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The isotopic composition of atmospheric methane
Paul Quay,
John Stutsman,
David Wilbur,
Amy Snover,
Ed Dlugokencky,
Tom Brown,
John Stutsman
Search for more papers by this authorDavid Wilbur
Search for more papers by this authorAmy Snover
Search for more papers by this authorEd Dlugokencky
Search for more papers by this author
Paul Quay,
John Stutsman,
David Wilbur,
Amy Snover,
Ed Dlugokencky,
Tom Brown,
John Stutsman
Search for more papers by this authorDavid Wilbur
Search for more papers by this authorAmy Snover
Search for more papers by this authorEd Dlugokencky
Search for more papers by this authorAbstract
Measurements of the 13C/12C, D/H and 14C composition of atmospheric methane (CH4) between 1988 and 1995 are presented. The 13C/12C measurements represent the first global data set with time series records presented for Point Barrow, Alaska (71°N), Olympic Peninsula, Washington (48°N), Mauna Loa, Hawaii (20°N), American Samoa (14°S), Cape Grim, Australia (41°S), and Baring Head, New Zealand (41°S). North-south trends of the 13C/12C and D/H of atmospheric CH4 from air samples collected during oceanographic research cruises in the Pacific Ocean are also presented. The mean annual δ13C increased southward from about −47.7 ‰ at 71°N to −41.2 ‰ at 41°S. The amplitude of the seasonal cycle in δ13C ranged from about 0.4 ‰ at 71°N to 0.1 ‰ at 14°S. The seasonal δ13C cycle at sites in tropical latitudes could be explained by CH4 loss via reaction with OH radical, whereas at temperate and polar latitudes in the northern hemisphere seasonal changes in the δ13C of the CH4 source were needed to explain the seasonal cycle. The higher δ13C value in the southern (−47.2 ‰) versus northern (−47.4 ‰) hemisphere was a result of interhemispheric transport of CH4. A slight interannual δ13C increase of 0.02±0.005 ‰ yr−1 was measured at all sites between 1990 and 1995. The mean δD of atmospheric CH4 was −86±3 ‰ between 1989 and 1995 with a 10 ‰ depletion in the northern versus southern hemisphere. The 14C content of CH4 measured at 48°N increased from 122 to 128 percent modern between 1987 and 1995. The proportion of CH4 released from fossil sources was 18±9% in the early 1990s as derived from the 14C content of CH4.
References
- Alei, M., et al., Determination of deuterated methanes for use as atmospheric tracers, Atmos. Environ., 214, 909–915, 1987.
- Beck, L. L., S. D. Piccot, D. A. Kirchgessner, Industrial sources, Atmospheric Methane: Sources, Sinks and Role in Global Change M. A. K. Khalil, 399–431, Springer-Verlag, New York, 1993.
10.1007/978-3-642-84605-2_17 Google Scholar
- Bekki, S., K. S. Law, J. A. Pyle, Effect of ozone depletion on atmospheric CH4 and CO concentrations, Nature, 371, 595–597, 1994.
- Blake, D. R., F. S. Rowland, Continuing worldwide increase in tropospheric methane, 1978 to 1987, Science, 239, 1129–1131, 1988.
- Brenninkmeijer, C. A. M., D. C. Lowe, M. R. Manning, R. J. Sparks, P. F. J. vanVelthoven, The 13C, 14C, and 18O isotopic composition of CO, CH4, and CO2 in the higher southern latitudes lower stratosphere, J. Geophys. Res., 100, 26,163–26,172, 1995.
- , British Petroleum, Statistical Review of World Energy, London, 1994.
- Brown, M., The singular value decomposition method applied to the deduction of emissions and the isotope composition of atmospheric methane, J. Geophys. Res., 100, 11425–11446, 1995.
- Brown, T. A., G. W. Farwell, P. M. Grootes, Current status of the 14C AMS program at the University of Washington, Nucl. Instrum. Methods Phys. Res., Sect. B, 92, 16–20, 1994.
