LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
H. Schaefer; M. J. Whiticar; J. R. Melton (2012)
Publisher: Copernicus Publications
Journal: Climate of the Past
Languages: English
Types: Article
Subjects: DOAJ:Earth and Environmental Sciences, GE1-350, G, DOAJ:Environmental Sciences, Environmental pollution, Geography. Anthropology. Recreation, TD172-193.5, Environmental sciences, Environmental protection, TD169-171.8
The abrupt warming across the Younger Dryas termination (~11 600 yr before present) was marked by a large increase in the global atmospheric methane mixing ratio. The debate over sources responsible for the rise in methane centers on the roles of global wetlands, marine gas hydrates, and thermokarst lakes. We present a new, higher-precision methane stable carbon isotope ratio (δ13CH4) dataset from ice sampled at Påkitsoq, Greenland that shows distinct 13C-enrichment associated with this rise. We investigate the validity of this finding in face of known anomalous methane concentrations that occur at Påkitsoq. Comparison with previously published datasets to determine the robustness of our results indicates a similar trend in ice from both an Antarctic ice core and previously published Påkitsoq data measured using four different extraction and analytical techniques. The δ13CH4 trend suggests that 13C-enriched CH4 sources played an important role in the concentration increase. In a first attempt at quantifying the various contributions from our data, we apply a methane triple mass balance of stable carbon and hydrogen isotope ratios and radiocarbon. The mass balance results suggest biomass burning (42–66% of total methane flux increase) and thermokarst lakes (27–59%) as the dominant contributing sources. Given the high uncertainty and low temporal resolution of the 14CH4 dataset used in the triple mass balance, we also performed a mass balance test using just δ13C and δD. These results further support biomass burning as a dominant source, but do not allow distinguishing of thermokarst lake contributions from boreal wetlands, aerobic plant methane, or termites. Our results in both mass balance tests do not suggest as large a role for tropical wetlands or marine gas hydrates as commonly proposed.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Allan, W., Lowe, D. C., and Cainey, J. M.: Active chlorine in the remote marine boundary layer: Modeling anomalous measurements of δ13C in methane, Geophys. Res. Lett., 28, 3239-3242, 2001.
    • Allan, W., Struthers, H., and Lowe, D. C.: Methane carbon isotope effects caused by atomic chlorine in the marine boundary layer: Global model results compared with Southern Hemisphere measurements, J. Geophys. Res., 112, D04306, doi:10.1029/2006jd007369, 2007.
    • Behrens, M., Schmitt, J., Richter, K. U., Bock, M., Richter, U. C., Levin, I., and Fischer, H.: A gas chromatography/combustion/isotope ratio mass spectrometry system for high-precision δ13C measurements of atmospheric methane extracted from ice core samples, Rapid Commun. Mass. Sp., 22, 3261-3269, doi:10.1002/Rcm.3720, 2008.
    • Bellisario, L. M., Bubier, J. L., Moore, T. R., and Chanton, J. P.: Controls on CH4 emissions from a northern peatland, Global Biogeochem. Cy., 13, 81-91, 1999.
    • Bender, M., Malaize´, B., Orchardo, J., Sowers, T., and Jouzel, J.: High precision correlations of Greenland and Antarctica ice core records over the last 100 kyr in: Global climate change at millenial timescales, edited by: Clark, P. U., Webb, R., and Keigwin, L., American Geophysical Union, Washington, D.C., 149-164, 1999.
    • Bock, M., Schmitt, J., Moller, L., Spahni, R., Blunier, T., and Fischer, H.: Hydrogen isotopes preclude marine hydrate CH4 emissions at the onset of Dansgaard-Oeschger events, Science, 328, 1686-1689, doi:10.1126/Science.1187651, 2010.
