Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice
Upon closer inspection, the classical view of the synchronous relationship between tropospheric methane mixing ratio and Greenland temperature observed in ice samples reveals clearly discernable variations in the magnitude of this response during the Late Pleistocene (<50 kyr BP). During the Holo...
Published in: | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
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crroyalsociety:10.1098/rsta.2007.2048 2024-06-23T07:53:24+00:00 Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice Whiticar, Michael Schaefer, Hinrich 2007 http://dx.doi.org/10.1098/rsta.2007.2048 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2007.2048 https://royalsocietypublishing.org/doi/full-xml/10.1098/rsta.2007.2048 en eng The Royal Society https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences volume 365, issue 1856, page 1793-1828 ISSN 1364-503X 1471-2962 journal-article 2007 crroyalsociety https://doi.org/10.1098/rsta.2007.2048 2024-06-04T06:23:09Z Upon closer inspection, the classical view of the synchronous relationship between tropospheric methane mixing ratio and Greenland temperature observed in ice samples reveals clearly discernable variations in the magnitude of this response during the Late Pleistocene (<50 kyr BP). During the Holocene this relationship appears to decouple, indicating that other factors have modulated the methane budget in the past 10 kyr BP. The δ 13 CH 4 and δD-CH 4 of tropospheric methane recorded in ice samples provide a useful constraint on the palaeomethane budget estimations. Anticipated changes in palaeoenvironmental conditions are recorded as changes in the isotope signals of the methane precursors, which are then translated into past global δ 13 CH 4 and δD-CH 4 signatures. We present the first methane budgets for the late glacial period that are constrained by dual stable isotopes. The overall isotope variations indicate that the Younger Dryas (YD) and Preindustrial Holocene have methane that is 13 C- and 2 H-enriched, relative to Modern. The shift is small for δ 13 CH 4 (approx. 1‰) but greater for δD-CH 4 (approx. 9‰). The YD δ 13 CH 4 –δD-CH 4 record shows a remarkable relationship between them from 12.15 to 11.52 kyr BP. The corresponding C- and H-isotope mass balances possibly indicate fluctuating emissions of thermogenic gas. This δ 13 CH 4 –δD-CH 4 relationship breaks down during the YD–Preboreal transition. In both age cases, catastrophic releases of hydrates with Archaeal isotope signatures can be ruled out. Thermogenic clathrate releases are possible during the YD period, but so are conventional natural gas seepages. Article in Journal/Newspaper Greenland The Royal Society Greenland Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365 1856 1793 1828 |
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The Royal Society |
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crroyalsociety |
language |
English |
description |
Upon closer inspection, the classical view of the synchronous relationship between tropospheric methane mixing ratio and Greenland temperature observed in ice samples reveals clearly discernable variations in the magnitude of this response during the Late Pleistocene (<50 kyr BP). During the Holocene this relationship appears to decouple, indicating that other factors have modulated the methane budget in the past 10 kyr BP. The δ 13 CH 4 and δD-CH 4 of tropospheric methane recorded in ice samples provide a useful constraint on the palaeomethane budget estimations. Anticipated changes in palaeoenvironmental conditions are recorded as changes in the isotope signals of the methane precursors, which are then translated into past global δ 13 CH 4 and δD-CH 4 signatures. We present the first methane budgets for the late glacial period that are constrained by dual stable isotopes. The overall isotope variations indicate that the Younger Dryas (YD) and Preindustrial Holocene have methane that is 13 C- and 2 H-enriched, relative to Modern. The shift is small for δ 13 CH 4 (approx. 1‰) but greater for δD-CH 4 (approx. 9‰). The YD δ 13 CH 4 –δD-CH 4 record shows a remarkable relationship between them from 12.15 to 11.52 kyr BP. The corresponding C- and H-isotope mass balances possibly indicate fluctuating emissions of thermogenic gas. This δ 13 CH 4 –δD-CH 4 relationship breaks down during the YD–Preboreal transition. In both age cases, catastrophic releases of hydrates with Archaeal isotope signatures can be ruled out. Thermogenic clathrate releases are possible during the YD period, but so are conventional natural gas seepages. |
format |
Article in Journal/Newspaper |
author |
Whiticar, Michael Schaefer, Hinrich |
spellingShingle |
Whiticar, Michael Schaefer, Hinrich Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
author_facet |
Whiticar, Michael Schaefer, Hinrich |
author_sort |
Whiticar, Michael |
title |
Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
title_short |
Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
title_full |
Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
title_fullStr |
Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
title_full_unstemmed |
Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
title_sort |
constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice |
publisher |
The Royal Society |
publishDate |
2007 |
url |
http://dx.doi.org/10.1098/rsta.2007.2048 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2007.2048 https://royalsocietypublishing.org/doi/full-xml/10.1098/rsta.2007.2048 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences volume 365, issue 1856, page 1793-1828 ISSN 1364-503X 1471-2962 |
op_rights |
https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ |
op_doi |
https://doi.org/10.1098/rsta.2007.2048 |
container_title |
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
container_volume |
365 |
container_issue |
1856 |
container_start_page |
1793 |
op_container_end_page |
1828 |
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1802645006062714880 |