- Cantrell, C. A., R. E. Shetter, A. H. McDaniel, J. G. Calvert, J. A. Davidson, D. C. Lowe, S. C. Tyler, R. J. Cicerone, J. P. Greenberg, Carbon kinetic isotope effect in the oxidation of methane by hydroxyl radicals, J. Geophys. Res., 95, 22455–22462, 1990.
- Crutzen, P. J., The role of methane in atmospheric chemistry and climate, Ruminant Physiology: Digestion, Metabolism, Growth and Reproduction: Proceedings of the Eighth International Symposium on Ruminant Physiology W. V. Engelhardt, S. Leonhardt-Marek, G. Breves, D. Giesecke, 291–315Springer-Verlag, New York, 1995.
- DeMore, W. B., Rate constant ratio for the reactions of OH with CH4D and CH4, J. Phys. Chem., 97, 8564–8566, 1993.
- Dlugokencky, E. J., K. A. Masarie, P. M. Lang, P. P. Tans, L. P. Steele, E. G. Nisbet, Dramatic decrease in the growth rate of atmospheric methane in the during 1992, Geophys. Res. Lett., 21, 45–48, 1994a.
- Dlugokencky, E. J., P. M. Lang, K. A. Masarie, L. P. Steele, Atmospheric CH4 records from sites in the NOAA/CMDL air sampling network, Trends '93: A Compendium of Data on Global Change T. A. Boden, D. P. Kaiser, R. J. Sepanski, F. W. Stoss, Rep. ORNL/CDIAC-65, 247–350Carbon Dioxide Inf. Anal. Cent., Oak Ridge Nat. Lab., Oak Ridge, Tenn., 1994b.
- Dlugokencky, E. J., K. A. Masarie, P. M. Lang, P. P. Tans, Continuing decline in the growth rate of the atmospheric methane burden, Nature, 393, 447–450, 1998.
- Ehhalt, D. H., Methane in the atmosphere, The Proceedings of Symposium on Carbon and the Biosphere, Symp. Ser., 30, 144–158, U.S. At. Energy Comm., Oak Ridge, Tenn., 1982.
- Etheridge, D. M., G. I. Pearman, P. J. Fraser, Changes in tropospheric methane between 1841 and 1978 from a high accumulation-rate antarctic ice core, Tellus, 44B, 282–294, 1992.
- Fung, I., J. John, J. Lerner, E. Mathew, M. Prather, L. P. Steele, P. J. Fraser, Three-dimensional model synthesis of the global methane cycle, J. Geophys. Res., 96, 13033–13065, 1991.
- Gierczak, T., R. K. Talukdar, S. C. Herndon, G. L. Vaghjiani, A. R. Ravishankara, Rate coefficients for the reactions of hydroxyl radicals with methane and deuterated methane, J. Phys. Chem., 101, 3125–3134, 1997.
- Gupta, M., S. Tyler, R. Cicerone, Modeling atmospheric δ13CH4 and the causes of the recent changes in atmospheric CH4 amounts, J. Geophys. Res., 101, 22923–22932, 1996.
- Gupta, M. L., M. P. McGrath, R. J. Cicerone, F. S. Rowland, M. Wolfsberg, 12C/13C kinetic isotope effects in the reaction of CH4 with OH and Cl, Geophys. Res. Lett., 24, 2761–2764, 1997.
- Halter, B. C., J. M. Harris, T. J. Conway, Component signals in the record of atmospheric CO2 concentration at American Samoa, J. Geophys. Res., 93, 15914–15918, 1988.
- Hao, W. M., M.-H. Liu, Spatial and temporal distribution of tropical biomass burning, Global Biogeochem. Cycles, 8, 495–503, 1994.
- Hao, W. M., D. E. Ward, Methane production from global biomass burning, J. Geophys. Res., 98, 20657–20661, 1993.
- Hein, R., P. J. Crutzen, M. Heimann, An inverse modeling approach to investigate the global atmospheric methane cycle, Global Biogeochem. Cycles, 11, 43–76, 1997.
- , International Atomic Energy Agency (IAEA), Nuclear power reactors in the worldPubl. IAEA-RDS-2/9, Vienna, 1994.
- , Intergovernmental Panel on Climate Change (IPCC), Climate Change: The IPCC Scientific Assessment J. T. Houghton, G. J. Jenkins, J. J. Ephraums, 365, Cambridge Univ. Press, New York, 1992.
