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| Titel |
New insights on the phasing of atmospheric methane and temperature change during the Last Glacial Termination from the North Greenland Eemian (NEEM) Ice Core |
| VerfasserIn |
Julia Rosen, Edward Brook, Jeffrey Severinghaus, Logan Mitchell |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053698
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| Zusammenfassung |
| The phasing of changes in temperature, precipitation, and other environmental variables
between different regions of the globe during the abrupt climate transitions of the last glacial
termination provides a valuable constraint on the possible mechanisms that drive such
changes. However, determining precise temporal relationships between records
remains a challenge in paleoclimate research. In some cases, this difficulty can
be overcome when multiple variables recorded in the same paleoclimate record
reflect geographically distinct processes. We apply such an approach to new, very
high-resolution measurements of gases from the North Greenland Eemian (NEEM)
ice core across the deglacial transition, from the onset of the Bølling-Allerød to
the earliest Holocene (~15 to 11 ka). We capitalize on the fact that changes in
atmospheric methane, a gas with widely distributed sources, can be compared with the
isotopic composition of atmospheric nitrogen, a proxy for local temperature change
and climate-dependent firn properties, with essentially no relative age uncertainty
(Severinghaus et al., 1998; Severinghaus and Brook, 1999). Our data include 419
methane and total air content measurements made at Oregon State University and 177
measurements of δ15N made at the Scripps Institution of Oceanography, University of
California, San Diego. Both records are sampled at less than 15 cm ( |
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