One-to-one coupling of glacial climate variability in Greenland and Antarctica

• Published in: Nature
• Main Authors: Barbante, C., Barnola, J.M., Becagli, S., Beer, J., Bigler, M., Boutron, C., Blunier, T., Castellano, E., Cattani, O., Chappellaz, J., Wolff, E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Nature 2006
• Subjects: Antarctic; The Antarctic; Dronning Maud Land; Greenland; Antarc*; Antarctica; Dansgaard-Oeschger events; Greenland ice core; ice core; North Greenland
• Online Access: https://doi.org/10.1038/nature05301

Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies 1,2 have revealed strong coupling of the largest millennial-scale warm events in Antarctica with the longest Dansgaard - Oeschger events in Greenland 3-5 through the Atlantic meridional overturning circulation 6-8 . It has been unclear, however, whether the shorter Dansgaard - Oeschger events have counterparts in the shorter and less prominent Antarctic temperature variations, and whether these events are linked by the same mechanism. Here we present a glacial climate record derived from an ice core from Dronning Maud Land, Antarctica, which represents South Atlantic climate at a resolution comparable with the Greenland ice core records. After methane synchronization with an ice core from North Greenland 9 , the oxygen isotope record from the Dronning Maud Land ice core shows a one-to-one coupling between all Antarctic warm events and Greenland Dansgaard - Oeschger events by the bipolar seesaw 6 . The amplitude of the Antarctic warm events is found to be linearly dependent on the duration of the concurrent stadial in the North, suggesting that they all result from a similar reduction in the meridional overturning circulation.