- Irion, F. W., et al., Stratospheric observations of CH3D and HDO from ATMOS infrared solar spectra: Enrichments of deuterium in methane and implications for HD, Geophys. Res. Lett., 23, 2381–2384, 1996.
- Khalil, M. A. K., R. A. Rasmussen, Causes of increasing atmospheric methane: Depletion of hydroxyl radicals and rise of emissions, Atmos. Environ, 719, 397–407, 1985.
- Khalil, M. A. K., M. J. Shearer, Sources of methane: an overview, Atmospheric Methane: Sources, Sinks and Role in Global Change M. A. K. Khalil, 180–198, Springer-Verlag, New York, 1993.
10.1007/978-3-642-84605-2_10 Google Scholar
- King, S. L., P. D. Quay, J. M. Lansdown, The 13C/12C kinetic isotope effect for soil oxidation of methane at ambient atmospheric concentrations, J. Geophys. Res., 94, 18273–18277, 1989.
- Kunz, C., Carbon-14 discharge at three light water reactors, Health Phys., 49, 25–35, 1985.
- Lansdown, J. M., The carbon and hydrogen stable isotope composition of methane released from natural wetlands and ruminants, Ph.D. thesis,Univ. of Wash.,Seattle,1992.
- Lassey, K. R., D. C. Lowe, C. A. M. Brenninkmeijer, A. J. Gomez, Atmospheric methane and its carbon isotopes in the southern hemisphere: Their time series and an instructive model, Chemosphere, 26, 95–109, 1993.
- Levin, I., P. Bergamaschi, H. Dorr, D. Trapp, Stable isotopic signature of methane from different sources in Germany, Chemosphere, 26, 163–179, 1993.
- Liscom, W. L., The Energy Decade, 1970–1980, Ballinger, Cambridge, Mass., 1982.
- Lowe, D. C., C. A. M. Brenninkmeijer, G. W. Brailsford, K. R. Lassey, A. J. Gomez, Concentration and 13C records of atmospheric methane in New Zealand and Antarctica: Evidence for changes in methane sources, J. Geophys. Res., 99, 16913–16925, 1994.
- Manning, M. R., D. C. Lowe, W. H. Melhuish, R. J. Sparks, G. Wallace, C. A. M. Brenninkmeijer, The use of radiocarbon measurements in atmospheric studies, Radiocarbon, 32, 37–58, 1990.
- Prinn, R. G., R. F. Weiss, B. R. Miller, J. Huang, F. N. Alyea, D. M. Cunnold, P. J. Fraser, D. E. Hartley, P. G. Simmonds, Atmospheric trends and lifetimes of CH3CCl3 and global OH concentrations, Science, 269, 187–192, 1995.
- Quay, P. D., S. L. King, J. M. Lansdown, D. O. Wilbur, Isotopic composition of methane released from wetlands: Implications for the increase in atmospheric methane, Global Biogeochem. Cycles, 2, 385–397, 1988.
- Quay, P. D., et al., Carbon isotopic composition of atmospheric CH4: Fossil and biomass burning source strengths, Global Biogeochem. Cycles, 5, 25–47, 1991.
- Reeburgh, W. S., A. I. Hirsch, F. J. Sansone, B. N. Popp, T. M. Rust, Carbon kinetic isotope effect accompanying microbial oxidation of methane in boreal forest soils, Geochim. Cosmochim. Acta, 61, 4761–4767, 1997.
- Rice, D. D., G. E. Claypool, Generation, accumulation and resource potential of biogenic gas, AAPG Bull., 65, 2–25, 1981.
- Saueressig, G., P. Bergamaschi, J. N. Crowley, H. Fischer, G. W. Harris, Carbon kinetic isotope effect in the reaction of CH4 with Cl atoms, Geophys. Res. Lett., 22, 1225–1228, 1995.
- Schoell, M., The hydrogen and carbon isotopic composition of methane from natural gases of various origins, Geochim. Cosmochim. Acta, 44, 649–661, 1980.
