Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation

• Published in: Geophysical Research Letters
• Main Authors: Gray, William Robert, Wills, Robert CJ, Rae, James William Buchanan, Burke, Andrea, Ivanovic, Ruza F, Roberts, William HG, Ferreira, David, Valdes, Paul J
• Other Authors: NERC, University of St Andrews. School of Earth & Environmental Sciences, University of St Andrews. St Andrews Isotope Geochemistry
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: North Pacific; Deglaciation; Gyre circulation; Westerlies; Oxygen isotopes; Climate models; QC Physics; QE Geology; DAS; SDG 13 - Climate Action; QC; QE; Pacific; Ice Sheet
• Online Access: http://hdl.handle.net/10023/21638; https://doi.org/10.1029/2019GL086328

Funding: UK Natural Environment Research Council (NERC) grant NE/N011716/1 (JWBR and AB). Tamaki Foundation, NASA (Grant NNX17AH56G), and NSF (Grant AGS-1929775) (RCJW). NERC Independent Research Fellowship NE/K008536/1 (RFI). North Pacific atmospheric and oceanic circulations are key missing pieces in our understanding of the reorganisation of the global climate system since the Last Glacial Maximum (LGM). Here, using a basin‐wide compilation of planktic foraminiferal δ18O, we show that the North Pacific subpolar gyre extended ~3° further south during the LGM, consistent with sea surface temperature and productivity proxy data. Climate models indicate that the expansion of the subpolar gyre was associated with a substantial gyre strengthening, and that these gyre circulation changes were driven by a southward shift of the mid‐latitude westerlies and increased wind‐stress from the polar easterlies. Using single‐forcing model runs, we show that these atmospheric circulation changes are a non‐linear response to ice‐sheet topography/albedo, and CO2. Our reconstruction indicates that the gyre boundary (and thus westerly winds) began to migrate northward at ~16.5 ka, driving changes in ocean heat transport, biogeochemistry, and North American hydroclimate. Publisher PDF Peer reviewed