1. Timing and nature of AMOC recovery across Termination 2 and magnitude of deglacial CO2 change
- Author
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Deaney, Emily L, Barker, Stephen, Van de Flierdt, Tina, and Natural Environment Research Council (NERC)
- Subjects
GC ,Science & Technology ,PAST 800,000 YEARS ,OCEAN CIRCULATION CHANGES ,Science ,PENULTIMATE DEGLACIATION ,Article ,Multidisciplinary Sciences ,LAST INTERGLACIAL PERIOD ,BIPOLAR SEESAW ,GLACIAL CYCLES ,CLIMATE VARIABILITY ,MD Multidisciplinary ,Science & Technology - Other Topics ,OVERTURNING CIRCULATION ,ATMOSPHERIC CO2 ,DEEP-SEA - Abstract
Large amplitude variations in atmospheric CO2 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 CO2 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 CO2, we suggest that the net change in CO2 across the last 2 terminations was approximately equal if the transient effects of deglacial oscillations in ocean circulation are taken into account., Differences in the sequence and timing of ocean circulation changes across glacial terminations could affect the magnitude of deglacial atmospheric CO2 rise. Here, the authors argue that late ocean circulation recovery during the penultimate deglaciation (T2) led to a larger rise in CO2 compared with T1.
- Published
- 2017