral concentrate port operations

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Mark Patrick, E-mail: mark.taylor@mq.edu.au

    2015-05-15

    Although metal exposures in the environment have declined over the last two decades, certain activities and locations still present a risk of harm to human health. This study examines environmental dust metal and metalloid hazards (arsenic, cadmium, lead and nickel) associated with bulk mineral transport, loading and unloading port operations in public locations and children's playgrounds in the inner city of Townsville, northern Queensland. The mean increase in lead on post-play hand wipes (965 μg/m{sup 2}/day) across all sites was more than 10-times the mean pre-play loadings (95 μg/m{sup 2}/day). Maximum loading values after a 10-minute play period were 3012 μg/m{sup 2}, more than seven times the goal of 400 μg/m{sup 2} used by the Government of Western Australia (2011). Maximum daily nickel post-play hand loadings (404 μg/m{sup 2}) were more than 26 times above the German Federal Immission Control Act 2002 annual benchmark of 15 μg/m{sup 2}/day. Repeat sampling over the 5-day study period showed that hands and surfaces were re-contaminated daily from the deposition of metal-rich atmospheric dusts. Lead isotopic composition analysis of dust wipes ({sup 208}Pb/{sup 207}Pb and {sup 206}Pb/{sup 207}Pb) showed that surface dust lead was similar to Mount Isa type ores, which are exported through the Port of Townsville. While dust metal contaminant loadings are lower than other mining and smelting towns in Australia, they exceeded national and international benchmarks for environmental quality. The lessons from this study are clear — even where operations are considered acceptable by managing authorities, targeted assessment and monitoring can be used to evaluate whether current management practices are truly best practice. Reassessment can identify opportunities for improvement and maximum environmental and human health protection. - Graphical abstract: Post-play hand wipe, Headland Park, Townsville, Australia. - Highlights: • Bulk mineral port

  20. Noble gases as tracers of the origin and evolution of the Martian atmosphere and the degassing history of the planet

    Science.gov (United States)

    Swindle, T. D.

    1988-01-01

    Noble gas analysis of Martian samples can provide answers to a number of crucial questions. Some of the most obvious benefits will be in Martian chronology, using techniques that have been applied to lunar samples. However, these are by no means the only relevant noble gas studies possible. Since Mars has a substantial atmosphere, noble gases can be used to study the origin and evolution of that atmosphere, including the degassing history of the planet. This type of study can provide constraints on: (1) the total noble gas inventory of the planet, (2) the number of noble gas reservoirs existing, and (3) the exchange of gases between these reservoirs. How to achieve these goals are examined.

  1. Vertical Distribution of Gases and Aerosols in Titan's Atmosphere Observed by VIMS/Cassini Solar Occultations

    Science.gov (United States)

    Maltagliati, Luca; Vinatier, Sandrine; Sicardy, Bruno; Bézard, Bruno; Sotin, Christophe; Nicholson, Philip D.; Hedman, Matt; Brown, Robert H.; Baines, Kevin; Buratti, Bonnie; Clark, Robert

    2013-04-01

    We present the vertical distribution of gaseous species and aerosols in Titan's atmosphere through the analysis of VIMS solar occultations. We employ the infrared channel of VIMS, which covers the 1 - 5 μm wavelength range. VIMS occultations can provide good vertical resolution (~10 km) and an extended altitude range (from 70 to 700 km), complementing well the information from other Cassini instruments. VIMS has retrieved 10 solar occultations up to now. They are distributed through the whole Cassini mission and they probe different latitudes in both hemispheres. Two main gases can be observed by VIMS occultations: methane, through its bands at 1.2, 1.4, 1.7, 2.3 and 3.3 μm, and CO, at 4.7 μm. We can extract methane's abundance between 70 and 750 km and CO's between 70 and 180 km. Regarding aerosols, the VIMS altitude range allows to get information on the properties of both the main haze and the detached layer. Aerosols also affect the transmittance through their spectral signatures. In particular, a spectral signature at 3.4 μm that was attributed to aerosols was recently discovered by the analysis of the first VIMS occultation. We will monitor the latitudinal and temporal variations of the 3.4 μm feature through various occultations. A change in the global circulation regime of Titan sets in with the approaching to the vernal equinox, and a strong decrease of the altitude of the detached layer between the winter solstice and the equinox has indeed been observed. The temporal coverage of VIMS occultations allows the study the effect of these variations in the vertical distribution of aerosol optical and spectral properties.

  2. Miniaturized Sensors for Monitoring of Atmospheric Trace Gases using Multiple Deployment Platforms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Daylight Solutions proposes a miniaturized sensor package based on ECqcLTM and QEPAS technology that were independently developed by Daylight Solutions (San Diego,...

  3. Trace gas retrieval for limb DOAS under changing atmospheric conditions: The X-gas scaling method vs optimal estimation

    Science.gov (United States)

    Hueneke, Tilman; Grossmann, Katja; Knecht, Matthias; Raecke, Rasmus; Stutz, Jochen; Werner, Bodo; Pfeilsticker, Klaus

    2016-04-01

    Changing atmospheric conditions during DOAS measurements from fast moving aircraft platforms pose a challenge for trace gas retrievals. Traditional inversion techniques to retrieve trace gas concentrations from limb scattered UV/vis spectroscopy, like optimal estimation, require a-priori information on Mie extinction (e.g., aerosol concentration and cloud cover) and albedo, which determine the atmospheric radiative transfer. In contrast to satellite applications, cloud filters can not be applied because they would strongly reduce the usable amount of expensively gathered measurement data. In contrast to ground-based MAX-DOAS applications, an aerosol retrieval based on O4 is not able to constrain the radiative transfer in air-borne applications due to the rapidly decreasing amount of O4 with altitude. Furthermore, the assumption of a constant cloud cover is not valid for fast moving aircrafts, thus requiring 2D or even 3D treatment of the radiative transfer. Therefore, traditional techniques are not applicable for most of the data gathered by fast moving aircraft platforms. In order to circumvent these limitations, we have been developing the so-called X-gas scaling method. By utilising a proxy gas X (e.g. O3, O4, …), whose concentration is either a priori known or simultaneously in-situ measured as well as remotely measured, an effective absorption length for the target gas is inferred. In this presentation, we discuss the strengths and weaknesses of the novel approach along with some sample cases. A particular strength of the X-gas scaling method is its insensitivity towards the aerosol abundance and cloud cover as well as wavelength dependent effects, whereas its sensitivity towards the profiles of both gases requires a priori information on their shapes.

  4. Volcano emissions of trace metals, atmospheric deposition, and supply to biogeochemical cycles

    Science.gov (United States)

    Hinkley, T.; Thornber, C. R.; Matsumoto, A.

    2003-12-01

    Quiescently degassing (not exploding) volcanoes inject into the troposphere plumes that have remarkably high concentrations of ordinarily-rare, volatile trace metals. In pre-industrial times, these emissions appear to have accounted for the strong "enrichments" (relative to concentrations in crustal material or in ocean solute) of many such trace metals in the material deposited from the atmosphere. This has been shown by measuring the source strength of the emissions of metals from volcanoes, and comparing that to the amounts of the metals (excess over amounts accounted for by rock dust and sea salt) deposited onto high-latitude ice sheets: volcano degassing outputs of metals and deposition masses of metals to ice are comparable, on the basis of the masses (fluxes) and proportions of the metals, and from the proportions of lead (Pb) isotopes. There is indication that in modern industrial times the elevated trace metal fractions in the atmospheric material that has small particle size and long atmospheric residence time is still more strongly influenced by volcano emissions than by industrial emissions. Throughout earth's history it is likely that volcano emissions were a major control on the environmental background levels of trace elements, in which plants and animals evolved their tolerances to these mostly-poisonous substances.

  5. The ExoMars Trace Gas Orbiter NOMAD Spectrometer Suite for Nadir and Solar Occultation Observations of Mars' Atmosphere

    Science.gov (United States)

    Thomas, Ian; Carine Vandaele, Ann; López-Moreno, José Juan; Patel, Manish; Bellucci, Giancarlo; Drummond, Rachel; Neefs, Eduard; Depiesse, Cedric; Daerden, Frank; Rodriguez-Gómez, Julio; Neary, Lori; Robert, Séverine; Willame, Yannick; Mahieux, Arnaud

    2015-04-01

    NOMAD (Nadir and Occultation for MArs Discovery) is one of four instruments on board the ExoMars Trace Gas Orbiter, scheduled for launch in January 2016 and to begin nominal science mission around Mars in late 2017. It consists of a suite of three high-resolution spectrometers - Solar Occultation (SO), LNO (Limb Nadir and Occultation) and UVIS (Ultraviolet-Visible) - which will generate a huge dataset of Martian atmospheric observations during the mission, across a wide spectral range. Specifically, the SO spectrometer channel will perform occultation measurements, operating between 2.2-4.3μm at a resolution of 0.15cm-1, with 180-1000m vertical spatial resolution and an SNR of 1500-3000. LNO will perform limb scanning, nadir and occultation measurements, operating between 2.2-3.8μm at a resolution of 0.3cm-1. In nadir, global coverage will extend between ±74O latitude with an IFOV of 0.5x17km on the surface. This channel can also make occultation measurements should the SO channel fail. UVIS will make limb, nadir and occultation measurements between 200-650nm, at a resolution of 1nm. It will have 300-1000m vertical resolution during occultation and 5x60km ground resolution during 15s nadir observations. An order-of-magnitude increase in spectral resolution over previous instruments will allow NOMAD to map previously unresolvable gas species, such as important trace gases and isotopes. CO, CO2, H2O, C2H2, C2H4, C2H6, H2CO, CH4, SO2, H2S, HCl, O3 and several isotopologues of methane and water will be detectable, providing crucial measurements of the Martian D/H and methane isotope ratios. It will also be possible to map the sources and sinks of these gases, such as regions of surface volcanism/outgassing and atmospheric production, over the course of an entire Martian year, to further constrain atmospheric dynamics and climatology. NOMAD will also continue to monitor the Martian water, carbon, ozone and dust cycles, extending existing datasets made by successive

  6. Use of mosses as biomonitors of atmospheric deposition of trace elements

    International Nuclear Information System (INIS)

    Some basic facts about the use of mosses as biomonitors of atmospheric trace element deposition are reviewed, and advantages and limitations of this approach are discussed, largely on the basis of experience from regular use of this technique in Norway over the last 20 years. Topics discussed include different versions of the moss technique, mechanisms and efficiencies of trace element uptake, conversion of concentrations in moss to bulk deposition rates, and contribution from sources other than air pollution to the elemental composition of different elements. Suggestions are presented for further work in order to extend the use of mosses as biomonitors. (author)

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    D. W. T. Griffith

    2013-02-01

    Full Text Available 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

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

    Directory of Open Access Journals (Sweden)

    D. W. T. Griffith

    2012-09-01

    Full Text Available 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

  10. Elimination of carbon dioxide and other atmospheric gases by means of calcium rich industrial w aste

    OpenAIRE

    Esquivias, L.; Santos, Alberto; Morales, Alberto

    2010-01-01

    [EN] The present invention relates to the use of an aqueous suspension comprising calcium in a proportion exceeding 15% by weight, the solid phase of such aqueous suspension being preferably portlandite proceeding from chemical industry waste, for the elimination of CO2 and other greenhouse effect gases. The present invention moreover relates to a procedure of elimination of said gases under conditions of ambient pressure and temperatures, through both induced and environmental carbo...

  11. The Heidelberg Airborne Imaging DOAS Instrument (HAIDI) – a novel imaging DOAS device for 2-D and 3-D imaging of trace gases and aerosols

    OpenAIRE

    S. General; D. Pöhler; H. Sihler; N. Bobrowski; Frieß, U.; J. Zielcke; M. Horbanski; P. B. Shepson; Stirm, B. H.; Simpson, W. R.; Weber, K; C. Fischer; U. Platt

    2014-01-01

    Many relevant processes in tropospheric chemistry take place on rather small scales (e.g., tens to hundreds of meters) but often influence areas of several square kilometer. Thus, measurements of the involved trace gases with high spatial resolution are of great scientific interest. In order to identify individual sources and sinks and ultimately to improve chemical transport models, we developed a new airborne instrument, which is based on the well established Differential ...

  12. Agricultural fires in the southeastern U.S. during SEAC4RS: Emissions of trace gases and particles and evolution of ozone, reactive nitrogen, and organic aerosol

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Measurement of the Residual Gases O2 and CO2 in Meat Products Packed in Modified Atmosphere

    Directory of Open Access Journals (Sweden)

    Jozef Čapla

    2013-02-01

    Full Text Available Nowadays, consumers have increased demand for quality and food safety and also rising demand for natural foods without chemical additives. There are many ways to presserve freshness of these products, one of them is modified atmosphere packaging, which can mean elimination and/or replacement surrounding the product before closing it in package with a mixture of gases other than the original ambient air atmosphere. for replacement of atmosphere are generally used three types of gases such as carbon dioxide, oxygen and nitrogen. this type of packaging is often used for meat and meat products, which belongs to foods that are under normal conditions perishable and for increasing the shelf life of meat products are also used various other preservation methods or their combinations. Packaging of meat and meat products in modified atmosphere is usually made with a high content of carbon dioxide, which has good bacteriostatic and fungistatic effect and is also an effective mean for increasing the shelf life of packaged products during storage and sale.

  15. Characteristic emission enhancement in the atmosphere with Rn trace using metal assisted LIBS

    International Nuclear Information System (INIS)

    Several characteristic emission lines from the metal targets (Cu, Zn and Pb) were investigated in trace presence of radon gas in the atmospheric air, using Q-SW Nd:YAG laser induced plasma inside a control chamber. The emission lines of metal species are noticeably enhanced in (Rn+air), relative to those in the synthetic air alone. Similar spectra were also taken in various sub-atmospheric environments in order to determine the optimum pressure for enhancement. Solid-state nuclear track detectors were also employed to count the tracks due to alpha particles for the activity assessment

  16. Delonix regia and Casuarina equisetifolia as passive biomonitors and as bioaccumulators of atmospheric trace metals.

    Science.gov (United States)

    Ukpebor, Emmanuel Ehiabhi; Ukpebor, Justina Ebehirieme; Aigbokhan, Emmanuel; Goji, Idris; Onojeghuo, Alex Okiemute; Okonkwo, Anthony Chinedum

    2010-01-01

    The suitability of two common and ubiquitously distributed and exotic ornamental plant species in Nigeria-Delonix regia and Casuarina equisetifolia as biomonitors and as effective bioaccumulators of atmospheric trace metals (Cd, Pb, Zn and Cu) has been evaluated. Bark and leaf samples from these plant species were collected in June and July 2006 at five locations in Benin City. Four of the sampling sites were in areas of high traffic density and commercial activities, the fifth site is a remote site, selected to act as a control and also to provide background information for the metals. The plant samples were collected and processed using standard procedures and trace metals were determined using atomic absorption spectrometer. The bark of the plants was able to bioaccumulate the trace metals, especially Pb which originates from anthropogenic contributions in the city. The Pb range of 20.00-70.00 microg/g measured for the bark samples of D. regia, exceeded the normal plant Pb concentration of 0.2-20.0 microg/g and most Pb data available in literature. The bark of the plants was observed to accumulate more metals compared to the leave, while D. regia was found to be slightly better than C. equisetifolia in trace metal uptake efficiency. Spatial variations in the distributions of Pb and Zn were significant (p < 0.05), and the continuous use of leaded fuel in Nigeria was identified as the predominant source of Pb in the atmosphere.

  17. The Influence of Urban Emissions on Background Aerosols and Trace Gases in Amazonia as Seen in the GoAmazon2014/2015 Experiment.

    Science.gov (United States)

    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

    As part of the GoAmazon2014/2015 experiment, several aerosol and trace gas monitoring stations are being operated for two years before and after the Manaus urban plume in Central Amazonia. Three sites are being operated in pristine conditions, with atmospheric properties under natural biogenic conditions. These three sites named T0 are ATTO (Amazon Tall Tower Observatory), ZF2 and EMBRAPA. After the air masses are exposed to the Manaus plume, one site (called T2) is being operated under the direct influence of the Manaus plume at 5 Km downwind. Finally, at about 150 Km downwind of Manaus is the T3 Manacapuru site. Aerosol chemical composition is being analysed using filters for fine (PM2.5) and coarse mode aerosol as well as three Aerodyne ACSM (Aerosol Chemical Speciation Monitors) instruments. Optical properties were measured with several AE33 aethalometers and MAAP, and multi wavelengths nephelometers. Aerosol size distribution is determined using scanning mobility particle sizers. The aerosol column is measures using AERONET sunphotometers before and after the Manaus plume, as well as several Lidar systems. The three sites before the Manaus plume show remarkable similar variability in aerosol concentrations and optical properties. This pattern is very different at the T2 site, with large aerosol concentrations enhancing aerosol absorption and scattering significantly as a result of the Manaus pollution plume. The aerosol is very oxidized before being exposed to the Manaus plume, and this pattern changes significantly for T2 and T3 sites, with a much higher presence of less oxidized aerosol. Typical ozone concentrations at mid-day before Manaus plume is a low 10-12 ppb, value that changes to 50-70 ppb for air masses suffering the influence of Manaus plume. Aerosol size distribution also change significantly, with stronger presence of nucleation mode particles. A detailed comparison of aerosol characteristics and composition for the several sites will be

  18. System and Method for Providing Vertical Profile Measurements of Atmospheric Gases

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A system and method for using an air collection device to collect a continuous air sample as the device descends through the atmosphere are provided. The air...

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

    Directory of Open Access Journals (Sweden)

    S. J. Lawson

    2015-07-01

    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 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  2. Remote sensing of atmospheric trace gas columns: an efficient approach for regularization and calculation of total column averaging kernels

    Directory of Open Access Journals (Sweden)

    T. Borsdorff

    2013-06-01

    Full Text Available A concept is proposed to retrieve the vertical column densities of atmospheric trace gases from remote sensing measurements. It combines the numerical simplicity of a least-squares profile scaling retrieval with the numerically robust calculation of the total column averaging kernel using an analytic expression. The approach enables calculation of the total column averaging kernel on arbitrary vertical grids. Formally, the proposed method is equivalent to Tikhonov regularization of the first kind with an infinite regularization strength. Due to its efficiency it is particularly suited for implementation in operational data processing with high demands on processing time. To demonstrate the method, we apply it to CO column retrieval from simulated measurements in the 2.3 μm spectral region and to O3 column retrieval from the UV, which represents ideal measurements of a series of space-borne spectrometers like SCIAMACHY, TROPOMI, GOME, and GOME-2. For both spectral ranges, we consider clear-sky and cloudy scenes where clouds are modelled as an elevated Lambertian surface. Here, the smoothing error for the clear-sky and cloudy atmosphere is significant and reaches several percent, depending on the reference profile which is used for scaling. This underlines the importance of the column averaging kernel for a proper interpretation of retrieved column densities. Furthermore, we show that the total column smoothing error is affected by a discretization error when total column averaging kernels are not represented on a fine enough vertical grid. For both retrievals this effect becomes negligible by using a vertical grid with 20–40 equally thick layers between 0 and 50 km.

  3. Concentrations and isotope ratios of helium and other noble gases in the Earth's atmosphere during 1978-2011

    CERN Document Server

    Brennwald, Matthias S; Figura, Simon; Vollmer, Martin K; Langenfelds, Ray; Steele, L Paul; Kipfer, Rolf

    2012-01-01

    The evolution of the atmospheric noble gas composition during the past few decades has hardly been studied because, in contrast to many other atmospheric gases, systematic time-series measurements have not been available. Based on theoretical considerations, the atmospheric noble gas isotope composition is assumed to be stable on time scales of up to about 10^6 years, with the potential exception of anthropogenic changes predicted for the He concentration and the 3He/4He ratio. However, experimental assessments of the predicted changes in the atmospheric He isotope composition are controversial. To empirically test these assumptions and predictions, we analysed the noble gas isotope composition in samples of the Cape Grim Air Archive, a well-defined archive of marine boundary layer air in the southern hemisphere. The resulting time series of the 20Ne, 40Ar, 86Kr and 136Xe concentrations and 20Ne/22Ne and 40Ar/36Ar ratios during 1978-2011 demonstrate the stability of the atmospheric Ne, Ar, Kr and Xe compositi...

  4. Contribution to the chromatography of atmospheric gases (1963); Contribution a la chromatographie des gaz de l'air (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Ghalamsiah, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-06-15

    In the first part, the author studies the gas-phase chromatographic separation of the atmospheric rare gases, of hydrogen, and of some gaseous compounds of carbon (CO, CO{sub 2}, CH{sub 4}) using inactive gases to obtain the most favourable operational conditions far this separation. In the second part, the optimum conditions for detecting non-active gases using an ionisation chamber and a {sup 239}Pu radioactive source emitting 5.15 MeV {alpha} particles are determined. (author) [French] Dans une premiere partie, l'auteur etudie la separation par chromatographie en phase gazeuse des gaz rares de l'air, de l'hydrogene, et de quelques composes gazeux du carbone (CO, CO{sub 2}, CH{sub 4}) en utilisant des gaz inactifs an vue d'obtenir les conditions experimenales les plus favorables en vue de cette separation. Dans une deuxieme partie, les conditions optimales de detection de gaz non actifs a l'aide d'une chambre d'ionisation, en utilisant comme source radioactive du {sup 239}Pu qui emet des particules {alpha} de 5,15 MeV, sont determinees. (auteur)

  5. Atmospheric greenhouse gases retrieved from SCIAMACHY: comparison to ground-based FTS measurements and model results

    OpenAIRE

    Schneising, O.; Bergamaschi, P.; H. Bovensmann; M. Buchwitz; Burrows, J.P.; Deutscher, N.M.; Griffith, D. W. T.; J. Heymann; Macatangay, R.; J. Messerschmidt; Notholt, J.; M. Rettinger; Reuter, M.; Sussmann, R.; V. A. Velazco

    2012-01-01

    SCIAMACHY onboard ENVISAT (launched in 2002) enables the retrieval of global long-term column-averaged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO2 and XCH4). In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Tra...

  6. Fractionation of trace elements in total atmospheric deposition by filtrating-bulk passive sampling.

    Science.gov (United States)

    Rueda-Holgado, F; Palomo-Marín, M R; Calvo-Blázquez, L; Cereceda-Balic, F; Pinilla-Gil, E

    2014-07-01

    We have developed and validated a new simple and effective methodology for fractionation of soluble and insoluble forms of trace elements in total atmospheric deposition. The proposed methodology is based on the modification of a standard total deposition passive sampler by integrating a quartz fiber filter that retains the insoluble material, allowing the soluble fraction to pass through and flow to a receiving bottle. The quartz filter containing the insoluble fraction and the liquid containing the soluble fraction are then separately assayed by standardized ICP-MS protocols. The proposed atmospheric elemental fractionation sampler (AEFS) was validated by analyzing a Coal Fly Ash reference material with proper recoveries, and tested for field fractionation of a set of 10 key trace elements in total atmospheric deposition at the industrial area of Puchuncaví-Ventanas, Chile. The AEFS was proven useful for pollution assessment and also to identify variability of the soluble and insoluble fractions of the selected elements within the study area, improving the analytical information attainable by standard passive samplers for total deposition without the need of using sophisticated and high cost wet-only/dry only collectors.

  7. Atmospheric CO{sub 2}, trace gas and CN concentrations in Vaerrioe

    Energy Technology Data Exchange (ETDEWEB)

    Ahonen, T.; Aalto, P.; Kulmala, M.; Rannik, U.; Vesala, T. [Helsinki Univ. (Finland). Dept. of Physics; Hari, P.; Pohja, T. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1995-12-31

    The Vaerrioe environmental measurement station is founded in 1991. The aim of the station is to obtain more information on air quality influenced by Kola industrial areas and effects of pollutants on photosynthesis in subarctic climate. In the station air quality and meteorological quantities are measured together with photosynthesis, which makes it quite unique in comparison with other measurement stations located in northern Finland. The measurements also provide information of aerosol and trace gas concentrations in order to study the direct and indirect aerosol effects on climate. These measurements also increase the knowledge of atmospheric chemistry and deposition in subarctic conditions

  8. Critical Masses for Various Terrestrial Planet Atmospheric Gases and Water in/on Mars

    OpenAIRE

    Lin-gun Liu

    2014-01-01

    The lower critical mass boundaries (CM) for various atmospheric gas species on terrestrial planets are estimated. The CM is different for different gas molecules. Except for He, the observed atmospheric compositions of the terrestrial planets are consistent with these estimates. The lower CM boundary for gaseous H2O is calculated as 8.06 ×× 1026 g, which is significantly greater than the Martian mass (6.419 ×× 1026 g). Thus, Mars is not capable of retaining H2O in its atmosphere. If the specu...

  9. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2012-08-01

    Full Text Available 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

  10. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2013-01-01

    Full Text Available 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

  11. The role of atmospheric greenhouse gases, orbital parameters, and southern ocean gateways: an idealized model study

    OpenAIRE

    Hertwig, Eileen; Lunkeit, Frank; Fraedrich, Klaus

    2016-01-01

    A set of idealized experiments are performed to analyze the competing effects of declining atmospheric CO2 concentrations, the opening of an ocean gateway, and varying orbital parameters. These forcing mechanisms, which influence the global mean climate state, may have played a role for triggering climate transitions of the past (for example during the Eocene-Oligocene climate transition and the build-up of the Antarctic Ice Sheet). Sensitivity simulations with a coupled atmosphere-ocean gene...

  12. PREP-CHEM-SRC – 1.0: a preprocessor of trace gas and aerosol emission fields for regional and global atmospheric chemistry models

    Directory of Open Access Journals (Sweden)

    S. R. Freitas

    2011-05-01

    Full Text Available The preprocessor PREP-CHEM-SRC presented in the paper is a comprehensive tool aiming at preparing emission fields of trace gases and aerosols for use in atmospheric-chemistry transport models. The considered emissions are from the most recent databases of urban/industrial, biogenic, biomass burning, volcanic, biofuel use and burning from agricultural waste sources. For biomass burning, emissions can be also estimated directly from satellite fire detections using a fire emission model included in the tool. The preprocessor provides emission fields interpolated onto the transport model grid. Several map projections can be chosen. The inclusion of these emissions in transport models is also presented. The preprocessor is coded using Fortran90 and C and is driven by a namelist allowing the user to choose the type of emissions and the databases.

  13. Multipass optical absorption spectroscopy: a fast-scanning laser spectrometer for the in situ determination of atmospheric trace-gas components, in particular OH.

    Science.gov (United States)

    Armerding, W; Spiekermann, M; Walter, J; Comes, F J

    1996-07-20

    The optical design of an absorption spectrometer for in situ measurements of atmospheric trace gases is reported. The light source is a rapidly tuned and power-stabilized dye-ring laser, which is frequency doubled by an intracavity BBO crystal. The second harmonic and the fundamental are used simultaneously for measurement of OH, SO(2), CH(2)O, and naphthalene in the UV and of NO(2) in the visible. The 1.2-km absorption path is folded within a 6-m White-cell-type multiple-reflection system with an open-path setup. The absorption sensitivity of the spectrometer is better than 1 part in 10(-5) under tropospheric conditions (integration time 1 min., signal-to-noise ratio 1).

  14. Atmospheric inverse modeling with known physical bounds: an example from trace gas emissions

    Directory of Open Access Journals (Sweden)

    S. M. Miller

    2013-09-01

    Full Text Available Many inverse problems in the atmospheric sciences involve parameters with known physical constraints. Examples include non-negativity (e.g., emissions of some urban air pollutants or upward limits implied by reaction or solubility constants. However, probabilistic inverse modeling approaches based on Gaussian assumptions cannot incorporate such bounds and thus often produce unrealistic results. The atmospheric literature lacks consensus on the best means to overcome this problem, and existing atmospheric studies rely on a limited number of the possible methods with little examination of the relative merits of each. This paper investigates the applicability of several approaches to bounded inverse problems and is also the first application of Markov chain Monte Carlo (MCMC to estimation of atmospheric trace gas fluxes. The approaches discussed here are broadly applicable. A common method of data transformations is found to unrealistically skew estimates for the examined example application. The method of Lagrange multipliers and two MCMC methods yield more realistic and accurate results. In general, the examined MCMC approaches produce the most realistic result but can require substantial computational time. Lagrange multipliers offer an appealing alternative for large, computationally intensive problems when exact uncertainty bounds are less central to the analysis. A synthetic data inversion of US anthropogenic methane emissions illustrates the strengths and weaknesses of each approach.

  15. Atmospheric dry deposition fluxes of trace elements measured in Queretaro City, Mexico

    Science.gov (United States)

    Garcia, R.; Hernandez, R.; Solis, S.; Perez, R.; Hernandez, G.; Morton, O.; Hernandez, E.; Torres, M. C.; Baez, A.