    • Bousquet, P., Ciais, P., Miller, J. B., Dlugokencky, E. J., Hauglustaine, D. A., Prigent, C., Van der Werf, G. R., Peylin, P., Brunke, E.-G., Carouge, C., Langenfelds, R. L., Lathie´re, J., Papa, F., Ramonet, M., Schmidt, M., Steele, L. P., Tyler, S. C., and White, J. W. C.: Contribution of anthropogenic and natural sources to atmospheric methane variability, Nature, 443, 439-444, 2006.
    • Bowman, D. M. J. S., Balch, J. K., Artaxo, P., Bond, W. J., Carlson, J. M., Cochrane, M. A., D'Antonio, C. M., DeFries, R. S., Doyle, J. C., Harrison, S. P., Johnston, F. H., Keeley, J. E., Krawchuk, M. A., Kull, C. A., Marston, J. B., Moritz, M. A., Prentice, I. C., Roos, C. I., Scott, A. C., Swetnam, T. W., van der Werf, G. R., and Pyne, S. J.: Fire in the Earth system, Science, 324, 481-484, doi:10.1126/Science.1163886, 2009.
    • Brenninkmeijer, C. A. M., Lowe, D. C., Manning, M. R., Sparks, R. J., and vanVelthoven, P. F. J.: The 13C, 14C and 18O isotopic composition of CO, CH4, and CO2 in the higher southern latitudes lower stratosphere, J. Geophys. Res.-Atmos., 100, 26163- 26172, 1995.
    • Brook, E. J., Sowers, T., and Orchardo, J.: Rapid variations in atmospheric methane concentration during the past 110,000 years, Science, 273, 1087-1091, 1996.
    • Brook, E. J., Harder, S., Severinghaus, J., Steig, E. J., and Sucher, C. M.: On the origin and timing of rapid changes in atmospheric methane during the last glacial period, Global Biogeochem. Cy., 14, 559-572, 2000.
    • Brook, E. J., White, J. W. C., Schilla, A. S. M., Bender, M. L. , Barnett, B., Severinghaus, J. P., Taylor, K. E., Alley, R. B., and Steig, E. J.: Timing of millennial-scale climate change at Siple Dome, West Antarctica, during the last glacial period, Quaternary Sci. Rev., 24, 1333-1343, 2005.
    • Buizert, C.: The influence of firn air transport processes and radiocarbon production on gas records from polar firn and ice, PhD, Faculty of Science, University of Copenhagen, Denmark, Copenhagen, 175 pp., 2012.
    • Cantrell, C. A., Shetter, R. E., Mcdaniel, A. H., Calvert, J. G., Davidson, J. A., Lowe, D. C., Tyler, S. C., Cicerone, R. J., and Greenberg, J. P.: Carbon kinetic isotope effect in the oxidation of methane by the hydroxyl radical, J. Geophy. Res., 95, 22455- 22462, 1990.
    • Chappellaz, J., Barnola, J.-M., Raynaud, D., Korotkevich, Y. S., and Lorius, C.: Ice-core record of atmospheric methane over the past 160,000 years, Nature, 345, 127-131, 1990.
    • Chappellaz, J., Fung, I. Y., and Thompson, A. M.: The atmospheric CH4 increase since the Last Glacial Maximum (1) source estimates, Tellus B, 45, 228-241, 1993.
    • Collatz, G. J., Berry, J. A., and Clark, J. S.: Effects of climate and atmospheric CO2 partial pressure on the global distribution of C4 grasses: Present, past, and future, Oecologia, 114, 441-454, 1998.
    • Craig, H., Chou, C. C., Welhan, J. A., Stevens, C. M., and Engelkemeir, A.: The isotopic composition of methane in polar ice cores, Science, 242, 1535-1539, 1988.
    • Da¨llenbach, A., Blunier, T., Fl u¨ckiger, J., Stauffer, B., Chappellaz, J., and Raynaud, D.: Changes in the atmospheric CH4 gradient between Greenland and Antarctica during the Last Glacial and the transition to the Holocene, Geophys. Res. Lett., 27, 1005- 1008, 2000.
