The Southern Ocean’s role in carbon exchange during the last deglaciation

• Published in: Science
• Main Authors: Burke, Andrea, Robinson, Laura F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: Southern Ocean
• Online Access: https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-southern-oceans-role-in-carbon-exchange-during-the-last-deglaciation(fe1fefbe-fe9f-4ebd-b45d-091ac687284c).html; https://doi.org/10.1126/science.1208163

Changes in the upwelling and degassing of carbon from the Southern Ocean form one of the leading hypotheses for the cause of glacial-interglacial changes in atmospheric carbon dioxide. We present a 25,000-year-long Southern Ocean radiocarbon record reconstructed from deep-sea corals, which shows radiocarbon-depleted waters during the glacial period and through the early deglaciation. This depletion and associated deep stratification disappeared by ~14.6 ka (thousand years ago), consistent with the transfer of carbon from the deep ocean to the surface ocean and atmosphere via a Southern Ocean ventilation event. Given this evidence for carbon exchange in the Southern Ocean, we show that existing deep-ocean radiocarbon records from the glacial period are sufficiently depleted to explain the ~190 per mil drop in atmospheric radiocarbon between ~17 and 14.5 ka.