Eicher, O.; Baumgartner, M.; Schilt, A.; Schmitt, J.; Schwander, J.; Stocker, T. F.; Fischer, H. (2016). Climatic and insolation control on the high-resolution total air content in the NGRIP ice core. Climate of the past, 12(6), pp. 1979-1993. Copernicus Publications 10.5194/cpd-11-5509-2015
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Because the total air content (TAC) of polar ice is directly affected by the atmospheric pressure, its record in polar ice cores was considered as a proxy for past ice sheet elevation changes. However the Antarctic ice core TAC record is known to also contain an insolation signature, although the underlying physical mechanisms are still a matter of debate. Here we present a high-resolution TAC record over the whole North Greenland Ice Core Project ice core, covering the last 120 000 years, which independently supports an insolation signature in Greenland. Wavelet analysis reveals a clear precession
and obliquity signal similar to previous findings on Antarctic TAC, with different
insolation history. In our high-resolution record we also find a decrease of 3–5% (3–4.2mLkg⁻¹) in TAC as a response to Dansgaard-Oeschger-Events (DO-events). TAC starts to decrease in parallel to increasing Greenland surface temperature and slightly before CH₄ reacts to the warming, but also shows a two-step decline that lasts for several centuries into the warm phase/interstadial. The TAC response is larger than expected considering only local temperature and atmospheric pressure as a driver, pointing to transient firnification response caused by the accumulation-induced increase in
the load on the firn at bubble close-off, while temperature changes deeper in the firn are still small.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
08 Faculty of Science > Physics Institute > Climate and Environmental Physics 10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR) 08 Faculty of Science > Physics Institute |
UniBE Contributor: |
Eicher, Olivier, Baumgartner, Matthias, Schilt, Adrian, Schmitt, Jochen, Schwander, Jakob, Stocker, Thomas, Fischer, Hubertus |
Subjects: |
500 Science > 530 Physics |
ISSN: |
1814-9324 |
Publisher: |
Copernicus Publications |
Language: |
English |
Submitter: |
Doris Rätz |
Date Deposited: |
14 Nov 2016 16:50 |
Last Modified: |
05 Dec 2022 14:59 |
Publisher DOI: |
10.5194/cpd-11-5509-2015 |
BORIS DOI: |
10.7892/boris.89328 |
URI: |
https://boris.unibe.ch/id/eprint/89328 |
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