    2012-04-01

    Sampling was made in the southern section of downtown Mexico City. Samples were collected with an Mini-Vol PM10 . Eight different sources were identified for PM10 aerosols: secondary sulfate, wood combustion, fireworks, road traffic, mineral dust, de-icing salt, industrial and local anthropogenic activities. The ions SO42-, NO3-, Cl-, Na+, K+, Ca2+, Mg2+ and NH4+,were analyzed by ion chromatography and the trace metals using an atomic absorption spectrometer. The result indicated that SO42- was the most abundant ion and with respect to trace metal. All the trace elements except Mn and V show statistically significant differences between monitoring sites. The Pearson's correlation applied to all data, showed a high correlation among SO42-, NO3- and NH4+, indicating a common anthropogenic origin. In addition the correlation found between Ca2+ and Al indicated a crustal origin. On the other hand, in considering the total sampling period for particles as well as for all the metals, it is appreciable the significant differences between sites and meteorological seasons. The cluster analysis of air back-trajectories employed in the paper is a technique widely used to identify transport patterns and potential sources of both anthropogenic pollution and natural constituents of the atmosphere, including atmospheric aerosols. It is also used to determine how aerosol optical properties observed over the station differ depending on source region and transport pathways In order to gain a better insight into the origin of trace metal and major inorganic ions, a Principal Component Analysis was applied to the results for 6 elements and 8 ions, from the years 2009 and 2010. Further, the statistical analysis demonstrated the adequate selection of the monitoring areas, confirming that main emission source of these atmospheric pollutants is anthropogenic origin. Evidence suggests that the organic and inorganic species are not always internally mixed, especially in the small modes. The

  16. 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

    Energy Technology Data Exchange (ETDEWEB)

    Zaveri, Rahul A.; Berkowitz, Carl M.; Brechtel, Fred J.; Gilles, Marry K.; Hubbe, John M.; Jayne, J. T.; Kleinman, Lawrence I.; Laskin, Alexander; Madronich, Sasha; Onasch, Timothy B.; Pekour, Mikhail S.; Springston, Stephen R.; Thornton, Joel A.; Tivanski, Alexei V.; Worsnop, Douglas R.

    2010-06-22

    Chemical evolution of aerosols and trace gases in the Salem Harbor power plant plume was monitored with the DOE G-1 aircraft on the night of July 30-31, 2002. Quasi-Lagrangian sampling in the plume at increasing downwind distances/processing times was guided by a constant-volume tetroon 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 nearby background air. These 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 to be as secondary organic aerosol, possibly formed from the NO3 radical-initiated oxidation of isoprene and other trace organic gases in the presence of acidic sulfate particles. The enhanced particulate sulfate concentrations observed in the plume were attributed to direct emissions of gaseous SO3/H2SO4 from the power plant. Furthermore, concentration of nucleation mode particles was significantly higher in the plume than in background air, suggesting that some of the emitted H2SO4 had nucleated to form new particles. Spectromicroscopic analyses of particle samples suggested that some sulfate was likely in the form of organosulfates. Constrained Lagrangian model analysis of the aircraft and tetroon observations showed that heterogeneous hydrolysis of N2O5 was negligibly slow. These results have significant implications for several scientific and regulatory issues related to the impacts of power plant emissions on atmospheric chemistry, air quality, visibility, and climate.

  17. A comparison of minor trace gas retrievals from the Tropospheric Emission Spectrometer (TES) and the Infrared Atmospheric Sounding Interferometer (IASI)

    Science.gov (United States)

    Cady-Pereira, K. E.; Shephard, M. W.; Henze, D. K.; Millet, D. B.; Gombos, D.; Van Damme, M.; Clarisse, L.; Coheur, P. F.; Pommier, M.; Clerbaux, C.

    2014-12-01

    The advent of hyperspectral infrared instruments orbiting the Earth has allowed for detecting and measuring numerous trace gas species that play important roles in atmospheric chemistry and impact air quality, but for which there is a dearth of information on their distribution and temporal variability. Here we will present global and regional comparisons of measurements from the NASA TES and the European MetOp IASI instruments of three of these gases: ammonia (NH3), formic acid (HCOOH) and methanol (CH3OH). Ammonia is highly reactive and thus very variable in space and time, while the sources and sinks of methanol and formic acid are poorly quantified: thus space-based measurements have the potential of significantly increasing our knowledge of the emissions and distributions of these gases. IASI and TES have many similarities but some significant differences. TES has significantly higher spectral resolution (0.06 cm-1), and its equator crossing times are ~1:30 am and 1:30 pm, local time, while IASI has lower resolution (0.5 cm-1) and an earlier equator crossing time (9:30 am and 9:30 pm), which leads to lower thermal contrast; however IASI provides much greater temporal and spatial coverage due to its cross-track scanning. Added to the instrumental differences are the differences in retrieval algorithms. The IASI team uses simple but efficient methods to estimate total column amounts of the species above, while the TES team performs full optimal estimation retrievals. We will compare IASI and TES total column measurements averaged on a 2.5x2.5 degree global grid for each month in 2009, and we will examine the seasonal cycle in some regions of interest, such as South America, eastern China, and the Midwest and the Central Valley in the US. In regions where both datasets are in agreement this analysis will provide confidence that the results are robust and reliable. In regions where there is disagreement we will look for the causes of the discrepancies, which will

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

    Science.gov (United States)

    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

  19. Influence of atmospheric 14CO2 on determination of the ratio of biogenic carbon to fossil one in exhaust gases using accelerator mass spectrometry. Experimental evaluation for industrial flue gases

    International Nuclear Information System (INIS)

    The influence of atmospheric 14CO2 was evaluated on the determination of biogenic carbon ratios in industrial flue gases using accelerated mass spectrometry(AMS). Bioethanol, n-hexane, and their mixtures were combusted with a four-stroke engine, and 14CO2 in exhaust gases was analyzed by AMS. The experimental biogenic carbon ratio determined by ASTM D6866 method was 1.2 times higher than the theoretical value of mixed fuel containing 3.18% biogenic carbons. In general, the influence of atmospheric 14CO2 taken in combustion gases is neglected. It seems that the error cannot be neglected under international trading of emission allowances, where a large amount of carbons in the fuel were evaluated. The experimental value became to be the theoretical value by subtracting the amount of atmospheric 14C from that of the samples. As the contents of biofuel increased, the experimental biogenic carbon ratios reached the theoretical values and the influence of atmospheric 14CO2 decreased. We recommend that the influence of atmospheric 14CO2 should be corrected when fuel samples contain low amounts of 14C. (author)

  20. Improvement of Thermoplastic Polyurethane Nonwoven Hydrophilicity by Atmospheric Pressure Plasma Treatment with He and N2 Mixed Gases

    Science.gov (United States)

    Chen, Ko-Shao; Liao, Shu-Chuan; Lin, Shen-Wei; Hung, Tsui-Shan; Tsao, Shao-Hsuan; Wu, Hsin-Ming; Inagaki, Norihiro; Chen, Wei-Yu

    2012-01-01

    Thermoplastic polyurethane (TPU) nonwoven has good mechanical properties for use in biomaterial. However, its inherent hydrophobic nature restricts its application. In this study, atmospheric pressure plasma treatment with He and N2 gases was employed to TPU nonwoven material to improve the surface hydrophilicity while retaining the hydrophobicility on the back side of the material. The surface wettability was measured by water contact angle analysis, and the surface chemical composition was analyzed by X-ray photoelectron spectroscopy (XPS). The surface morphology was examined using scanning electron microscopy (SEM). The experimental results reveal that oxygen-containing groups such as C-O and O-C=O are generated on the plasma-treated TPU surface, leading to improved wettablility of the material.

  1. Impacts of greenhouse gases and aerosol direct and indirect effects on clouds and radiation in atmospheric GCM simulations of the 1930-1989 period

    OpenAIRE

    Quaas, Johannes; Dufresne, Jean-Louis; Boucher, Olivier; Le Treut, Hervé

    2015-01-01

    Among anthropogenic perturbations of the Earth\\'s atmosphere, greenhouse gases and aerosols are considered to have a major impact on the energy budget through their impact on radiative fluxes. We use three ensembles of simulations with the LMDZ general circulation model to investigate the radiative impacts of five species of greenhouse gases (CO2, CH4, N2O, CFC-11 and CFC-12) and sulfate aerosols for the period 1930-1989. Since our focus is on the atmospheric changes in clouds and radiation f...

  2. The role of atmospheric greenhouse gases, orbital parameters, and southern ocean gateways: an idealized model study

    CERN Document Server

    Hertwig, Eileen; Fraedrich, Klaus

    2016-01-01

    A set of idealized experiments are performed to analyze the competing effects of declining atmospheric CO2 concentrations, the opening of an ocean gateway, and varying orbital parameters. These forcing mechanisms, which influence the global mean climate state, may have played a role for triggering climate transitions of the past (for example during the Eocene-Oligocene climate transition and the build-up of the Antarctic Ice Sheet). Sensitivity simulations with a coupled atmosphere-ocean general circulation model are conducted to test these three forcings and their roles for the global climate. The simulations are carried out under idealized conditions to focus on the essentials. The combination of all three forcings triggers a climate transition which resembles the onset of the Antarctic glaciation. In particular, the temperatures in the southern high latitudes decrease and snow accumulates constantly. Moreover, the relative importance of each possible forcing is explored. All three of the mechanisms (atmosp...

  3. Atmospheric electrification in dusty, reactive gases in the solar system and beyond

    CERN Document Server

    Helling, Ch; Honary, F; Diver, D A; Aplin, K; Dobbs-Dixon, I; Ebert, U; Inutsuka, S; Gordillo-Vazquez, F J; Littlefair, S

    2016-01-01

    Detailed observations of the solar system planets reveal a wide variety of local atmospheric conditions. Astronomical observations have revealed a variety of extrasolar planets none of which resembles any of the solar system planets in full. Instead, the most massive amongst the extrasolar planets, the gas giants, appear very similar to the class of (young) Brown Dwarfs which are amongst the oldest objects in the universe. Despite of this diversity, solar system planets, extrasolar planets and Brown Dwarfs have broadly similar global temperatures between 300K and 2500K. In consequence, clouds of different chemical species form in their atmospheres. While the details of these clouds differ, the fundamental physical processes are the same. Further to this, all these objects were observed to produce radio and X-ray emission. While both kinds of radiation are well studied on Earth and to a lesser extent on the solar system planets, the occurrence of emission that potentially originate from accelerated electrons o...

  4. Apoptotic effects on cultured cells of atmospheric-pressure plasma produced using various gases

    Science.gov (United States)

    Tominami, Kanako; Kanetaka, Hiroyasu; Kudo, Tada-aki; Sasaki, Shota; Kaneko, Toshiro

    2016-01-01

    This study investigated the effects of low-temperature atmospheric-pressure plasma on various cells such as rat fibroblastic Rat-1 cell line, rat neuroblastoma-like PC12 cell line, and rat macrophage-like NR8383 cell line. The plasma was irradiated directly to a culture medium containing plated cells for 0-20 s. The applied voltage, excitation frequency, and argon or helium gas flow were, respectively, 3-6 kV, 10 kHz, and 3 L/min. Cell viability and apoptotic activity were evaluated using annexin-V/propidium iodide staining. Results showed that the low-temperature atmospheric-pressure plasma irradiation promoted cell death in a discharge-voltage-dependent and irradiation-time-dependent manner. Furthermore, different effects are produced depending on the cell type. Moreover, entirely different mechanisms might be responsible for the induction of apoptosis in cells by helium and argon plasma.

  5. [Errors Analysis and Correction in Atmospheric Methane Retrieval Based on Greenhouse Gases Observing Satellite Data].

    Science.gov (United States)

    Bu, Ting-ting; Wang, Xian-hua; Ye, Han-han; Jiang, Xin-hua

    2016-01-01

    High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 μm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method. PMID:27228765

  6. Effect of atmospheric gases, surface albedo and cloud overlap on the absorbed solar radiation

    Directory of Open Access Journals (Sweden)

    Ashok Sinha

    Full Text Available Recent studies have provided new evidence that models may systematically underestimate cloud solar absorption compared to observations. This study extends previous work on this "absorption anomaly'' by using observational data together with solar radiative transfer parameterisations to calculate fs (the ratio of surface and top of the atmosphere net cloud forcings and its latitudinal variation for a range of cloud types. Principally, it is found that (a the zonal mean behaviour of fs varies substantially with cloud type, with the highest values obtained for low clouds; (b gaseous absorption and scattering can radically alter the pattern of the variation of fs with latitude, but gaseous effects cannot in general raise fs to the level of around 1.5 as recently determined; (c the importance of the gaseous contribution to the atmospheric ASR is such that whilst fs rises with surface albedo, the net cloud contribution to the atmospheric ASR falls; (d the assumed form of the degree of cloud overlap in the model can substantially affect the cloud contribution to the atmospheric ASR whilst leaving the parameter fs largely unaffected; (e even large uncertainties in the observed optical depths alone cannot account for discrepancies apparent between modelled and newly observed cloud solar absorption. It is concluded that the main source of the anomaly may derive from the considerable uncertainties regarding impure droplet microphysics rather than, or together with, uncertainties in macroscopic quantities. Further, variable surface albedos and gaseous effects may limit the use of contemporaneous satellite and ground-based measurements to infer the cloud solar absorption from the parameter fs.

  7. [Errors Analysis and Correction in Atmospheric Methane Retrieval Based on Greenhouse Gases Observing Satellite Data].

    Science.gov (United States)

    Bu, Ting-ting; Wang, Xian-hua; Ye, Han-han; Jiang, Xin-hua

    2016-01-01

    High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 μm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method.

  8. Critical Masses for Various Terrestrial Planet Atmospheric Gases and Water in/on Mars

    Directory of Open Access Journals (Sweden)

    Lin-gun Liu

    2014-01-01

    Full Text Available The lower critical mass boundaries (CM for various atmospheric gas species on terrestrial planets are estimated. The CM is different for different gas molecules. Except for He, the observed atmospheric compositions of the terrestrial planets are consistent with these estimates. The lower CM boundary for gaseous H2O is calculated as 8.06 ×× 1026 g, which is significantly greater than the Martian mass (6.419 ×× 1026 g. Thus, Mars is not capable of retaining H2O in its atmosphere. If the speculated ocean on Mars and the claimed H2O ice in the Martian soil are true, both the ocean and ice had to be derived earlier from H2O degassed from the Martian interior after the surface temperature cooled much below 100°C.100°C. These watery bodies cannot be sustained for long durations because evaporation and sublimation would turn them into gaseous H2O, which would be lost to outer-space. It is concluded that H2O in/on Mars is inherent and that the primordial planetesimals that formed Mars must have contained appreciable amounts of hydrous minerals, if the oceans and/or H2O ice on Mars are true.

  9. An Experimental Study on Atmospheric Pressure Glow Discharge in Different Gases

    Institute of Scientific and Technical Information of China (English)

    刘鹏; 詹如娟; 等

    2002-01-01

    Usually,the electrical breakdown of dielectric barrier discharge(DBD) at atmospheric pressure leads to a filamentary non-homogeneous discharge,However,it is also possible to obtain a diffuse DBD in homogeneous form,called atmospheric pressure glow discharge(APGD).We obtained a uniform APGD in helium and in the mixture of argon with alcohol,and studied the electrical characteristics of helium APGD.It if found that the relationship between discharge current and source frequency is different depending on the difference in gas gap when the applied voltage is kept constant.The discharge current shows an increasing trend with the increased frequency when gas gap is 0.8cm ,but the discharge current tends to decrease with the increased frequency when the gas gap increases.The discharge current always increases with the increased applied voltage when the source frequency is kept constant.We also observed a glow-like discharge in nitrogen at atmospheric pressure.

  10. Reusable In Situ AirCore System for CO2 and Trace Gas Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel design for an in situ atmospheric sensor for CO2 and trace gases is proposed. The sensor, named AirCore, provides the advantages of existing in situ sensors...

  11. Atmospheric wet and dry deposition of trace elements at ten sites in Northern China

    Directory of Open Access Journals (Sweden)

    Y. P. Pan

    2014-08-01

    Full Text Available Atmospheric deposition is considered to be a major process that removes pollutants from the atmosphere and an important source of nutrients and contaminants for ecosystems. Trace elements (TEs, especially toxic metals deposited on plants and into soil and water, can cause substantial damage to the environment and human health due to their transfer and accumulation in food chains. Despite public concerns, quantitative knowledge of metal deposition from the atmosphere to ecosystems remains scarce. To advance our understanding of the spatio-temporal variations in the magnitudes, pathways, compositions and impacts of atmospherically deposited TEs, precipitation (rain and snow and dry-deposited particles were collected simultaneously at ten sites in Northern China from December 2007 to November 2010. The measurements showed that the wet and dry depositions of TEs in the target areas were orders of magnitude higher than previous observations within and outside China, generating great concern over the potential risks. The spatial distribution of the total (wet plus dry deposition flux was consistent with that of the dry deposition, with a significant decrease from industrial and urban areas to suburban, agricultural and rural sites. In contrast, the wet deposition exhibited less spatial variation. The seasonal variation of wet deposition was also different from that of dry deposition, although they were both governed by the precipitation and emission patterns. For the majority of TEs that exist as coarse particles, dry deposition dominated the total flux at each site. This was not the case for K, Ni, As, Pb, Zn, Cd, Se, Ag and Tl, for which the relative importance between wet and dry deposition fluxes varied by site. Whether wet deposition is the major atmospheric cleansing mechanism for the TEs depends on the size distribution and solubility of the particles. We found that atmospheric inputs of Cu, Pb, Zn, Cd, As and Se were of the same magnitude as

  12. Atmospheric wet and dry deposition of trace elements at 10 sites in Northern China

    Science.gov (United States)

    Pan, Y. P.; Wang, Y. S.

    2015-01-01

    Atmospheric deposition is considered to be a major process that removes pollutants from the atmosphere and an important source of nutrients and contaminants for ecosystems. Trace elements (TEs), especially toxic metals deposited on plants and into soil or water, can cause substantial damage to the environment and human health due to their transfer and accumulation in food chains. Despite public concerns, quantitative knowledge of metal deposition from the atmosphere to ecosystems remains scarce. To advance our understanding of the spatiotemporal variations in the magnitudes, pathways, compositions and impacts of atmospherically deposited TEs, precipitation (rain and snow) and dry-deposited particles were collected simultaneously at 10 sites in Northern China from December 2007 to November 2010. The measurements showed that the wet and dry depositions of TEs in the target areas were orders of magnitude higher than previous observations within and outside China, generating great concern over the potential risks. The spatial distribution of the total (wet plus dry) deposition flux was consistent with that of the dry deposition, with a significant decrease from industrial and urban areas to suburban, agricultural and rural sites, while the wet deposition exhibited less spatial variation. In addition, the seasonal variation of wet deposition was also different from that of dry deposition, although they were both governed by the precipitation and emission patterns. For the majority of TEs that exist as coarse particles, dry deposition dominated the total flux at each site. This was not the case for potassium, nickel, arsenic, lead, zinc, cadmium, selenium, silver and thallium, for which the relative importance between wet and dry deposition fluxes varied by site. Whether wet deposition is the major atmospheric cleansing mechanism for the TEs depends on the size distribution of the particles. We found that atmospheric inputs of copper, lead, zinc, cadmium, arsenic and

  13. Simulation of ion motion at atmospheric pressure: particle tracing versus electrokinetic flow.

    Science.gov (United States)

    Wissdorf, Walter; Pohler, Larissa; Klee, Sonja; Müller, David; Benter, Thorsten

    2012-02-01

    Results obtained with two computational approaches for the simulation of ion motion at elevated pressure are compared with experimentally derived ion current data. The computational approaches used are charged particle tracings with the software package SIMION ver. 8 and finite element based calculations using the software package Comsol Multiphysics ver. 4.0/4.0a. The experimental setup consisted of a tubular corona discharge ion source coupled to a cylindrical measurement chamber held at atmospheric pressure. Generated ions are flown into the chamber at essentially subsonic laminar isothermal conditions. In the simulations, strictly stationary conditions were assumed. The results show very good agreement between the SIMION/SDS model and experimental data. For the Comsol model, only qualitative agreement is observed.

  14. Predicting the thermal/structural performance of the atmospheric trace molecules spectroscopy /ATMOS/ Fourier transform spectrometer

    Science.gov (United States)

    Miller, J. M.

    1980-01-01

    ATMOS is a Fourier transform spectrometer to measure atmospheric trace molecules over a spectral range of 2-16 microns. Assessment of the system performance of ATMOS includes evaluations of optical system errors induced by thermal and structural effects. In order to assess the optical system errors induced from thermal and structural effects, error budgets are assembled during system engineering tasks and line of sight and wavefront deformations predictions (using operational thermal and vibration environments and computer models) are subsequently compared to the error budgets. This paper discusses the thermal/structural error budgets, modelling and analysis methods used to predict thermal/structural induced errors and the comparisons that show that predictions are within the error budgets.

  15. Atmospheric electrification in dusty, reactive gases in the solar system and beyond

    OpenAIRE

    Helling, Christiane; Harrison, R. Giles; Honary, Farideh; Diver, Declan A; Aplin, Karen; Dobbs-Dixon, Ian; Ebert, Ute; Inutsuka, Shu-ichiro; Gordillo-Vazquez, Francisco J.; Littlefair, Stuart

    2016-01-01

    ChH highlight financial support of the European Community under the FP7 by an ERC starting Grant 25743. DAD gratefully acknowledges support from EPSRC via Grant Numbers EP/K006142/1 and EP/K006088/1. FJGV thanks the Spanish Ministry of Economy and Competitiveness (MINECO) under projects FIS2014-61774-EXP and ESP2013-48032-C5-5-R and the EU through the FEDER programme. Detailed observations of the solar system planets reveal a wide variety of local atmospheric conditions. Astronomical obser...

  16. Barometric pumping of burial trench soil gases into the atmosphere at the 740-G Sanitary Landfill

    International Nuclear Information System (INIS)

    In 1991, a soil gas survey was performed at the Savannah River Site Sanitary Landfill as part of the characterization efforts required under the integrated Resource Conservation and Recovery Act (RCRA) Facility Investigation and Comprehensive Environmental Resource Conservation and Recovery Act (CERCLA) Remedial Investigation (RFI/RI) program. This report details the findings of this survey, which identified several areas of the landfill that were releasing volatile organic compounds to the atmosphere at levels exceeding regulatory standards. Knowledge of the rates of VOC outgassing is necessary to protect site workers, provide input into the human health and environmental risk assessment documents and provide input into the remedial design scenario

  17. Barometric pumping of burial trench soil gases into the atmosphere at the 740-G Sanitary Landfill

    Energy Technology Data Exchange (ETDEWEB)

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-12-01

    In 1991, a soil gas survey was performed at the Savannah River Site Sanitary Landfill as part of the characterization efforts required under the integrated Resource Conservation and Recovery Act (RCRA) Facility Investigation and Comprehensive Environmental Resource Conservation and Recovery Act (CERCLA) Remedial Investigation (RFI/RI) program. This report details the findings of this survey, which identified several areas of the landfill that were releasing volatile organic compounds to the atmosphere at levels exceeding regulatory standards. Knowledge of the rates of VOC outgassing is necessary to protect site workers, provide input into the human health and environmental risk assessment documents and provide input into the remedial design scenario.

  18. Tracing atmospheric nitrate in groundwater using triple oxygen isotopes: evaluation based on bottled drinking water

    Directory of Open Access Journals (Sweden)

    F. Nakagawa

    2013-06-01

    Full Text Available The stable isotopic compositions of nitrate dissolved in 49 brands of bottled drinking water collected worldwide were measured, to trace the fate of atmospheric nitrate (NO3− atm that had been deposited into subaerial ecosystems, using the 17O anomalies (Δ17O of nitrate as tracers. The use of bottled water enables collection of groundwater recharged at natural, background watersheds. The nitrate in groundwater had small Δ17O values ranging from −0.2‰ to +4.5‰ n = 49. The average Δ17O value and average mixing ratio of atmospheric nitrate to total nitrate in the groundwater samples were estimated to be 0.8‰ and 3.1%, respectively. These findings indicated that the majority of atmospheric nitrate had undergone biological processing before being exported from the surface ecosystem to the groundwater. Moreover, the concentrations of atmospheric nitrate were estimated to range from less than 0.1 μmol L−1 to 8.5 μmol L−1 with higher NO3−atm concentrations being obtained for those recharged in rocky, arid or elevated areas with little vegetation and lower NO3−atm concentrations being obtained for those recharged in forested areas with high levels of vegetation. Additionally, many of the NO3−atm-depleted samples were characterized by elevated δ15N values of more than +10‰. Uptake by plants and/or microbes in forested soils subsequent to deposition and the progress of denitrification within groundwater likely plays a significant role in the removal of NO3−atm.

  19. Temporal and spatial trends studied by lichen analysis: atmospheric deposition of trace elements in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Aspiazu, J.; Cervantes, L.; Ramirez, J.; Lopez, J.; Villasenor, P. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Ramos, R.; Munoz, R. [Secretaria del Medio Ambiente, Gestion Ambiental del Aire, Mexico City (Mexico)

    2007-07-01

    Ball moss on Tillandsia recurvata (Bromeliaceae), collected in an area previously identified as unpolluted, was transplanted to thirteen bio-monitoring sites in the downtown and metropolitan areas of Mexico City (which cover a surface of 9,560 km{sup 2}) during the periods August 2002 - January 2003 and July 2003 - October 2003. A total of 52 lichens (weighing 300 g) were transplanted to each place. Two were analysed as zero or reference, El Chico National Park, a location 100 Km upwind from the city and the remaining 26 were hung in nylon net bags in order to be able to collect two transplanted tree month, out of every season over a one-year period. The concentrations were measured by the quantitative PIXE method based on an extemal beam facility. The atmospheric deposition for trace elements was inferred by its concentration in lichen samples collected in 2002 from 13 sites in Mexico and compared with data from a similar survey in 2003. The concentration of Cr, Cu, Co, Fe, Mn, Ni, Pb and Zn and other elements was determined for each sample. Maps for each element were drawn after a geostatistical estimate of the metal concentration in the sample was made. Maps were drawn for all elements with the estimated values. Geographical distribution patterns were obtained for the different metals, reflecting the contribution of natural and anthropogenic emission sources. The deposition patterns of V, As, Se, Cd and Pb are substantially influenced by long-range transport from other parts of Mexico City. For Cr, Fe, Co, Ni, and Cu, the deposition patterns are largely determined by contribution from point sources within Mexico and in the metropolitan area. The lichen data for Br and, in part, Se reflect an airborne supply from the environment. Contributions to trace element concentrations in lichen sources other than atmospheric deposition are identified and discussed. The Spatial and temporal variations in the distribution of metal concentration are discussed. (Author)

  20. Detection of trace gases from fermentation processes using photoacoustic spectroscopy and proton-transfer-reaction mass spectrometry

    NARCIS (Netherlands)

    Boamfă-Ivan, Elena Iuliana

    2005-01-01

    This thesis presents novel interdisciplinary Physics - Biology research work that employed Photoacoustic Spectroscopy and Proton-Transfer-Reaction Mass Spectrometry. Both techniques were used in biological studies of trace gasses emitted by crop plants and fruit under stress situations. The findings

  1. Technical Note: Ensuring consistent, global measurements of very short-lived halocarbon gases in the ocean and atmosphere

    Directory of Open Access Journals (Sweden)

    J. H. Butler

    2010-01-01

    Full Text Available Very short-lived halocarbons are significant sources of reactive halogen in the marine boundary layer, and likely in the upper troposphere and lower stratosphere. Quantifying ambient concentrations in the surface ocean and atmosphere is essential for understanding the atmospheric impact of these trace gas fluxes. Despite the body of literature increasing substantially over recent years, calibration issues complicate the comparison of results and limit the utility of building larger-scale databases that would enable further development of the science (e.g. sea-air flux quantification, model validation, etc.. With this in mind, thirty-one scientists from both atmospheric and oceanic halocarbon communities in eight nations gathered in London in February 2008 to discuss the scientific issues and plan an international effort toward developing common calibration scales (http://tinyurl.com/c9cg58. Here, we discuss the outputs from this meeting, suggest the compounds that should be targeted initially, identify opportunities for beginning calibration and comparison efforts, and make recommendations for ways to improve the comparability of previous and future measurements.

