Publications and Data

Below is a listing of Jürgen's first- and co-authored publications available for download. For now, only the most important papers are included; if you don't see a particular publication here, it is not yet available. Also, some journals do not allow electronic distribution of their papers, hence those papers will not appear here. In either case, if you click on their link, you will get a note to request a paper copy.

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Until I find enough time to typeset the papers, Acrobat files for some of the publications are simple image scans of the printed versions. Articles that contain color images make the files very large and are hence provided in two versions, in black and white (smaller) and in color (larger). Similarly, color versions of type-set files (such as RCEI papers) are provided in a screen-optimized version (smaller) and a print-optimized version (larger).

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  • Full list of Jürgen's publications (PDF 37 kb)
  • Biomass burning - Lobert et al., Nature, 346, 6284, 552-554, 1990
  • Experimental Evaluation of Biomass Burning - Lobert et al., in: Levine, MIT Press, Cambridge, Mass., 289-304, 1991.
  • Combustion process in vegetation - Lobert and Warnatz, 1993
  • CH3Br - Lobert et al., Science 267, 1002-1005, 1995
  • OAXTC data report - Lobert et al., NOAA Technical Memorandum, 1995
  • BLAST data report on CH3Br - Lobert et al., NOAA Technical Memorandum, 1996
  • CH3Br - Lobert et al., Geophys. Res. Lett. 24, 171-172, 1997
  • SF6 - Geller et al., Geophys. Res. Lett. 24, 675-678, 1997
  • CO from forest litter - Sanhueza et al., Tellus 50B, 51-58, 1998
  • CO2, N2O, CH4 from forest litter - Dong et al., Tellus 50B, 243-252, 1998
  • CO instrumentation - Cogan & Lobert, 43rd Annual ISA Analysis Division Symposium
  • RCEI chlorine from biomass burning, Lobert et al., J. Geophys. Res. 104, 8373-8390, 1999
  • INDOEX, Lelieveld et al., Science 291, 1031-1036, 2001
  • CO / KCO / INDOEX, Lobert & Harris, J. Geophys. Res., 107, 8013-8025, doi:10.1029/2001JD000731, 2002
  • SAFARI 2000, Keene et al., J. Geophys. Res., 111, D04301, doi:10.1029/2005JD006319, 2006
  • Oceanic short-lived halocarbons, Butler et al., Global Biogeochem. Cycles, 21, GB1023, doi:10.1029/2006GB002732

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    Importance of biomass burning in the atmospheric budgets of nitrogen-containing gases.

    Jürgen M. Lobert, Dieter H. Scharffe, Wei M. Hao & Paul J. Crutzen
    Nature, 346, 6284, 552-554, 1990.

    Abstract: Biomass burning is a primary source of many trace substances that are important in atmospheric chemistry. More than 80% of the world's biomass burning takes place in the tropics as a result of savanna fires, forest-clearing activity, and the burning of agricultural waste and wood. Here we report results from laboratory studies on the emissions of nitrogen-containing compounds from the burning of dry vegetation. We find that the emission rates of NOX, HCN, CH3CN are sufficient to contribute signficantly to the global budget of the compounds. Furthermore, possibly up to half of the biomass nitrogen can be converted to molecular nitrogen, N2, leading to an estimated anniual loss of 12-28x1012 g of biomass nitrogen ('pyrodenitrification'), equal to ~9-20% of the estimated global rate of terrestrial nitrogen fixation.

    Reprinted with permission from Nature 346, 6284, 552-554, 1990. Copyright © 1990 Nature Publishing Group.

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    Nature commentary by J.S. Levine (2.8 mb)

    New York Times commentary (44 kb)

    EXPERIMENTAL EVALUATION OF BIOMASS BURNING EMISSIONS: NITROGEN AND CARBON CONTAINING COMPOUNDS.

    Jürgen M. Lobert, Dieter H. Scharffe, Wei-Min Hao, Thomas A. Kuhlbusch, Ralph Seuwen, Peter Warneck & Paul J. Crutzen
    In: Global Biomass Burning: Atmospheric, Climatic and Biospheric Implications, edited by J. S. Levine, pp. 289-304, MIT Press, Cambridge, Mass., 1991.

