HYDROGRAPHY OF THE KUROSHIO NORTHEAST OF TAIWAN WITH A STREAMFUNCTION PROJECTION METHOD
台湾东北部黑潮在流函数空间的水文分析

A streamfunction projection method called Geostrophic Empirical Mode (GEM) was used to diagnose the historical hydrographic data in the Kuroshio northeast of Taiwan. By examining the spatial and seasonal variations of the GEM fields, we found that the Kuroshio Shallow Water (<300 m) in the Okinawa Trough is fresher and colder than that south of the Su-Ao Ridge. It provides evidence that the returning branch of the cyclonic cold eddy north of Taiwan exerts a strong influence on the water properties in the southern Okinawa Trough. Meanwhile, the Kuroshio Deep Water (>1000 m) is comparatively fresher and warmer within the Okinawa Trough, reflecting the topographic blocking on the Kuroshio Deep Water mass by the ridge. A regional salinity maximum of the Kuroshio Intermediate Water (KIW) was revealed in southwestern corner of the Okinawa Trough, which is, in hypothesis, the result of the intensive mixing in the confluence region between the Kuroshio and the perennial cold eddy.