Studies of upper layer circulations of the South China Sea from Satellite altimeter observation

Abstract

Seventeen years Sea Surface Current (SSC) data from multi-satellite altimeters were used to investigate the upper layer circulation structure over the South China Sea (SCS) . And combined with QuikScat Sea Surface Wind (SSW) data, the relationship between upper layer circulation over SCS and SSW were analyzed. The results show that the largest current velocity and the greatest change of the circulation over the SCS are in the area east of the Indochina Peninsula; There are two main modes of the SCS upper layer circulation, the winter mode from October to next February and the summer mode from June to August. SCS circulations in other months are in the transitional period of the two main modes; Through the correlation analysis of the SSW and SSC, a significant positive correlation, about 0.5, between current and wind was found at the boundary area of the SCS. However, there was a significant negative correlation, about −0.5, near the middle of the SCS. The results also show that the variation of the upper layer circulation structure over the SCS is significant seasonal, and it was mostly dominated by the monsoon.