  2. Technical Note: Ensuring consistent, global measurements of short-lived halocarbon gases in the ocean and atmosphere

    Directory of Open Access Journals (Sweden)

    J. H. Butler

    2009-05-01

    Full Text Available Short-lived halocarbons are significant sources of reactive halogen in the troposphere and likely the lower stratosphere. Quantifying ambient concentrations in the surface ocean and atmosphere is essential for understanding the impact of fluxes of these gases on marine boundary layer oxidation and lower stratospheric ozone-depletion processes. Despite the body of literature increasing substantially over recent years, calibration issues complicate comparison of results and limit the utility of building larger-scale databases that would enable further development of the science (e.g. sea-air flux quantification, model validation, etc.. With this in mind, thirty-two scientists representing eight nations and from both atmospheric and oceanic halocarbon communities gathered in London in February 2008 to discuss the scientific issues and plan an international effort toward a common calibration scale. Here, we discuss the outputs from this meeting, suggest the compounds that should be targeted initially, identify opportunities for beginning calibration and comparison efforts, and make recommendations for ways to improve the comparability of previous and future measurements.

  3. Atmospheric Electrification in Dusty, Reactive Gases in the Solar System and Beyond

    Science.gov (United States)

    Helling, Christiane; Harrison, R. Giles; Honary, Farideh; Diver, Declan A.; Aplin, Karen; Dobbs-Dixon, Ian; Ebert, Ute; Inutsuka, Shu-ichiro; Gordillo-Vazquez, Francisco J.; Littlefair, Stuart

    2016-07-01

    Detailed observations of the solar system planets reveal a wide variety of local atmospheric conditions. Astronomical observations have revealed a variety of extrasolar planets none of which resembles any of the solar system planets in full. Instead, the most massive amongst the extrasolar planets, the gas giants, appear very similar to the class of (young) brown dwarfs which are amongst the oldest objects in the Universe. Despite this diversity, solar system planets, extrasolar planets and brown dwarfs have broadly similar global temperatures between 300 and 2500 K. In consequence, clouds of different chemical species form in their atmospheres. While the details of these clouds differ, the fundamental physical processes are the same. Further to this, all these objects were observed to produce radio and X-ray emissions. While both kinds of radiation are well studied on Earth and to a lesser extent on the solar system planets, the occurrence of emissions that potentially originate from accelerated electrons on brown dwarfs, extrasolar planets and protoplanetary disks is not well understood yet. This paper offers an interdisciplinary view on electrification processes and their feedback on their hosting environment in meteorology, volcanology, planetology and research on extrasolar planets and planet formation.

  4. Influence of Biomass Burning on Temporal and Diurnal Variations of Acidic Gases, Particulate Nitrate, and Sulfate in a Tropical Urban Atmosphere

    OpenAIRE

    Sailesh N. Behera; Rajasekhar Balasubramanian

    2014-01-01

    The present study investigated the temporal and diurnal distributions of atmospheric acidic gases (sulphur dioxide (SO2), nitrous acid (HONO), and nitric acid (HNO3)) and those of particulate nitrate (NO3-) and sulfate (SO42-) through a comprehensive field campaign during the largest smoke haze episode in Singapore, a representative country in Southeast Asia (SEA). To identify the atmospheric behavior of these pollutants during the smoke haze period, the data generated from the measurement ca...

  5. A laser based procedure for the detection of atmospheric NOx gases

    International Nuclear Information System (INIS)

    It has been known for some time that the combustion of fossil fuels, biomass burning and the automobile, have principally lead to the increased presence of NOX (x=1,2) in the atmosphere especially in the urban environment. The average concentrations of NOX in American, European cities and specifically in Glasgow is about 35 ppb. A laser based procedure, using ionization chambers, has been developed, which will detect NO down to sub ppb levels and NO2 to a few parts per billion. A number of wavelengths can be used but a three photon process at 380 nm is likely to be the most sensitive and selective wavelength for this analysis. This procedure can also be used for a number of other urban pollutants with a single laser operating in the range 200-400 nm

  6. Cosmic-ray induced production of radioactive noble gases in the atmosphere, ground, and seawater

    International Nuclear Information System (INIS)

    This paper describes the development of an MCNP6 model and a suite of supporting MATLAB scripts being developed to conduct detailed studies of the radioactive noble gas background activity concentrations resulting from cosmic-neutron-induced reactions in the Earth's atmosphere, in various geologies, and in seawater. Initial results generated using the MCNP6 model and the suite of supporting MATLAB scripts indicate that the cosmic-neutron-induced 133Xe background activity concentrations at a depth of 1 m in a geology representative of the Earth's upper crust and a depth of 5 m in seawater are about 3.48 × 10-1 and 8.49 × 10-7 mBq m-3, respectively. (author)

  7. On the marine atmospheric boundary layer characteristics over Bay of Bengal and Arabian Sea during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB)

    Indian Academy of Sciences (India)

    Denny P Alappattu; D Bala Subrahamanyam; P K Kunhikrishnan; K M Somayaji; G S Bhat; R Venkatesan; C B S Dutt; A Bagavath Singh; V K Soni; A S Tripathi

    2008-07-01

    Detailed measurements were carried out in the Marine Atmospheric Boundary Layer (MABL) during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) which covered both Arabian Sea and Bay of Bengal during March to May 2006. In this paper, we present the meteorological observations made during this campaign. The latitudinal variation of the surface layer turbulent fluxes is also described in detail.

  8. Gases Working Group: Why is it important to study Air-Sea Gas Exchange?

    NARCIS (Netherlands)

    Liss, P.; Grimalt, J.O.; Hov, O.; Johannessen, T.; Larsen, S.E.; Oost, W.A.; Leeuw, G. de

    1998-01-01

    Exchange of trace gases between the oceans and the atmosphere affects the atrnospheric content and cycling of a range of chemical trace species which are related to climate change, ozone layer depletion, acid deposition, eutrophication amospheric pafticle formation, photo-oxidants, heavy metals and

  9. Atmospheric pollution in an urban environment by tree bark biomonitoring--part I: trace element analysis.

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Lahd Geagea, Majdi; Boutin, René

    2012-03-01

    Tree bark has been shown to be a useful biomonitor of past air quality because it accumulates atmospheric particulate matter (PM) in its outermost structure. Trace element concentrations of tree bark of more than 73 trees allow to elucidate the impact of past atmospheric pollution on the urban environment of the cities of Strasbourg and Kehl in the Rhine Valley. Compared to the upper continental crust (UCC) tree barks are strongly enriched in Mn, Ni, Cu, Zn, Cd and Pb. To assess the degree of pollution of the different sites in the cities, a geoaccumulation index I(geo) was applied. Global pollution by V, Ni, Cr, Sb, Sn and Pb was observed in barks sampled close to traffic axes. Cr, Mo, Cd pollution principally occurred in the industrial area. A total geoaccumulation index I(GEO-tot) was defined; it is based on the total of the investigated elements and allows to evaluate the global pollution of the studied environment by assembling the I(geo) indices on a pollution map.

  10. Atmospheric supply of trace elements studied by peat samples from ombrotrophic bogs.

    Science.gov (United States)

    Steinnes, E; Hvatum, O Ø; Bølviken, B; Varskog, P

    2005-01-01

    Concentrations of Fe and 12 trace elements in peat from ombrotrophic bogs were used to estimate the atmospheric deposition of these elements on a temporal and spatial scale. Peat samples were collected at 21 different sites in Norway encompassing large geographical differences in marine influence and air pollution. The study demonstrates that surface peat is an excellent medium to study geographical differences in heavy metal deposition, provided that effects of the surface plant cover are properly considered. Long-range atmospheric transport of pollutants is the main source for As, Cd, Pb, Sb, and Zn, and to a lesser extent for Cu and Se. Biogenic emissions from the ocean appear to be the main source of Se to the peat. The metals Co, Cr, Fe, and Ni are mainly associated with wind-blown local soil dust. Surface enrichment of Mn, and in part Zn, is mainly caused by nutrient circulation between the surface peat and vascular plants growing on it. Deposition of marine salts appears to be the main reason for lower Mn concentrations in the peat near the coast.

  11. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO{sub 2}-water systems

    Energy Technology Data Exchange (ETDEWEB)

    Warr, Oliver, E-mail: oliver.warr@earth.ox.ac.uk; Ballentine, Christopher J. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom); Rochelle, Christopher A. [British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Masters, Andrew J. [School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M13 9PL (United Kingdom)

    2016-01-15

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO{sub 2}-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.

  12. Impact features tracing hypervelocity airbursts on earth from the atmosphere to the ground

    Science.gov (United States)

    Courty, M. M.

    2012-12-01

    In the absence of deep craters, impact features have been debated to possibly tracing proximal ejecta from yet undetected structure or airburst debris from a meteorite collision with the terrestrial atmosphere or lithosphere. We examine the possibility for impact features to have originated from the shock layer formed ahead of a hypervelocity collider in the earth atmosphere. This hypothesis is approached by comparing impact features from controlled materials to puzzling geological ones: (1) debris collected at the ground from a high altitude meteor airburst recorded on 2011 August 2nd in Southern France; (2) laboratory experiments performed for defense purposes at the CEA Gramat Center (France) with the Persephone hypervelocity light gas gun; (3) the Zhamanshin impact breccia, the Lybian glass, the Egyptian Dakhleh glass, the Tasmanian Darwin glass, the Australasian tektite strewnfield and the Australian Henbury crater field. The Persephone experiments include collisions from 4.1 to 7.9 km/s by a steel projectile embedded into a polycarbonate holder with a polystyrene separator on to a 40 mm thick aluminum target. The impact features been characterized by coupling Environmental SEM with EDS, Raman micro-spectrometry, XRD, TEM, Tof-SIMS, ICP-MS and isotope analyses. Similar carbonaceous polymorphs that are closely imbricated at meso to nano-scales to the crystallized components (including the metal blebs) and to the glass phases (spherules or matrix) are present in all the impact features studied. They dominantly consist of aliphatic polymers, rare aromatic compounds, with graphite-lonsdaleite inclusions. The Persephone experiments help relating the graphite-lonsdaleite couple to transformed organic residues by the transient high pressure shock (a few tens MPa) and the transient heating (ca 100°C) and the aliphatic polymers to new hydrocarbons that formed from the pulverized polycarbonate and polystyrene. The Persephone experiments provide the controlled situation

  13. Atmospheric greenhouse gases retrieved from SCIAMACHY: comparison to ground-based FTS measurements and model results

    Directory of Open Access Journals (Sweden)

    O. Schneising

    2012-02-01

    Full Text Available SCIAMACHY onboard ENVISAT (launched in 2002 enables the retrieval of global long-term column-averaged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO2 and XCH4. In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Transform Spectrometer (FTS measurements and comparisons with model results at eight Total Carbon Column Observing Network (TCCON sites providing realistic error estimates of the satellite data. Such validation is a prerequisite to assess the suitability of data sets for their use in inverse modelling.

    It is shown that there are generally no significant differences between the carbon dioxide annual increases of SCIAMACHY and the assimilation system CarbonTracker (2.00 ± 0.16 ppm yr−1 compared to 1.94 ± 0.03 ppm yr−1 on global average. The XCO2 seasonal cycle amplitudes derived from SCIAMACHY are typically larger than those from TCCON which are in turn larger than those from CarbonTracker. The absolute values of the northern hemispheric TCCON seasonal cycle amplitudes are closer to SCIAMACHY than to CarbonTracker and the corresponding differences are not significant when compared with SCIAMACHY, whereas they can be significant for a subset of the analysed TCCON sites when compared with CarbonTracker. At Darwin we find discrepancies of the seasonal cycle derived from SCIAMACHY compared to the other data sets which can probably be ascribed to occurrences of undetected thin clouds. Based on the comparison with the reference data, we conclude that the carbon dioxide data set can be characterised by a regional relative precision (mean standard deviation of the differences of about 2.2 ppm and a relative accuracy (standard deviation of the mean differences

  14. ALTIUS, a future small mission for O3 and other atmospheric trace species concentration profiles retrieval

    Science.gov (United States)

    Dekemper, Emmanuel; Fussen, Didier; Vanhellemont, Filip; Pieroux, Didier; Mateshvili, Nina; Franssens, Ghislain; Errera, Quentin; Vanhamel, Jurgen; Neefs, Eddy; De Vos, Lieve; Aballea, Ludovic

    2016-04-01

    The ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) mission aims at the retrieval of atmospheric trace species concentration profiles with a good vertical resolution and a global coverage. It will be flown on a PROBA-type platform on a Sun-synchronous orbit with a 10:00 AM typical local time. The instrument exploits the concept of hyperspectral imaging of different light sources: limb-scattered radiance, Sun, Moon, stars, planets. These sources are observed sequentially, depending on their availability and good positioning. This multi-mode observation capability enables measurements in both bright and dark side of the orbit, extending the coverage to virtually all latitudes and different illumination conditions (including polar night). The instrument concept relies on three independent spectral channels: UV, VIS and NIR. The imaging technique alleviates the need for scanning systems as the field of view will capture the atmosphere from cloud top to the lower thermosphere at once. It also makes the pointing calibration more easy and robust, an important feature knowing that tangent altitude misregistration is one of the major sources of bias in the retrieved products. In each channel, the wavelength selection for each image will be performed by a tunable filter: an AOTF (Acousto-Optical Tunable Filter) for the VIS and NIR, and a FPI (Fabry-Perot Interferometer) in the UV. ALTIUS has recently completed a phase B1 under ESA supervision. The next milestone will be the preliminary design review (PDR) that will take place within a few months from now. Launch is expected for 2020 with a 3-5 years design lifetime. We will present the scientific objectives of the mission, and the current status of the payload and platform concepts. An overview of the main in-flight calibration strategies will be given, and the expected performance of the O3 level-2 product for the different modes of observation will be shown.

  15. Sources of Sahelian-Sudan moisture: Insights from a moisture-tracing atmospheric model

    Science.gov (United States)

    Salih, Abubakr A. M.; Zhang, Qiong; Pausata, Francesco S. R.; Tjernström, Michael

    2016-07-01

    The summer rainfall across Sahelian-Sudan is one of the main sources of water for agriculture, human, and animal needs. However, the rainfall is characterized by large interannual variability, which has attracted extensive scientific efforts to understand it. This study attempts to identify the source regions that contribute to the Sahelian-Sudan moisture budget during July through September. We have used an atmospheric general circulation model with an embedded moisture-tracing module (Community Atmosphere Model version 3), forced by observed (1979-2013) sea-surface temperatures. The result suggests that about 40% of the moisture comes with the moisture flow associated with the seasonal migration of the Intertropical Convergence Zone (ITCZ) and originates from Guinea Coast, central Africa, and the Western Sahel. The Mediterranean Sea, Arabian Peninsula, and South Indian Ocean regions account for 10.2%, 8.1%, and 6.4%, respectively. Local evaporation and the rest of the globe supply the region with 20.3% and 13.2%, respectively. We also compared the result from this study to a previous analysis that used the Lagrangian model FLEXPART forced by ERA-Interim. The two approaches differ when comparing individual regions, but are in better agreement when neighboring regions of similar atmospheric flow features are grouped together. Interannual variability with the rainfall over the region is highly correlated with contributions from regions that are associated with the ITCZ movement, which is in turn linked to the Atlantic Multidecadal Oscillation. Our result is expected to provide insights for the effort on seasonal forecasting of the rainy season over Sahelian Sudan.

  16. Monitoring and modelling of biosphere/atmosphere exchange of gases and aerosols in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Erisman, Jan Willem [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands)]. E-mail: erisman@ecn.nl; Vermeulen, Alex [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands); Hensen, Arjan [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands); Flechard, Chris [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands); Daemmgen, Ulrich [Federal Agricultural Research Centre, Institute of Agroecology, D-38116 Braunschweig, (Germany); Fowler, David [CEH, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Sutton, Mark [CEH, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Gruenhage, Ludger [Institute for Plant Ecology, Justus-Liebig-University, D-35392 Giessen (Germany); Tuovinen, Juha-Pekka [Finnish Meteorological Institute, FIN-00810 Helsinki (Finland)

    2005-02-01

    Monitoring and modelling of deposition of air pollutants is essential to develop and evaluate policies to abate the effects related to air pollution and to determine the losses of pollutants from the atmosphere. Techniques for monitoring wet deposition fluxes are widely applied. A recent intercomparison experiment, however, showed that the uncertainty in wet deposition is relatively high, up to 40%, apart from the fact that most samplers are biased because of a dry deposition contribution. Wet deposition amounts to about 80% of the total deposition in Europe with a range of 10-90% and uncertainty should therefore be decreased. During recent years the monitoring of dry deposition has become possible. Three sites have been operational for 5 years. The data are useful for model development, but also for model evaluation and monitoring of progress in policy. Data show a decline in SO{sub 2} dry deposition, whereas nitrogen deposition remained constant. Furthermore, surface affinities for pollutants changed leading to changes in deposition. Deposition models have been further developed and tested with dry deposition measurements and total deposition measurements on forests as derived from throughfall data. The comparison is reasonable given the measurement uncertainties. Progress in ozone surface exchange modelling and monitoring shows that stomatal uptake can be quantified with reasonable accuracy, but external surface uptake yields highest uncertainty. - Monitoring and modelling of the deposition of sulphur and nitrogen components and the exposure of ozone has gained much progress through the research within BIATEX.

  17. Non-atmospheric noble gases from CO(sub 2) well ga

    Science.gov (United States)

    Caffee, M. W.; Hudson, G. B.; Velsko, C.; Alexander, E. C., Jr.; Huss, G. R.; Chivas, A. R.

    1988-01-01

    In recent years a number of studies of both terrestrial and extraterrestrial material has allowed the piecing together of a picture of events occurring in the early solar system (4.5 Gyr ago), including the formation of the earth. However, before this picture can be completed with an appropriate amount of detail it will be necessary to make further advances. One of the areas where knowledge is lacking is the chemical and isotopic composition of the earth as a whole. The lack of knowledge has less to do with the capabilities of modern techniques than with the availability of samples to study. About 99.6 percent of the earth's mass is contained in the mantle and core, leaving less that 1 percent in the crust and atmosphere. Although the crust is derived from the mantle it has undergone extensive changes and it is therefore difficult (although not impossible) to use crustal material to study events occurring 4.5 Gyr ago. More information about the early earth could be obtained from studies of the mantle but it is difficult to obtain mantle material, because the mean thickness of the crust is 17 km, much greater than even the deepest mines or drill shafts. The two types of available mantle samples are discussed.

  18. Evidence for multiple magma ocean outgassing and atmospheric loss episodes from mantle noble gases

    CERN Document Server

    Tucker, Jonathan M

    2014-01-01

    The energy associated with giant impacts is large enough to generate global magma oceans during Earth's accretion. However, geochemical evidence requiring a terrestrial magma ocean is scarce. Here we present evidence for at least two separate magma ocean outgassing episodes on Earth based on the ratio of primordial 3He to 22Ne in the present-day mantle. We demonstrate that the depleted mantle 3He/22Ne ratio is at least 10 while a more primitive mantle reservoir has a 3He/22Ne ratio of 2.3 to 3. The 3He/22Ne ratios of the mantle reservoirs are higher than possible sources of terrestrial volatiles, including the solar nebula ratio of 1.5. Therefore, a planetary process must have raised the mantle's 3He/22Ne ratio. We show that long-term plate tectonic cycling is incapable of raising the mantle 3He/22Ne ratio and may even lower it. However, ingassing of a gravitationally accreted nebular atmosphere into a magma ocean on the proto-Earth explains the 3He/22Ne and 20Ne/22Ne ratios of the primitive mantle reservoir....

  19. Atmospheric input of N, P, Fe and trace metals to north Indian Ocean

    Science.gov (United States)

    Sarin, Manmohan; Srinivas, Bikkina

    2016-04-01

    The air-sea deposition of chemical constituents to the north Indian Ocean is influenced by seasonal continental outflow during the late NE-monsoon (December-April). Our recent studies have focused on deposition of mineral dust, nutrients (N, P and Fe) and toxic trace metals to the Arabian Sea (ARS) and Bay of Bengal (BoB), two important limbs of the north Indian Ocean. The chemical composition of PM2.5 in the continental outflow to the marine atmospheric boundary layer reveals dominance of nss-SO42- (as high as 25 μg m-3) and abundance of dust varies from 3 to 20 μg m-3. A striking similarity in the temporal variability of total inorganic acidity (TIA = NO3- + nss-SO42-) and fractional solubility of aerosol-Fe (FeTot: 60 - 1145 ng m-3) provides evidence for chemical processing of mineral dust during atmospheric transport. The enhanced solubility of Fe has implications to further increase in the deposition of this micro-nutrient to ocean surface. The mass ratio of nutrients (NInorg/NTot, Norg/NTot and PInorg/nss-Ca2+) also suggests further increase in their air-sea deposition to the surface BoB. The dry-deposition flux of PInorgto BoB varies by one order of magnitude (0.5 - 5.0 μmol-P m-2 d-1; Av: 0.02 Tg P yr-1). Based on atmospheric deposition of P and Fe, C-fixation in BoB (˜1 Pg yr-1) is dominated by anthropogenic sources and that in ARS (0.3 Pg yr-1) is limited by P and Fe. This is attributed to poor fractional solubility (˜1%) of mineral dust over the Arabian Sea. However, N-fixation by diazotrophs in the two oceanic regions is somewhat similar (0.03 Pg yr-1). Our estimate of N-deposition (0.2 Tg yr-1) to the northern Indian Ocean is significantly lower than the model results (˜800 - 1200 mg-N m-2 yr-1 ≈ 5.7 - 8.6 Tg yr-1 by Duce et al. (2008); ˜4.1 Tg yr-1 by Okin et al. (2011); and ˜0.8 Tg yr-1 by Kanakidou et al. (2012). The increase in aerosol toxicity is also evident from high enrichment factors of anthropogenic trace metal (Pb, Cd, Cr, Cu and

  20. Correlations between atmospheric aerosol trace element concentrations and red tide at Port Aransas, Texas, on the Gulf of Mexico

    International Nuclear Information System (INIS)

    Neutron activation analysis (NAA) was employed as an analytical technique to measure atmospheric aerosol concentrations of trace metals in Port Aransas, TX on the Gulf of Mexico. The sources of atmospheric aerosols and the seasonal variation of the sources are explored. High atmospheric iron concentrations are then shown to have a possible correlation to the occurrences of red tide in this region. The data shows that this correlation is plausible, but due to the many factors that affect red tide growth a definitive conclusion may not be reached. The period of study for these measurements was September 12, 2000 to January 4, 2002. (author)

  1. The Heidelberg Airborne Imaging DOAS Instrument (HAIDI – a novel Imaging DOAS device for 2-D and 3-D imaging of trace gases and aerosols

    Directory of Open Access Journals (Sweden)

    S. General

    2014-03-01

    Full Text Available Many relevant processes in tropospheric chemistry take place on rather small scales (e.g. tens to hundreds of meters but often influence areas of several square kilometer. Thus, measurements of the involved trace gases with high spatial resolution are of great scientific interest. In order to identify individual sources and sinks and ultimately to improve chemical transport models, we developed a new airborne instrument, which is based on the well established DOAS method. The Heidelberg Airborne Imaging Differential Optical Absorption Spectrometer Instrument (HAIDI is a passive imaging DOAS spectrometer, which is capable of recording horizontal and vertical trace gas distributions with a resolution of better than 100 m. Observable species include NO2, HCHO, C2H2O2, H2O, O3, O4, SO2, IO, OClO and BrO. Here we report a technical description of the instrument including its custom build spectrographs and CCD detectors. Also first results from measurements with the new instrument are presented. These comprise spatial resolved SO2 and BrO in volcanic plumes, mapped at Mt. Etna (Sicily, Italy, NO2 emissions in the metropolitan area of Indianapolis (Indiana, USA as well as BrO and NO2 distributions measured during arctic springtime in context of the BROMEX campaign, which was performed 2012 in Barrow (Alaska, USA.

  2. Atmospheric deposition of trace elements around Ulan Bator city studied by moss and lichen biomonitoring technique and INAA

    International Nuclear Information System (INIS)

    For the first time the moss and lichen biomonitoring technique has been applied to air pollution in Mongolia (Ulan-Bator, the capital city). INAA at the IBR-2 reactor has made it possible to determine the content of 35 elements in moss and lichen biomonitors. Samples collected at sites located 10-15 km from the center of Ulan-Bator were analyzed by Instrumental Neutron Activation Analysis (INAA) using epithermal neutrons. The mosses (Rhytidium rugosum, Thuidium abietinum, Entodon concinnus) and lichens (Cladonia stellaris, Parmelia separata) were used to study the atmospheric deposition of trace elements. It was shown that the suggested types of mosses could be used as suitable biomonitors to estimate the concentration levels of heavy metals and trace elements in Ulan-Bator atmospheric deposition. The results are compared to the data of atmospheric deposition of some European countries

  3. Atmospheric Deposition of Trace Elements Around Ulan-Bator City Studied by Moss and Lichen Biomonitoring Technique and INAA

    CERN Document Server

    Ganbold, G; Gundorina, S F; Frontasyeva, M V; Ostrovnaya, T M; Pavlov, S S; Tsendeekhuu, T

    2005-01-01

    For the first time the moss and lichen biomonitoring technique has been applied to air pollution in Mongolia (Ulan-Bator, the capital city). INAA at the IBR-2 reactor has made it possible to determine the content of 35 elements in moss and lichen biomonitors. Samples collected at sites located 10-15 km from the center of Ulan-Bator were analyzed by Instrumental Neutron Activation Analysis (INAA) using epithermal neutrons. The mosses (\\textit{Rhytidium rugosum}, \\textit{Thuidium abietinum}, \\textit{Entodon concinnus}) and lichens (\\textit{Cladonia stellaris}, \\textit{Parmelia separata}) were used to study the atmospheric deposition of trace elements. It was shown that the suggested types of mosses could be used as suitable biomonitors to estimate the concentration levels of heavy metals and trace elements in Ulan-Bator atmospheric deposition. The results are compared to the data of atmospheric deposition of some European countries.

  4. Atmospheric trace elements in aerosols observed over the Southern Ocean and coastal East Antarctica

    Directory of Open Access Journals (Sweden)

    Guojie Xu

    2014-11-01

    Full Text Available Atmospheric aerosol samples were collected over the Southern Ocean (SO and coastal East Antarctica (CEA during the austral summer of 2010/11. Samples were analysed for trace elements, including Na, Mg, K, Al, Fe, Mn, Ni, Cd and Se, by inductively coupled plasma mass spectrometry (ICP-MS. The mean atmospheric concentrations over the SO were 1100 ng m−3 for Na, 190 ng m−3 for Mg, 150 ng m−3 for Al, 14 ng m−3 for Fe, 0.46 ng m−3 for Mn and 0.25 ng m−3 for Se. Over CEA, the mean concentrations were 990 ng m−3 for Na, 180 ng m−3 for Mg, 190 ng m−3 for Al, 26 ng m−3 for Fe, 0.70 ng m−3 for Mn and 0.29 ng m−3 for Se. Particle size distributions, enrichment factors (EFs and correlation analysis indicate that Na, Mg and K mainly came from the marine source, while Al, Fe and Mn were mainly from the crustal source, which also contributed to Mg and K over CEA. High EFs were associated with Ni, Cd and Se, suggesting likely contributions from mixed sources from the Antarctic continent, long-range transport, marine biogenic emissions and anthropogenic emissions. Sea-salt elements (Na, Mg, K were mainly accumulated in the coarse mode, and crustal elements (Al, Fe, Mn presented a bimodal size distribution pattern. Bioactive elements (Fe, Ni, Cd were enriched in the fine mode, especially with samples collected over the SO, possibly affecting biogeochemical cycles in this oceanic region.

  5. Accelerated line-by-line calculations for the radiative transfer of trace gases related to climate studies

    International Nuclear Information System (INIS)

    In the present study we are studying the effects of including carbon dioxide, ozone, methane, and the halocarbons in addition to water vapor in the radiating atmosphere. The study has focused on two principal issues: the effect on the spectral fluxes and cooling rates of carbon dioxide, ozone and the halocarbons at 1990 concentration levels and the change in fluxes and cooling rates as a consequence of the anticipated ten year change in the profiles of these species. For the latter study the water vapor profiles have been taken as invariant in time. The radiative line-by-line calculations using LBLRTM (Line-By-Line Radiative Transfer Model) have been performed for tropical (TRP), mid-latitude winter (MLW) and mid-latitude summer (MLS) model atmospheres. The halocarbons considered in the present study are CCl4, CFC-11, CFC-12 and CFC-22. In addition to considering the radiative effects of carbon dioxide at 355 ppM, the assumed current level, we have also obtained results for doubled carbon dioxide at 710 ppM. An important focus of the current research effort is the effect of the ozone depletion profile on atmospheric radiative effects

  6. Estimation of the atmosphere-ocean fluxes of greenhouse gases and aerosols at the finer resolution of the coastal ocean.

