Timing and nature of AMOC recovery across Termination 2 and magnitude of deglacial CO change.

Large amplitude variations in atmospheric CO were associated with glacial terminations of the Late Pleistocene. Here we provide multiple lines of evidence suggesting that the ∼20 p.p.m.v. overshoot in CO at the end of Termination 2 (T2) ∼129 ka was associated with an abrupt (≤400 year) deepening of Atlantic Meridional Overturning Circulation (AMOC). In contrast to Termination 1 (T1), which was interrupted by the Bølling-Allerød (B-A), AMOC recovery did not occur until the very end of T2, and was characterized by pronounced formation of deep waters in the NW Atlantic. Considering the variable influences of ocean circulation change on atmospheric CO, we suggest that the net change in CO across the last 2 terminations was approximately equal if the transient effects of deglacial oscillations in ocean circulation are taken into account.