Decadal Variation of the Geostrophic Vorticity West of the Luzon Strait

ABSTRACT

Merged satellite altimeter data (from 1993 to 2008) are used to study the decadal variation of geostrophic vorticity west of the Luzon Strait. The decadal variation of the geostrophic vorticity west of the Luzon Strait indicates that the Kuroshio intrusion and separated anticyclonic eddies from the Kuroshio are stronger in 1995-2000 than that in 2001- 2004. Between 1995 and 2000, along with the intensification of the anticyclone separated from the Kuroshio intrusion west of the Luzon Strait, the cyclone south of the Kuroshio intrusion is strengthened. This result proved the close relationship between eddy shedding and the growth of the cyclone south of the Kuroshio front. In 1995-2000, when the anticyclonic vorticity west of the Luzon Strait was increased, at the same time, the decrease thermocline thickness and the Kuroshio transport east of Luzon Island are found by analyzing the Simple Ocean Data Assimilation datasets. This suggests that the decadal change in the Kuroshio intrusion and eddy shedding in the Luzon strait is influenced by the decadal change in thermocline thickness and Kuroshio transport east of the Luzon Island.