title: Climate impact of late quaternary equatorial pacific sea surface temperature variations
abstract: Magnesium/calcium data from planktonic foraminifera in equatorial Pacific sediment cores demonstrate that tropical Pacific sea surface temperatures (SSTs) were 2.8 degrees +/- 0.7 degrees C colder than the present at the last glacial maximum. Glacial-interglacial temperature differences as great as 5 degrees C are observed over the last 450 thousand years. Changes in SST coincide with changes in Antarctic air temperature and precede changes in continental ice volume by about 3 thousand years, suggesting that tropical cooling played a major role in driving ice-age climate. Comparison of SST estimates from eastern and western sites indicates that the equatorial Pacific zonal SST gradient was similar or somewhat larger during glacial episodes. Extraction of a salinity proxy from the magnesium/calcium and oxygen isotope data indicates that transport of water vapor into the western Pacific was enhanced during glacial episodes.
authors.affiliation: Department of Geological Sciences and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA. Department of Geology, University of California, Davis, CA 95616, USA.
authors.initials: DW
authors.lastname: Lea
authors.initials: DK
authors.lastname: Pak
authors.initials: HJ
authors.lastname: Spero