A coherent response of Southern Indian Ocean to the Antarctic climate: Implications to the lead, lags of atmospheric CO2 during deglaciation

Abstract

A record of δ18Oc from the Indian sector of Southern Ocean and atmospheric CO2, and δ18O of European Project for Ice Coring in Antarctica (EPICA) and Greenland Ice Sheet Project 2 (GISP2) reveals that a coherent response between δ18O record of Antarctic ice core and the δ18Oc record from Southern Indian Ocean during the deglaciation with initial warming starting around 18 kyr BP which is in agreement with the raise of atmospheric CO2 during same time. A distinct asynchrony between the records of δ18Oc from the Southern Indian Ocean and δ18O of GISP2 during the last deglaciation is noticed. We report that Southern Ocean degassing played an important role in raising atmospheric CO2 through Atlantic Meridional Overturning Circulation (AMOC), which has an implication in triggering abrupt climate events through coupling of ocean and atmospheric processes.