    Abstract: Today biomass burning is accepted to be an important source of many trace gases affecting atmospheric chemistry. Despite its global significance and in contrast to fossil fuel use, where detailed investigations on global amounts and their distributions are available, still little quantitative information is known about the emissions of some of the compounds emitted and the global amounts consumed by biomass burning. Estimates of these global quantities are difficult to derive because of a very uncertain database. The most recent values published by Crutzen et al. indicate that 1900-5000 Tg biomass carbon is released annually.
    In order to obtain more reliable emission data, improvement of measurement techniques as well as methods for calculating emission data are required. A growing number of measurements on biomass burning emissions have been published since the first estimates, but some of the trace gas emissions are still very uncertain or even unknown as, for example, in the case of some nitrogen-containing species.
    Most of the data on biomass burning emissions were derived from airborne measurements above large scale fires. An experimental System, on the other hand, is advantageous in cases when information cannot be derived from open fires or when field measurements are inappropriate. In this paper we describe results obtained by the latter technique. An important advantage of the apparatus described is the possibility of learning about burning behaviour and burning stages, and thus clarifying relationships between combustion processes and emissions, finally leading to new methods for estimating emissions.
    To extend our knowledge of the inventory of nitrogen and carbon in biomass burning, we took a close look at the most important emissions, trying to identify the major fractions which complete the mass balance. Such a balance cannot be achieved from natural fires due to the impossibility of exactly determining the absolute mass of burned and unburned plants.

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    Emissions From the Combustion Process in Vegetation

    Jürgen M. Lobert and Jürgen Warnatz
    In: P.J. Crutzen and J.G. Goldammer (eds) "Fire in the Environment: The Ecological, Climatic, and Atmospheric Chemical Importance of Vegetation Fires", John Wiley & Sons Ltd. Chichester, 15-37, 1993.

    Abstract: A detailed description of the processes involved in vegetation fires is given, emphasizing the flaming stage and the smoldering stage of biomass burning. The major factors influencing the appearance of the single stages are discussed as well as their impact on emissions from fires. General production patterns, especially the importance of the ratio of flaming to smoldering combustion, for several classes of compounds are outlined and some specific reaction paths are discussed which are likely to dominate certain emission formations. A summary of global estimates of the most important emissions is added in the end. A proposition is made to simplify the complex nature of vegetation fires to enable reliable predictions of the emissions from biomass burning in a global scientific effort.

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    A Net Sink for Atmospheric CH3Br in the East Pacific Ocean

    Jürgen M. Lobert, James H. Butler, Stephen A. Montzka, Laurie S. Geller, Richard C. Myers, and James W. Elkins
    Science 267, 1002-1005, 1995.

    Abstract: Surface waters along a cruise track in the East Pacific ocean were undersaturated in methyl bromide (CH3Br) in most areas except for coastal and upwelling regions, with saturation anomalies ranging from +100% in coastal waters to -50% in open ocean areas, representing a regionally weighted mean of -16 (-13 to -20) percent. The partial lifetime of atmospheric CH3Br with respect to calculated oceanic degradation along this cruise track is 3.0 (2.9 to 3.6) years. The global, mean dry mole fraction of CH3Br in the atmosphere was 9.8±0.6 parts per trillion (ppt) with an interhemispheric ratio of 1.31±0.08. These data indicate that ~8 percent (0.2 ppt) of the observed interhemispheric difference in atmospheric CH3Br could be attributed to an uneven global distribution of oceanic sources and sinks.

    Reprinted with permission from Science 267, 1002-1005, 1995. Copyright ©1995 American Association for the Advancement of Science.

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    OAXTC 92: OCEAN / ATMOSPHERE EXCHANGE OF TRACE COMPOUNDS 1992
    Measurements of HCFC-22, CFC-11, CFC-12, CFC-113, CH3CCl3, CCl4, and N2O in the Marine air and Surface Waters of the West Pacific Ocean (03. August to 21. October 1992)

    Jürgen M. Lobert, Thomas J. Baring, James H. Butler, Stephen A. Montzka, Richard C. Myers, James W. Elkins
    NOAA Technical Memorandum ERL CMDL-9, 1995.