    • Daniau, A.-L., Harrison, S. P., and Bartlein, P. J.: Fire regimes during the Last Glacial, Quaternary Sci. Rev., 29, 2918-2930, doi:10.1016/j.quascirev.2009.11.008, 2010.
    • Denman, K. L., Brasseur, G. P., Chidthaisong, A., Ciais, P., Cox, P., Dickinson, R., Hauglustaine, D. A., Heinze, C., Holland, E., Jacob, D., Lohmann, U., Ramachandran, S., da Silva Dias, P. L., Wofsy, S. C., and Zhang, X.: Couplings between changes in the climate system and biogeochemistry, Cambridge University Press, Cambridge, UK and New York, NY, USA, 2007.
    • Donahue, D. J., Linick, T. W., and Jull, A. J. T.: Isotope-ratio and background correction for accelerator mass spectrometry radiocarbon measurements, Radiocarbon, 32, 135-142, 1990.
    • Drevet, J.: Modeling study of the interannual variability in global tropospheric hydroxyl radical and methane concentrations over the last two decades, PhD, Faculte Environnement Naturel, Architectural et Construit, E´ cole Polytechnique Fe´de´rale de Lausanne, Switzerland, Lausanne, 133 pp., 2008.
    • EPICA Community Members: One-to-one coupling of glacial climate variability in Greenland and Antarctica, Nature, 444, 195- 198, doi:10.1038/Nature05301, 2006.
    • Etheridge, D. M., Steele, L. P., Francey, R. J., and Langenfelds, R. L.: Atmospheric methane between 1000 A.D. and present: Evidence of anthropogenic emissions and climatic variability, J. Geophys. Res., 103, 15979-15993, 1998.
    • Etiope, G., Milkov, A. V., and Derbyshire, E.: Did geologic emissions of methane play any role in Quaternary climate change?, Global Planet. Change, 61, 79-88, 2008.
    • Ferretti, D. F., Miller, J. B., White, J. W. C., Etheridge, D. M., Lassey, K. R., Lowe, D. C., MacFarling Meure, C. M., Dreier, M. F., Trudinger, C. M., van Ommen, T. D., and Langenfelds, R. L.: Unexpected changes to the global methane budget over the past 2000 years, Science, 309, 1714-1717, 2005.
    • Fischer, H., Behrens, M., Bock, M., Richter, U., Schmitt, J., Loulergue, L., Chappellaz, J., Spahni, R., Blunier, T., Leuenberger, M., and Stocker, T. F.: Changing boreal methane sources and constant biomass burning during the last termination, Nature, 452, 864-867, doi:10.1038/nature06825, 2008.
    • Friedrich, M., Kromer, B., Spurk, M., Hoffman, J., and Kaiser, K. F.: Paleo-environment and radiocarbon calibration as derived from Late Glacial/Early Holocene tree-ring chronologies, Quatern. Int., 61, 27-39, 1999.
    • Gierczak, T., Talukdar, R. K., Herndon, S. C., Vaghjiani, G. L., and Ravishankara, A. R.: Rate coefficients for the reactions of hydroxyl radicals with methane and deuterated methanes, J. Phys. Chem. A, 101, 3125-3134, 1997.
    • Grachev, A. M. and Severinghaus, J.: Determining the thermal diffusion factor for 40Ar/36Ar in air to aid paleoreconstruction of abrupt climate change, J. Phys. Chem. A, 107, 4636-4642, 2003.
    • Grootes, P. M. and Stuiver, M.: Oxygen 18/16 variability in Greenland snow and ice with 103 to 105 year time resolution, J. Geophys. Res., 102, 26455-26470, doi:10.1029/97jc00880, 1997.
    • Herron, M. M. and Langway, C. C. J.: Firn densification: An empirical model, J. Glaciol., 25, 373-385, 1980.
