장강담수가 동중국해 여름 해면수온에 미치는 영향

Abstract

Freshwater discharge from the Changjiang River plays a key role in controlling density stratifications in the Yellow and East China Seas (YECS) especially in summer. A barrier layer (BL) which is the layer between the base of a mixed layer and the top of a thermocline has been observed from hydrographic measurements in the region where the Changjiang Diluted Water (CDW) disperses. In this research, a global ocean-ice model was adopted to investigate effects of the CDW on the density stratifications and relevant surface temperature changes. A sensitivity experiment of considering year-to-year variation of the Changjiang discharge for 1960-2001 showed that the CDW increases surface temperature in August. The warming is mainly caused by the CDW-induced BL accompanied by the enhanced stratification at the base of the mixed layer. The SST difference between flood and drought years’ composite showed clearly the surface warming was relevant to surface freshening by dispersion of the CDW.