A new 27 ky high resolution East Antarctic climate record
Résumé
The ice core recently drilled at the Dome Concordia site on the East Antarctic plateau provides a new high resolution isotope record covering part of the last glacial, the last transition and the Holocene. The two step shape of the deglaciation is remarkably similar for all the ice cores now available on the East Antarctic plateau. The first warming trend ends about 14000 years ago and is followed by the well marked Antarctic Cold Reversal (ACR) with a secondary peak common to all records. During the deglaciation, there are more similarities between the near coastal site of Taylor Dome and inland East Antarctica than between Taylor Dome and central Greenland. However, the results for EPICA do appear to confirm the Taylor Dome timescale after about 14 ka, showing cooling into the ACR roughly in phase between Greenland and Antarctica. While the overall deglacial pattem is asynchronous, this suggests that the now classical picture of a temperature seesaw between Antarctica and Greenland may be too simplistic. 1. Introduction Whereas numerous deep-sea, continental and ice core records covering the last deglaciation are now available [e.g. Alley and Clark, 1999], the driving mechanisms of this climatic transition are still not fully understood. Recent studies highlight the central role of the huge unstable Northern Hemisphere ice caps and their interaction with the oceanic thermohaline circulation in the North Atlantic. They also reveal that the Antarctic deglacial warming started before the sharp Greenland warming marking the onset of the B611ing and was interrupted by the so-called Antarctic Cold Reversal [hereafter ACR; Jouzel et al., 1995].
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