    Abstract: CFC-11 (CCl3F), CFC-12 (CCl2F2), CFC-113 (CCl2FCClF2), methyl chloroform (CH3CCl3), carbon tetrachloride (CCl4), nitrous oxide (N2O) and HCFC-22 (CHClF2) were measured in the air and surface waters of the Pacific Ocean between 55°N and 22°S during the late summer and early fall of 1992. Atmospheric measurements of all gases agreed well with results from NOAA fixed stations at similar latitudes. CFC-11, CFC-12, and CFC-113, which have long atmospheric lifetimes and are essentially inert in seawater, responded mainly to physical processes in the air and water. The first two gases were supersaturated by 2-6% at higher, northern latitudes, reflecting the effects of radiative warming. Their saturation anomalies declined southward through the tropics and ultimately became slightly negative in the southern hemisphere. HCFC-22 showed signs of small losses in the tropics and subtropics, a sink that may account for 2% of the losses of this gas from the atmosphere. CH3CCl3 showed a similar pattern, with only a tropical sink, which is consistent with hydrolysis and, together with data from an earlier expedition, implies that about 6% of atmospheric CH3CCl3 is lost to the ocean. The net saturation anomaly for CCl4 was virtually negative everywhere and only slightly dependent upon latitude. This would be expected for a sink that was not particularly temperature dependent and it is consistent with evidence from deepwater profiles that indicate a sink at depth. Fluxes calculated from CCl4 saturation anomalies indicate that 15-35% of atmospheric CCl4 is lost to the ocean. N2O surface water data indicated weak equatorial upwelling. Saturation anomalies ranged from 1-6%, which would be consistent with a small source in the W. Pacific.

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    BLAST 94: Bromine Latitudinal Air/Sea Transect 1994.
    Report on Oceanic Measurements of Methyl Bromide and Other Compounds.

    Jürgen M. Lobert, Laurie S. Geller, Shari A. Yvon, Andrew D. Clarke, James H. Butler, Stephen A. Montzka, Richard C. Myers, James W. Elkins,
    NOAA Technical Memorandum ERL CMDL-10, 1996

    Abstract: The Nitrous Oxide And Halocompounds (NOAH) division of NOAA/CMDL participated in two research cruises in 1994 for the Bromine Latitudinal Air/Sea Transect project. Frequently collected CH3Br data from these expeditions constitute the largest data set for oceanic CH3Br to date, and the first solid estimate of oceanic emission, production and degradation of the compound. Our conclusion from these studies is that the ocean is probably not a net source of CH3Br, but rather a net sink. Although CH3Br is both produced and consumed everywhere in the surface ocean, the rate of consumption exceeds that of production in most waters sampled. Exceptions were coastal and coastally influenced waters, which were typically supersaturated, and areas of open ocean upwelling, where CH3Br saturations were close to zero. About 80% of the oceans are undersaturated in CH3Br, representing a net annual sink of 8-22 Gg y-1.

    In addition to conducting two research cruises, we investigated potential contamination effects from sampling flasks and potential analytical artifacts from GC/ECD systems, developed a calibration scale for atmospheric and oceanic CH3Br and a global, finite-increment model for more precisely estimating the partial lifetime of atmospheric CH3Br with respect to oceanic losses.

    CH3Br data from the second cruise indicate that our conclusions from the first expedition were qualitatively and quantitatively accurate. The latter results give greater strength to the global extrapolations of the first data set. Our best estimate of the partial lifetime of atmospheric CH3Br with respect to oceanic losses is 2.7 (2.4-6.5) y. This range was derived from a 40 year, global data set of sea surface temperatures and windspeeds. Data from the two expeditions suggest a shorter lifetime of CH3Br on the order of 2.4 y. The difference between the two estimates is due to the high windspeeds encountered during the cruises. Our estimate of the atmospheric lifetime, based upon combined atmospheric and oceanic losses, is now 1.0-1.1 y, compared to earlier estimates of 1.8­2.1 y when the ocean was considered an insignificant sink and tropospheric OH concentrations were underestimated by 15%. The oceanic sink correspondingly lowers the ODP for CH3Br by about one-third.

    Work on the sampling and analytical uncertainties has revealed significant problems with the measurement of CH3Br in flasks, which have been used historically for virtually all previous measurements of CH3Br in the atmosphere. Whereas results from the shipboard system were free of sample storage effects and both the shipboard and the laboratory-based GC/MS systems were free of problems with co-eluting compounds, our results in analyzing flasks from the first expedition show that CH3Br in flasks often is unstable and will increase or decrease with time. In addition, we found that results for CH3Br determined by GC/ECD can be compromised by some GC configurations.

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    Undersaturations of Methyl Bromide in the Southern Ocean

    Jürgen M. Lobert, Shari A. Yvon, James H. Butler, Stephen A. Montzka, and Richard C. Myers
    Geophys. Res. Lett. 24, 171-172, 1997.

