Multidecadal variations of the surface Kuroshio between 1950s and 2000s and its impacts on surrounding waters

Based on the analyses of 59 year (1950–2008) surface geostrophic velocities, the multidecadal changes of Kuroshio from the eastern Luzon to the southern Japan are investigated. Result shows that the upstream Kuroshio from the east of Luzon to southern East China Sea suffers much more obvious multidecadal changes. Except for the decade of 1980, the Kuroshio east of Luzon possesses a multidecadal tendency opposite to that east of Taiwan. Besides 1980s, the multidecadal change of Kuroshio bordering Taiwan is mainly governed by the eddy activity off the eastern Taiwan, while the wind stress curl plays a major role in the Kuroshio in the east of Luzon and in the Luzon Strait. The wind-stress-induced Ekman transport plays a secondary role in regulating the Kuroshio east of Luzon. In addition, the multidecadal fluctuation of Kuroshio east of Luzon also modulates the westward intrusion in the Luzon Strait. Instead, the Ekman transport dominated the whole upstream Kuroshio area from the eastern Luzon to the vicinity of Taiwan during the exceptional decade of 1980. Associated changes of water properties in the northern South China Sea and southern East China Sea are also ascribed to the multidecadal changes of surface Kuroshio in the upstream area.