Sea surface temperature variations in the southwestern South China Sea over the past 160 ka

Sea surface temperatures (SSTs) in the southwestern South China Sea have been reconstructed for the past 160 ka using the U₃₇^k paleothermometer from the core MD01-2392.The temperature differences between glacial times (MISs 6 and 2) and interglacial times (MISs 5.5 and 1) are 2.2~2.5℃.Younger Dryas event during the last deglaciation was documented in both the planktonic foraminiferal δ¹⁸O and SST records.After MIS 5.5, SSTs displayed a progressive cooling from 28.6 to 24.5℃, culminating at the LGM.During this gradual cooling period, warm events such as MISs 5.3, 5.1 and 3 were also clearly documented.By comparison of SST between the study core and Core 17954, a pattern of low or no meridional SST gradients during the interglacial periods and high meridional SST gradients during the glacial periods was exhibited.This pattern indicates the much stronger East Asian winter monsoon at the glacial than at the interglacial periods.Spectral analysis gives two prominent cycles:41 and 23 ka, with the former more pronounced, suggesting that SSTs in the southern SCS varied in concert with high-latitude processes through the connection of East Asian winter monsoon.