    Abstract: Dry mole fractions of methyl bromide (CH3Br) in marine boundary layer air and in air equilibrated with surface water were measured in the Southern Ocean. Saturation anomalies were consistently negative at -36±7%. The observed undersaturations do not support recently published predictions of highly supersaturated Antarctic waters, but instead suggest a net uptake of atmospheric CH3Br by cold, productive oceans. The observations do not appear to be supported by known chemical degradation rates and present strong evidence for an unidentified, oceanic sink mechanism such as biological breakdown. Our estimate for the global, net, oceanic sink for atmospheric methyl bromide remains negative at -21 (-11 to -32) Gg y-1.

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    Tropospheric SF6: Observed latitudinal distribution and trends, derived emissions and interhemispheric exchange time

    Geller, L. S., J.W. Elkins, J.M. Lobert, A.D. Clarke, D.F. Hurst, J.H. Butler and R.C. Myers
    Geophys. Res. Lett. 24, 675-678, 1997.

    Abstract: Sulfur hexafluoride (SF6), an anthropogenically produced compound that is a potent greenhouse gas, has been measured in a number of NOAA CMDL air sampling programs. These include high resolution latitudinal profiles over the Atlantic and Pacific oceans, weekly flask samples from seven remote, globally distributed sites, hourly in situ measurements in rural North Carolina, and a series of archived air samples from Niwot Ridge, Colorado. The observed increase in atmospheric mixing ratio is consistent with an overall quadratic growth rate, at 6.9 ± 0.2% yr-1 (0.24 ± 0.01 ppt yr-1) for early 1996. From these data we derive an early 1996 emission rate of 5.9 ± 0.2 Gg SF6 yr-1 and an interhemispheric exchange time of 1.3 ± 0.1 years.

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    Carbon monoxide uptake by temperate forest soils: the effects of leaves and humus layers.

    E. SANHUEZA, Y. DONG D. SCHARFFE, J.M. LOBERT and P. J. CRUTZEN
    Tellus 50B, 51-58, 1998.

    Abstract: Carbon monoxide (CO) fluxes between soil and atmosphere were measured between October 1990 and December 1991 in a temperate, deciduous forest near Darmstadt, Germany. Flux measurements were made with an enclosed chamber technique before and after the removal of leaves and humus from the forest floor as well as from leaves and humus alone. CO depth profiles were obtained during the period July to December, 1991. A net uptake of CO was observed under all conditions with an average of -47.3±24.0 ng CO m-2 s-1 for undisturbed forest soils, which increased significantly when the leaves or both leaves and humus were removed from the forest floor. The mean deposition velocity in undisturbed conditions was 0.027±0.008 cm s-1. Our results indicate that CO has a short lifetime within the soil and that the consumption of atmospheric CO occurs mainly in the top few centimeters of the humus layer (O horizon). We conclude that temperate forests are a significant net sink for atmospheric CO and that leaves and humus significantly aVect CO fluxes. The global soil sink for atmospheric CO was estimated to be 115–230 Tg CO yr-1.

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    Fluxes of CO2, CH4 and N2O from a temperate forest soil: the effects of leaves and humus layers.

    Y. DONG D. SCHARFFE, J.M. LOBERT, P. J. CRUTZEN and E. SANHUEZA
    Tellus 50B, 243-252, 1998.

    Abstract: Fluxes of CO2, CH4, and N2O from forest soils were measured with an enclosed chamber technique between October 1990 and December 1991 in a deciduous forest near Darmstadt, Germany. Flux measurements were made before and after the removal of leaves and humus layer from the forest floor, and gas fluxes from the leaves and humus alone were also measured as well as depth profiles of CH4, N2O, and soil moisture. Except for N2O, large seasonal variations were observed with generally higher gas fluxes during the summer. CO2 and CH4 fluxes were significantly dependent on changes in ambient temperature, whereas N2O fluxes were more aVected by soil moisture. A good correlation between CO2 production and CH4 uptake was observed, but no relationship was found between N2O emissions and either CO2 or CH4 fluxes. Depth profiles of the CH4 mixing ratio in soil air consistently showed an exponential decrease with depth, whereas N2O profiles were highly variable and appeared to be related to changes in soil moisture. The manipulated soil experiments indicate that the leaves and the humus layers contribute significantly to the soil-atmosphere exchange of trace gases.

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    Instrumentation For Trace-Level Measurement of Carbon Monoxide in Pristine Environments

    Mark A. Cogan and Jürgen M. Lobert
    Proceedings of the 43rd Annual ISA Analysis Division Symposium, Volume 31, p. 229, ISBN 1-55617-664-3, Instrument Society of America, Research Triangle Park, NC, April 26-29, 1998.