    • Hill, T. M., Kennett, J. P., Valentine, D. L., Yang, Z., Reddy, C. M., Nelson, R. K., Behl, R. J., Robert, C., and Beaufort, L.: Climatically driven emissions of hydrocarbons from marine sediments during deglaciation, P. Natl. Acad. Sci., 103, 13570- 13574, 2006.
    • Irion, F. W., Moyer, E. J., Gunson, M. R., Rinsland, C. P., Yung, Y. L., Michelsen, H. A., Salawitch, R. J., Chang, A. Y., Newchurch, M. J., Abbas, M. M., Abrams, M. C., and Zanders, R.: Stratospheric observations of CH3D and HDO from atmospheric infrared solar spectra: Enrichments of deuterium in methane and implications for HD, Geophys. Res. Lett., 23, 2381-2384, 1996.
    • Jones, M. C. and Yu, Z.: Rapid deglacial and early Holocene expansion of peatlands in Alaska, P. Natl. Acad. Sci., 107, 7347-7352, doi:10.1073/pnas.0911387107, 2010.
    • Jouzel, J., Hoffman, G., Koster, R. D., and Masson, V.: Water isotopes in precipitation: Data/model comparison for present-day and past climates, Quaternary Sci. Rev., 19, 363-379, 2000.
    • Kennett, J. P., Cannariato, K. G., Hendy, I. L., and Behl, R. J.: Methane hydrates in Quaternary climate change: The clathrate gun hypothesis, AGU Special Publication, 54, 216, 2003.
    • Keppler, F., Hamilton, J. T. G., Brab, M., and Ro¨ckmann, T.: Methane emissions from terrestrial plants under aerobic conditions, Nature, 439, 187-191, 2006.
    • King, S. L., Quay, P. D., and Lansdown, J. M.: The C-13/C-12 kinetic isotope effect for soil oxidation of methane at ambient atmospheric concentrations, J. Geophys. Res.-Atmos., 94, 18273- 18277, 1989.
    • Korhola, A., Ruppel, M., Seppa, H., Valiranta, M., Virtanen, T., and Weckstrom, J.: The importance of northern peatland expansion to the late-Holocene rise of atmospheric methane, Quaternary Sci. Rev., 29, 611-617, doi:10.1016/J.Quascirev.2009.12.010, 2010.
    • Lassey, K. R., Lowe, D. C., and Manning, M. R.: The trend in atmospheric methane δ13C and implications for isotopic constraints on the global methane budget, Global Biogeochem. Cy., 14, 41- 49, 2000.
    • Lassey, K. R., Etheridge, D. M., Lowe, D. C., Smith, A. M., and Ferretti, D. F.: Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?, Atmos. Chem. Phys., 7, 2119-2139, doi:10.5194/acp-7-2119-2007, 2007.
    • Levine, J. G., Wolff, E. W., Jones, A. E., and Sime, L. C.: The role of atomic chlorine in glacial-interglacial changes in the carbon13 content of atmospheric methane, Geophys. Res. Lett., 38, L04801, doi:10.1029/2010GL046122, 2011.
    • MacDonald, G. M., Beilman, D. W., Kremenetski, K. V., Sheng, Y., Smith, L. C., and Velichko, A. A.: Rapid early development of circumarctic peatlands and atmospheric CH4 and CO2 variations, Science, 314, 285-289, 2006.
    • Marlon, J. R., Bartlein, P. J., Walsh, M. K., Harrison, S. P., Brown, K. J., Edwards, M. E., Higuera, P. E., Power, M. J., Anderson, R. S., Briles, C., Brunelle, A., Carcaillet, C., Daniels, M., Hu, F. S., Lavoie, M., Long, C., Minckley, T., Richard, P. J. H., Scott, A. C., Schafer, D. S., Tinner, W., Umbanhowar Jr., C. E., and Whitlock, C.: Wildfire responses to abrupt climate change in North America, P. Natl. Acad. Sci., 106, 2519-2524, doi:10.1073/pnas.0808212106, 2009.
