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Ice Record of δ13C for Atmospheric CH4 Across the Younger Dryas-Preboreal Transition | |
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Fig. 1C. δ13CH4 (‰) versus sample age in Pakitsoq ice samples. Data corrected for gravitational, thermal, and diffusion fractionation. Colored error bars show the standard error of multiple samples. Black error bars on single measurements show analytical precision (±1σ) derived from standard ice. |
Ice Record of δ13C for Atmospheric CH4 Across the Younger Dryas-Preboreal Transition
Science Vol. 313, Issue 5790, pp. 1109-1112, 10.1126/science.1126562, 25 August 2006. Hinrich Schaefer1,2, Michael J. Whiticar1, Edward J. Brook2, Vasilii V. Petrenko3, Dominic F. Ferretti4,5, Jeffrey P. Severinghaus3 1 School of Earth and Ocean Sciences, University of Victoria, Post Office Box 3055, V8W 3P6, Canada. 2 Department of Geosciences, Oregon State University, 104 Wilkinson Hall, Corvallis, OR 97331, USA. 3 Scripps Institution of Oceanography, University of California, San Diego, Mail Code 0244, La Jolla, CA 92093, USA. 4 Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA. 5 National Institute of Water and Atmospheric Research Limited, Post Office Box 14901, Wellington, New Zealand. |
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ABSTRACT: We report atmospheric methane carbon isotope ratios (δ13CH4) from the Western Greenland ice margin spanning the Younger Dryas-to-Preboreal (YD-PB) transition. Over the recorded ~800 years, δ13CH4 was around -46 per mil; that is, ~1 per mil higher than in the modern atmosphere and ~5.5 per mil higher than would be expected from budgets without 13C-rich anthropogenic emissions. This requires higher natural 13C-rich emissions or stronger sink fractionation than conventionally assumed. Constant δ13CH4 during the rise in methane concentration at the YD-PB transition is consistent with additional emissions from tropical wetlands, or aerobic plant CH4 production, or with a multisource scenario. A marine clathrate source is unlikely. |
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Download data from the WDC Paleo archive: Pakitsoq outcrop δ13CH4 data, Text or Excel format. |
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To read or view the full study, please visit the Science website. It was published in Science, Vol. 313, Issue 5790, pp. 1109-1112, 10.1126/science.1126562, 25 August 2006. |
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http://www.ncdc.noaa.gov/paleo/pubs/schaefer2006/schaefer2006.html Downloaded Sunday, 18-May-2008 10:06:54 EDT Last Updated Thursday, 31-Aug-2006 12:50:05 EDT by paleo@noaa.gov Please see the Paleoclimatology Contact Page or the NCDC Contact Page if you have questions or comments. |