    Abstract: Trace level measurement of carbon monoxide (CO) in air is important to understanding of sources and sinks of CO in the atmosphere. Detection limits of 50 ppb or less are necessary to understanding the creation and propagation of CO in pristine environments. Modifications to existing EPA-type CO monitors to allow such low-level measurements are discussed, along with the comparative increases in detection limits that result from these modifications. Selectivity and possible interferent gases are also discussed.

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    Global chlorine emissions from biomass burning: Reactive Chlorine Emissions Inventory J.M. Lobert, W.C. Keene, J.A. Logan, R. Yevich
    J. Geophys. Res. 104, 8373-8390, 1999

    Abstract: Emissions of reactive chlorine-containing compounds from nine discrete classes of biomass burning were estimated on a 1° latitude by 1° longitude grid based on a biomass burning inventory for carbon emissions. Variations on approaches incorporating both emission ratios relative to CO and CO2 and the chlorine content of biomass burning fuels were used to estimate fluxes and associated uncertainties. Estimated, global emissions are 640 Gg Cl yr-1 for CH3Cl; 49 Gg Cl yr-1 for CH2Cl2; 1.8 Gg Cl yr-1 for CHCl3; 13 Gg Cl yr-1 for CH3CCl3; and 6350 Gg Cl yr-1 for the sum of volatile-inorganic and particulate chlorine. Biomass burning appears to be the single largest source of atmospheric CH3Cl and a significant source of CH2Cl2; contributions of CHCl3 and CH3CCl3 are less than 2% of known sources.

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    Associated data file CH3Cl.90.yr.1.1a.bioburn.htm (236 kb)
    Associated data file Cl.90.yr.1.1a.bioburn.htm (236 kb)
    Associated data file CHCl3.90.yr.1.1b.bioburn.htm (236 kb)
    Associated data file CH2Cl2.90.yr.1.1a.bioburn.htm (236 kb)
    Associated data file CH3CCl3.90.yr.1.1b.bioburn.htm (236 kb)


    The Indian Ocean Experiment: Widespread Air Pollution from South and Southeast Asia

    J. Lelieveld, P.J. Crutzen, V. Ramanathan, M.O. Andreae, C.A.M. Brenninkmeijer, T. Campos, G.R. Cass, R.R. Dickerson, H. Fischer, J.A. de Gouw, A. Hansel, A. Jefferson, D. Kley, A.T.J. de Laat, S. Lal, M.G. Lawrence, J.M. Lobert, O.L. Mayol-Bracero, A.P. Mitra, T. Novakov, S.J. Oltmans, K.A. Prather, T. Reiner, H. Rodhe, H.A. Scheeren, D. Sikka, J. Williams
    Science 291, 1031-1036, 2001.

    Abstract: The Indian Ocean Experiment (INDOEX) was an international, multiplatform field campaign to measure long-range transport of air pollution from South and Southeast Asia toward the Indian Ocean during the dry monsoon season in January to March 1999. Surprisingly high pollution levels were observed over the entire northern Indian Ocean toward the Intertropical Convergence Zone at about 6¡S. We show that agricultural burning and especially biofuel use enhance carbon monoxide concentrations. Fossil fuel combustion and biomass burning cause a high aerosol loading. The growing pollution in this region gives rise to extensive air quality degradation with local, regional, and global impli- cations, including a reduction of the oxidizing power of the atmosphere.

    Reprinted with permission from Science 291, 1031-1036, 2001. Copyright © 2001 American Association for the Advancement of Science.

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    Trace Gases and Air Mass Origin over Kaashidhoo, Indian Ocean

    J.M. Lobert, J.M. Harris
    J. Geophys. Res., 107, 8013-8025, 2002.

    Abstract: Carbon monoxide (CO) was measured at the Kaashidhoo Climate Observatory (KCO, Republic of Maldives) between February 1998 and March 2000 to assess the regional pollution of the remote atmosphere in the northern Indian Ocean. CO showed a distinct annual cycle with maximum daily mixing ratios of around 240 parts per billion (ppb), a seasonal difference of about 200 ppb, and high variability during the dry seasons. Detailed air mass trajectory analysis for 1998, 1999, and 2000 was used to identify source regions and to associate them with various levels of pollution encountered at KCO. We conclude that most significant changes in local pollution throughout the year are caused by changes in air masses. Air at KCO generally originated from three main regions with decreasing pollution: India and southeast Asia, the Arabian Sea, and the Southern Hemisphere. We show that isentropic air mass trajectories can be used to predict CO pollution levels at KCO to a certain extent and vice versa. Nitrous oxide, CFC-11, CFC-12, CCI4, and SF6 were measured during the Indian Ocean Experiment (February to March 1999) to support pollution analysis and to confirm that India is the main source for heavy pollution measured at KCO. Correlations between CO and other gases and aerosol properties measured at the surface illustrate that CO may also be used as a proxy for aerosol loading and general pollution at the surface.

