Response of mid‐latitude North Pacific surface temperatures to orbital forcing and linkage to the East Asian summer monsoon and tropical ocean–atmosphere interactions

<jats:title>Abstract</jats:title> <jats:p> We present a palaeoceanographic perspective of the North Pacific during the last two glacial cycles based on U‐derived palaeotemperature records of IMAGES Core MD01‐2421 off the coast of central Japan and cores from the Ocean Drilling Program (ODP) Sites 1014 and 1016 off the coast of California. The sea surface temperature (SST) differences between ODP Sites 1014 and 1016 (ΔSST <jats:sub>northeastern Pacific (NEP)</jats:sub>  = SST <jats:sub>ODP1014</jats:sub> – SST <jats:sub>ODP1016</jats:sub> ) indicate the intensity of the California Current. Comparison of ΔSST <jats:sub>NEP</jats:sub> and the SST from Core MD01‐2421 revealed anti‐phase variation; high ΔSST <jats:sub>NEP</jats:sub> (indicating weakening of the California Current) corresponded to low SST at the Japan margin (indicating the southward displacement of the north‐western Pacific subarctic boundary and weakening of the Kuroshio Extension), and vice versa. This finding suggests that the intensity of the North Pacific subtropical gyre circulation has varied in response to precessional forcing and that this response has been linked with changes in tropical ocean–atmosphere interactions. In the precessional cycle, the SST variation derived from Core MD01‐2421 lags ca. 2.5–4 ka behind the variations shown by Hulu and Sanbao stalagmite δ <jats:sup>18</jats:sup> O records and by the pollen temperature index from Core MD01‐2421, suggesting out‐of‐phase variations of the North Pacific subtropical gyre circulation and the East Asian summer monsoon. These findings indicate that the behaviour of interactions between tropical ocean–atmosphere dynamics and the East Asian summer monsoon may have varied in response to the precessional cycle. Copyright © 2009 John Wiley & Sons, Ltd. </jats:p>