ANALYSIS ON WATER MASSES IN THE SOUTH CHINA SEA IN SUMMER AND WINTER OF 1998

Abstract

The data of cruises in summer and winter in 1998 with regard to the water masses in the South China Sea(SCS) were analyzed with three methods, i.e., clustering method, discrimination method and fuzzy sets method. The water system off shore can be divided into six water masses in SCS: the Surface Water Mass(S), the Subsurface Water Mass (U), the Subsurface Intermediate Mixed Water Mass(UI), the Intermediate Water Mass(I), the Deep Water Mass(D) and the Bottom Basin Water Mass(B). There is a warm eddy in summer near Vietnam. The Kuroshio Surface Water Mass(KS) and Kuroshio Subsurface Water Mass(KU) can be distinguished in summer, but there is no Kuroshio Water entering into the SCS through 119.5°E in winter of 1998. Such a phenomena has probably some relation with E1Ni n o. The Sulu Sea water enters into the SCS at the depth from 50m to 75m through Mindoro Strait in summer.