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    Associated data files for CO from the INDOEX data archive: Carbon monoxide data
    Associated data files for CFCs from the INDOEX data archive: CFC data
    Associated data files for meteorological measurements from the INDOEX data archive: Meteorological data - daily means
                 Links to related data can be found on the INDOEX project page.


    Emissions of Major Gaseous and Particulate Species During Experimental Burns of Southern African Biomass

    William C. Keene, Jürgen M. Lobert, Paul J. Crutzen, John R. Maben, Dieter H. Scharffe, Tobias Landmann, Christelle Hély, and Conrad Brain
    J. Geophys. Res., 111, D04301, doi:10.1029/2005JD006319

    Abstract: Characteristic vegetation and biofuels in major ecosystems of southern Africa were sampled during summer and autumn 2000 and burned under semi-controlled conditions. Elemental compositions of fuels and ash and emissions of CO2, CO, CH3COOH, HCOOH, NOX, NH3, HONO, HNO3, HCl, total volatile inorganic Cl and Br, SO2 and particulate C, N, and major ions were measured. Modified combustion efficiencies (MCEs, median = 0.94) were similar to those of ambient fires. Elemental emissions factors (EFel) for CH3COOH were inversely correlated with MCEs; EFels for heading and mixed grass fires were higher than those for backing fires of comparable MCEs. NOX, NH3, HONO, and particulate N accounted for a median of 22% of emitted N; HNO3 emissions were insignificant. Grass fires with the highest EFels for NH3 corresponded to MCEs in the range of 0.93; grass fires with higher and low MCEs exhibited lower EFels. NH3 emissions for most fuels were poorly correlated with fuel N. Most Cl and Br in fuel was emitted during combustion (median for each = 73%). Inorganic gases and particulate ions accounted for medians of 53% and 30% of emitted Cl and Br, respectively. About half of volatile inorganic Cl was HCl indicating significant emissions of other gaseous inorganic Cl species. Most fuel S (median = 76%) was emitted during combustion; SO2 and particulate SO42- accounted for about half the flux. Mobilization of P by fire (median emission = 82%) implies large nutrient losses from burned regions and potentially important exogenous sources of fertilization for downwind ecosystems.

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                 Links to related data can be found on the SAFARI 2000 project page.


    Oceanic distributions and emissions of short-lived halocarbons

    Butler, J. H., D. B. King, J. M. Lobert, S. A. Montzka, S. A. Yvon-Lewis, B. D. Hall, N. J. Warwick, D. J. Mondeel, M. Aydin, and J. W. Elkins
    Global Biogeochem. Cycles, 21, GB1023, doi:10.1029/2006GB002732

    Abstract: Using data from seven cruises over a 10-year span, we report marine boundary layer mixing ratios (i.e., dry mole fractions as pmol mol.1 or ppt), degrees of surface seawater saturation, and air-sea fluxes of three short-lived halocarbons that are significant in tropospheric and potentially stratospheric chemistry. CHBr3, CH2Br2, and CH3I were all highly supersaturated almost everywhere, all the time. Highest saturations of the two polybrominated gases were observed in coastal waters and areas of upwelling, such as those near the equator and along ocean fronts. CH3I distributions reflected the different chemistry and cycling of this gas in both the water and the atmosphere. Seasonal variations in fluxes were apparent where cruises overlapped and were consistent among oceans. Undersaturations of these gases were noted at some locations in the Southern Ocean, owing to mixing of surface and subsurface waters, not necessarily biological or chemical sinks. The Pacific Ocean appears to be a much stronger source of CHBr3 to the marine boundary layer than the Atlantic. The high supersaturations, fluxes, and marine boundary layer mixing ratios in the tropics are consistent with the suggestion that tropical convection could deliver some portion of these gases and their breakdown products to the upper troposphere and lower stratosphere.

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                 Links to related data can be found on the NOAA/HATS/Ocean data archive.


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