    • Martinerie, P., Brasseur, G. P., and Granier, C.: The chemical composition of ancient atmospheres: A model study constrained by ice core data, J. Geophys. Res., 100, 14291-14304, 1995.
    • Melton, J. R.: Methane stable isotope dynamics spanning the last deglaciation, PhD, School of Earth and Ocean Sciences, University of Victoria, Canada, Victoria, 188 pp., 2010.
    • Melton, J. R., Whiticar, M. J., and Eby, P.: Stable carbon isotope ratio analyses on trace methane from ice samples, Chem. Geol., 288, 88-96, doi:10.1016/j.chemgeo.2011.03.003, 2011.
    • Mischler, J. A., Sowers, T. A., Alley, R. B., Battle, M., McConnell, J. R., Mitchell, L., Popp, T., Sofen, E., and Spencer, M. K.: Carbon and hydrogen isotopic composition of methane over the last 1000 years, Global Biogeochem. Cy., 23, GB4024, doi:10.1029/2009GB003460, 2009.
    • Mo¨ller, L., Sowers, T., Bock, M., Spahni, R., Behrens, M., Schmitt, J., Miller, H., and Fischer, H.: Climate and CO2 control on emissions and ecosystem composition of global methane sources over the last 160,000 years derived from δ13CH4 in ice cores, Geophys. Res. Abstr., Vol. 14, EGU2012-2366,http://meetingorganizer.copernicus.org/ EGU2012/EGU2012-13164.pdf (last access: July 2012), 2012.
    • Nakagawa, F., Yoshida, N., Nojiri, Y., and Makarov, V. N.: Production of methane from alasses in Eastern Siberia: Implications from its 14C and stable isotope compositions, Global Biogeochem. Cy., 16, 1041-1056, 2002a.
    • Nakagawa, F., Yoshida, N., Sugimoto, A., Wada, E., Yoshioka, T., Ueda, S., and Vijarnsorn, P.: Stable isotope and radiocarbon compositions of methane emitted from tropical rice paddies and swamps in Southern Thailand, Biogeochemistry, 61, 1-19, 2002b.
    • Nisbet, R. E. R., Fisher, R., Nimmo, R. H., Bendall, D. S., Crill, P. M., Gallego-Sala, A. V., Hornibrook, E. R. C., Lo´pezJuez, E., Lowry, D., Nisbet, P. B. R., Shuckburgh, E. F., Sriskantharajah, S., Howe, C. J., and Nisbet, E. G.: Emissions of methane from plants, P. Roy. Soc. B, 276, 1459-1468, doi:10.1098/rspb.2008.1731, 2009.
    • Peterson, L. C., Haug, G. H., Hughen, K. A., and Rohl, U.: Rapid changes in the hydrologic cycle of the tropical atlantic during the Last Glacial, Science, 290, 1947-1951, 2000.
    • Petrenko, V., Severinghaus, J., Brook, E. J., Reeh, N., and Schaefer, H.: Gas records from the West Greenland ice margin covering the last glacial maximum termination: A horizontal ice core, Quaternary Sci. Rev., 25, 865-875, 2006.
    • Petrenko, V., Smith, A. M., Brook, E. J., Lowe, D. C., Riedel, K., Brailsford, G. W., Hua, Q., Schaefer, H., Reeh, N., Weiss, R. F., Etheridge, D. M., and Severinghaus, J.: 14CH4 measurements in Greenland ice: Investigating Last Glacial termination CH4 sources, Science, 324, 506-508, 2009.
