33 / 2023-07-24 15:07:56

The condition for the significant upwelling and downwelling at eddy centers in the Northern South China Sea

Eddy pumping, ocean stratification, Sverdrup transport, Northern South China Sea

Cyclonic and anticyclonic eddies are usually characterized by upwelling and downwelling, respectively, which is induced by eddy pumping near their core. Using repeated expendable-bathythermograph transect (XBT) and Argo floats we determined that not all eddies in the northern South China Sea (NSCS) were accompanied by eddy pumping. Thus, the main purpose of this study is to find out the marine environments that are favorable for the upwelling or downwelling to occur at the eddy centers in the NSCS, by using in-situ and satellite observations. Our finding showed that the weakening of background thermocline was attributed to the strengthening of eddy pumping, affected by (1) the wind-induced meridional Sverdrup transports and (2) the Kuroshio intrusion into the NSCS.