Upper layer circulation in the Luzon Strait

Abstract

Several observations including Argos satellite-tracked drifters, Argo profilers and altimetry satellite data were analyzed to understand the upper layer circulation in the Luzon Strait. The different role of the wind and the Kuroshio on the Luzon upper layer circulation has been revealed using a reduced gravity model. The observations show that the Kuroshio has a relatively stable pattern with some of Kuroshio water entering the South China Sea in winter. Circulation in the Luzon Strait is mainly controlled by the Kuroshio and the monsoon wind, which have different roles. The Kuroshio could induce a cyclonic gyre west of the Luzon Strait in either summer or winter which is stronger and extends more westward as the Kuroshio becomes stronger. The monsoon wind could drive a cyclonic gyre in the Luzon Strait in summer. In winter, an anticyclonic gyre and a cyclonic gyre are produced southwest of Taiwan Island and northwest of Luzon Island respectively, resulting in a strong westward current in the middle of the Luzon Strait.

Keywords:

• Kuroshio
• monsoon
• South China Sea

Acknowledgements

This study was supported by National Basic Research Program of China (2007CB816003), NSFC Grants (40976017 and 41125019), and ‘863’ Hi-tech program (2006AA09Z156) and the International Corporation Program of China (2008DFA22230). Assistance in the preparation of this manuscript was graciously provided by Jin Baogang and Lian Tao. Helpful comments from two anonymous reviewers were greatly appreciated.