Slow warming of the northern South China sea during the last deglaciation

Abstract

We have generated a record of alkenone sea surface temperatures (SSTs) during the last 28000 years from Core MD97-2146 for the northern South China Sea (SCS). The SST record showed a typical pattern for change in the northern SCS SST. The SST during the LGM was ∼25°C, this decreased to ∼24°C to 17 ka, increased to -25.5°C to 14.5 ka, decreased again to ∼24.5°C to 11.8 ka, increased gradually to ∼27°C to 6 ka, and then increased more gradually to reach ∼27.5°C at present. The SST difference (ΔSSTNSCS = SSTMD97-2146- SSTMD97-2141) between Cores MD97-2146 (the northern SCS; this study) and MD97-2141 (the Sulu Sea; Rosenthal et al. 2003) was used to characterize the SST changes in the northern SCS relative to changes in the adjacent WTP region. The ΔSSTNSCS decreased from 21 to 11.8 ka and increased after 11.8 ka, indicating slower warming of the northern SCS during the last deglaciation than that of the adjacent western tropical Pacific region. We infer that the slow warming of the northern SCS was principally a result of stronger winter monsoon during the last deglaciation and early Holocene. In addition, the cool water inflow through the Taiwan Strait after 13 ka and the warm water inflow through the Sunda Shelf after 11 ka could influence the SST in the northern SCS.