The amplitude and phasing of climate change during the last deglaciation in the Sulu Sea, western equatorial Pacific

Abstract

Variations in tropical sea surface temperature patterns and the phasing relative to climate change in higher‐latitudes provide insight into the mechanisms of climate change on both orbital and shorter time‐scales. Here, we present well‐dated, high‐resolution records of planktonic foraminiferal δ18O and Mg/Ca‐based SST spanning the last deglaciation from the Sulu Sea, located in the western equatorial Pacific. The results indicate that the last glacial maximum was 2.3 ± 0.5°C cooler than present in the Sulu Sea with a concomitant decrease in sea surface salinity. The similarity between variations in surface salinity in the Sulu Sea, the western and eastern equatorial Pacific, and the Greenland ice‐core record suggests that the observed changes in salinity reflect large‐scale rearrangement of atmospheric patterns, which were coherent and synchronous throughout the Northern Hemisphere. The results suggest that the glacial equatorial Pacific climate was strongly influenced by both tropical, and extra‐tropical forcing, although it is not clear whether interannual (ENSO) variability is a good analogue of glacial‐interglacial climate change.