    Science.gov (United States)

    Vieira, Vasco; Sahlée, Erik; Jurus, Pavel; Clementi, Emanuela; Pettersson, Heidi; Mateus, Marcos

    2016-04-01

    The balances and fluxes of greenhouse gases and aerosols between atmosphere and ocean are fundamental for Earth's heat budget. Hence, the scientific community needs to know and simulate them with accuracy in order to monitor climate change from Earth-Observation satellites and to produce reliable estimates of climate change using Earth-System Models (ESM). So far, ESM have represented earth's surface with coarser resolutions so that each cell of the marine domain is dominated by the open ocean. In such case it is enough to use simple algorithms considering the wind speed 10m above sea-surface (u10) as sole driver of the gas transfer velocity. The formulation by Wanninkhof (1992) is broadly accepted as the best. However, the ESM community is becoming increasingly aware of the need to model with finer resolutions. Then, it is no longer enough to only consider u10 when modelling gas transfer velocities across the coastal oceans' surfaces. More comprehensive formulations are required that adjust better to local conditions by also accounting for the effects of sea-surface agitation, wave breaking, atmospheric stability of the Surface Boundary Layer, current drag with the bottom, surfactants and rain. Accurate algorithms are also fundamental to monitor atmosphere and ocean greenhouse gas concentrations using satellite data and reverse modelling. Past satellite missions ERS, Envisat, Jason-2, Aqua, Terra and Metop, have already been remotely sensing the ocean's surface at much finer resolutions than ESM using instruments like MERIS, MODIS, AMR, AATSR, MIPAS, Poseidon-3, SCIAMACHY, SeaWiFS, and IASI. The planned new satellite missions Sentinel-3, OCO-2 and GOSAT will further increase the resolutions. We developed a framework to congregate competing formulations for the estimation of the solubility and transfer velocity of virtually any gas on the biosphere taking into consideration the atmosphere and ocean fundamental variables and their derived geophysical processes

  7. Water soluble inorganic trace gases and related aerosol compounds in the tropical boundary layer. An analysis based on real time measurements at a pasture site in the Amazon Basin

    NARCIS (Netherlands)

    Trebs, I.

    2005-01-01

    This dissertation investigates the behavior of water-soluble inorganic trace gases and related aerosol species in the tropical boundary layer. Mixing ratios of ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), hydrochloric acid (HCl), sulfur dioxide (SO;,) and the corresponding water-soluble a

  8. 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

    Science.gov (United States)

    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

  9. Atmospheric wet deposition of mercury and other trace elements in Pensacola, Florida

    Directory of Open Access Journals (Sweden)

    W. M. Landing

    2010-05-01

    Full Text Available In an effort to understand and quantify the impact of local, regional, and far-distant atmospheric mercury sources to rainfall mercury deposition in the Pensacola, Florida watershed, a program of event-based rainfall sampling was started in late 2004. Modified Aerochem-Metrics wet/dry rainfall samplers were deployed at three sites in the region around the Crist coal-fired power plant and event-based samples were collected continuously for three years. Samples were analyzed for total Hg and a suite of trace elements including Al, As, Ba, Bi, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, La, Li, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Th, U, V, and Zn. Nutrients (ammonia and nitrate and major anions (chloride and sulfate were also measured on each sample. Multivariate statistical methods were used to sort these tracers into factors that represent potential source categories contributing to the rainfall chemistry. As, Hg, Sb, Se, Sn, and non sea-salt sulfate were all significantly correlated (R>0.6 with one factor which we interpret as an anthropogenic source term reflecting input from coal combustion throughout the southeastern US. Using ratios of total Hg to volatile elements, we estimate that 22–33% of the rainfall Hg results from coal combustion in the southeastern US with the majority coming from the global background.

  10. Atmospheric wet deposition of mercury and other trace elements in Pensacola, Florida

    Directory of Open Access Journals (Sweden)

    W. M. Landing

    2009-12-01

    Full Text Available To understand and quantify the impact of local, regional, and distant atmospheric mercury sources to rainfall mercury deposition in the Pensacola, Florida watershed, a program of event-based rainfall sampling was started in late 2004. Modified Aerochem-Metrics wet/dry rainfall samplers were deployed at three sites in the region around the Crist coal-fired power plant and event-based samples were collected continuously for three years. Samples were analyzed for total mercury, volatile elements As, Se, and Sn, and a suite of trace elements including Al, Bi, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ho, Ga, Gd, La, Li, Lu, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, Sb, Sc, Si, Sm, Sr, Tb, Th, Ti, Tm, U, V, Y, Yb, and Zn. Nutrients and major ions were also measured on each sample.

    Multivariate statistical methods are used to sort these tracers into factors that represent potential source components that contribute to the rainfall chemistry. Hg, As, Se, Sn, Sb, and non sea-salt sulfate were all significantly correlated with one anthropogenic factor. Using various Hg/element ratios, we can estimate that 22–33% of the rainfall mercury in the region results from coal combustion.

  11. Seasonal and spatial variations of atmospheric trace elemental deposition in the Aliaga industrial region, Turkey

    Science.gov (United States)

    Kara, Melik; Dumanoglu, Yetkin; Altiok, Hasan; Elbir, Tolga; Odabasi, Mustafa; Bayram, Abdurrahman

    2014-11-01

    Atmospheric bulk deposition (wet + dry deposition) samples (n = 40) were collected concurrently at ten sites in four seasons between June 2009 and April 2010 in the Aliaga heavily industrialized region, Turkey, containing a number of significant air pollutant sources. Analyses of trace elements were carried out using inductively coupled plasma-mass spectrometry (ICP-MS). While there were significant differences in the particulate matter (PM) deposition fluxes among the sampling sites, seasonal variations were not statistically significant (Kruskal-Wallis test, p deposition and elemental fluxes were increased at the sampling sites in the vicinity of industrial activities. The crustal elements (i.e., Ca, Mg) and some anthropogenic elements (such as Fe, Zn, Mn, Pb, Cu, and Cr) were high, and the highest fluxes were mostly measured in summer and winter seasons. The enrichment factor (EF) and principal component analysis (PCA) was applied to the data to determine the possible sources in the study area. High EF values were obtained for the anthropogenic elements such as Ag, Cd, Zn, Pb, Cu and Sb. The possible sources were identified as anthropogenic sources (i.e., iron-steel production) (45.4%), crustal and re-suspended dust (27.1%), marine aerosol (7.9%), and coal and wood combustion (8.2%). Thus, the iron-steel production and its related activities were found to be the main pollutant sources for this region.

  12. Heavy Metals and Trace Elements Atmospheric Deposition Studies in Tula Region Using Moss Biomonitors Technique

    CERN Document Server

    Ermakova, E V; Steinnes, E

    2002-01-01

    For the first time the moss biomonitors technique was used in air pollution studies in Tula Region (Central Russia), applying NAA, AAS. Moss samples were collected at 83 sites in accordance with the sampling strategy adopted in European projects on biomonitoring atmospheric deposition. A wide set of trace elements in mosses was determined. The method of epithermal neutron activation at IBR-2 reactor of FLNP JINR has made it possible to identify 33 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Tb, Yb, Hf, Ta, W, Th, U) in the large-scale concentration range - from 10000 ppm for K to 0,001 ppm for Tb and Ta. Cu, Cd and Pb were determined by the flame AAS in the Norwegian Institute of Science and Technology. Using the graphical technique and principal component analysis allowed to separate plant, crustal and general pollution components in the moss. The obtained data will be used for constructing coloured maps of the distribution of elements over t...

  13. Field measurement of acid gases and soluble anions in atmospheric particulate matter using a parallel plate wet denuder and an alternating filter-based automated analysis system.

    Science.gov (United States)

    Boring, C Bradley; Al-Horr, Rida; Genfa, Zhang; Dasgupta, Pumendu K; Martin, Michael W; Smith, William F

    2002-03-15

    We present a new fully automated instrument for the measurement of acid gases and soluble anionic constituents of atmospheric particulate matter. The instrument operates in two independent parallel channels. In one channel, a wet denuder collects soluble acid gases; these are analyzed by anion chromatography (IC). In a second channel, a cyclone removes large particles and the aerosol stream is then processed by another wet denuder to remove potentially interfering gases. The particles are then collected by one of two glass fiber filters which are alternately sampled, washed, and dried. The washings are preconcentrated and analyzed by IC. Detection limits of low to subnanogram per cubic meter concentrations of most gaseous and particulate constituents can be readily attained. The instrument has been extensively field-tested; some field data are presented. Results of attempts to decipher the total anionic constitution of urban ambient aerosol by IC-MS analysis are also presented.

  14. Advancement and application of gas chromatography isotope ratio mass spectrometry techniques for atmospheric trace gas analysis

    Science.gov (United States)

    Giebel, Brian M.

    2011-12-01

    The use of gas chromatography isotope ratio mass spectrometry (GC-IRMS) for compound specific stable isotope analysis is an underutilized technique because of the complexity of the instrumentation and high analytical costs. However stable isotopic data, when coupled with concentration measurements, can provide additional information on a compounds production, transformation, loss, and cycling within the biosphere and atmosphere. A GC-IRMS system was developed to accurately and precisely measure delta13C values for numerous oxygenated volatile organic compounds having natural and anthropogenic sources. The OVOCs include methanol, ethanol, acetone, methyl ethyl ketone, 2-pentanone, and 3-pentanone. Guided by the requirements for analysis of trace components in air, the GC-IRMS system was developed with the goals of increasing sensitivity, reducing dead-volume and peak band broadening, optimizing combustion and water removal, and decreasing the split ratio to the IRMS. The technique relied on a two-stage preconcentration system, a low-volume capillary reactor and water trap, and a balanced reference gas delivery system. Measurements were performed on samples collected from two distinct sources (i.e. biogenic and vehicle emissions) and ambient air collected from downtown Miami and Everglades National Park. However, the instrumentation and the method have the capability to analyze a variety of source and ambient samples. The measured isotopic signatures that were obtained from source and ambient samples provide a new isotopic constraint for atmospheric chemists and can serve as a new way to evaluate their models and budgets for many OVOCs. In almost all cases, OVOCs emitted from fuel combustion were enriched in 13C when compared to the natural emissions of plants. This was particularly true for ethanol gas emitted in vehicle exhaust, which was observed to have a uniquely enriched isotopic signature that was attributed to ethanol's corn origin and use as an alternative

  15. A system for measuring fluxes of trace gases to and from soil and vegetation with a chamber technique

    International Nuclear Information System (INIS)

    A mobile system for measurements of gaseous fluxes of SO2 NOx, O3 and water vapour between the atmosphere and the vegetation soil system using a chamber technique is described. Equipment, instruments and instrumental sensitivities are listed. A gas-handling system including calibration procedures and information on the chamber construction is also presented. With this system it is possible to make measurements using a wide range of concentrations including subambient levels. The environment in the chamber can be kept very close to ambient conditions. The mechanisms regulating the flux can be studied. A limitation of this system is the problem of extrapolating the fluxes obtained to larger areas. (author)

  16. Relationship between trace gases and aerosols from biomass burning in Southeast Asia using satellite and emission data

    Science.gov (United States)

    Azuma, Yoshimi; Nakamura, Maya; Kuji, Makoto

    2012-11-01

    Southeast Asia is one of the biggest regions of biomass burning with forest fires and slash-and-burn farming. From the fire events, a large amount of air pollutants are emitted such as carbon monoxide (CO), nitrogen oxide (NOx) and aerosol (black carbon; BC). Biomass burning generally causes not only local, but also transboundary air pollution, and influences the atmospheric environment in the world accordingly. However, impact of air pollutants' emissions from large-scale fire in Southeast Asia is not well investigated compared to other regions such as South America and Africa. In this study, characteristics of the atmospheric environment were investigated with correlative analyses among several satellite data (MOPITT, OMI, and MODIS) and emission inventory (GFEDv3) in Southeast Asia from October 2004 to June 2008 on a monthly basis. As a result, it is suggested that the transboundary air pollution from the biomass burning regions occurred over Southeast Asia, which caused specifically higher air pollutants' concentration at Hanoi, Vietnam in spring dry season.

  17. On the role of atmosphere-ocean interactions in the expected long-term changes of the Earth's ozone layer caused by greenhouse gases

    Science.gov (United States)

    Zadorozhny, Alexander; Dyominov, Igor

    It is well known that anthropogenic emissions of greenhouse gases into the atmosphere produce a global warming of the troposphere and a global cooling of the stratosphere. The expected stratospheric cooling essentially influences the ozone layer via increased polar stratospheric cloud formation and via temperature dependences of the gas phase reaction rates. One more mechanism of how greenhouse gases influences the ozone layer is enhanced water evaporation from the oceans into the atmosphere because of increasing temperatures of the ocean surface due to greenhouse effect. The subject of this paper is a study of the influence of anthropogenic pollution of the atmosphere by the greenhouse gases CO2, CH4, N2O and ozone-depleting chlorine and bromine compounds on the expected long-term changes of the ozone layer with taking into account an increase of water vapour content in the atmosphere due to greenhouse effect. The study based on 2-D zonally averaged interactive dynamical radiative-photochemical model of the troposphere and stratosphere. The model allows to self-consistently calculating diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds of two types. It was supposed in the model that an increase of the ocean surface temperature caused by greenhouse effect is similar to calculated increase of atmospheric surface temperature. Evaporation rate from the ocean surface was computed in dependence of latitude. The model time-dependent runs were made for the period from 1975 to 2100 using two IPCC scenarios depicting maximum and average expected increases of greenhouse gases in the atmosphere. The model calculations show that anthropogenic increasing of water vapour abundance in the atmosphere due to heating of the ocean surface caused by greenhouse effect gives a sensible contribution to the expected ozone

  18. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis – Part 2: Evaluation of measured and modeled trace gases and particle size distributions

    Directory of Open Access Journals (Sweden)

    C. Ochoa

    2012-04-01

    Full Text Available 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 the 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 predictions of the diurnal trends of the gases were well correlated with the measurements before the regional mixed layer (RML reached the measurement site but underestimated the concentration after that time. The differences are caused by an over rapid growth of the boundary layer by the model and too much dilution. There also is more O3 being actually 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 lognormal with most of the mass in the accumulation mode and the geometric diameter centered at 200±20 nm, showing little observed or predicted change with respect to the time when the RML is above the Altzomoni research station. Only the total mass changed with time and air mass origin. The invariability of average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation past about six hours of aging downwind of the major sources of anthropogenic emissions in Mexico's Megapolis. This could greatly simplify parameterization in climate models although it is not known at this time if this invariance can be extended to other megacity regions.

  19. Simulations of atmospheric pressure discharge in a high-voltage nanosecond pulse using the particle-in-cell Monte Carlo collision model in noble gases

    International Nuclear Information System (INIS)

    Atmospheric pressure discharge nonequilibrium plasmas have been applied to plasma processing with modern technology. Simulations of discharge in pure Ar and pure He gases at one atmospheric pressure by a high voltage trapezoidal nanosecond pulse have been performed using a one-dimensional particle-in-cell Monte Carlo collision (PIC-MCC) model coupled with a renormalization and weighting procedure (mapping algorithm). Numerical results show that the characteristics of discharge in both inert gases are very similar. There exist the effects of local reverse field and double-peak distributions of charged particles' density. The electron and ion energy distribution functions are also observed, and the discharge is concluded in the view of ionization avalanche in number. Furthermore, the independence of total current density is a function of time, but not of position

  20. Simulations of atmospheric pressure discharge in a high-voltage nanosecond pulse using the particle-in-cell Monte Carlo collision model in noble gases

    Science.gov (United States)

    Shi, Feng; Wang, Dezhen; Ren, Chunsheng

    2008-06-01

    Atmospheric pressure discharge nonequilibrium plasmas have been applied to plasma processing with modern technology. Simulations of discharge in pure Ar and pure He gases at one atmospheric pressure by a high voltage trapezoidal nanosecond pulse have been performed using a one-dimensional particle-in-cell Monte Carlo collision (PIC-MCC) model coupled with a renormalization and weighting procedure (mapping algorithm). Numerical results show that the characteristics of discharge in both inert gases are very similar. There exist the effects of local reverse field and double-peak distributions of charged particles' density. The electron and ion energy distribution functions are also observed, and the discharge is concluded in the view of ionization avalanche in number. Furthermore, the independence of total current density is a function of time, but not of position.

  1. Vertical Distribution of Gases and Aerosols in Titan’s Atmosphere Observed by VIMS/Cassini Solar Occultations

    Science.gov (United States)

    Maltagliati, Luca; Vinatier, S.; Sicardy, B.; Bézard, B.; Sotin, C.; Nicholson, P. D.; Brown, R. H.; Baines, K.; Buratti, B.; Clark, R.

    2012-10-01

    We present the vertical distribution of gaseous species and aerosols in Titan’s atmosphere through the analysis of VIMS solar occultations. We employ the infrared channel of VIMS, which covers the 1 - 5 µm wavelength range. VIMS occultations can provide good vertical resolution ( 10 km) and an extended altitude range (from 70 to 700 km), complementing well the information from other Cassini instruments. VIMS has retrieved 8 solar occultations up to now. They are distributed through the whole Cassini mission and they probe different latitudes in both hemispheres. Two main gases can be observed by VIMS occultations: methane, through its bands at 1.2, 1.4, 1.7, 2.3 and 3.3 µm, and CO, at 4.7 µm. We can extract methane’s abundance between 70 and 700 km and CO’s between 70 and 180 km. Regarding aerosols, the VIMS altitude range allows to get information on the properties of both the main haze and the detached layer. Aerosols also affect the transmittance through their spectral signatures. In particular, a spectral signature at 3.4 µm that was attributed to aerosols was recently discovered by the analysis of the first VIMS occultation. We will monitor the latitudinal and temporal variations of the 3.4 µm feature through various occultations. A change in the global circulation regime of Titan sets in with the approaching to the vernal equinox, and a strong decrease of the altitude of the detached layer between the winter solstice and the equinox has indeed been observed. The temporal coverage of VIMS occultations allows the study the effect of these variations in the vertical distribution of aerosol optical and spectral properties.

  2. Dissociation against oxidation kinetics for the conversion of VOCs in non-thermal plasmas of atmospheric gases

    Science.gov (United States)

    Pasquiers, Stéphane; Blin-Simiand, Nicole; Magne, Lionel

    2016-08-01

    The kinetics of four volatile organic compounds (VOCs) (propene, propane, acetaldehyde, acetone) were studied in plasmas of atmospheric gases using a photo-triggered discharge (homogeneous plasma) or a dielectric barrier discharge (filamentary plasma). It was shown for the homogeneous plasma that quenchings of nitrogen metastable states, A3Ʃ+u and the group of singlets a' 1Ʃ-u, a 1Πg and w 1∆u, are important processes for the decomposition of such molecules. Recent measurements of the H2 concentration produced in the N2/C3H6 mixture emphasize that the hydrogen molecule can be an exit route for propene dissociation. It is also found that H2 and CO molecules are efficiently produced following the dissociation of CH3COCH3 and the subsequent chemical reactivity induced by radicals coming from acetone. Addition of oxygen to a N2/VOC mixture can change drastically the kinetics. However, the quenching processes of N2 metastables by the VOC are always present and compete with oxidation reactions for the conversion of the pollutant. At low temperature, oxidations by O or by OH are not always sufficiently effective to induce an increase of the molecule decomposition when oxygen is added to the mixture. In particular, the presence of O2 has a detrimental effect on the acetone removal. Also, as evidenced for acetaldehyde and propane, some kinetic analogies appear between filamentary and homogeneous plasmas. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  3. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    Directory of Open Access Journals (Sweden)

    I. R. Burling

    2011-06-01

    Full Text Available 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 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 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 of 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.

  4. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    Directory of Open Access Journals (Sweden)

    I. R. Burling

    2011-12-01

    Full Text Available 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.

  5. Airborne and ground-based measurements of the trace gases and particles emitted from prescribed fires in the United States

    Energy Technology Data Exchange (ETDEWEB)

    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

  6. Trace element content of sedimentary pyrite as a new proxy for deep-time ocean-atmosphere evolution

    Science.gov (United States)

    Large, Ross R.; Halpin, Jacqueline A.; Danyushevsky, Leonid V.; Maslennikov, Valeriy V.; Bull, Stuart W.; Long, John A.; Gregory, Daniel D.; Lounejeva, Elena; Lyons, Timothy W.; Sack, Patrick J.; McGoldrick, Peter J.; Calver, Clive R.

    2014-03-01

    Sedimentary pyrite formed in the water column, or during diagenesis in organic muds, provides an accessible proxy for seawater chemistry in the marine rock record. Except for Mo, U, Ni and Cr, surprisingly little is known about trace element trends in the deep time oceans, even though they are critical to developing better models for the evolution of the Earth's atmosphere and evolutionary pathways of life. Here we introduce a novel approach to simultaneously quantify a suite of trace elements in sedimentary pyrite from marine black shales. These trace element concentrations, at least in a first-order sense, track the primary elemental abundances in coeval seawater. In general, the trace element patterns show significant variation of several orders of magnitude in the Archaean and Phanerozoic, but less variation on longer wavelengths in the Proterozoic. Certain trace elements (e.g., Ni, Co, As, Cr) have generally decreased in the oceans through the Precambrian, other elements (e.g., Mo, Zn, Mn) have generally increased, and a further group initially increased and then decreased (e.g., Se and U). These changes appear to be controlled by many factors, in particular: 1) oxygenation cycles of the Earth's ocean-atmosphere system, 2) the composition of exposed crustal rocks, 3) long term rates of continental erosion, and 4) cycles of ocean anoxia. We show that Ni and Co content of seawater is affected by global Large Igneous Province events, whereas redox sensitive trace elements such as Se and Mo are affected by atmosphere oxygenation. Positive jumps in Mo and Se concentrations prior to the Great Oxidation Event (GOE1, c. 2500 Ma) suggest pulses of oxygenation may have occurred as early as 2950 Ma. A flat to declining pattern of many biologically important nutrient elements through the mid to late Proterozoic may relate to declining atmosphere O2, and supports previous models of nutrient deficiency inhibiting marine evolution during this period. These trace elements (Mo

  7. 载人航天器密封舱微量有害气体质谱检测方法%Mass spectrometric detection of harmful trace gases in manned spacecraft capsule

    Institute of Scientific and Technical Information of China (English)

    陈联; 邱家稳; 王丽红; 张晓曦

    2011-01-01

    Detection of multi -component harmful trace gases in manned spacecraft capsule by miniature vacuum mass spectrometer was introduced. Online monitoring of a variety of harmful trace gases in the capsule was realized through detecting the gas concentration. Experimental data of relative sensitivity of some gases such as toluene, dimethylbenzene, dichloromethane, methane and acetone were given and the experiment also verified that the minimum detectable concentration of before -mentioned gases can reach lppm. The results indicated that monitoring of harmful trace gas concentration by miniature vacuum mass spectrometer in manned spacecraft capsule is feasible.%介绍了采用小型真空质谱计进行载人航天器密封舱内多组分微量有害气体的检测方法.通过测量微量气体浓度,实现密封舱内多种微量有害气体在线监测.给出了甲苯、二甲苯、二氯甲烷、甲烷、丙酮等5种气体的相对灵敏度试验数据,验证了现有小型真空质谱计最小可检浓度可以达到1ppm要求.研究结果表明,采用小型真空质谱计进行舱内微量有害气体浓度监测是可行的.

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

    Science.gov (United States)

    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.

  9. Emission of greenhouse gases in the atmosphere of the Manaus city due to burning of fossil fuels; Emissao de gases poluentes na atmosfera urbana da cidade de Manaus devida a queima de combustiveis fosseis

    Energy Technology Data Exchange (ETDEWEB)

    Valois, I.M. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Fac. de Tecnologia], E-mail: ivalois@ufam.edu.br; Cartaxo, E.F. [Universidade Federal do Amazonas (NIEMA/UFAM), Manaus, AM (Brazil). Fac. de Tecnologia. Nucleo de Energia, Meio Ambiente e Agua], E-mail: ecartaxo@ufam.edu.br; Chaar, Jamal da Silva [Universidade Federal do Amazonas (ICE/UFAM), Manaus, AM (Brazil). Inst. de Ciencias Exatas

    2009-07-01

    This paper intends to think over the impacts of pollutants gases in the atmosphere of the city of Manaus, caused by the thermal, the main electricity source in the State of Amazonas. The focus of the study is the urban atmosphere where physical and chemical phenomenon accelerate the effects of increased concentration of some components and secondary pollutants, which are produced due to human activities. It is based on two studies: monitoring the exhaust gas applied at a factory in the district of Aparecida, located in the urban area, and monitoring conducted by the energy operating company, about the influence of exhaust gas around the district of Mauazinho, also in urban area. It is a preliminary research that seeks to demonstrate the inconsistency of some studies and the need to make progress in search for more efficient methods and techniques. This is an important step toward a policy of environmental management that will complement future studies about air pollution in the city. (author)

  10. Evaluation of trace elemental composition of aerosols in the atmosphere of Rawalpindi and Islamabad using radio analytical methods

    Energy Technology Data Exchange (ETDEWEB)

    Qadir, Muhammad Abdul, E-mail: mabdulqadir@gmail.com [Institute of Chemistry, University of the Punjab, Lahore-54590 (Pakistan); Zaidi, Jamshaid Hussain [Pakistan Institute of Nuclear Science and Technology, Nilore, Islamabad Capital Territory (Pakistan); Ahmad, Shaikh Asrar; Gulzar, Asad [Division of Science and Technology, University of Education, Township, Lahore (Pakistan); Yaseen, Muhammad [Department of Chemistry, Gugrat University, Gugrat (Pakistan); Atta, Sadia; Tufail, Asma [Institute of Chemistry, University of the Punjab, Lahore-54590 (Pakistan)

    2012-05-15

    Geological and anthropogenic contributions to air pollution were monitored by analyzing aerosol particulates present in the atmosphere of Rawalpindi and Islamabad, Pakistan, using instrumental neutron activation for trace elemental analysis. A scanning electron microscope was used to study particulate size distribution and morphology. Twenty two elements were analyzed and their likely sources were identified. It was found that 69% of the suspended particulate matter in the atmosphere of Islamabad, and 52% in Rawalpindi, were of a diameter less than 3 {mu}m. The presence of Yb, Cs, Sc, Rb, Co, Eu, La, Ba, Zn and Hf indicates that a major portion of the trace elements in the aerosol particulates was due to the geological nature of the land, while Sc was considered to be arising from coal burning. The presence of Cr, Fe, Ce, Pb and Cd was attributed to anthropogenic activities at Rawalpindi and Islamabad. Unusually high concentrations of Mo and Nb were found in the atmosphere of Islamabad, based on soil derived aerosols. - Highlights: Black-Right-Pointing-Pointer Discussion is made on Total suspended Particulate (TSP) matter in the atmosphere. Black-Right-Pointing-Pointer Measurement of Radio active elements in the TSP by using SSNTD which was found non significant. Black-Right-Pointing-Pointer 23 Trace element analysis of the TSPs in the atmosphere of twin cities i.e. Rawalpindi and Islamabad and their relation to their sources by using Neutron activation analysis. Black-Right-Pointing-Pointer The mountain of Islamabad has some unique and important deposits of Nb and Gd , this paper will help the Geological survey of Pakistan to explore their deposits. Black-Right-Pointing-Pointer There is high level of TSPs>10 um, which is a great threat to the peoples of Islamabad.

  11. An evaluation of atmospheric deposition of trace elements into the Great Lakes.

    Science.gov (United States)

    Biegalski, S; Landsberger, S

    1999-01-01

    High-volume air samplers were used to collect aerosol samples on Whatman 41 air filters at the Canadian air sampling stations Burnt Island, Egbert, and Point Petre. Once collected, the samples were analyzed for trace elements by neutron activation analysis. Air concentrations of over 30 trace elements were determined. A special focus was made to utilize Compton suppression gamma-ray spectroscopy and epithermal irradiations to enhance the detection limits of neutron activation analysis. These techniques allowed for the determination of trace elements at very low levels. Results of the study of the trace-metal dry deposition into Lakes Huron and Ontario indicated that the majority of the total deposition resulted from crustal materials. However, dry deposition is also a significant pathway for many toxic anthropogenic trace metals into the Great Lakes. PMID:10676498

  12. Soil-atmosphere trace gas exchange from tropical oil palm plantations on peat

    Science.gov (United States)

    Arn Teh, Yit; Manning, Frances; Zin Zawawi, Norliyana; Hill, Timothy; Chocholek, Melanie; Khoon Kho, Lip

    2015-04-01

    Oil palm is the largest agricultural crop in the tropics, accounting for 13 % of all tropical land cover. Due to its large areal extent, oil palm cultivation may have important implications not only for terrestrial stores of C and N, but may also impact regional and global exchanges of material and energy, including fluxes of trace gases and water vapor. In particular, recent expansion of oil palm into tropical peatlands has raised concerns over enhanced soil C emissions from degradation of peat, and elevated N-gas fluxes linked to N fertilizer application. Here we report our preliminary findings on soil carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes from a long-term, multi-scale project investigating the C, N and greenhouse gas (GHG) dynamics of oil palm ecosystems established on peat soils in Sarawak, Malaysian Borneo. Flux chamber measurements indicate that soil CO2, CH4 and N2O fluxes averaged 20.0 ± 16.0 Mg CO2-C ha-1 yr-1, 37.4 ± 29.9 kg CH4-C ha-1 yr-1 and 4.7 ± 4.2 g N2O-N ha-1 yr-1, respectively. Soil CO2 fluxes were on par with other drained tropical peatlands; whereas CH4 fluxes exceeded observations from similar study sites elsewhere. Nitrous oxide fluxes were in a similar range to fluxes from other drained tropical peatlands, but lower than emissions from mineral-soil plantations by up to three orders of magnitude. Fluxes of soil CO2 and N2O were spatially stratified, and contingent upon the distribution of plants, deposited harvest residues, and soil moisture. Soil CO2 fluxes were most heavily influenced by the distribution of palms and their roots. On average, autotrophic (root) respiration accounted for approximately 78 % of total soil CO2 flux, and total soil respiration declined steeply away from palms; e.g. soil CO2 fluxes in the immediate 1 m radius around palms were up to 6 times greater than fluxes in inter-palm spaces due to higher densities of roots. Placement of harvest residues played an important - but secondary

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

    Science.gov (United States)

    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.