    • Power, M. J., Marlon, J. R., Ortiz, N., Bartlein, P. J., Harrison, S. P., Mayle, F. E., Ballouche, A., Bradshaw, R. H. W., Carcaillet, C., Cordova, C., Mooney, S., Moreno, P. I., Prentice, C. I., Thonicke, K., Tinner, W., Whitlock, C., Zhang, Y., Zhao, Y., Ali, A. A., Anderson, R. S., Beer, R., Behling, H., Briles, C., Brown, K. J., Brunelle, A., Bush, M., Camil, P., Chu, G. Q., Clark, J., Colombarli, D., Connor, S., Daniau, A.-L., Daniels, M., Dodson, J., Doughty, E., Edwards, M. E., Finsinger, W., Foster, D., Frechette, J., Gaillard, M.-J., Gavin, D. G., Gobet, E., Haberle, S., Hallett, D. J., Higuera, P. E., Hope, G., Horn, S., Inoue, J., Kaltenrieder, P., Kennedy, L., Kong, Z. C., Larsen, C., Long, C. J., Lynch, J., Lynch, E. A., McGlone, M., Meeks, S., Mensing, S., Meyer, G., Minckley, T., Mohr, J., Nelson, D. M., New, J., Newnham, R., Noti, R., Oswald, W., Pierce, J., Richard, P. J. H., Rowe, C., Sanchez Gon˜i, M. F., Shuman, B. N., Takahara, H., Toney, J., Turney, C., Urrego-Sanchez, D. H., Umbanhowar Jr., C. E., Vandergoes, M., Vanniere, B., Vescovi, E., Walsh, M. K., Wang, X., Williams, N., Wilmshurst, J., and Zhang, J. H.: Changes in fire regimes since the Last Glacial Maximum: An assessment based on a global synthesis and analysis of charcoal data, Clim. Dynam., 30, 887-907, doi:10.1007/s00382-007-0334-x, 2008.
    • Quay, P., Stutsman, J., Wilbur, D., Snover, A., Dlugokencky, E. J., and Brown, T.: The isotopic composition of atmospheric methane, Global Biogeochem. Cy., 13, 445-461, 1999.
    • Reeburgh, W. S., Hirsch, A. I., Sansone, F. J., Popp, B. N., and Rust, T. M.: Carbon kinetic isotope effect accompanying microbial oxidation of methane in boreal forest soils, Geochim. Cosmochim. Acta, 61, 4761-4767, 1997.
    • Reyes, A. V. and Cooke, C. A.: Northern peatland initiation lagged abrupt increases in deglacial atmospheric CH4, P. Natl. Acad. Sci., 108, 4748-4753, doi:10.1073/pnas.1013270108, 2011.
    • Saueressig, G., Bergamaschi, P., Crowley, J. N., Fischer, H., and Harris, G. W.: Carbon kinetic isotope effect in the reaction of CH4 with Cl atoms, Geophys. Res. Lett., 22, 1225-1228, 1995.
    • Saueressig, G., Crowley, J. N., Bergamaschi, P., Bruhl, C., Brenninkmeijer, C. A. M., and Fischer, H.: Carbon 13 and D kinetic isotope effects in the reactions of CH4 with O(D-1) and OH: New laboratory measurements and their implications for the isotopic composition of stratospheric methane, J. Geophys. Res.-Atmos., 106, 23127-23138, 2001.
    • Schaefer, H.: Stable carbon isotopic composition of methane from ice samples, PhD, School of Earth and Ocean Sciences, University of Victoria, Victoria, 166 pp., 2005.
    • Schaefer, H. and Whiticar, M. J.: Measurement of stable carbon isotope ratio of methane in ice samples, Org. Geochem., 38, 216- 226, 2007.
    • Schaefer, H. and Whiticar, M. J.: Potential glacial-interglacial changes in stable carbon isotope ratios of methane sources and sink fractionation, Global Biogeochem. Cy., 22, GB1001, doi:10.1029/2006GB002889, 2008.
    • Schaefer, H., Whiticar, M. J., Brook, E. J., Petrenko, V., Ferretti, D. F., and Severinghaus, J.: Ice record of δ13C for atmospheric CH4 across the Younger Dryas-Preboreal transition, Science, 313, 1109-1112, 2006.
