Abstract

The end of the Last Glacial Maximum (Termination I), roughly 20 thousand years ago (ka), was marked by cooling in the Northern Hemisphere, a weakening of the Asian monsoon, a rise in atmospheric CO 2 concentrations and warming over Antarctica. The sequence of events associated with the previous glacial-interglacial transition (Termination II), roughly 136 ka, is less well constrained. Here we present high-resolution records of atmospheric CO 2 concentrations and isotopic composition of N 2 - an atmospheric temperature proxy - from air bubbles in the EPICA Dome C ice core that span Termination II. We find that atmospheric CO 2 concentrations and Antarctic temperature started increasing in phase around 136 ka, but in a second phase of Termination II, from 130.5 to 129 ka, the rise in atmospheric CO 2 concentrations lagged that of Antarctic temperature unequivocally. We suggest that during this second phase, the intensification of the low-latitude hydrological cycle resulted in the development of a CO 2 sink, which counteracted the CO 2 outgassing from the Southern Hemisphere oceans over this period. © 2013 Macmillan Publishers Limited.

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