  14. Study of Atmospheric Trace Gas Amounts at the Stara Zagora Ground-Based Station

    Science.gov (United States)

    Werner, R.; Valev, D.; Kostadinov, I.; Atanassov, At.; Giovanelli, G.; Petritoli, A.; Bortoli, D.; Ravegnani, F.

    2006-03-01

    Since the end of August 1999 twilight daily measurements of scattered zenith sky radiation have been carried out at Stara Zagora for determination of trace gas amounts, deploying GASCOD instrument. It was developed at the Institute of Atmospheric Science and Climate, Bologna. Reference spectra are obtained at midday. The instrument, appearing a UV-VIS spectrometer, registers the zenith sky spectra automatically and 410 nm to 460 nm spectral interval is used to retrieve NO2 and O3 slant column amounts (SCA) by application of the DOAS methodology. The spectral analysis uses minimum least squares fitting of the cross sections at the expected absorbers to a logarithm of the twilight spectrum and a reference spectrum. The accumulated time series show the well-known typical seasonal variations, caused by the solar insulation. The residual time series of the removed semi-annual seasonal cycles from the measured original series show many different variations, with short periods up to inter-annual variations. Single spikes of SCA are detected and we consider them a result of over-passing weather fronts and/or lightning. Variations of SCA with time scale up to about 10 days are the consequence of weather cyclones. Some short-term variations of NO2 and O3 SCA are a result of intensive stratospheric-tropospheric exchange. Other residual time series periods are caused by Rossby waves, by over-passing of the polar vortex filaments. The inter-annual variations can be affected by QBO and NAO. Applying wavelet analysis of the obtained NO2 slant column amount data series, and the total O3 amount obtained by the GOME instrument, during the 23-rd solar cycle maximum, time intervals are found with periods of 27 days on the time scale. The applied cross-correlation analysis demonstrates a phase lag of some days of the NO2 and O3 response to the 27-days solar cycle. The calculated vertical column amounts of NO2 are used for validation of the satellite measurements, e.g. SCIAMACHY NO2

  15. Detailed history of atmospheric trace elements from the Quelccaya ice core (Southern Peru) during the last 1200 years

    Science.gov (United States)

    Uglietti, C.; Gabrielli, P.; Thompson, L. G.

    2013-12-01

    The recent increase in trace element concentrations, for example Cr, Cu, Zn, Ag, Pb, Bi, and U, in polar snow and ice has provided compelling evidence of a hemispheric change in atmospheric composition since the nineteenth century. This change has been concomitant with the expansion of the Industrial Revolution and points towards an anthropogenic source of trace elements in the atmosphere. There are very few low latitude trace element ice core records and these are believed to be sensitive to perturbations of regional significance. To date, these records have not been used to document a preindustrial anthropogenic impact on atmospheric composition at low latitudes. Ice cores retrieved from the tropical Andes are particularly interesting because they have the potential to reveal detailed information about the evolution and environmental consequences of mineral exploitation related to the Pre Inca Civilizations, the Inca Empire (1438-1533 AD) and the subsequent Spanish invasion and dominance (1532-1833 AD). The chemical record preserved in the ice of the Quelccaya ice cap (southern Peruvian Andes) offers the exceptional opportunity to geochemically constrain the composition of the tropical atmosphere at high resolution over the last ~1200 years. Quantification of twenty trace elements (Ag, Al, As, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Rb, Sb, Sn, Ti, Tl, U, V, and Zn) was performed by ICP-SFMS over 105 m of the Quelccaya North Dome core (5600 m asl, 128.57 m) by analyzing 2450 samples. This provides the first atmospheric trace element record in South America spanning continuously and at high resolution for the time period between 1990 and 790 AD. Ag, As, Bi, Cd, Cr, Co, Cu, Mn, Mo, Sb, Sn, Pb and Zn show increases in concentration and crustal enrichment factor starting at different times between 1450 and 1550 AD, in concomitance with the expansions of the Inca Empire and, subsequently, the Spanish Empire well before the inception of the Industrial Revolution. This

  16. Features of motivation of the crewmembers in an enclosed space at atmospheric pressure changes during breathing inert gases.

    Science.gov (United States)

    Komarevcev, Sergey

    Since the 1960s, our psychologists are working on experimenting with small groups in isolation .It was associated with the beginning of spaceflight and necessity to study of human behaviors in ways different from the natural habitat of man .Those, who study human behavior especially in isolation, know- that the behavior in isolation markedly different from that in the natural situаtions. It associated with the development of new, more adaptive behaviors (1) What are the differences ? First of all , isolation is achieved by the fact ,that the group is in a closed space. How experiments show - the crew members have changed the basic personality traits, such as motivation Statement of the problem and methods. In our experimentation we were interested in changing the features of human motivation (strength, stability and direction of motivation) in terms of a closed group in the modified atmosphere pressure and breathing inert gases. Also, we were interested in particular external and internal motivation of the individual in the circumstances. To conduct experimentation , we used an experimental barocomplex GVK -250 , which placed a group of six mаns. A task was to spend fifteen days in isolation on barokomplex when breathing oxigen - xenon mixture of fifteen days in isolation on the same complex when breathing oxygen- helium mixture and fifteen days of isolation on the same complex when breathing normal air All this time, the subjects were isolated under conditions of atmospheric pressure changes , closer to what you normally deal divers. We assumed that breathing inert mixtures can change the strength and stability , and with it , the direction and stability of motivation. To check our results, we planned on using the battery of psychological techniques : 1. Schwartz technique that measures personal values and behavior in society, DORS procedure ( measurement of fatigue , monotony , satiety and stress ) and riffs that give the test once a week. Our assumption is

  17. Water soluble inorganic trace gases and related aerosol compounds in the tropical boundary layer. An analysis based on real time measurements at a pasture site in the Amazon Basin

    OpenAIRE

    I. Trebs

    2005-01-01

    This dissertation investigates the behavior of water-soluble inorganic trace gases and related aerosol species in the tropical boundary layer. Mixing ratios of ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), hydrochloric acid (HCl), sulfur dioxide (SO;,) and the corresponding water-soluble aerosol species, ammonium (NH,,1), nitrate (NO3 ), nitrite (NO,), chloride (CI) and sulfate (SO,") were measured at a pasture site in the Amazon Basin (Rondónia, Brazil). Sampling was performed from...

  18. Application of the LIRIC algorithm for the characterization of aerosols during the Airborne Romanian Measurements of Aerosols and Trace gases (AROMAT) campaign

    Science.gov (United States)

    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. Noble gases in meteorites and terrestrial planets

    Science.gov (United States)

    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.

  20. Biomonitoring of atmospheric pollution (with emphasis on trace elements) - BioMAP. Proceedings of an international workshop

    International Nuclear Information System (INIS)

    Some organisms accumulate atmospheric contaminants over certain periods of time and concentrate them, thus allowing reliable analytical measurements if the organisms are suitably chosen. Measurements of contaminants accumulated by such organisms (biomonitors) provide information on the integrated exposure over an extended period of time. They may also be present in remote areas, and no expensive technical equipment is involved in collecting them. Therefore, biomonitoring can be an effective tool for pollutant mapping and trend monitoring by real time and retrospective analysis. The IAEA is making concerted efforts to promote the practical use of nuclear and related analytical techniques in studies of non-radioactive environmental pollutants that may impact human health, and one of the main emphases is on studying air contaminants. The idea of organizing a workshop on biomonitoring atmospheric pollution arose during an IAEA Technical Co-operation Project on Monitoring of Trace Element Air Pollution, carried out at the Instituto Tecnologico e Nuclear (ITN), Portugal, with substantial technical support by the Interfaculty Reactor Institute (IRI) of the Delft University of Technology (TUDelft), Netherlands. The International Workshop on Biomonitoring of Atmospheric Pollution (With Emphasis on Trace Elements) - BioMAP, was held in Lisbon, Portugal, from 21 to 24 September 1997. The meeting was organized in co-operation with the Instituto Tecnologico e Nuclear

  1. Trace metal determination in total atmospheric deposition in rural and urban areas

    OpenAIRE

    Azimi, Sam; Ludwig, Alexandre; Thevenot, Daniel,; Colin, Jean-Louis

    2003-01-01

    International audience The wet, dry and total atmospheric depositions of some metals (Al, Cd, Cr, Cu, Fe, Na, Pb and Zn) were sampled at two sites and atmospheric fallout fluxes were determined for these locations. This work, led by two different research groups, allowed to reach two main goals: to define a simple analytical procedure to secure accurate shipboard sampling and analysis of atmospheric deposition, and to assess anthropogenic impacts of heavy metals to the environment. The fir...

  2. Effect of particulate matter, atmospheric gases, temperature, and humidity on respiratory and circulatory diseases’ trends in Lisbon, Portugal

    NARCIS (Netherlands)

    Freitas, M.C.; Pacheco, A.M.G.; Verburg, T.G.; Wolterbeek, H.T.

    2009-01-01

    This study addresses the significant effects of both well-known contaminants (particles, gases) and less-studied variables (temperature, humidity) on serious, if relatively common, respiratory and circulatory diseases. The area of study is Lisbon, Portugal, and time series of health outcome (daily a

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Remote Sensing of Greenhouse Gases by Combining Lidar and Optical Correlation Spectroscopy

    OpenAIRE

    Anselmo C.; Thomas B; Miffre A.; Francis M; Cariou J.P.; Rairoux P.

    2016-01-01

    In this contribution, we present recent work on the ability to achieve range-resolved greenhouse gases concentration measurements in the Earth’s atmosphere (CH4, H2O) by combining broadband optical correlation spectroscopy (OCS) with lidar. We show that OCS-Lidar is a robust methodology, allowing trace gases remote sensing with a low dependence on the temperature and pressure-variation absorption cross section. Moreover, we evaluate, as an experimental proof, the water vapor profile in the pl...

  5. Atmospheric wet deposition of trace elements to a suburban environment, Reston, Virginia, USA

    Science.gov (United States)

    Conko, K.M.; Rice, K.C.; Kennedy, M.M.

    2004-01-01

    Wet deposition from a suburban area in Reston, Virginia was collected during 1998 and analyzed to assess the anion and trace-element concentrations and depositions. Suburban Reston, approximately 26km west of Washington, DC, is densely populated and heavily developed. Wet deposition was collected bi-weekly in an automated collector using trace-element clean sampling and analytical techniques. The annual volume-weighted concentrations of As, Cd, and Pb were similar to those previously reported for a remote site on Catoctin Mt., Maryland (70km northwest), which indicated a regional signal for these elements. The concentrations and depositions of Cu and Zn at the suburban site were nearly double those at remote sites because of the influence of local vehicular traffic. The 1998 average annual wet deposition (??gm-2yr -1) was calculated for Al (52,000), As (94), Cd (54), Cr (160), Cu (700), Fe (23,000), Mn (2000), Ni (240), Pb (440), V (430), and Zn (4100). The average annual wet deposition (meqm-2yr-1) was calculated for H+ (74), Cl- (8.5), NO3- (33), and SO42- (70). Analysis of digested total trace-element concentrations in a subset of samples showed that the refractory elements in suburban precipitation comprised a larger portion of the total deposition of trace elements than in remote areas. ?? 2004 Elsevier Ltd. All rights reserved.

  6. Iterative maximum a posteriori (IMAP-DOAS for retrieval of strongly absorbing trace gases: Model studies for CH4 and CO2 retrieval from near infrared spectra of SCIAMACHY onboard ENVISAT

    Directory of Open Access Journals (Sweden)

    C. Frankenberg

    2005-01-01

    Full Text Available In the past, differential optical absorption spectroscopy (DOAS has mostly been employed for atmospheric trace gas retrieval in the UV/Vis spectral region. New spectrometers such as SCIAMACHY onboard ENVISAT also provide near infrared channels and thus allow for the detection of greenhouse gases like CH4, CO2, or N2O. However, modifications of the classical DOAS algorithm are necessary to account for the idiosyncrasies of this spectral region, i.e. the temperature and pressure dependence of the high resolution absorption lines. Furthermore, understanding the sensitivity of the measurement of these high resolution, strong absorption lines by means of a non-ideal device, i.e. having finite spectral resolution, is of special importance. This applies not only in the NIR, but can also prove to be an issue for the UV/Vis spectral region. This paper presents a modified iterative maximum a posteriori-DOAS (IMAP-DOAS algorithm based on optimal estimation theory introduced to the remote sensing community by rodgers76. This method directly iterates the vertical column densities of the absorbers of interest until the modeled total optical density fits the measurement. Although the discussion in this paper lays emphasis on satellite retrieval, the basic principles of the algorithm also hold for arbitrary measurement geometries. This new approach is applied to modeled spectra based on a comprehensive set of atmospheric temperature and pressure profiles. This analysis reveals that the sensitivity of measurement strongly depends on the prevailing pressure-height. The IMAP-DOAS algorithm properly accounts for the sensitivity of measurement on pressure due to pressure broadening of the absorption lines. Thus, biases in the retrieved vertical columns that would arise in classical algorithms, are obviated. Here, we analyse and quantify these systematic biases as well as errors due to variations in the temperature and pressure profiles, which is indispensable for

  7. Annual input fluxes and source identification of trace elements in atmospheric deposition in Shanxi Basin: the largest coal base in China.

    Science.gov (United States)

    Zhong, Cong; Yang, Zhongfang; Jiang, Wei; Yu, Tao; Hou, Qingye; Li, Desheng; Wang, Jianwu

    2014-11-01

    Industrialization and urbanization have led to a great deterioration of air quality and provoked some serious environmental concerns. One hundred and five samples of atmospheric deposition were analyzed for their concentrations of 13 trace elements (As, Cd, Cu, Fe, Al, Co, Cr, Hg, Mn, Mo, Pb, Se, and Zn) in Shanxi Basin, which includes six isolate basins. The input fluxes of the trace elements in atmospheric deposition were observed and evaluated. Geostatistical analysis (EF, PCA, and CA ) were conducted to determine the spatial distribution, possible sources, and enrichment degrees of trace elements in atmospheric deposition. Fe/Al and K/Al also contribute to identify the sources of atmospheric deposition. The distribution of trace elements in atmospheric deposition was proved to be geographically restricted. The results show that As, Cd, Pb, Zn, and Se mainly come from coal combustion. Fe, Cu, Mn, Hg, and Co originate mainly from interactions between local polluted soils and blowing dust from other places, while the main source of Al, Cr, and Mo are the soil parent materials without pollution. This work provides baseline information to develop policies to control and reduce trace elements, especially toxic elements, from atmospheric deposition. Some exploratory analytical methods applied in this work are also worth considering in similar researches.

  8. Greenhouse gases regional fluxes estimated from atmospheric measurements; Estimation des flux de gaz a effet de serre a l'echelle regionale a partir de mesures atmospheriques

    Energy Technology Data Exchange (ETDEWEB)

    Messager, C

    2007-07-15

    build up a new system to measure continuously CO{sub 2} (or CO), CH{sub 4}, N{sub 2}O and SF{sub 6} mixing ratios. It is based on a commercial gas chromatograph (Agilent 6890N) which have been modified to reach better precision. Reproducibility computed with a target gas on a 24 hours time step gives: 0.06 ppm for CO{sub 2}, 1.4 ppb for CO, 0.7 ppb for CH{sub 4}, 0.2 ppb for N{sub 2}O and 0.05 ppt for SF{sub 6}. The instrument's run is fully automated, an air sample analysis takes about 5 minutes. In July 2006, I install instrumentation on a telecommunication tall tower (200 m) situated near Orleans forest in Trainou, to monitor continuously greenhouse gases (CO{sub 2}, CH{sub 4}, N{sub 2}O, SF{sub 6}), atmospheric tracers (CO, Radon-222) and meteorological parameters. Intake lines were installed at 3 levels (50, 100 and 180 m) and allow us to sample air masses along the vertical. Continuous measurement started in January 2007. I used Mace Head (Ireland) and Gif-sur-Yvette continuous measurements to estimate major greenhouse gases emission fluxes at regional scale. To make the link between atmospheric measurements and surface fluxes, we need to quantify dilution due to atmospheric transport. I used Radon-222 as tracer (radon tracer method) and planetary boundary layer heights estimates from ECMWF model (boundary layer budget method) to parameterize atmospheric transport. In both cases I compared results to available emission inventories. (author)

  9. Tracing the fate of carbon and the atmospheric evolution of Mars

    CERN Document Server

    Hu, Renyu; Ehlmann, Bethany L; Yung, Yuk L

    2015-01-01

    The climate of Mars likely evolved from a warmer, wetter early state to the cold, arid current state. However, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements of the atmosphere. Here we show that a family of solutions exist, invoking no missing reservoirs or loss processes. Escape of carbon via CO photodissociation and sputtering enriches heavy carbon (13C) in the Martian atmosphere, partially compensated by moderate carbonate precipitation. The current atmospheric 13C/12C and rock and soil carbonate measurements indicate an early atmosphere with a surface pressure <1 bar. Only scenarios with large amounts of carbonate formation in open lakes permit higher values up to 1.8 bar. The evolutionary scenarios are fully testable with data from the MAVEN mission and further studies of the isotopic composition of carbonate in the Martian rock record through time.

  10. Atmospheric trace compounds and their measurement; Atmosphaerische Spurenstoffe und ihre Sondierung

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, J.; Richter, A. [Bremen Univ. (Germany). Inst. fuer Umweltphysik und Fernerkundung; Fischer, H. [Forschungszentrum Karlsruhe (Germany). Inst. fuer Meteorologie und Klimaforschung; Technische Univ. Karlsruhe (Germany); Pfeilsticker, K. [Heidelberg Univ. (Germany). Fakultaet fuer Physik und Astronomie; Platt, U. [Heidelberg Univ. (Germany). Inst. fuer Umweltphsyik; Riese, M. [Forschungszentrum Juelich (Germany). Inst. fuer Chemie und dynamik der Geosphaere; Wuppertal Univ. (Germany). Fachbereich Mathematik und Naturwissenschaften; Stiller, G. [Forschungszentrum Karlsruhe (Germany). Inst. fuer Meteorologie und Klimaforschung; Wagner, T. [Max-Planck-Inst. fuer Chemie, Mainz (Germany). Forschungsgruppe fuer Satellitenfernerkundung; Kuenzi, K.

    2007-06-15

    Monitoring of the atmosphere is an important challenge in understanding global atmospheric change. In particular, weather forecasting and the ongoing climate change require detailed investigations. This includes the continuous monitoring of the atmosphere for a number of meteorological parameters that drive the prognostic weather models. On the other hand, the natural and anthropogenic atmospheric change is of increasing public concern. Accordingly, reliable forecasting of the consequences of this atmospheric change is crucial for human life. In this respect, sophisticated investigations of the change in atmospheric composition, radiation, energy budget, and dynamics are necessary. Such studies are undertaken in virtually in all atmospheric regions using dedicated in-situ instruments that are deployed at the ground, on airships, aircrafts, high flying balloons and rockets. Of equal importance in atmospheric observation is the remote sensing of the atmosphere. This involves an analysis of the characteristic electromagnetic radiation which is emitted or absorbed by the atmospheric constituent. An special and unprecedented form of remote sensing is that from satellites using optical or UV/VIS/IR/MW spectrally resolved observations. The development of increasingly more sophisticated instruments in combination with different satellite platforms has led to a much increased and improved data base of many atmospheric constituents of global coverage. (orig.) [German] In der Zeit des globalen Wandels stellt die Untersuchung der Erdatmosphaere eine grosse Herausforderung dar. Zum einen werden fuer belastbare Wettervorhersagen staendig meteorologische Parameter benoetigt. Zum anderen ist der durch natuerliche und menschliche Ursachen beschleunigte Wandel der Atmosphaere so besorgniserregend, dass die moeglichen Folgen dieses Wandels fuer die heutige und zukuenftige Zivilisation besser vorhergesagt werden sollten. Hierfuer sind umfangreiche und genaue Untersuchungen der

  11. Urban deciduous tree leaves as biomonitors of trace element (As, V and Cd atmospheric pollution in Belgrade, Serbia

    Directory of Open Access Journals (Sweden)

    KATARINA M. ŠUĆUR

    2010-10-01

    Full Text Available Leaves of common deciduous trees: horse chestnut (Aesculus hippocastanum and linden (Tilia spp. from three parks within the urban area of Belgrade were studied as biomonitors of trace element (As, V, and Cd atmospheric pollution. The May–September trace element accumulation in the leaves, and their temporal trends, were assayed in a multi-year period (2002–2006. Significant accumulation in the leaves was evident for As and V, but not so regularly for Cd. Slightly decreasing temporal trends of V and As ac-cumulated in the leaf tissues were observed over the years. During the time span, the concentrations of Cd remained approximately on the same level, except in May 2002 and September 2005, when a rapid increase was observed. The May–September accumulations of As and V were higher in horse chestnut than in linden, although both may be used as biomonitors for these elements, and optionally for Cd in conditions of its high atmospheric loadings.

  12. Trace gases, aerosols and their interactions with synoptic weather: An overview of in-situ measurements at the SORPES Station in the western Yangtze River Delta, China

    Science.gov (United States)

    Ding, A.; Fu, C.; Yang, X.; Petaja, T.; Kerminen, V.; Kulmala, M. T.

    2013-12-01

    This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5pollution in this region. Case studies for typical O3 and PM2.5 episodes showed that synoptic weather played an important role in air pollution, especially for O3. Observation during the typical biomass burning seasons also shows clear air pollution - weather interactions. For the typical episode occurred on 10 June, 2012, the measurement suggest that the mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease of solar radiation by more than 70 %, of sensible heat flux over 85 %, a temperature drop by almost 10 K, and a change 10 of rainfall during daytime and nighttime. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions, and

  13. A Minimized Mutual Information retrieval for simultaneous atmospheric pressure and temperature

    OpenAIRE

    Koner, Prabhat K.; Drummond, James R.

    2010-01-01

    The primary focus of the Mars Trace Gas Orbiter (TGO) collaboration between NASA and ESA is the detection of the temporal and spatial variation of the atmospheric trace gases using a solar occultation Fourier transform spectrometer. To retrieve any trace gas mixing ratios from these measurements, the atmospheric pressure and temperature have to be known accurately. Thus, a prototype retrieval model for the determination of pressure and temperature from a broadband high resolution infrared Fou...

  14. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores.

    Science.gov (United States)

    Baccolo, Giovanni; Clemenza, Massimiliano; Delmonte, Barbara; Maffezzoli, Niccolò; Nastasi, Massimiliano; Previtali, Ezio; Prata, Michele; Salvini, Andrea; Maggi, Valter

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10(-13)-10(-6) g, improving previous results of 1-3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. PMID:27154827

  15. Trace metals in atmospheric particulates characterized of aerosol emitted by industrial and urban sources

    Energy Technology Data Exchange (ETDEWEB)

    Del Borghi, A.; Solisio, C.; Zilli, M.; Del Borghi, M. [Genoa University, Genoa (Italy). Chemical and Process Engineering Institute G.B. Bonino

    1998-12-31

    The results of a year`s study in the Savona area (Italy) for dust deposition have been analyzed in order to characterize the emission sources. The contribution of the major pollutant sources has been determined by tracer metals and their enrichment factors. The selected metals were Cd, Cu, Pb, An, Cr, and Ni. The obtained results show four types of emission sources responsible for airborne trace metals; traffic, industrial plants a large oil and coal fired power station, resuspension of soil particles and residential heating. 9 refs., 9 figs., 1 tab.

  16. Challenges in tracing the fate and effects of atmospheric polycyclic aromatic hydrocarbon deposition in vascular plants.

    Science.gov (United States)

    Desalme, Dorine; Binet, Philippe; Chiapusio, Geneviève

    2013-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that raise environmental concerns because of their toxicity. Their accumulation in vascular plants conditions harmful consequences to human health because of their position in the food chain. Consequently, understanding how atmospheric PAHs are taken up in plant tissues is crucial for risk assessment. In this review we synthesize current knowledge about PAH atmospheric deposition, accumulation in both gymnosperms and angiosperms, mechanisms of transfer, and ecological and physiological effects. PAHs emitted in the atmosphere partition between gas and particulate phases and undergo atmospheric deposition on shoots and soil. Most PAH concentration data from vascular plant leaves suggest that contamination occurs by both direct (air-leaf) and indirect (air-soil-root) pathways. Experimental studies demonstrate that PAHs affect plant growth, interfering with plant carbon allocation and root symbioses. Photosynthesis remains the most studied physiological process affected by PAHs. Among scientific challenges, identifying specific physiological transfer mechanisms and improving the understanding of plant-symbiont interactions in relation to PAH pollution remain pivotal for both fundamental and applied environmental sciences.

  17. Mass Dependency of Isotope Fractionation of Gases Under Thermal Gradient and Its Possible Implications for Planetary Atmosphere Escaping Process

    Science.gov (United States)

    Sun, Tao; Niles, Paul; Bao, Huiming; Socki, Richard

    2014-01-01

    Physical processes that unmix elements/isotopes of gas molecules involve phase changes, diffusion (chemical or thermal), effusion and gravitational settling. Some of those play significant roles for the evolution of chemical and isotopic compositions of gases in planetary bodies which lead to better understanding of surface paleoclimatic conditions, e.g. gas bubbles in Antarctic ice, and planetary evolution, e.g. the solar-wind erosion induced gas escaping from exosphere on terrestrial planets.. A mass dependent relationship is always expected for the kinetic isotope fractionations during these simple physical processes, according to the kinetic theory of gases by Chapman, Enskog and others [3-5]. For O-bearing (O16, -O17, -O18) molecules the alpha O-17/ alpha O-18 is expected at 0.5 to 0.515, and for S-bearing (S32,-S33. -S34, -S36) molecules, the alpha S-33/ alpha S-34 is expected at 0.5 to 0.508, where alpha is the isotope fractionation factor associated with unmixing processes. Thus, one isotope pair is generally proxied to yield all the information for the physical history of the gases. However, we recently] reported the violation of mass law for isotope fractionation among isotope pairs of multiple isotope system during gas diffusion or convection under thermal gradient (Thermal Gradient Induced Non-Mass Dependent effect, TGI-NMD). The mechanism(s) that is responsible to such striking observation remains unanswered. In our past studies, we investigated polyatomic molecules, O2 and SF6, and we suggested that nuclear spin effect could be responsible to the observed NMD effect in a way of changing diffusion coefficients of certain molecules, owing to the fact of negligible delta S-36 anomaly for SF6.. On the other hand, our results also showed that for both diffusion and convection under thermal gradient, this NMD effect is increased by lower gas pressure, bigger temperature gradient and lower average temperature, which indicate that the nuclear spin effect may

  18. Sulfuric acid vapor and other cloud-related gases in the Venus atmosphere - Abundances inferred from observed radio opacity

    Science.gov (United States)

    Steffes, P. G.; Eshleman, V. R.

    1982-01-01

    It is suggested that the absorbing characteristics of sulfuric acid vapor appear to reconcile what had been thought to be an inconsistency among measurements and deductions regarding the constituents of the Venus atmosphere and radio occultation, radar reflection, and radio emission measurements of its opacity. Laboratory measurements of sulfuric acid, sulfur dioxide, water vapor, and carbon dioxide are used to model relative contributions to opacity as a function of height in a way that is consistent with observations of the constituents and absorbing properties of the atmosphere. It is concluded that sulfuric acid vapor is likely to be the principal microwave absorber in the 30-50 km altitude range of the middle atmosphere of Venus.