    • Schaefer, H., Petrenko, V., Brook, E. J., Severinghaus, J., Reeh, N., Melton, J. R., and Mitchell, L.: Ice stratigraphy at the Pakitsoq West Greenland ice margin derived from gas records, J. Glaciol., 55, 411-422, 2009.
    • Schrag, D. P., Adkins, J. F., McIntyre, K., Alexander, J. L., Hodell, D. A., Charles, C. D., and McManus, J. F.: The oxygen isotopic composition of seawater during the Last Glacial Maximum, Quaternary Sci. Rev., 21, 331-342, 2002.
    • Schwander, J., Barnola, J.-M., Andrie´, C., Leuenberger, M., Ludin, A., Raynaud, D., and Stauffer, B.: The age of the air in the firn and the ice at Summit, Greenland, J. Geophys. Res., 98, 2831- 2838, 1993.
    • Schwander, J., Sowers, T., Barnola, J.-M., Blunier, T., Fuchs, A., and Malaize´, B.: Age scale of the air in the Summit ice: Implications for glacial-interglacial temperature change, J. Geophys. Res., 102, 19483-419493, 1997.
    • Severinghaus, J., Sowers, T., Brook, E. J., Alley, R. B., and Bender, M.: Timing of abrupt climate change at the end of the Younger Dryas interval from thermally fractionated gases in polar ice, Nature, 391, 141-146, 1998.
    • Severinghaus, J., Beaudette, R., Headly, M. A., Taylor, K. C., and Brook, E. J.: Oxygen-18 of O2 records the impact of abrupt climate change on the terrestrial biosphere, Science, 324, 1431- 1434, doi:10.1126/science.1169473, 2009.
    • Snover, A. K. and Quay, P. D.: Hydrogen and carbon kinetic isotope effects during soil uptake of atmospheric methane, Global Biogeochem. Cy., 14, 25-39, 2000.
    • Sowers, T.: Late quaternary atmospheric CH4 isotope record suggests marine clathrates are stable, Science, 311, 838-840, 2006.
    • Sowers, T.: Atmospheric methane isotope records covering the Holocene period, Quaternary Sci. Rev., 29, 213-221, doi:10.1016/j.quascirev.2009.05.023, 2010.
    • Stevens, G. A. and de Vries, A. E.: The influence of the distribution of atomic masses within the molecule on thermal diffusion, II. Isotopic methane and methane/argon mixtures, Physica, 39, 346-360, 1968.
    • Tans, P. P.: A note on isotopic ratios and the global atmospheric methane budget, Global Biogeochem. Cy., 11, 77-81, 1997.
    • Thompson, A. M., Chappellaz, J., Fung, I. Y., and Kucsera, T. L.: The atmospheric CH4 increase since the Last Glacial Maximum, Tellus B, 45, 242-257, 1993.
    • Trudinger, C. M., Enting, I. G., Etheridge, D. M., Francey, R. J., Levchenko, V. A., Steele, L. P., Raynaud, D., and Arnaud, L.: Modeling air movement and bubble trapping in firn, J. Geophys. Res., 102, 6747-6763, 1997.
    • Tyler, S. C., Crill, P. M., and Brailsford, G. W.: 13C/12C fractionation of methane during oxidation in a temperate forested soil, Geochim. Cosmochim. Acta, 58, 1625-1633, 1994.
    • Tyler, S. C., Ajie, H. O., Rice, A. L., Cicerone, R. J., and Tuazon, E. C.: Experimentally determined kinetic isotope effects in the reaction of CH4 with Cl: Implications for atmospheric CH4, Geophys. Res. Lett., 27, 1715-1718, 2000.
    • Vigano, I., Ro¨ckmann, T., Holzinger, R., van Dijk, A., Keppler, F., Greule, M., Brand, W. A., Geilmann, H., and van Weelden, H.: The stable isotope signature of methane emitted from plant material under UV radiation, Atmos. Environ., 43, 5637-5646, doi:10.1016/j.atmosenv.2009.07.046, 2009.
