The de-correlation of westerly winds and westerly-wind stress over the Southern Ocean during the Last Glacial Maximum

• Published in: Climate Dynamics
• Main Authors: Liu, Wei, Lu, Jian, Leung, L. Ruby, Xie, Shang-Ping, Liu, Zhengyu, Zhu, Jiang
• Other Authors: Liu, W (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, CASPO, 9500 Gilman Dr, La Jolla, CA 92093 USA., Univ Calif San Diego, Scripps Inst Oceanog, CASPO, La Jolla, CA 92093 USA., Pacific NW Natl Lab, Richland, WA 99352 USA., Univ Wisconsin, Nelson Ctr Climat Res, Dept Atmospher & Ocean Sci, Madison, WI USA., Peking Univ, Sch Phys, LaCOAS, Beijing 100871, Peoples R China., Univ Calif San Diego, Scripps Inst Oceanog, CASPO, 9500 Gilman Dr, La Jolla, CA 92093 USA.
• Format: Journal/Newspaper
• Language: English
• Published: CLIMATE DYNAMICS 2015
• Subjects: Southern Westerly Winds; Westerly wind stress; Antarctic sea ice; LGM; PMIP3/CMIP5; SEA-ICE; HYDROLOGICAL CYCLE; MODEL SIMULATIONS; CLIMATE; RECORDS; POLLEN; ANTARCTICA; VEGETATION; PACIFIC; AMERICA; Antarctic; Pacific; Southern Ocean; Antarc*; Antarctica; Sea ice
• Online Access: https://hdl.handle.net/20.500.11897/439187; https://doi.org/10.1007/s00382-015-2530-4

Motivated by indications from paleo-evidence, this paper investigates the changes of the Southern Westerly Winds (SWW) and westerly-wind stress between the Last Glacial Maximum (LGM) and pre-industrial in the PMIP3/CMIP5 simulations, highlighting the role of Antarctic sea ice in modulating the wind effect on ocean. Particularly, a de-correlation occurs between the changes in SWW and westerly-wind stress, caused primarily by an equatorward expansion of winter Antarctic sea ice that undermines the efficacy of wind in generating stress over the liquid ocean. Such de-correlation may reflect the LGM condition in reality, in view of the fact that the model which simulates this condition has most fidelity in simulating modern SWW and Antarctic sea ice. Therein two models stand out for their agreements with paleo-evidence regarding the change of SWW and the westerly-wind stress. They simulate strengthened and poleward-migrated LGM SWW in the atmosphere, consistent with the indications from dust records. Whilst in the ocean, they well capture an equatorward-shifted pattern of the observed oceanic front shift, with most pronounced equatorward-shifted westerly wind stress during the LGM. NSF [AGS-1249145]; Office of Science of the US Department of Energy as part of the Regional and Global Climate Modeling program; DOE [DE-AC05-76RL01830] SCI(E) ARTICLE [e-mail] 11-12 3157-3168 45