- Spivakovsky, C. M., R. Yevich, J. A. Logan, S. C. Wofsy, M. B. McElroy, M. J. Prather, Tropospheric OH in a three-dimensional chemical tracer model: An assessment based on observations of CH3CCl3, J. Geophys. Res., 95, 18441–18471, 1990.
- Stevens, C. M., Isotopic abundance in the atmosphere and sources, Atmospheric Methane: Sources, Sinks and Role in Global Change M. A. K. Khalil, 62–88, Springer-Verlag, New York, 1993.
10.1007/978-3-642-84605-2_4 Google Scholar
- Stevens, C. M., C-13 isotopic abundance and concentration of atmospheric methane for background air in the southern and northern hemispheres from 1978 to 1989, Publ., 4388, Environ. Sci. Div., U.S. Dep. of Energy, Washington, D.C., 1995.
- Stevens, C. M., A. Engelkemeir, Stable carbon isotopic composition of methane from some natural and anthropogenic sources, J. Geophys. Res., 93, 725–733, 1988.
- Stevens, C. M., F. E. Rust, The carbon isotopic composition of atmospheric methane, J. Geophys. Res., 87, 4879–4882, 1982.
- Tanaka, N., Y. Xiao, A. C. Lasagna, Ab initio study on the carbon kinetic isotope effect (KIE) in the reaction of CH4 + Cl, J. Atmos. Chem., 23, 37–49, 1996.
- Tans, P., A note on isotopic ratios and the global methane budget, Global Biogeochem. Cycles, 11, 77–82, 1997.
- Tanweer, A., G. Hut, J. O. Burgman, Optimal conditions for the reduction of water to hydrogen by zinc for mass spectrometric analysis of the deuterium content, Chem. Geol., 73, 199–203, 1988.
- Tyler, S. C., 13C/12C of atmospheric methane and some of its sources, Stable Isotopes in Ecological Research, 68, 395–409, Springer-Verlag, New York, 1989.
- Tyler, S. C., The global methane budget, Microbial Production and Consumption of Greenhouse Gases: Methane, Nitrogen Oxides and Halomethanes, 7–38, Am. Soc. for Microbiol., Washington, D.C., 1991.
- Tyler, S. C., P. M. Crill, G. W. Brailsford, 13C/12C fractionation of methane during oxidation in a temperate forested soil, Geochim. Cosmochim. Acta, 58, 1625–1633, 1994a.
- Tyler, S. C., G. W. Brailsford, K. Yagi, K. Minami, R. J. Cicerone, Seasonal variations in methane flux and δ13CH4 values for rice paddies in Japan and their implications, Global Biogeochem. Cycles, 8, 1–12, 1994b.
- , United Nations, Food and Agricultural Organization, Production Yearbook, 17, Rome, 1994.
- , U.S. Department of Agriculture Foreign Agricultural Service, Grains: World markets and trade, Circ. Ser., FG-3-95, Washington, D.C., 1995.
- Wahlen, M., The global methane cycle, Annu. Rev. Earth Planet. Sci., 21, 407–426, 1993.
- Wahlen, M., B. Deck, R. Henry, N. Tanaka, A. Shemesh, R. Fairbanks, W. Broecker, H. Meyer, B. Marino, J. Logan, Profiles of δ13C of CH4 from the lower stratosphere, Eos Trans. AGU, 70, 1017, 1989a.
- Wahlen, M., N. Tanaka, R. Henry, B. Deck, J. Zeglen, J. S. Vogel, J. Southon, A. Shemesh, R. Fairbanks, W. S. Broecker, Carbon-14 in methane sources and in atmospheric methane: The contribution from fossil carbon, Science, 245, 286–290, 1989b.
- Whiticar, M. J., Stable isotopes and global budgets, Atmospheric Methane: Sources, Sinks and Role in Global Change M. A. K. Khalil, 138–167, Springer-Verlag, New York, 1993.
10.1007/978-3-642-84605-2_8 Google Scholar
- Xiao, Y., N. Tanaka, A. C. Lasaga, An evaluation of hydrogen kinetic isotope effect in the reaction of CH4 with OH free radical (abstract), Eos Trans. AGU, 7416, Spring Meet. Suppl, 71, 1993.
