Surface ocean cooling in the subarctic North Pacific during the late Pliocene suggests an atmospheric reorganization prior to extensive Northern Hemisphere glaciation

This paper presents records of TEX86L- and U37K-derived sea-surface temperatures (SSTs) from Ocean Drilling Program Site 882 in the subarctic North Pacific over the last 5.8 million years. The TEX86L-derived SST record shows a cooling trend from 17 °C at 3.6 Ma to 8 °C at 2.3 Ma. This cooling preceded the onset of extensive Northern Hemisphere glaciation (NHG) at 2.7 Ma, coinciding with the intensification of the East Asian winter monsoon, surface cooling in the North Atlantic, and the gradual development of NHG. The results of this study suggest that the reorganization of atmospheric circulations in the northern high latitudes from 3.6 to 2.3 Ma was associated with the early-stage development of the ice sheets and sea ice in the arctic and subarctic regions, inducing the cooling of the North Atlantic and the subarctic North Pacific and the intensification of the East Asian winter monsoon.