  19. Toward reconciling the influence of atmospheric aerosols and greenhouse gases on light precipitation changes in Eastern China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuan; Ma, Po-Lun; Jiang, Jonathan; Su, Hui; Rasch, Philip J.

    2016-05-21

    The attribution of the widely observed shifted precipitation extremes to different forcing agents represents a critical issue for understanding of changes in the hydrological cycle. To compare aerosol and greenhouse-gas effects on the historical trends of precipitation intensity, we performed AMIP-style NCAR/DOE CAM5 model simulations from 1950-2005 with and without anthropogenic aerosol forcings. Precipitation rates at every time step in CAM5 are used to construct precipitation probability distribution functions. By contrasting the two sets of experiments, we found that the global warming induced by the accumulating greenhouse gases is responsible for the changes in precipitation intensity at the global scale. However, regionally over the Eastern China, the drastic increase in anthropogenic aerosols primarily accounts for the observed light precipitation suppression since the 1950s. Compared with aerosol radiative effects, aerosol microphysical effect has a predominant role in determining the historical trends of precipitation intensity in Eastern China.

  20. Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine.

    Science.gov (United States)

    Kristensen, Louise Jane; Taylor, Mark Patrick; Evans, Andrew James

    2016-07-01

    Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data. PMID:27037773

  1. Real-time atmospheric chemistry field instrumentation.

    Science.gov (United States)

    Farmer, Delphine K; Jimenez, Jose L

    2010-10-01

    Quantifying the concentrations of trace atmospheric species in complex, reactive, and constantly changing gas and particle mixtures is challenging. This article provides a broad overview of recent advances in instrumentation used for analyzing ambient gases and particles continuously and with fast time resolution during field campaigns. PMID:20722374

  2. Tracing dust sources in different atmosphere levels of Tehran using hybrid single-particle lagrangian integrated trajectory (HYSPLIT model

    Directory of Open Access Journals (Sweden)

    Fahimeh Mohammadi

    2014-07-01

    Full Text Available Thepresent study aims to tracing dust sources of Tehran (capital city of Iranusing HYSPLIT model and atmospheric circulationsystems atdifferent levels. The statistical analyses within the period 1981-2005 indicatethat one of the most significant dust events in Tehran province occurred in May2000 and continued for more than 4 days in Abali, Chitgar, Firuzkuh, Karaj andNorth Tehran stations. For this purpose, in order to identify the sources of dustparticles and their directions, firstly, high-level atmospheric data includingzonal and meridional wind, geopotential height at pressure levelof 700 and 850 hPa and atmospheric circulation patterns werestudied from two days before the storm, the first of May until the end of thesecond, fourth and fifth day. By using atmospheric circulation maps, the synoptic systems effective in causing dust events, flowsdirections and their speeds were determined. In this modeling approach, a backwardparticle tracking method was applied to determine the direction of dustparticles, 48 hours before dust storm in Tehran, at three elevations of 100,500 and 1000 meter. With regard to the fact that the pressure systems ofnorthern latitudes are active over Iran in transition period of spring, itshould be noted that the results of the present study were affected by thesesystems. Results indicate that the high-pressure system hovering above theSaudi Arabia and the low-pressure tongue at higher latitudes play an importantrole in forming particle motion patterns and flow speeds of mentioned levels.Using HYSPLIT Lagrangian model shows the effects of arid regions of SaudiArabia, Iraq and some parts of Syria on producing greatest amount of dustparticles transferred to Tehran.

  3. Investigation of trace element atmospheric pollution by nuclear analytical techniques at a global scale: Harmonized approaches supported by the IAEA

    International Nuclear Information System (INIS)

    Full text: There are two conceptually different approaches for assessing trace element atmospheric pollution: (1) compositional analysis of directly collected APM, precipitation, and/or total deposit, and (2) the analysis of suitable air pollution bio indicators. In both approaches, multielement databases should be generated for subsequent emission source identification and apportionment. Nuclear analytical techniques are very suitable for the analysis of such kind of samples because they are multielement and non-destructive, having a high degree of sensitivity and selectivity for a large number of elements. For these reasons the International Atomic Energy Agency (IAEA) has been systematically supporting air pollution research since 1992. As part of general support to improving analytical performance of laboratories in its Member States (MS) the IAEA has carried out several interlaboratory comparisons and proficiency tests on filters loaded with particulate matter, lichens and mosses. The results obtained over the years has showed a definite performance improvement in the laboratories carrying out such analyses. Some typical results are summarised and presented in the paper. The IAEA has been supporting its MS' activities aimed at identifying major sources of air pollution affecting each of the participating countries and obtaining comparative data on pollution levels in areas of high pollution and low pollution. For these purposes an appropriate APM sampler was selected (about 100 such samplers have been distributed to nearly 50 countries worldwide), detailed sampling and sample preparation procedures elaborated, and data evaluation/interpretation procedures harmonized. The obtained results evidence that the levels of several pollutants (e.g. mass, S, Pb) in many countries exceed the United States Environmental Protection Agency prescribed limits. The IAEA has also been co-ordinating development of biomonitoring metrology for assessing (trace) element atmospheric

  4. A new sampler for collecting separate dry and wet atmospheric depositions of trace organic chemicals

    Science.gov (United States)

    Waite, Don T.; Cessna, Allan J.; Gurprasad, Narine P.; Banner, James

    Studies conducted in Saskatchewan and elsewhere have demonstrated the atmospheric transport of agricultural pesticides and other organic contaminants and their deposition into aquatic ecosystems. To date these studies have focused on ambient concentrations in the atmosphere and in wet precipitation. To measure the dry deposition of organic chemicals, a new sampler was designed which uses a moving sheet of water to passively trap dry particles and gasses. The moving sheet of water drains into a reservoir and, during recirculation through the sampler, is passed through an XAD-2 resin column which adsorbs the trapped organic contaminants. All surfaces which contact the process water are stainless steel or Teflon. Chemicals collected can be related to airborne materials depositing into aquatic ecosystems. The sampler has received a United States patent (number 5,413,003 - 9 May 1996) with the Canadian patent pending. XAD-2 resin adsorption efficiencies for 10 or 50 μg fortifications of ten pesticides ranged from 76% for atrazine (2-chloro-4-ethylamino-6-isopropylamino- S-triazine) to 110% for triallate [ S-(2,3,3-trichloro-2-phenyl)bis(1-methylethyl)carbamothioate], dicamba (2-methoxy-3,6-dichlorobenzoic acid) and toxaphene (chlorinated camphene mixture). Field testing using duplicate samplers showed good reproducibility and amounts trapped were consistent with those from high volume and bulk pan samplers located on the same site. Average atmospheric dry deposition rates of three chemicals, collected for 5 weeks in May and June, were: dicamba, 69 ng m -2 da -1; 2,4-D (2,4-dichlorophenoxyacetic acid), 276 ng m -2 da -1: and, γ-HCH ( γ-1, 2, 3, 4, 5, 6-hexachlorocyclohexane), 327 ng m -2 da -1.

  5. 17O-excess traces atmospheric nitrate in paleo groundwater of the Saharan desert

    Science.gov (United States)

    Dietzel, M.; Leis, A.; Abdalla, R.; Savarino, J.; Morin, S.; Böttcher, M. E.; Köhler, S.

    2013-12-01

    Saharan paleo groundwater from the Hasouna area of Libya contains up to 1.8 mM of nitrate, the origin of which is still disputed. Herein we show that a positive 17O-excess in NO3- (Δ17ONO3 = δ17ONO3 - 0.52 δ18ONO3) is preserved in the paleo groundwater. The 17O-excess provides an excellent tracer of atmospheric NO3-, which is caused by the interaction of ozone with NOx via photochemical reactions, coupled with a non-mass dependent isotope fractionation. Our Δ17ONO3 data from 0.4 to 5.0‰ (n = 28) indicate that up to x [NO3-]atm = 20 mol % of total dissolved NO3- originated from the Earth's atmosphere. High Δ17ONO3 values correspond to soils that are barren in dry periods, while low Δ17ONO3 values correspond to more fertile soils. Coupled high Δ17ONO3 and high x [NO3-]atm values are caused by a sudden wash out of dry deposition of atmospheric NO3- on plant or soil surfaces within humid-wet cycles. The individual isotope and chemical composition of the Hasouna groundwater can be followed by a binary mixing approach using the lowest and highest mineralized groundwater as end-members without considering evaporation. Using the δ34SSO4 and δ18OSO4 isotope signature of dissolved sulfate, no indication is found for a superimposition by denitrification, e.g. involving pyrite minerals within the aquifers. It is suggested that dissolved sulfate originates from the dissolution of calcium sulfate minerals during groundwater evolution.

  6. 17O excess traces atmospheric nitrate in paleo-groundwater of the Saharan desert

    Science.gov (United States)

    Dietzel, M.; Leis, A.; Abdalla, R.; Savarino, J.; Morin, S.; Böttcher, M. E.; Köhler, S.

    2014-06-01

    Saharan paleo-groundwater from the Hasouna area of Libya contains up to 1.8 mM of nitrate, which exceeds the World Health Organization limit for drinking water, but the origin is still disputed. Herein we show that a positive 17O excess in NO3- (Δ17ONO3 = Δ17ONO3 - 0.52 δ18ONO3) is preserved in the paleo-groundwater. The 17O excess provides an excellent tracer of atmospheric NO3-, which is caused by the interaction of ozone with NOx via photochemical reactions, coupled with a non-mass-dependent isotope fractionation. Our Δ17ONO3 data from 0.4 to 5.0 ‰ (n = 28) indicate that up to 20 mol % of total dissolved NO3- originated from the Earth's atmosphere (x[NO3-]atm), where the remaining NO3- refers to microbially induced nitrification in soils. High Δ17ONO3 values correspond to soils that are barren in dry periods, while low Δ17ONO3 values correspond to more fertile soils. Coupled high Δ17ONO3 and high x[NO3-]atm values are caused by a sudden wash-out of accumulated disposition of atmospheric NO3- on plants, soil surfaces and in vadose zones within humid-wet cycles. The individual isotope and chemical composition of the Hasouna groundwater can be followed by a binary mixing approach using the lowest and highest mineralised groundwater as end members without considering evaporation. Using the δ34SSO4 and δ18OSO4 isotope signature of dissolved SO42-, no indication is found for a superimposition by denitrification, e.g. involving pyrite minerals within the aquifers. It is suggested that dissolved SO42- originates from the dissolution of CaSO4 minerals during groundwater evolution.

  7. Comparative study of the suitability of two lichen species for trace element atmospheric monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Saiki, Mitiko; Alves, Edson R.; Genezini, Frederico A., E-mail: mitiko@ipen.br, E-mail: eralves@ipen.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN-SP), Sao Paulo, SP (Brazil); Saldiva, Paulo H.N., E-mail: pepino@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

    2013-07-01

    Lichens have been widely used in monitoring studies. Consequently, it is very useful to study the suitability of lichen species to monitor pollutants allowing in this way the best choice. The aim of this study was to compare the accumulation of trace elements by two epiphytic lichen species Canoparmelia texana (Tuck) Elix and Hale and Usnea amblyoclada (Mull. Arg.) Zahlbr. Five samples of each species were collected during the period from November 2010 in a same site far from downtown Sao Paulo city. Lichens collected from tree barks were cleaned, freeze-dried, ground and analyzed by neutron activation analysis. Aliquots of lichen samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor. The induced gamma activities were measured using a hyperpure Ge detector coupled to a digital spectrum analyzer. Concentrations of As, Ba, Cd, Cr, Cs, Fe, Mg, Mn, Na, Rb, V and Zn were determined in both lichen species. The results demonstrated that both species can be used for evaluating air quality. The element concentrations showed difference between lichen species and also among their sampling periods. These differences may be attributed to the distinct mechanisms of element absorption by lichens as well as various other factors that affect their element accumulation. The comparative evaluation made calculating the ratios between C. texana species sample and that in Usnea amblyoclada for elemental concentrations indicated that, in general, foliose C. texana present similar or higher concentrations than those presented by fruticose Usnea. (author)

  8. Urban and industrial contribution to trace elements in the atmosphere as measured in holm oak bark

    Science.gov (United States)

    Drava, Giuliana; Brignole, Daniele; Giordani, Paolo; Minganti, Vincenzo

    2016-11-01

    The concentrations of As, Cd, Co, Cu, Fe, Mn, Ni, Pb, V and Zn were measured by ICP-OES in samples of bark of the holm oak (Quercus ilex L.) collected from trees in different urban environments (residential and mixed residential/industrial). The use of tree bark as a bioindicator makes it easy to create maps that can provide detailed data on the levels and on the spatial distribution of each trace element. For most of the elements considered (As, Co, Fe, Mn, Ni, V and Zn), the concentrations in the industrial sites are about twice (from 1.9 to 2.8 times higher) of those in the residential area. Arsenic, Fe and Zn show the highest concentrations near a steel plant (operational until 2005), but for the other elements it is not possible to identify any localized source, as evident from the maps. In areas where urban pollution is summed up by the impact of industrial activities, the population is exposed to significantly higher amounts of some metals than people living in residential areas.

  9. Trace determination of the flame retardant tetrabromobisphenol A in the atmosphere by gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Xie Zhiyong [GKSS Research Centre, Institute for Coastal Research, Department of Environmental Chemistry, Max-Planck-Str. 1, D-21502 Geesthacht (Germany) and Johann Wolfgang Goethe-University Frankfurt at Main, Institute of Atmospheric and Environmental Sciences, Department of Analytical Environmental Chemistry, Georg-Voigt-Str. 14, 60054 Frankfurt (Germany)]. E-mail: zhiyong.xie@gkss.de; Ebinghaus, Ralf [GKSS Research Centre, Institute for Coastal Research, Department of Environmental Chemistry, Max-Planck-Str. 1, D-21502 Geesthacht (Germany); Lohmann, Rainer [Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882-1197 (United States); Heemken, Olaf [LAVES, Philosophenweg 36/38, D-26121 Oldenburg (Germany); Caba, Armando [GKSS Research Centre, Institute for Coastal Research, Department of Environmental Chemistry, Max-Planck-Str. 1, D-21502 Geesthacht (Germany); Puettmann, Wilhelm [Johann Wolfgang Goethe-University Frankfurt at Main, Institute of Atmospheric and Environmental Sciences, Department of Analytical Environmental Chemistry, Georg-Voigt-Str. 14, 60054 Frankfurt (Germany)

    2007-02-19

    A simple and effective method has been developed for analysis of the flame retardant tetrabromobisphenol A (TBBPA) in environmental samples by using modified soxhlet extraction in combination with silica gel clean-up, derivatization with silylation reagent and gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring mode (SIM). Satisfactory recoveries were achieved for the large volume sampling, soxhlet extraction and silica gel clean-up. The overall recovery is 79 {+-} 1%. The derivatization procedure is simple and fast, and produces stable TBBPA derivative. GC-MS with electronic impact (EI) ionization mode shows better detection power than using negative chemical ionization (NCI) mode. EI gives a method detection limit of 0.04 pg m{sup -3} and enables to determine trace TBBPA in ambient air in remote area. The method was successfully applied to the determination of TBBPA in atmospheric samples collected over land and coastal regions. The concentrations of TBBPA ranged from below the method detection limit (0.04 pg m{sup -3}) to 0.85 pg m{sup -3}. A declining trend with increasing latitude was present from the Wadden Sea to the Arctic. The atmospheric occurrence of TBBPA in the Arctic is significant and might imply that TBBPA has long-range transport potential.

  10. Biomonitoring of atmospheric pollution (with emphasis on trace elements) - BioMap II. Proceedings of an international workshop

    International Nuclear Information System (INIS)

    Certain types of organisms integrate pollution over time, reducing the need for continuous chemical monitoring, thus avoiding the difficulty of interpreting 'snapshot' measurements and offering the potential of retrospective monitoring. Such organisms enrich the substance to be determined so that the analytical accessibility is improved and the measurement uncertainty reduced. By observing and measuring the changes in an appropriately selected organism, a conclusion as to the kind of pollution, its source, and its intensity can be drawn. The IAEA is making concerted efforts to promote the practical use of nuclear and related analytical techniques in studies of non-radioactive environmental pollutants that may impact on human health, and one of the main emphasis is on studying air contaminants. The IAEA has been systematically supporting biomonitoring atmospheric pollution for 10 years in the framework of its project on Environmental Pollution Monitoring and Research Using Nuclear and Related Analytical Techniques. The objective of this project is to identify the source and evaluate the fate of key non-radioactive environmental contaminants and provide the basis for improved health for human populations. The project has been implemented through a Coordinated Research Project on Validation and Application of Plants as Biomonitors of Trace Element Atmospheric Pollution Analysed by Nuclear and Related Techniques, several technical co-operation projects, and some dedicated analytical quality control activities. Within the scope of these efforts, the Second International Workshop on Biomonitoring of Atmospheric Pollution (with Emphasis on Trace Elements) - BioMAP, was organized as a follow-up to the 1997 BioMAP workshop held in Lisbon, Portugal. The proceedings of the first workshop were published in IAEA-TECDOC-1152. The second workshop was held in Praia da Vitoria, Azores Islands, Portugal, from 28 August to 3 September 2000. It was organized in co-operation with the

  11. Poster 6: Influence of traces elements in the organic chemistry of upper atmosphere of Titan

    Science.gov (United States)

    Mathe, Christophe; Carrasco, Nathalie; Trainer, Melissa G.; Gautier, Thomas; Gavilan, Lisseth; Dubois, David; Li, Xiang

    2016-06-01

    In the upper atmosphere of Titan, complex chemistry leads to the formation of organic aerosols. Since the work of Khare et al. in 1984, several experiments investigated the formation of Titan aerosols, so called tholins, in the laboratory. It has been suggested that nitrogen-containing compounds may contribute significantly to the aerosols formation process. In this study, we focused on the influence of pyridine, the simplest nitrogenous aromatic hydrocarbon, on the chemistry of Titan's atmosphere and on aerosol formation. To assess the effect of pyridine on aerosol formation chemistry, we used two different experimental setups : a capacitively coupled radio-frequency (electronic impact), and a VUV Deuterium lamp (photochemistry) in a collaboration between LATMOS (Guyancourt) and NASA-GSFC (Greenbelt), respectively. Aerosols produced with both setups were first analyzed using a FTIR-ATR (Fourier Transform Infrared spectroscopy - Attenuated Total Reflection) with a spectral range of 4000-800 cm-1 to characterize their optical properties. Next the samples were analysed using a Bruker Autoflex Speed MALDI mass spectrometer with a m/z range up to 2000 Da in order to infer their composition. Infrared spectroscopy analysis showed that tholins produced with a nitrogen-methane gas mixture (95:5) and nitrogenpyridine gas mixture (99:250ppm) present very similar spectra features. Tholins produced with a mixture of nitrogenmethane-pyridine (99:1:250ppm) do not present aliphatic CH2 or CH3 vibrational signatures. This could indicate a cyclic polymerization by a pyridine skeleton. Mass spectrometry is still in progress to confirm this.

  12. Heavy metals and trace elements in atmospheric fall-out: Their relationship with topsoil and wheat element composition

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, Gonzalo M.A., E-mail: gbermudez@com.uncor.edu [Instituto Multidisciplinario de Biologia Vegetal (IMBIV), CONICET (Argentina); Catedra de Quimica General, FCEFyN, Universidad Nacional de Cordoba, Avda. Velez Sarsfield 1611, Ciudad Universitaria (X5016 GCA), Cordoba (Argentina); Jasan, Raquel; Pla, Rita [Tecnicas Analiticas Nucleares, Comision Nacional de Energia Atomica (CAE), Presbitero Gonzalez y Aragon N Degree-Sign 15 (B1802AYA), Ezeiza (Argentina); Pignata, Maria L. [Instituto Multidisciplinario de Biologia Vegetal (IMBIV), CONICET (Argentina); Catedra de Quimica General, FCEFyN, Universidad Nacional de Cordoba, Avda. Velez Sarsfield 1611, Ciudad Universitaria (X5016 GCA), Cordoba (Argentina)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Metal and trace element deposition rates and concentrations in bulk samples. Black-Right-Pointing-Pointer Anthropogenic vs. natural sources were identified using enrichment factors and PCA. Black-Right-Pointing-Pointer Anthropogenic sources for Ca, Cd, Cu, Fe, Mn, Ni, Pb, Sb, U, Zn and lanthanides. Black-Right-Pointing-Pointer Main sources were a cement plant, chemical-mechanical industries, cities and mining. Black-Right-Pointing-Pointer Metals in wheat grain were predicted by soil and bulk deposition composition. - Abstract: The objectives of this study were to determine the average concentrations and deposition rates of 28 elements in atmospheric bulk deposition and to elucidate associations among topsoil, bulk deposition and wheat element composition. The fluxes of arsenic (As), copper (Cu), lead (Pb) and zinc (Zn) deposition in Cordoba were higher than in other agro-ecosystems, which reflects both natural (geochemistry and topsoil removal) and anthropogenic sources. High lanthanide, uranium (U) and thorium (Th) concentrations revealed the impact of an open cast uranium mine. The highest enrichment factors (EF) were those of Cu, Pb, Zn and nickel (Ni), with calcium (Ca) being the most prominent in the surroundings of a cement plant. Industries and the transport of airborne urban pollutants were the main anthropogenic sources for Ca, Cu, Ni, Pb, Zn, cadmium (Cd), iron (Fe), manganese (Mn) and antimony (Sb). The concentrations of metals in wheat grain were predicted using the topsoil and atmospheric fall-out composition with R{sup 2} = 0.90, with the latter being the best explanatory variable. The present study highlights the potential health hazards of wheat consumption (Environmental Protection Agency) by the assessment of heavy metals in bulk atmospheric deposition.

  13. Responses of dissolved trace gases (CH4, N2O, CO, NMHCs, CH3Cl) to phytoplankton bloom during in situ iron enrichment (SEEDII) in the western subarctic Pacific

    Science.gov (United States)

    Kameyama, S.; Nakagawa, F.; Sasakawa, M.; Yamaguchi, J.; Komatsu, D. D.; Ijiri, A.; Tsunogai, U.; Horiguchi, T.; Kawamura, H.; Tsuda, A.

    2006-12-01

    Biogeochemical processes in ocean surface are known to play important roles in the global circulation of many trace gases: not only CO2 but also non-CO2 gases, such as CH4, N2O, CO, NMHCs and CH3Cl. The mixing ratios of these components in air are highly responsible for controlling global warming, stratospheric and tropospheric O3, tropospheric OH, organic aerosols, and peroxides. While future global changes could alter air-sea fluxes of these components in ocean surface, the detailed processes to produce/consume these components, as well as the range of the variations, are not clarified as yet. The iron fertilization experiment offers us a wonderful chance to quantify the effect of phytoplankton bloom to the production of the trace gases. During 2004 iron-enrichment experiment in the northwest subarctic Pacific (SEEDSII), we monitored mixing ratios of the trace gases (CH4, N2O, CO, NMHCs and CH3Cl) within the phytoplankton bloom. Besides, the stable isotopic ratios were also monitored to clarify the processes that are responsible for the variations. Both the mixing ratios and the stable isotopic ratios of dissolved CH4, N2O and CH3Cl exhibit little changes during the 23 days observation. On the other hand, dissolved CO exhibit remarkable change in the carbon isotopic composition as phytoplankton bloomed. The maximum variation reached to about 25‰ depletion in δ13C. We conclude that the enrichment of the CO precursor must be responsible for the variation. Furthermore, in accordance with the phytoplankton bloomed, the concentration of NMHCs, especially alkane, exhibit remarkable enrichment in the mixing rations: 3 times for ethane, 4 times for propane, 13 times for butane compared with those prior to the bloom. In accordance with the enrichment, the stable carbon isotopic composition of ethane and propane increased, while that of butane decreased. To clarify the source of alkane during the bloom, we determined both concentration and δ13C of alkane emitted from

  14. Planetary noble gases

    Science.gov (United States)

    Zahnle, Kevin

    1993-01-01

    An overview of the history and current status of research on planetary noble gases is presented. The discovery that neon and argon are vastly more abundant on Venus than on earth points to the solar wind rather than condensation as the fundamental process for placing noble gases in the atmospheres of the terrestrial planets; however, solar wind implantation may not be able to fully reproduce the observed gradient, nor does it obviously account for similar planetary Ne/Ar ratios and dissimilar planetary Ar/Kr ratios. More recent studies have emphasized escape rather than accretion. Hydrodynamic escape, which is fractionating, readily accounts for the difference between atmospheric neon and isotopically light mantle neon. Atmospheric cratering, which is nearly nonfractionating, can account for the extreme scarcity of nonradiogenic noble gases (and other volatiles) on Mars.

  15. Influence of Biomass Burning on Temporal and Diurnal Variations of Acidic Gases, Particulate Nitrate, and Sulfate in a Tropical Urban Atmosphere

    Directory of Open Access Journals (Sweden)

    Sailesh N. Behera

    2014-01-01

    Full Text Available The present study investigated the temporal and diurnal distributions of atmospheric acidic gases (sulphur dioxide (SO2, nitrous acid (HONO, and nitric acid (HNO3 and those of particulate nitrate (NO3- and sulfate (SO42- through a comprehensive field campaign during the largest smoke haze episode in Singapore, a representative country in Southeast Asia (SEA. To identify the atmospheric behavior of these pollutants during the smoke haze period, the data generated from the measurement campaign were divided into three distinct periods: prehaze, during haze, and posthaze periods. The 24 hr average data indicated that ambient SO2, HONO, and HNO3 during the smoke haze episodes increased by a factor ranging from 1.2 to 2.6 compared to those during the prehaze and posthaze periods. Similarly, in the case of particulates SO42- and NO3-, the factor ranged from 2.3 to 4.2. Backward air trajectories were constructed and used to find the sources of biomass burning to the recurring smoke haze in this region. The air trajectory analysis showed that the smoke haze episodes experienced in Singapore were influenced by transboundary air pollution, caused by severe biomass burning events in the islands of Indonesia.

  16. Acidic gases and nitrate and sulfate particles in the atmosphere in the city of Guadalajara, México.

    Science.gov (United States)

    Saldarriaga-Noreña, Hugo; Waliszewski, Stefan; Murillo-Tovar, Mario; Hernández-Mena, Leonel; de la Garza-Rodríguez, Iliana; Colunga-Urbina, Edith; Cuevas-Ordaz, Rosalva

    2012-05-01

    Atmospheric concentrations of nitrous acid, nitric acid, nitrate and sulfate particles were obtained in this study from April to June 2008 in the center of the city of Guadalajara, while concentrations of ozone, sulfur dioxide, nitrogen dioxide and meteorological parameters (temperature and relative humidity), were acquired by the Secretaría del Medio Ambiente para el Desarrollo Sustentable del Estado de Jalisco (SEMADES). The results showed that nitric acid (2.7 μg m(-3)) was 2.7 times higher than nitrous acid (1.0 μg m(-3)). The sulfur dioxide (SO(2)) concentration indicated an opposite trend to sulfate (SO(4) (2-)), with the average concentration of SO(2) (6.9 μg m(-3)) higher in almost the entire period of study. The sulfur conversion ratio (Fs, 24.9%) and nitrogen conversion ratio (Fn, 6.2%), were revealed to be similar to that reported in other urban areas during warm seasons. It is also noted that ozone is not the main oxidizer of nitrogen dioxide and sulfur dioxide. This determination was made by taking into account the slightly positively correlation determined for Fn (r(2) = 0.084) and Fs (r(2) = 0.092) with ozone that perhaps suggests there are other oxidizing species such as the radical OH, which are playing an important role in the processes of atmospheric oxidation in this area.

  17. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer dataset

    Directory of Open Access Journals (Sweden)

    A. Jones

    2011-11-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry Climate Model validation activity. The ACE-FTS climatological dataset is available through the ACE website.

  18. [Characteristics of Atmospheric Dry and Wet Deposition of Trace Metals in the Hinterland of the Three Gorges Reservoir, China].

