Climatic and insolation control on the high-resolution total air content in the NGRIP ice core ...
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 un...
Main Authors: | , , , , , , |
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Format: | Text |
Language: | English |
Published: |
Copernicus Publications
2016
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Subjects: | |
Online Access: | https://dx.doi.org/10.7892/boris.89328 http://boris.unibe.ch/89328/ |
Summary: | 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 ... |
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