Synchronous centennial abrupt events in the ocean and atmosphere during the last deglaciation

• Published in: Science
• Main Authors: Chen, Tianyu, Robinson, Laura F., Burke, Andrea, Southon, John, Spooner, Peter, Morris, Paul J., Ng, Hong Chin
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: Antarctic; Drake Passage; Antarc*; ice core
• Online Access: https://risweb.st-andrews.ac.uk/portal/en/researchoutput/synchronous-centennial-abrupt-events-in-the-ocean-and-atmosphere-during-the-last-deglaciation(b70b42d8-bb1b-43a9-b3b6-3fe7b39957ff).html; https://doi.org/10.1126/science.aac6159; https://research-repository.st-andrews.ac.uk/bitstream/10023/7649/5/Burke_2015_Science_Synchronous_AM.pdf; https://research-repository.st-andrews.ac.uk/bitstream/10023/7649/4/Burke_2015_Science_Synchronous_Supplement_AM.pdf; https://research-repository.st-andrews.ac.uk/bitstream/10023/7649/1/figure_1.pdf; https://research-repository.st-andrews.ac.uk/bitstream/10023/7649/3/figure_2.pdf; https://research-repository.st-andrews.ac.uk/bitstream/10023/7649/2/figure_3.pdf

Antarctic ice-core data reveal that the atmosphere experienced abrupt centennial increases in CO 2 concentration during the last deglaciation (~18-11 thousand years, ka). Establishing the role of ocean circulation in these changes requires high-resolution, accurately-dated marine records. Here we report radiocarbon data from uranium-thorium dated deep-sea corals in the Equatorial Atlantic and Drake Passage over the last 25 ka. Two major deglacial radiocarbon increases occurred in phase with centennial atmospheric CO 2 rises at 14.8 ka and 11.7 ka. We interpret these radiocarbon-enriched signals to represent two short-lived (<500 years) ‘overshoot’ events with Atlantic meridional overturning stronger than modern. These results provide compelling evidence for a close coupling of ocean circulation and centennial climate events during the last deglaciation