The Deglacial Evolution of North Atlantic Deep Convection

• Main Authors: Thornalley, DJR, Barker, S, Broecker, WS, Elderfield, H, McCave, IN
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Antarctic; Greenland; Antarc*; North Atlantic; Northeast Atlantic; Northwest Atlantic
• Online Access: https://discovery.ucl.ac.uk/id/eprint/1396381/1/Thornalley_The%20deglacial%20evolution%20of%20North%20Atlantic%20deep.pdf; https://discovery.ucl.ac.uk/id/eprint/1396381/

Deepwater formation in the North Atlantic by open-ocean convection is an essential component of the overturning circulation of the Atlantic Ocean, which helps regulate global climate. We use water-column radiocarbon reconstructions to examine changes in northeast Atlantic convection since the Last Glacial Maximum. During cold intervals, we infer a reduction in open-ocean convection and an associated incursion of an extremely radiocarbon (14C)–depleted water mass, interpreted to be Antarctic Intermediate Water. Comparing the timing of deep convection changes in the northeast and northwest Atlantic, we suggest that, despite a strong control on Greenland temperature by northeast Atlantic convection, reduced open-ocean convection in both the northwest and northeast Atlantic is necessary to account for contemporaneous perturbations in atmospheric circulation.