    Science.gov (United States)

    Zhang, Liu-yi; Liu, Yuan; Qiao, Bao-qing; Fu, Chuan; Wang, Huan-bo; Huang, Yi-min; Yang, Fu-mo

    2016-02-15

    In order to investigate the characteristics of atmospheric trace metals deposition in the hinterland of the Three Gorges Reservoir, the wet and dry deposition samples were collected at an urban area sampling site in Wanzhou during January to June 2014. Besides, the samples were collected at five other sampling sites in April 2014 for comparative analysis, including factory region, town suburb, nature reserve, county suburb, and rural area. pH, conductivity, and trace metals (Al, As, B, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Pb, Ni, Sb, Sr, Sn, Ti, Zn, V) were analyzed. In urban area, the acid rain frequency was 48.44% , and the acid rain occurred mainly in the period of January to April. The order of acid rain frequency in various functional areas was factory region > urban area > county suburb > town suburb > nature reserve > county rural area. All of the trace metals in wet deposition during the sampling period were lower than the National Environmental Quality Standard for Surface Water Standard of Class III. Cd, Cu, Ph and Zn were found exceeding the standard of class I , and the pollution in factory region was more serious compared to other functional areas. The extract pH of dry deposition in urban area was in the range of 4.91-6.74, with an average value of 5.79. The order of dry deposition in various functional areas was factory region > county suburb > urban area > county rural area > town suburb > nature reserve, which was exactly the same as that of the wet deposition, indicating the similar sources of dry and wet deposition. In urban area, the contents of Ba, Co, Cu, Cr, Li, Mn, Ni, Sr, Zn in dry deposition were greater than those in wet deposition, but the contents of Al, As, B, Bi, Cd, Fe, Ph, Sb, Sn, Ti, V showed the opposite trend. Analysis of the enrichment factors showed that Al was in moderate enrichment, while Bi and Cd were significantly enriched. PMID:27363132

  19. High-sensitivity remote detection of atmospheric pollutants and greenhouse gases at low ppm levels using near-infrared tunable diode lasers

    Science.gov (United States)

    Roy, Anirban; Upadhyay, Abhishek; Chakraborty, Arup Lal

    2016-05-01

    The concentration of atmospheric pollutants and greenhouse gases needs to be precisely monitored for sustainable industrial development and to predict the climate shifts caused by global warming. Such measurements are made on a continuous basis in ecologically sensitive and urban areas in the advanced countries. Tunable diode laser spectroscopy (TDLS) is the most versatile non-destructive technology currently available for remote measurements of multiple gases with very high selectivity (low cross-sensitivity), very high sensitivity (on the order of ppm and ppb) and under hazardous conditions. We demonstrate absolute measurements of acetylene, methane and carbon dioxide using a fielddeployable fully automated TDLS system that uses calibration-free 2f wavelength modulation spectroscopy (2f WMS) techniques with sensitivities of low ppm levels. A 40 mW, 1531.52 nm distributed feedback (DFB) diode laser, a 10 mW, 1650 nm DFB laser and a 1 mW, 2004 nm vertical cavity surface emitting laser (VCSEL) are used in the experiments to probe the P9 transition of acetylene, R4 transition of methane and R16 transition of carbon dioxide respectively. Data acquisition and on-board analysis comprises a Raspberry Pi-based embedded system that is controllable over a wireless connection. Gas concentration and pressure are simultaneously extracted by fitting the experimental signals to 2f WMS signals simulated using spectroscopic parameters obtained from the HITRAN database. The lowest detected concentration is 11 ppm for acetylene, 275 ppm for methane and 285 ppm for carbon dioxide using a 28 cm long single-pass gas cell.

  20. Are coarse particles unexpected common reservoirs for some atmospheric anthropogenic trace elements? A case study

    Science.gov (United States)

    Catinon, Mickaël; Ayrault, Sophie; Boudouma, Omar; Bordier, Louise; Agnello, Gregory; Reynaud, Stéphane; Tissut, Michel

    2013-08-01

    Without specific experimental equipment, it is very difficult to sample long-term atmospheric deposits on a pure state. That is why the composition of air-transferred solid material accumulated for 40 years in the 2 m-high walls, pierced with numerous holes of an outdoor public shelter, Grenoble city, France, was studied. An appropriate fractionation procedure allowed to obtain several fractions which were i) a sand fraction (8.3%) (fraction A), ii) a large mass of organic matter corresponding mostly to large fragments (>250 μm) of plant origin (66.7%) (fraction B) or to pollen fraction C (0.4%), iii) a slowly depositing organo-clay fraction (20%) (fractions D1 and D2) and iv) a solution mixed with non-settable particles (4.3%) (fraction E). The composition of each fraction was determined for 20 elements. The sand fraction showed very high concentrations specifically in Cu, Pb and Fe corresponding respectively to 81.5, 48.2 and 35.2% of the samples content in these elements. In contrast, Cd and Zn were mainly accumulated in the fraction B (67.5 and 62.2%, respectively). The scanning electron microscopy coupled to energy dispersive X-ray analysis (SEM-EDX) study of the fraction A showed the presence of large particles bearing Pb and Fe, particles rich in Cu and typical fly ashes originating mostly from iron industry. Most of these particles had a crystalline shape suggesting that they were formed after emission at a high temperature. The Pb-Fe-Cu deposit seen in fraction A likely originates from the neighbouring road surface contaminated by car traffic for several decades. The 206Pb/207Pb ratio (1.146 ± 0.004) showed that in the coarse sandy fraction A, Pb was represented at 65% by non-gasoline lead and 35% by "gasoline" lead emitted before 1999. The fraction A particles can only be transported on a limited distance by high magnitude events. They constitute a large reservoir for Cu and Pb and may play a major role in the long-term contamination of urban soils.

  1. The Relation of Stratospheric Aerosols with Trace Gases and Temperature%平流层气溶胶与多种微量气体以及温度的关系

    Institute of Scientific and Technical Information of China (English)

    蔡宏珂; 郭静超; 周任君; 刘鹏兵; 傅云飞

    2011-01-01

    The HALOE (Halogen Occultation Experiment) dataset is used to study the relation of stratospheric aerosols with trace gases (O3, H2O, HC1, NOX, CH4, and HF) and temperature in a period of relative volcanic quiescence. The lag-correlation analysis shows trace gases and temperature are significantly related to aerosol surface area density. Characteristics of the relevance vary with different components. Temperature is negatively correlated with aerosol for 70 - 20 hPa over low-and mid-latitudes. Standardized multiple linear regression demonstrates that greenhouse gases are the primary direct contributor for temperature change, and the direct contribution of aerosols is much less. The impact of aerosols on the stratosphere is simulated with the two-dimensional model SOCRATES (Simulation of Chemistry, Radiation, and Transport of Environmentally important Species). The response of trace gases and temperature coincides with the analysis of the HALOE. The rangeability of temperature is much less than that of aerosols. The result suggests that the stratospheric heterogeneous processes on aerosol surfaces are important for the relation between aerosols and trace gases in the aerosol-enriched layers. The radiation effect of aerosolsis cooling in the period of relative volcanic quiescence, which is different from the warming effect after volcanic eruptions. The phenomenon depends on the aerosol contents. The indirect radiation effect via heterogeneous processes is stronger than the direct effect of aerosols themselves, but the total radiation effect makes little impact on temperature.%本文采用卤素掩星试验(Halogen Occultation Experiment,HALOE)资料探讨了火山活动相对平静期平流层气溶胶与O3、H2O、HC1、NOx、CH4、HF等微量气体以及温度的关系.滞后相关分析显示气溶胶与微量气体和温度有显著关系,不同成分的相关性特征有所差异,中低纬度上空70~20 hPa高度上气溶胶与温度旱负相关.标准化多

  2. Performance evaluation of atmospheric biomass integrated gasifier combined cycle systems under different strategies for the use of low calorific gases

    International Nuclear Information System (INIS)

    This work aims at a performance evaluation of atmospheric BIGCC (biomass integrated gasifier combined cycle) systems operating under different strategies for the use of low calorific fuel in gas turbines. The fuel is a synthetic gas derived from gasification of sugar cane residues. Two analysed strategies for surge control on gas turbines originally designed for operation on natural gas are de-rating and air extraction from the compressor. Another strategy for use of biomass derived gas is the retrofit of a gas turbine through modification of the expander geometry. Three generic gas turbines, whose main parameters have been taken from off the shelf machines, are proposed as representative of certain classes of gas turbines. Results are compared to the hypothetical situation in which it is possible to accept any increase in gas turbine pressure ratio. According to the results, de-rating is the worst surge control strategy, both from the point of view of power production and thermal efficiency. Conversely, results showed considerable gains that can be obtained on cycle power production when the gas turbine expander is modified. Additionally, an overview of issues concerning the suitability of sugar cane residues (bagasse and trash) for the production of gasified gas and its use in BIGCC plants is presented

  3. Atmospheric dry deposition of mineral dust to the Gulf of Aqaba, Red Sea: rate and trace elements.

    Science.gov (United States)

    Al-Taani, Ahmed A; Rashdan, Maen; Khashashneh, Safaa

    2015-03-15

    Atmospheric dry deposition to the Gulf of Aqaba (GoA) is particularly a significant source of trace elements. Amid desert regions, the Gulf receives high fluxes of mineral dust with an average rate of 34.68 g/m(2)/year measured in 2012. Patterns of dry deposition showed seasonal fluxes with highest rates observed in summer and lowest in winter. The observed variations were attributed to wind direction, timing of deposition and sources of dust. The average dry fluxes of Al, Fe, Mn, Cr, Cd, Cu, Pb and Zn were 551, 440, 10.29, 1.42, 0.04, 0.68, 1.42 and 4.02 mg/m(2)/year, respectively. While the dry deposition fluxes were enriched in Cd, Cu, Pb and Zn indicating their dominant anthropogenic sources, they appeared to be less influenced compared to the neighboring Mediterranean area and other industrial countries, but were similar to or slightly higher than those in remote areas. The enrichment values for Fe and Mn were low, consistent with their crustal origin. The fluxes of all elements suggested the impacts of both crustal (due to climate change) and anthropogenic sources became stronger in this region. The Sahara dust was probably a minor contributor to dry deposition in the GoA.

  4. Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy

    Directory of Open Access Journals (Sweden)

    R. Caggiano

    2014-10-01

    Full Text Available The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy. The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy. The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6–12 month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6 and 12 month-exposed samples. Moreover, principal component analysis (PCA results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes, agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA plant emissions and the African dust long-range transport were also identified.

  5. Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

    Science.gov (United States)

    Caggiano, R.; Trippetta, S.; Sabia, S.

    2015-02-01

    The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn) were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy). The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy), about 30 km away from the study area along the north direction. The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC) ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6-12-month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6-month and 12-month-exposed samples. Moreover, principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA) plant emissions and the African dust long-range transport were also identified.

  6. Tracing the Sources of Atmospheric Phosphorus Deposition to a Tropical Rain Forest in Panama Using Stable Oxygen Isotopes.

    Science.gov (United States)

    Gross, A; Turner, B L; Goren, T; Berry, A; Angert, A

    2016-02-01

    Atmospheric dust deposition can be a significant source of phosphorus (P) in some tropical forests, so information on the origins and solubility of atmospheric P is needed to understand and predict patterns of forest productivity under future climate scenarios. We characterized atmospheric dust P across a seasonal cycle in a tropical lowland rain forest on Barro Colorado Nature Monument (BCNM), Republic of Panama. We traced P sources by combining remote sensing imagery with the first measurements of stable oxygen isotopes in soluble inorganic phosphate (δ(18)OP) in dust. In addition, we measured soluble inorganic and organic P concentrations in fine (1 μm) aerosol fractions and used this data to estimate the contribution of P inputs from dust deposition to the forest P budget. Aerosol dry mass was greater in the dry season (December to April, 5.6-15.7 μg m(-3)) than the wet season (May to November, 3.1-7.1 μg m(-3)). In contrast, soluble P concentrations in the aerosols were lower in the dry season (980-1880 μg P g(-1)) than the wet season (1170-3380 μg P g(-1)). The δ(18)OP of dry-season aerosols resembled that of nearby forest soils (∼19.5‰), suggesting a local origin. In the wet season, when the Trans-Atlantic Saharan dust belt moves north close to Panama, the δ(18)OP of aerosols was considerably lower (∼15.5‰), suggesting a significant contribution of long-distance dust P transport. Using satellite retrieved aerosol optical depth (AOD) and the P concentrations in aerosols we sampled in periods when Saharan dust was evident we estimate that the monthly P input from long distance dust transport during the period with highest Saharan dust deposition is 88 ± 31 g P ha(-1) month(-1), equivalent to between 10 and 29% of the P in monthly litter fall in nearby forests. These findings have important implications for our understanding of modern nutrient budgets and the productivity of tropical forests in the region under future climate scenarios.

  7. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from temperate fuels common in the United States

    Directory of Open Access Journals (Sweden)

    J. B. Gilman

    2015-08-01

    Full Text Available 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

  8. Parameterization of the Absorption of the H2O Continuum, CO2, O2, and Other Trace Gases in the Fu-Liou Solar Radiation Program

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; ZENG Qingcun; Y.GU; K.N.LIOU

    2005-01-01

    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 singlemixture 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-1 solar 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

  9. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from fuels common in the US

    Science.gov (United States)

    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

  10. Trapped noble gases in meteorites

    Science.gov (United States)

    Swindle, Timothy D.

    1988-01-01

    The trapped noble gases in meteorites come in two main varieties, usually referred to as solar and planetary. The solar noble gases are implanted solar-wind or solar-flare materials, and thus their relative elemental abundances provide a good estimate of those of the sun. The planetary noble gases have relative elemental abundances similar to those in the terrestrial atmosphere, but there are also important distinctions. At least one other elemental pattern (subsolar) and several isotopic patterns have also been identified.

  11. Study on the effect of atmospheric gases adsorbed in MnFe2O4/MCM-41 nanocomposite on ortho-positronium annihilation

    Directory of Open Access Journals (Sweden)

    Wiertel Marek

    2015-12-01

    Full Text Available In this paper, results of positron annihilation lifetime spectroscopy (PALS studies of MnFe2O4/MCM-41 nanocomposites in N2 and O2 atmosphere have been presented. In particular, the influence of manganese ferrite loading and gas filling on pick-off ortho-positronium (o-Ps annihilation processes in the investigated samples was a point of interest. Disappearance of the longest-lived o-Ps component with τ5 present in the PAL spectrum of initial MCM-41 mesoporous material in the PAL spectra of MnFe2O4-impregnated MCM-41 measured in vacuum is a result of either a strong chemical o-Ps quenching or the Ps inhibition effects. The intensity I4 of the medium-lived component initially increases, reaching a maximum value for the sample with minimum manganese ferrite content, and then decreases monotonically. Analogous dependence for the intensity I3 of the shortest-lived component shows a maximum at higher MnFe2O4 content. Filling of open pores present in the studied nanocomposites by N2 or O2 at ambient pressure causes partial reappearance of the τ4 and τ5 components, except a sample with maximum ferrite content. The lifetimes of these components measured in O2 are shortened in comparison to that observed in N2 because of paramagnetic quenching. Anti-inhibition and anti-quenching effects of atmospheric gases observed in the MnFe2O4/MCM-41 samples are a result of neutralization of some surface active centers acting as inhibitors and weakening of pick-off annihilation mechanism, respectively.

  12. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. High-resolution reconstruction of atmospheric deposition of trace metals and metalloids since AD 1400 recorded by ombrotrophic peat cores in Hautes-Fagnes, Belgium

    International Nuclear Information System (INIS)

    The objective of our study was to determine the trace metal accumulation rates in the Misten bog, Hautes-Fagnes, Belgium, and assess these in relation to established histories of atmospheric emissions from anthropogenic sources. To address these aims we analyzed trace metals and metalloids (Pb, Cu, Ni, As, Sb, Cr, Co, V, Cd and Zn), as well as Pb isotopes, using XRF, Q-ICP-MS and MC-ICP-MS, respectively in two 40-cm peat sections, spanning the last 600 yr. The temporal increase of metal fluxes from the inception of the Industrial Revolution to the present varies by a factor of 5–50, with peak values found between AD 1930 and 1990. A cluster analysis combined with Pb isotopic composition allows the identification of the main sources of Pb and by inference of the other metals, which indicates that coal consumption and metallurgical activities were the predominant sources of pollution during the last 600 years. -- Highlights: •Study of trace metals and metalloids in two cores from Belgian peat bog. •Reconstruction of trace metals and metalloids deposition over last 600 years. •Maximum trace metals accumulation rates are recorded between 1930 and 1990 AD. •A cluster analysis combined with Pb isotopic composition used to identify the main sources of Pb and by inference the other metals. •The predominant anthropogenic trace metals sources were consumption and metallurgical activities. -- In this study we used trace metals concentrations and fluxes from two cores sampled in a Belgium bog to document with high resolution the history of trace metals deposition over the last 600 years

  14. Determination of trace water content in gases by calcium carbide reaction method%电石反应法测定气体中微量水分

    Institute of Scientific and Technical Information of China (English)

    乔贺兴; 王玉莲; 陈绍理

    2012-01-01

    介绍了一种测定气体中水含量的方法:依据电石吸收气体中水分并生成乙炔气的原理,采用氢火焰离子检测器气相色谱分析乙炔含量,从而计算出气体中水含量。指出该方法具有精确、方便的特点。%This paper introduced a method for the determination of water content in gases.The method was based on the principle that water contained in gas could be absorbed by calcium carbide and generate acetylene gas,which was then analyzed by gas chromatography with hydrogen flame ionization detector,so the water content in gas could be calculated.The method was accurate and simple.

  15. Characteristics of trace gaseous pollutants at a regional background station in Northern China

    OpenAIRE

    Meng, Z. Y.; X. B. Xu; Yan, P; Ding, G. A.; Tang, J; W. L. Lin; Xu, X. D.; Wang, S. F.

    2009-01-01

    Measurements of trace gaseous pollutants were taken at the Shangdianzi site, a WMO Global Atmosphere Watch (GAW) background station in Northern China. The results are presented for the period from September 2003 to December 2006. Seasonal and diurnal variations of the O3, NOx, SO2, and CO concentration are characterized and possible causes for them are discussed. The observed levels of the trace gases are comparable to those...

  16. Stratospheric and mesospheric pressure-temperature profiles from rotational analysis of CO2 lines in atmospheric trace molecule spectroscopy/ATLAS 1 infrared solar occultation spectra

    Science.gov (United States)

    Stiller, G. P.; Gunson, M. R.; Lowes, L. L.; Abrams, M. C.; Raper, O. F.; Farmer, C. B.; Zander, R.; Rinsland, C. P.

    1995-01-01

    A simple, classical, and expedient method for the retrieval of atmospheric pressure-temperature profiles has been applied to the high-resolution infrared solar absorption spectra obtained with the atmospheric trace molecule spectroscopy (ATMOS) instrument. The basis for this method is a rotational analysis of retrieved apparent abundances from CO2 rovibrational absorption lines, employing existing constituent concentration retrieval software used in the analysis of data returned by ATMOS. Pressure-temperature profiles derived from spectra acquired during the ATLAS 1 space shuttle mission of March-April 1992 are quantitatively evaluated and compared with climatological and meteorological data as a means of assessing the validity of this approach.

  17. Stratospheric NO, NO2, and N2O5 - A comparison of model results with Spacelab 3 Atmospheric Trace Molecule Spectroscopy (ATMOS) measurements

    Science.gov (United States)

    Allen, Mark; Delitsky, Mona L.

    1990-01-01

    The Spacelab 3 Atmospheric Trace Molecule Spectroscopy measurements in 1985 of stratospheric NO/NO2 abundance ratios were compared with abundance ratios calculated using a time-dependent photochemical model. A good agreement between calculated and observed values of the NO/NO2 abundance ratio was found through much of the stratosphere, indicating that the temperature-dependent rate constant K3 (NO + O3) used in the model is properly parameterized.

  18. Detection Method of Trace Multi-component Gases Based on SVM and PCA%基于SVM和PCA的痕量多组分气体检测方法

    Institute of Scientific and Technical Information of China (English)

    余道洋; 戚功美; 瞿顶军; 李民强; 刘锦淮

    2015-01-01

    Gas sensors and optical sensors are difficult to detect trace multi﹣component gases. In this paper, a detection method of fast chromatography combined with gas sensor array is introduced to obtain the characteristic signal of trace multi﹣component gases. Support vector machine ( SVM ) is introduced to classify the samples according to the features. Then, to obtain a better gas identification model, particle swarm optimization algorithm is utilized to optimize the parameters of SVM. Based on actual sample detection and recognition, and compared to detection method by similar testing instrument, the proposed method has better selectivity of mixed gases. Using SVM、 PCA and PSO method is more suitable for processing and identification of small sample data. Developed multi﹣component gas detection prototype has better recognition rate, repeatability and stability.%针对气敏和光学传感器等常规方法难以检测痕量多组分气体的问题,采用快速色谱与气敏传感器阵列结合的检测方法获取痕量多组分气体的信号,然后对信号采用支持向量机( SVM)训练分类气体模式特征。为获得较好的气体识别模型,使用粒子群算法( PSO)优化SVM参数。通过对实际样品检测和识别,并对比评估同类检测仪器采用的检测识别方法,验证文中方法对混合气体的选择性更好,采用的SVM、PCA和PSO组合方法更适合处理和识别小样本数据。研制的多组分痕量气体检测样机具有更高的识别率、重复性和稳定性。

  19. Impact of western Siberia heat wave 2012 on greenhouse gases and trace metal concentration in thaw lakes of discontinuous permafrost zone

    Directory of Open Access Journals (Sweden)

    O. S. Pokrovsky

    2013-08-01

    Full Text Available 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 (2 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 (

  20. Numerical sensitivity study of the nocturnal low-level jet over a forest canopy and implications for nocturnal surface exchange of carbon dioxide and other trace gases

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Leclerc, M.Y.; Duarte, H.F.;

    2010-01-01

    The development of a wind speed maximum in the nocturnal boundary layer, commonly referred to as a low-level jet (LLJ) (Blackadar, 1957), is a common feature of the vertical structure of the atmospheric boundary layer (ABL) and impacts the meteorology and the local climate of a region. A variety...... and are typically intertwined with other contributing factors, they constitute an important cause of jet formation. This mechanism is the only one that can be simulated by one-dimensional atmospheric boundary-layer model. This mechanism is a strong function of the distribution of surface energy properties which...... one-dimensional mode, to examine specific effects of tall vegetation on the structure of nocturnal jets. The unique feature of the model, based on a two-equation closure approach, is the treatment of buoyancy and plant drag effects in a way that does not require a predefined mixing length (Sogachev...

  1. Trace Gas Emissions From Tropical North Australian Savanna Fires

    Science.gov (United States)

    Paton-Walsh, C.; Deutscher, N. M.; Griffith, D. W.; Wilson, S. R.; Jones, N. B.; Forgan, B.

    2008-12-01

    We present measurements of atmospheric trace gases within smoke plumes from tropical North Australian savanna fires. The remote sensing measurements are made from Darwin (12.4°S, 130.9°E) using Fourier Transform spectroscopy with the sun as the source. From these infrared spectra column amounts of carbon monoxide (CO), formaldehyde (H2CO), acetylene (C2H2), ethane (C2H6) and hydrogen cyanide (HCN) have been determined. Literature esimates of emission factors for CO are then used to infer emission factors for these other gases.

  2. Characterization and source identification of trace elements in airborne particulates at urban and suburban atmospheres of Tabriz, Iran.

    Science.gov (United States)

    Gholampour, Akbar; Nabizadeh, Ramin; Hassanvand, Mohammad Sadegh; Taghipour, Hasan; Rafee, Mohammad; Alizadeh, Zahra; Faridi, Sasan; Mahvi, Amir Hossein

    2016-01-01

    Concentration of particulate matter (PM10 and total suspended particulate (TSP)) and their elemental constituents were measured to identify the major sources of elements in urban and industrial suburban sites in Tabriz, Iran, from September 2012 to June 2013. TSP and PM10 samples were collected using high-volume samplers. Concentrations of 31 elements in aerosols and crustal soil were determined by ICPMS. The most abundant detected metals in the urban sampling sites were Al (217.5-4019.9 ng m(-3)), Fe (272.5-7658.0 ng m(-3)), Pt (4.7-1994.4 ng m(-3)), and P (13.6-2054.8 ng m(-3) (for TSP and Al (217.6-3687.3 ng m(-3)), Fe (197.1-3724.9 ng m(-3)), Pt (65.9-2054.5 ng m(-3)), and P (11.0-756.6 ng m(-3)( for PM10. In the suburban sampling site, the most abundant detected metals were Al (2083.0-9664.0 ng m(-3)), Fe (360.0-7221.5 ng m(-3)), P (229.4-870.5 ng m(-3)), and Ti (137.3-849.7 ng m(-3)) for TSP and Al (218.5-4179.6 ng m(-3)), Fe (106.3-2005.1 ng m(-3)), P (251.9-908.4 ng m(-3)), and Ba (10.6-584.9 ng m(-3)) for PM10. For the crustal soil, the most abundant detected elements included Al (60,088-60,694 ppm), Fe (19,886-20,474 ppm), Ti (894-3481 ppm), and Si (365-4246 ppm). Key emission sources were identified, and the concentrations contributed from individual sources were estimated. Enrichment factor (EF) explaining a preponderance of the variance in the data was applied to the datasets. EF calculations revealed that non-crustal trace elements were more enriched in the urban than suburban sampling sites. Results of the factor analysis on the elements showed that emissions from road traffic (involving oil and fuel combustions by vehicles, platinum group elements from vehicle exhaust, and resuspension of particulate matter from polluted soil) and construction dust from nearby construction sites and electricity generation plant were the major contributors of anthropogenic metals at ambient atmosphere in Tabriz. Results of this study elucidated the need for

  3. Atmospheric composition

    Science.gov (United States)

    Daniels, G. E.

    1973-01-01

    The earth's atmosphere is made up of a number of gases in different relative amounts. Near sea level and up to about 90 km, the amount of these atmospheric gases in clean, relatively dry air is practically constant. Four of these gases, nitrogen, oxygen, argon, and carbon dioxide, make up 99.99 percent by volume of the atmosphere. Two gases, ozone and water vapor, change in relative amounts, but the total amount of these two is very small compared to the amount of the other gases. The atmospheric composition shown in a table can be considered valid up to 90 km geometric altitude. Above 90 km, mainly because of molecular dissociation and diffusive separation, the composition changes.

  4. Remote Sensing of Greenhouse Gases by Combining Lidar and Optical Correlation Spectroscopy

    Science.gov (United States)

    Anselmo, C.; Thomas, B.; Miffre, A.; Francis, M.; Cariou, J. P.; Rairoux, P.

    2016-06-01

    In this contribution, we present recent work on the ability to achieve range-resolved greenhouse gases concentration measurements in the Earth's atmosphere (CH4, H2O) by combining broadband optical correlation spectroscopy (OCS) with lidar. We show that OCS-Lidar is a robust methodology, allowing trace gases remote sensing with a low dependence on the temperature and pressure-variation absorption cross section. Moreover, we evaluate, as an experimental proof, the water vapor profile in the planetary boundary layer using the 4ν 720 nm absorption band.

  5. Remote Sensing of Greenhouse Gases by Combining Lidar and Optical Correlation Spectroscopy

    Directory of Open Access Journals (Sweden)

    Anselmo C.

    2016-01-01

    Full Text Available In this contribution, we present recent work on the ability to achieve range-resolved greenhouse gases concentration measurements in the Earth’s atmosphere (CH4, H2O by combining broadband optical correlation spectroscopy (OCS with lidar. We show that OCS-Lidar is a robust methodology, allowing trace gases remote sensing with a low dependence on the temperature and pressure-variation absorption cross section. Moreover, we evaluate, as an experimental proof, the water vapor profile in the planetary boundary layer using the 4ν 720 nm absorption band.

  6. Microbial production and consumption of greenhouse gases: methane, nitrogen oxides, and halomethanes

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.E.; Whitman, W.B.

    1991-01-01

    The aim is to provide an overview of the biological processes that contribute to the increase in trace gases (CH[sub 4], N[sub 2]O, NO[sub x] and halocarbons) in the atmosphere. Physical and chemical processes are discussed as they relate to biological processes. It is an introduction to biological processes that contribute to changes in global climate and processes that can be influenced by biofeedback mechanisms as climate changes occur.

  7. Design and application of a mobile ground-based observatory for continuous measurements of atmospheric trace gas and criteria pollutant species

    Science.gov (United States)

    Bush, S. E.; Hopkins, F. M.; Randerson, J. T.; Lai, C.-T.; Ehleringer, J. R.

    2015-08-01

    Ground-based measurements of atmospheric trace gas species and criteria pollutants are essential for understanding emissions dynamics across space and time. Gas composition in the lower 50 m of the atmosphere has the greatest direct impacts on human health as well as ecosystem processes; hence data at this level are necessary for addressing carbon-cycle- and public-health-related questions. However, such surface data are generally associated with stationary measurement towers, where spatial representation is limited due to the high cost of establishing and maintaining an extensive network of measurement stations. We describe here a compact mobile laboratory equipped to provide high-precision, high-frequency, continuous, on-road synchronous measurements of CO2, CO, CH4, H2O, NOx, O3, aerosol, meteorological, and geospatial position data. The mobile laboratory has been deployed across the western USA. In addition to describing the vehicle and its capacity, we present data that illustrate the use of the laboratory as a powerful tool for investigating the spatial structure of urban trace gas emissions and criteria pollutants at spatial scales ranging from single streets to whole ecosystem and regional scales. We assess the magnitude of known point sources of CH4 and also identify fugitive urban CH4 emissions. We illustrate how such a mobile laboratory can be used to better understand emissions dynamics and quantify emissions ratios associated with trace gas emissions from wildfire incidents. Lastly, we discuss additional mobile laboratory applications in health and urban metabolism.

