Asynchrony of Antarctic and Greenland climate

Modified from Blunier et al. (1998) Nature 394: 739-743.

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Caption: GRIP, Byrd and Vostok isotopic and CH4 records on the common time scale (GRIP timescale in years before 1989). For the data of Byrd, a solid line shows the lower-temperature scenario, and the shaded area indicates the range of gasage-ice age difference for the two temperature scenarios. The CH4 scale at lower left corresponds to the GRIP values; Byrd and Vostok values were lowered by 200 and 400 ppbv, respectively, for better visibility. The numbers on the top of the GRIP isotopic record indicate the location of Dansgaard-Oeschger events; ACR is the location of the Antarctic Cold Reversal. Antarctic warmings are indicated by A1 and A2; dotted lines show the location of Greenland warmings 1, 8 and 12 in the Antarctic cores. The Byrd δ18O variation between 25 and 17 kyr BP shows most likely local climate characteristics because: (1) it is not seen in the Vostok or in the Dome C record, and (2) it is not compatible with the climate mechanism seen during events A1, A2 and also the ACR present in all Antarctic records.

Blunier et al., 1998, Nature 394, 739-743