    • Wahlen, M., Deck, B., Shemesh, A., Fairbanks, R. G., Broecker, W. S., Weyer, H., Marino, B., and Logan, J.: Profiles of δ13C and δD of CH4 from the lower stratosphere, EOS Transactions AGU, 70, p. 1017, 1989a.
    • Wahlen, M., Tanaka, N., Henry, R., Deck, B., Zeglen, J., Vogel, J. S., Southon, J., Shemesh, A., Fairbanks, R. G., and Broecker, W. S.: Carbon-14 in methane sources and in atmospheric methane: The contribution from fossil carbon, Science, 245, 286-290, 1989b.
    • Waldron, S., Lansdown, J. M., Scott, E. M., Fallick, A. E., and Hall, A. J.: The global influence of the hydrogen isotope composition of water on that of bacteriogenic methane from shallow freshwater environments, Geochim. Cosmochim. Acta, 63, 2237-2245, 1999.
    • Walter, K. M., Zimov, S. A., Chanton, J. P., Verbyla, D., and Chapin, F. S. I.: Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming, Nature, 443, 71-76, doi:10.1038/nature05040, 2006.
    • Walter, K. M., Edwards, M. E., Grosse, G., Zimov, S. A., and Chapin, F. S. I.: Thermokarst lakes as a source of atmospheric CH4 during the Last Deglaciation, Science, 318, 633- 638, 10.1126/science.1142924, 2007.
    • Walter, K. M., Chanton, J. P., Chapin, F. S., Schuur, E. A. G., and Zimov, S. A.: Methane production and bubble emissions from arctic lakes: Isotopic implications for source pathways and ages, J. Geophys. Res.-Biogeo., 113, G00A08, doi:10.1029/2007jg000569, 2008.
    • Wang, Z., Chappellaz, J., Park, K., and Mak, J. E.: Large variations in Southern Hemisphere biomass burning during the last 650 years, Science, 330, 1663-1666, 2010.
    • Westerling, A. L., Hidalgo, H. G., Cayan, D. R., and Swetnam, T. W.: Warming and earlier spring increase Western U.S. forest wildfire activity, Science, 313, 940-943, doi:10.1126/science.1128834, 2006.
    • Westerling, A. L.: Wildfires, in: Climate change science and policy, edited by: Schneider, S. H., Rosencranz, A., Mastrandrea, M. D., and Kuntz-Duriseti, K., Island Press, Washington, D.C., USA, 92-104, 2009.
    • Whiticar, M. J.: Stable isotopes and global budgets, in: Atmospheric methane: Sources, sinks, and role in global climate, edited by: Khalil, M. A. K., Springer-Verlag, Berlin, Heidelberg, 138-167, 1993.
    • Whiticar, M. J.: Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane, Chem. Geol., 161, 291- 314, 1999.
    • Whiticar, M. J. and Schaefer, H.: Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice, P. Roy. Soc., 365, 1793-1828, doi:10.1098/rsta.2007.2048, 2007.
    • Winckler, G., Aeschbach-Hertig, W., Holocher, J., Kipfer, R., Levin, I., Poss, C., Rehder, G., Suess, E., and Schlosser, P.: Noble gases and radiocarbon in natural gas hydrates, Geophys. Res. Lett., 29, 63-1-63-4, doi:10.1029/2001gl014013, 2002.
    • Wuebbles, D. J. and Hayhoe, K.: Atmospheric methane and global change, Earth-Sci. Rev., 57, 177-210, 2002.
    • Zimov, S. A., Schuur, E. A. G., and Chapin, F. S. I.: Permafrost and the global carbon budget, Science, 312, 1612-1613, 2006.
  • No related research data.
  • No similar publications.

Share - Bookmark

Funded by projects

  • NSF | Collaborative Research: Det...
  • NSF | Collaborative Research: Det...

Cite this article