Spatial and temporal sea-surface temperatures in the eastern equatorial Pacific over the past 150 kyr

Abstract

We present the new alkenone-based sea-surface temperature (SST) records from the eastern equatorial Pacific over the past 150 kyr. Core HY04 (4°N) at the North Equatorial Countercurrent (NECC) registered the invariant SSTs (25.8-27.2°C), whereas core HY06 (0°N) registered cyclic glacial-interglacial SST variations (22.4-26.1°C). Although HY06 alkenone-based SST evolution was almost consistent with the previously published SST records from around the equator, at site HY04 alkenone-and foraminiferal Mg/Ca-based SSTs showed a large difference in the magnitude of LGM SST cooling. We hypothesize that alkenone-based SSTs might not fully express the true magnitude of glacial SST cooling in the NECC, as suggested by the coincidence of higher glacial productivity and unchanged glacial SSTs at site HY04. However, farther SST data in the NECC are needed before this can be accepted with any degree of confidence. Copyright 2006 by the American Geophysical Union.