Mr. Kai ZHU Department of Earth Sciences, HKU
The SCS is the largest marginal basin in the western Pacific, and under the influence of Western Pacific Warm Pool and the Asian Monsoon system. It is very sensitive to both land and sea climatic changes. Previous studies on East Asian Monsoon (EAM) mainly focused on its imprints of EAM on continental regions, and the understanding of atmosphere-land interactions remains unclear.
A high-resolution Holocene SST record based on long-chain alkenones revealed a relative stable period during 8.5 ka to 3 ka, corresponding to the Holocene Climate Optimum. The decreasing trend from 3 ka to 1.2 ka reflected the intensification of EAWM during this period. The Sea level was minus 8,500 yrs ago at YJ site, influencing the lithology of sediments. The alkenone-based SST of YJ core over the past 2,000 years revealed imprints of climatic events, like MWP and LIA. The comparison of alkenone-based SST records of YJ core and other sites showed that YJ site was mainly influenced by EAWM. The intensification of EASM over the past few centuries caused the increase of SST record of YJ, revealing that YJ site was less influenced by the EASM-induced coastal mixing, possibly due to the terrestrial fresh water input.