Dynamical and observational constraints on tropical Pacific sea surface temperatures at the last glacial maximum

Liu, Z., Shin, S., Behling, P., Prell, W., Trend-Staid, M., Harrison, S. P. ORCID: https://orcid.org/0000-0001-5687-1903 and Kutzbach, J. E. (2000) Dynamical and observational constraints on tropical Pacific sea surface temperatures at the last glacial maximum. Geophysical Research Letters, 27 (1). pp. 105-108. ISSN 1944-8007 doi: 10.1029/1999GL002321

Abstract/Summary

Asynchronously coupled atmosphere and ocean general circulation model simulations are used to examine the consequences of changes in the west/east sea-surface temperature (SST) gradient across the equatorial Pacific at the last glacial maximum (LGM). Simulations forced by the CLIMAP SST for the LGM, where the west/east SST gradient across the Pacific is reduced compared to present, produce a reduction in the strength of the trade winds and a decrease in the west/east slope of the equatorial thermocline that is incompatible with thermocline depths newly inferred from foraminiferal assemblages. Stronger-than-present trade winds, and a more realistic simulation of the thermocline slope, are produced when eastern Pacific SSTs are 2°C cooler than western Pacific SSTs. Our study highlights the importance of spatial heterogeneity in tropical SSTs in determining key features of the glacial climate.