Glacial-interglacial variation in the North Pacific subtropical gyre

Abstract

This study presents a new perspective of North Pacific paleoceanography over the last two glacial cycles, based on assessments of U₃₇^K’-derived paleotemperature records from IMAGES Core MD01-2421 off central Japan and Ocean Drilling Program (ODP) Sites 1014 and 1016 off California. The temperature differences between ODP Sites 1014 and 1016 (ΔSST_NEP=SST_ODP1014-SST_ODP1016) reflect the intensity of the California Current. Comparison of ΔSST_NEP and SST derived from Core MD01-2421 reveals anti-phase variations: high ΔSST_NEP (weakening of the California Current) corresponds to low SST at the Japan margin (southward displacement of the NW Pacific subarctic boundary and weakening of the Kuroshio Extension), and vice versa. This finding suggests that the intensity of the North Pacific subtropical gyre varies in response to precessional forcing, and that the response is linked to temporal changes in tropical ocean-atmosphere interactions.