  8. Agriculture's share in the emission of trace gases affecting the climate and some cause-oriented proposals for sufficiently reducing this share.

    Science.gov (United States)

    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

  9. Volumes with guarantee - calibration of volume measuring equipment for gases by means of a gas measurement bell at varying atmospheric air pressure; Volumen mit Garantie - Kalibrierung von Volumenmessgeraeten fuer Gase mittels einer Gasmessglocke bei schwankendem atmosphaerischen Luftdruck

    Energy Technology Data Exchange (ETDEWEB)

    Brunnemann, H.; Aschenbrenner, A.

    1994-09-01

    The gas measurement bell of the German Physical/Technical Institute (PTB) is used to represent the volume unit in the field of gas measurement technique, ie: It is the national volume standard for gas in the low pressure range. By a direct and indirect connection of secondary standard equipments, the units of the volume and volume flow for gases can be passed on to the very varied users. (orig.) [Deutsch] Die Gasmessglocke der Physikalisch-Technischen Bundesanstalt (PTB) dient zur fundamentalen Darstellung der Volumeneinheit im Bereich der Gasmesstechnik, d.h. sie ist das nationale Volumennormal fuer Gas im Niederdruckbereich. Durch einen unmittelbaren und mittelbaren Anschluss von sekundaeren Normalgeraeten koennen die Einheiten des Volumens und Volumendurchflusses fuer Gase an die verschiedensten Anwender weitergegeben werden. (orig.)

  10. Transport and build-up of tropospheric trace gases during the MINOS campaign: comparision of GOME, in situ aircraft measurements and MATCH-MPIC-data

    Directory of Open Access Journals (Sweden)

    A. Ladstätter-Weißenmayer

    2003-01-01

    Full Text Available The MINOS (Mediterranean INtensive Oxidant Study campaign was an international, multi-platform field campaign to measure long-range transport of air-pollution and aerosols from South East Asia and Europe towards the Mediterranean basin during August 2001. High pollution events were observed during this campaign. For the Mediterranean region enhanced tropospheric nitrogen dioxide (NO2 and formaldehyde (HCHO, which are precursors of tropospheric ozone (O3, were detected by the satellite based GOME (Global Ozone Monitoring Experiment instrument and compared with airborne in situ measurements as well as with the output from the global 3D photochemistry-transport model MATCH-MPIC (Model of Atmospheric Transport and CHemistry - Max Planck Institute for Chemistry. The increase of pollution in that region leads to severe air quality degradation with regional and global implications.

  11. Real-time profiling of organic trace gases in the planetary boundary layer by PTR-MS using a tethered balloon

    Directory of Open Access Journals (Sweden)

    R. Schnitzhofer

    2009-12-01

    Full Text Available A method for real-time profiling of volatile organic compounds (VOCs was developed combining the advantages of a tethered balloon as a research platform and of proton transfer reaction mass spectrometry (PTR-MS as an analytical technique for fast and highly sensitive VOC measurements. A 200 m Teflon tube was used to draw sampling air from a tethered aerodynamic balloon to the PTR-MS instrument. Positive and negative artefacts (i.e. formation and loss of VOCs in the tube were characterised in the laboratory and in the field by a set of 11 atmospherically relevant VOCs including both pure and oxygenated hydrocarbons. The only two compounds that increased or decreased when sampled through the tube were acetone (+7% and xylene (-6%. The method was successfully deployed during a winter field campaign to determine the small scale spatial and temporal patterns of air pollutants under winter inversion conditions.

  12. Convection and Chemistry in the Atmospheric Boundary Layer

    OpenAIRE

    A. C. Petersen

    1999-01-01

    The earth’s troposphere is the lowest layer of the atmosphere and has a thickness of about 10 km. It is the layer that contains most of the mass (80%) of the atmosphere. All weather phenomena that we experience have their origin in the troposphere. It is the stage for some well-known environmental problems: climate change, ozone smog, and acidification. These problems are related to the trace amount of gases that are emitted into the troposphere from anthropogenic sources. Alth...

  13. Energy gases: The methane age and beyond

    OpenAIRE

    Nakicenovic, N.

    1994-01-01

    The combustion of fossil fuels results in the emissions of gases and pollutants that produce adverse ecological effects. Evidence is also accumulating that suggest they may also cause global climate change. The combustion gases that are connected with global climate change are primarily carbon dioxide (CO2) and to a lesser degree methane (CH4). All of these gases already occur in low concentrations in the atmosphere and, in fact, together with other greenhouse gases, such as water vapor, have...

  14. The practicalities of using CFCs and SF6 for groundwater dating and tracing

    OpenAIRE

    Darling, W.G.; Gooddy, D.C.; Macdonald, A. M.; Morris, B L

    2012-01-01

    Knowledge of groundwater residence time is important in understanding key issues in the evolution of water quality, whether this occurs due to water–rock interaction or simply by mixing or contamination. The build-up in the atmosphere of the trace gases chlorofluorocarbons (CFCs) and sulphur hexafluoride (SF6) from the middle of the last century offers a convenient way of dating waters up to ~60 yrs old. The gases are well-mixed in the atmosphere so their input functions are not area-specific...

  15. Quantification of fluorine traces in solid samples using CaF molecular emission bands in atmospheric air Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Alvarez-Llamas, C.; Pisonero, J.; Bordel, N.

    2016-09-01

    Direct solid determination of trace amounts of fluorine using Laser-Induced Breakdown Spectroscopy (LIBS) is a challenging task due to the low excitation efficiency of this element. Several strategies have been developed to improve the detection capabilities, including the use of LIBS in a He atmosphere to enhance the signal to background ratios of F atomic emission lines. An alternative method is based on the detection of the molecular compounds that are formed with fluorine in the LIBS plasma. In this work, the detection of CaF molecular emission bands is investigated to improve the analytical capabilities of atmospheric air LIBS for the determination of fluorine traces in solid samples. In particular, Cu matrix samples containing different fluorine concentration (between 50 and 600 μg/g), and variable amounts of Ca, are used to demonstrate the linear relationships between CaF emission signal and F concentration. Limits of detection for fluorine are improved by more than 1 order of magnitude using CaF emission bands versus F atomic lines, in atmospheric-air LIBS. Furthermore, a toothpaste powder sample is used to validate this analytical method. Good agreement is observed between the nominal and the predicted fluorine mass-content.

  16. Influence of processing gases on the properties of cold atmospheric plasma SiO{sub x}C{sub y} coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hamze, H. [UMET, ISP, CNRS 8207, Université Lille Nord de France, Villeneuve d’Ascq (France); Jimenez, M., E-mail: maude.jimenez@univ-lille1.fr [UMET, ISP, CNRS 8207, Université Lille Nord de France, Villeneuve d’Ascq (France); Deresmes, D. [IEMN, CNRS 8520, Université Lille Nord de France, Villeneuve d’Ascq (France); Beaurain, A. [UCCS, CNRS 8181, Université Lille Nord de France, Villeneuve d’Ascq (France); Nuns, N. [Institut Chevreul, Université Lille Nord de France, Villeneuve d’Ascq (France); Traisnel, M. [UMET, ISP, CNRS 8207, Université Lille Nord de France, Villeneuve d’Ascq (France)

    2014-10-01

    Highlights: • Air plasma gas influences the hydrophobicity and morphology of SiO{sub x}C{sub y} coating. • SiO{sub x}C{sub y} coating contains more than 80% SiO{sub 2} and the rest contains CSiO{sub 3}. • Percentage of Si-O-C bonds (XPS analyses) increases linearly with the SiO{sub x}C{sub y} coating hydrophibicity. • The carbon in the SiO{sub x}C{sub y} coatings is proven, by Tof-sims analyses, to be due to incomplete dissociation of precursor. - Abstract: Thin layers of SiO{sub x}C{sub y} (y = 4−x and 3 ≤ x ≤ 4) were applied using a cold atmospheric plasma torch on glass substrates. The aim was to investigate using Atomic Force Microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (Tof-Sims) the influence of the gases used on the morphology and composition of the deposits. A hexamethyldisilane (HMDS) precursor was injected in post-discharge in an air or nitrogen plasma using a carrier gas (air or nitrogen) and was applied on the substrate previously pre-treated by an air or nitrogen plasma. The carrier gas and plasma gas flows and the distance between the substrate and the plasma torch, the scanning speed, and the precursor flows were kept constant during the study. The gas used during activation pre-treatment showed no particular influence on the characteristics of the deposit. When air is used both as plasma and carrier gas, the coating layer is thicker (96 nm) than when nitrogen is used (64 nm). It was also evidenced that the gas carrying the precursor has little influence on the hydrophobicity of the coating, contrary to the plasma gas. The latter significantly influences the surface characteristics of the coatings. When air is used as plasma gas, a compact coating layer is obtained and the surface has a water contact angle (WCA) of 82°. When nitrogen is used, the deposit is more hydrophobic (WCA of 100°) and the deposit morphology is different. This increase in hydrophobicity could be

  17. Field measurements of trace gases emitted by prescribed fires in southeastern US pine forests using an open-path FTIR system

    Directory of Open Access Journals (Sweden)

    S. K. Akagi

    2013-07-01

    Full Text Available 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

  18. Interferences of commercial NO2 instruments in the urban atmosphere and in a smog chamber

    OpenAIRE

    G. Villena; I. Bejan; R. Kurtenbach; P. Wiesen; Kleffmann, J.

    2012-01-01

    Reliable measurements of atmospheric trace gases are necessary for both, a better understanding of the chemical processes occurring in the atmosphere, and for the validation of model predictions. Nitrogen dioxide (NO2) is a toxic gas and is thus a regulated air pollutant. Besides, it is of major importance for the oxidation capacity of the atmosphere and plays a pivotal role in the formation of ozone and acid precipitation. Detection of NO2 is a difficult task since many of the different comm...

  19. Determination of two dimensional trace gas distributions using tomographic LP-DOAS measurements in the city of Heidelberg, Germany

    OpenAIRE

    Pöhler, Denis

    2010-01-01

    Tomographic Long path Differential Optical Absorption Spectroscopy (LP-DOAS) allows two and three dimensional determination of trace gas distributions by measuring the average concentration along 10 to 20 intersecting light paths and applying tomographic inversion techniques. In this thesis such a setup was developed and applied for the first time to determine the horizontal distribution of several trace gases in the open atmosphere. The measurements took place in the city of Heidelberg, Germ...

  20. Field measurements of trace gases emitted by prescribed fires in southeastern U.S. pine forests using an open-path FTIR system

    Energy Technology Data Exchange (ETDEWEB)

    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

  1. "Atmospheric Measurements by Ultra-Light SpEctrometer" (AMULSE) dedicated to vertical profile measurements of greenhouse gases (CO2, CH4) under stratospheric balloons: instrumental development and field application.

    Science.gov (United States)

    Maamary, Rabih; Joly, Lilian; Decarpenterie, Thomas; Cousin, Julien; Dumelié, Nicolas; Grouiez, Bruno; Albora, Grégory; Chauvin, Nicolas; Miftah-El-Khair, Zineb; Legain, Dominique; Tzanos, Diane; Barrié, Joel; Moulin, Eric; Ramonet, Michel; Bréon, François-Marie; Durry, Georges

    2016-04-01

    Human activities disrupt natural biogeochemical cycles such as the carbon and contribute to an increase in the concentrations of the greenhouse gases (carbone dioxide and methane) in the atmosphere. The current atmospheric transport modeling (the vertical trade) still represents an important source of uncertainty in the determination of regional flows of greenhouse gases, which means that a good knowledge of the vertical distribution of CO2 is necessary to (1) make the link between the ground measurements and spatial measurements that consider an integrated concentration over the entire column of the atmosphere, (2) validate and if possible improve CO2 transport model to make the link between surface emissions and observed concentration. The aim of this work is to develop a lightweight instrument (based on mid-infrared laser spectrometry principles) for in-situ measuring at high temporal/spatial resolution (5 Hz) the vertical profiles of the CO2 and the CH4 using balloons (meteorological and BSO at high precision levels (authorizations, costs and logistics flights. These laser spectrometers are built on recent instrumental developments. Several flights were successfully done in the region Champagne-Ardenne and in Canada recently. Aknowledgments: The authors acknowledge financial supports from CNES, CNRS défi instrumental and the region Champagne-Ardenne.

  2. "Atmospheric Measurements by Ultra-Light SpEctrometer" (AMULSE) dedicated to vertical profile measurements of greenhouse gases (CO2, CH4) under stratospheric balloons: instrumental development and field application.

    Science.gov (United States)

    Maamary, Rabih; Joly, Lilian; Decarpenterie, Thomas; Cousin, Julien; Dumelié, Nicolas; Grouiez, Bruno; Albora, Grégory; Chauvin, Nicolas; Miftah-El-Khair, Zineb; Legain, Dominique; Tzanos, Diane; Barrié, Joel; Moulin, Eric; Ramonet, Michel; Bréon, François-Marie; Durry, Georges

    2016-04-01

    Human activities disrupt natural biogeochemical cycles such as the carbon and contribute to an increase in the concentrations of the greenhouse gases (carbone dioxide and methane) in the atmosphere. The current atmospheric transport modeling (the vertical trade) still represents an important source of uncertainty in the determination of regional flows of greenhouse gases, which means that a good knowledge of the vertical distribution of CO2 is necessary to (1) make the link between the ground measurements and spatial measurements that consider an integrated concentration over the entire column of the atmosphere, (2) validate and if possible improve CO2 transport model to make the link between surface emissions and observed concentration. The aim of this work is to develop a lightweight instrument (based on mid-infrared laser spectrometry principles) for in-situ measuring at high temporal/spatial resolution (5 Hz) the vertical profiles of the CO2 and the CH4 using balloons (meteorological and BSO at high precision levels (logistics flights. These laser spectrometers are built on recent instrumental developments. Several flights were successfully done in the region Champagne-Ardenne and in Canada recently. Aknowledgments: The authors acknowledge financial supports from CNES, CNRS défi instrumental and the region Champagne-Ardenne.

  3. Design and application of a mobile ground-based observatory for continuous measurements of atmospheric trace-gas and criteria pollutant species

    Science.gov (United States)

    Bush, S. E.; Hopkins, F. M.; Randerson, J. T.; Lai, C.-T.; Ehleringer, J. R.

    2015-01-01

    Ground-based measurements of atmospheric trace gas species and criteria pollutants are essential for understanding emissions dynamics across space and time. Gas composition in the surface 50 m has the greatest direct impacts on human health as well as ecosystem processes, hence data at this level is necessary for addressing carbon cycle and public health related questions. However, such surface data are generally associated with stationary measurement towers, where spatial representation is limited due to the high cost of establishing and maintaining an extensive network of measurement stations. We describe here a compact mobile laboratory equipped to provide high-precision, high-frequency, continuous, on-road synchronous measurements of CO2, CO, CH4, H2O, NOx, O3, aerosol, meteorological, and geospatial position data. The mobile laboratory has been deployed across the western USA. In addition to describing the vehicle and its capacity, we present data that illustrate the use of the laboratory as a powerful tool for investigating the spatial structure of urban trace gas emissions and criteria pollutants at spatial scales ranging from single streets to whole ecosystem and regional scales. We identify fugitive urban CH4 emissions and assess the magnitude of CH4 emissions from known point sources. We illustrate how such a mobile laboratory can be used to better understand emissions dynamics and quantify emissions ratios associated with trace gas emissions from wildfire incidents. Lastly, we discuss additional mobile laboratory applications in health and urban metabolism.

  4. Design and application of a mobile ground-based observatory for continuous measurements of atmospheric trace-gas and criteria pollutant species

    Directory of Open Access Journals (Sweden)

    S. E. Bush

    2015-01-01

    Full Text Available Ground-based measurements of atmospheric trace gas species and criteria pollutants are essential for understanding emissions dynamics across space and time. Gas composition in the surface 50 m has the greatest direct impacts on human health as well as ecosystem processes, hence data at this level is necessary for addressing carbon cycle and public health related questions. However, such surface data are generally associated with stationary measurement towers, where spatial representation is limited due to the high cost of establishing and maintaining an extensive network of measurement stations. We describe here a compact mobile laboratory equipped to provide high-precision, high-frequency, continuous, on-road synchronous measurements of CO2, CO, CH4, H2O, NOx, O3, aerosol, meteorological, and geospatial position data. The mobile laboratory has been deployed across the western USA. In addition to describing the vehicle and its capacity, we present data that illustrate the use of the laboratory as a powerful tool for investigating the spatial structure of urban trace gas emissions and criteria pollutants at spatial scales ranging from single streets to whole ecosystem and regional scales. We identify fugitive urban CH4 emissions and assess the magnitude of CH4 emissions from known point sources. We illustrate how such a mobile laboratory can be used to better understand emissions dynamics and quantify emissions ratios associated with trace gas emissions from wildfire incidents. Lastly, we discuss additional mobile laboratory applications in health and urban metabolism.

  5. Mobile Instruments Measure Atmospheric Pollutants

    Science.gov (United States)

    2009-01-01

    As a part of NASA's active research of the Earth s atmosphere, which has included missions such as the Atmospheric Laboratory of Applications and Science (ATLAS, launched in 1992) and the Total Ozone Mapping Spectrometer (TOMS, launched on the Earth Probe satellite in 1996), the Agency also performs ground-based air pollution research. The ability to measure trace amounts of airborne pollutants precisely and quickly is important for determining natural patterns and human effects on global warming and air pollution, but until recent advances in field-grade spectroscopic instrumentation, this rapid, accurate data collection was limited and extremely difficult. In order to understand causes of climate change and airborne pollution, NASA has supported the development of compact, low power, rapid response instruments operating in the mid-infrared "molecular fingerprint" portion of the electromagnetic spectrum. These instruments, which measure atmospheric trace gases and airborne particles, can be deployed in mobile laboratories - customized ground vehicles, typically - to map distributions of pollutants in real time. The instruments must be rugged enough to operate rapidly and accurately, despite frequent jostling that can misalign, damage, or disconnect sensitive components. By measuring quickly while moving through an environment, a mobile laboratory can correlate data and geographic points, revealing patterns in the environment s pollutants. Rapid pollutant measurements also enable direct determination of pollutant sources and sinks (mechanisms that remove greenhouse gases and pollutants), providing information critical to understanding and managing atmospheric greenhouse gas and air pollutant concentrations.

  6. Quantitative sampling and analysis of trace elements in atmospheric aerosols: impactor characterization and Synchrotron-XRF mass calibration

    Directory of Open Access Journals (Sweden)

    A. Richard

    2010-10-01

    Full Text Available Identification of trace elements in ambient air can add substantial information to pollution source apportionment studies, although they do not contribute significantly to emissions in terms of mass. A method for quantitative size and time-resolved trace element evaluation in ambient aerosols with a rotating drum impactor and synchrotron radiation based X-ray fluorescence is presented. The impactor collection efficiency curves and size segregation characteristics were investigated in an experiment with oil and salt particles. Cutoff diameters were determined through the ratio of size distributions measured with two particle sizers. Furthermore, an external calibration technique to empirically link fluorescence intensities to ambient concentrations was developed. Solutions of elemental standards were applied with an ink-jet printer on thin films and area concentrations were subsequently evaluated with external wet chemical methods. These customized and reusable reference standards enable quantification of different data sets analyzed under varying experimental conditions.

  7. 大气压介质阻挡放电中电子碰撞电离系数α的测定%Preliminary Measurement of Electron Impact Ionization Coefficient in Gases at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    冉俊霞; 罗海云; 梁卓; 王新新

    2012-01-01

    电子碰撞电离系数α是气体放电研究中的一个重要物理参数,但现有的α系数数值都是在低气压Townsend放电实验中得到的,它们不适用于大气压下气体放电。为了尝试解决这个问题,提出了一种大气压下α系数的光学测量方法,它借助介质阻挡电极结构,在某些大气压气体中产生瞬态或稳态Townsend放电,利用带像增强器高速数码相机的纳秒曝光功能,记录气隙中瞬态发光强度空间分布,并与Townsend放电对应的理论发光强度分布进行比较,根据两者的最佳拟合效果推导出α系数。该方法被用于测定大气压氮气α系数,结果表明其基本可行,但仍需继续加以完善。%Electron impact ionization coefficient a is one of the most important parameters used in the study of gas discharge. However, the a values usually determined in the experiments on Townsend discharge in gases at low pressure are not applicable to the gas discharges in atmospheric gases. Aiming at solving this problem, a method for determining the a values in the gases at atmospheric pressure was proposed. Dielectric barrier Townsend discharges were produced in some gases at atmospheric pressure. The distribution of the light intensity in the discharge gap was recorded by taking side-view photograph using an ICCD camera with an extremely short exposure time and compared with the theoretical distributions with different presumed ~. The a value was determined by the best fitting of the theoretical distribution to the experimental one. The method was proved to be applicable in the determination of a for nitrogen at atmospheric pressure.

  8. Noble Gases

    Science.gov (United States)

    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

  9. DOAS spectroscopy onboard the CARIBIC passenger aircraft – trace gas concentration, and flux measurement of localized sources

    OpenAIRE

    Walter, David Josef

    2013-01-01

    This thesis deals with the remote sensing and the flux calculation of atmospheric trace gases, using Differential Optical Absorption Spectroscopy (DOAS). Since 2010, within the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container), a new DOAS instrument is installed in the cargo compartment of a passenger aircraft once per month as part of a fully automated measurement container. With this instrument, nitrogen dioxide (NO2), sulfphur...

  10. Continuous on-line calibration of diffusive soil-atmosphere trace gas transport using vertical {sup 220}Rn- and {sup 222}Rn-activity profiles

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, B.E. [Bern Univ. (Switzerland). Physics Inst.; Neftel, A. [Inst. of Environmental Protection and Agriculture, Bern (Switzerland); Tarakanov, S.V. [Inst. of Silicate Chemistry, St. Petersburg (Russian Federation)

    2001-07-01

    Continuous monitoring of {sup 220}Rn- and {sup 222}Rn-activities above and below the soil surface combined with sporadic direct {sup 222}Rn-flux measurements is used to quantify diffusive trace gas transport in the air-filled pore space of soil, through the soil-atmosphere interface and in the lowest layers of the atmosphere. In a calm night, {sup 222}Rn-activities above the surface first build-up near the ground (z < 10 cm) and subsequently with a delay of 2-3 hours at higher altitudes (z < 5 m). Knowing (1) the {sup 222}Rn-flux from activity profiles measured in soil gas, (2) from direct flux determinations and (3) using information about atmospheric diffusion parameters from {sup 220}Rn-activities measured near the surface it is possible to model the temporal evolution of the vertical {sup 222}Rn-profiles in a night with stable weather and constant soil conditions. The system operates automatically for extended periods of time in the field enabling a better understanding of transport processes in response to changing environmental conditions (wind, rain, soil humidity). (orig.)

  11. Worldwide trend of atmospheric mercury since 1995

    Directory of Open Access Journals (Sweden)

    F. Slemr

    2011-01-01

    Full Text Available Concern about the adverse effects of mercury on human health and ecosystems has led to tightening emission controls since the mid 1980s. But the resulting mercury emissions reductions in many parts of the world are believed to be offset or even surpassed by the increasing emissions in rapidly industrializing countries. Consequently, concentrations of atmospheric mercury are expected to remain roughly constant. Here we show that the worldwide atmospheric mercury concentration have decreased by about 20 to 38% since 1996 as indicated by long term monitoring at stations in the Southern and Northern Hemispheres combined with intermittent measurements of latitudinal distribution over the Atlantic Ocean. The total reduction of the atmospheric mercury burden of this magnitude within 14 yrs is unprecedented among most of atmospheric trace gases and is at odds with the current mercury emission inventories with nearly constant emissions over the period. It suggests a major shift in the biogeochemical cycle of mercury including oceans and soil reservoirs. Decreasing reemissions from the legacy of historical mercury emissions are the most likely explanation for this decline since the hypothesis of an accelerated oxidation rate of elemental mercury in the atmosphere is not supported by the observed trends of other trace gases. Consequently, models of the atmospheric mercury cycle have to include soil and ocean mercury pools and their dynamics to be able to make projections of future trends.

  12. Trace analysis in the atmosphere, water bodies and uranium ores by means of X-ray fluorescence

    International Nuclear Information System (INIS)

    Analysis with X-ray fluorescence is an instrumental method that evaluates concentrations, at trace levels, of elements in samples of all kinds. The applications of this method are broad, specially useful in the analysis of metals as contaminators in air and water, and as impurities in minerals. The preparation of the samples is very important to obtain good accuracy, and at the same time, you should make a series of standards of known concentrations so you can compare the counting of each sample against the standard, for each of the elements. You should make, depending on the nature of the sample, several corrections with respect to the background, interferences, overlaps, or for effects of a third element. (author)

  13. Compendium of NASA data base for the global tropospheric experiment's Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE-A)

    Science.gov (United States)

    Gregory, Gerald L.; Scott, A. Donald, Jr.

    1995-01-01

    This compendium describes aircraft data that are available from NASA's Transport and Atmospheric Chemistry near the Equator - Atlantic (TRACE-A) conducted in September/October 1992. The broad objectives of TRACE-A were to study chemical processes and long-range transport associated with South American and African continental outflow during periods of widespread vegetation burning, and to understand the ozone enhancements observed from satellite data measured over the southern tropical Atlantic Ocean during the September/October time period. Flight experiments were conducted from Brazil, South Africa, Namibia, and the Ascension Island. This document provides a representation of aircraft data that are available from NASA Langley's Distributed Active Archive Center (DAAC). The data format of time series and altitude profile plots is not intended to support original analyses, but to assist the reader in identifying data that are of interest. This compendium is for only the NASA aircraft data. The DAAC data base includes numerous supporting data-meteorological products, results from surface studies, satellite observations, and data from sonde releases.

  14. Atmospheric mercury and fine particulate matter in coastal New England: implications for mercury and trace element sources in the northeastern United States

    Science.gov (United States)

    Kolker, Allan; Engle, Mark A.; Peucker-Ehrenbrink, Bernhard; Geboy, Nicholas J.; Krabbenhotft, David P. Krabbenhoft; Bothner, Michael H. Bothner; Tate, Michael T.

    2013-01-01

    Intensive sampling of ambient atmospheric fine particulate matter was conducted at Woods Hole, Massachusetts over a four-month period from 3 April to 29 July, 2008, in conjunction with year-long deployment of the USGS Mobile Mercury Lab. Results were obtained for trace elements in fine particulate matter concurrently with determination of ambient atmospheric mercury speciation and concentrations of ancillary gasses (SO2, NOx, and O3). For particulate matter, trace element enrichment factors greater than 10 relative to crustal background values were found for As, Bi, Cd, Cu, Hg, Pb, Sb, V, and Zn, indicating contribution of these elements by anthropogenic sources. For other elements, enrichments are consistent with natural marine (Na, Ca, Mg, Sr) or crustal (Ba, Ce, Co, Cs, Fe, Ga, La, Rb, Sc, Th, Ti, U, Y) sources, respectively. Positive matrix factorization was used together with concentration weighted air-mass back trajectories to better define element sources and their locations. Our analysis, based on events exhibiting the 10% highest PM2.5 contributions for each source category, identifies coal-fired power stations concentrated in the U.S. Ohio Valley, metal smelting in eastern Canada, and marine and crustal sources showing surprisingly similar back trajectories, at times each sampling Atlantic coastal airsheds. This pattern is consistent with contribution of Saharan dust by a summer maximum at the latitude of Florida and northward transport up the Atlantic Coast by clockwise circulation of the summer Bermuda High. Results for mercury speciation show diurnal production of RGM by photochemical oxidation of Hg° in a marine environment, and periodic traverse of the study area by correlated RGM-SO2(NOx) plumes, indicative of coal combustion sources.

  15. Thermodynamics of Trapping Gases for Underwater Superhydrophobicity.

    Science.gov (United States)

    Patankar, Neelesh A

    2016-07-12

    Rough surfaces submerged in a liquid can remain almost dry if the liquid does not fully wet the roughness, and gases are sustained in roughness grooves. Such partially dry surfaces can help reduce drag, enhance boiling, and reduce biofouling. Gases sustained in roughness grooves would be composed of air and the vapor phase of the liquid itself. In this work, the thermodynamics of sustaining gases (e.g., air) is considered. Governing equations are presented along with a solution methodology to determine a critical condition to sustain gases. The critical roughness scale to sustain gases is estimated for different degrees of saturation of gases dissolved in the liquid. It is shown that roughness spacings of less than a micron are essential to sustain gases on surfaces submerged in water at atmospheric pressure. This is consistent with prior empirical data. PMID:27276525