Arctic and Antarctic forcing of ocean interior warming during the last deglaciation

• Published in: Scientific Reports
• Main Authors: Stewart, Joseph A., Robinson, Laura F., Rae, James W. B., Burke, Andrea, Chen, Tianyu, Li, Tao, de Carvalho Ferreira, Maria Luiza, Fornari, Daniel J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Antarctic; Arctic; Pacific; Southern Ocean; Antarc*
• Online Access: https://research-portal.st-andrews.ac.uk/en/researchoutput/arctic-and-antarctic-forcing-of-ocean-interior-warming-during-the-last-deglaciation(27122b5c-046b-46ee-a79c-e0bab40103aa).html; https://doi.org/10.1038/s41598-023-49435-0; https://research-repository.st-andrews.ac.uk/bitstream/10023/29054/1/Stewart_2023_SR_ArcticAntarctic_CCBY.pdf

Subsurface water masses formed at high latitudes impact the latitudinal distribution of heat in the ocean. Yet uncertainty surrounding the timing of low-latitude warming during the last deglaciation (18–10 ka) means that controls on sub-surface temperature rise remain unclear. Here we present seawater temperature records on a precise common age-scale from East Equatorial Pacific (EEP), Equatorial Atlantic, and Southern Ocean intermediate waters using new Li/Mg records from cold water corals. We find coeval warming in the tropical EEP and Atlantic during Heinrich Stadial 1 (+ 6 °C) that closely resemble warming recorded in Antarctic ice cores, with more modest warming of the Southern Ocean (+ 3 °C). The magnitude and depth of low-latitude ocean warming implies that downward accumulation of heat following Atlantic Meridional Overturning Circulation (AMOC) slowdown played a key role in heating the ocean interior, with heat advection from southern-sourced intermediate waters playing an additional role.