ANALYSIS OF WATER MASSES IN THE MIDDLE AND NOR-THERN TAIWAN STRAIT IN SPRING AND SUMMER
Weng Xuechuan, Zhang Qilong, Yan Tingzhuang, Wang Congmin(Institute of Oceanology, Academia Sinica, Qingdao 266071)Liang Hongxing(Fujian Oceanology Institute, Xiamen 361012)
This paper analyses the water mass in the middle and northern Taiwan Strait in spring and summer (May-August) and other related problems by using "the comparison analysis method." The results are given below. 1) There are two distributive types of water mass in this area between May and August, the winter type in May and the summer type in June-August. Two water masses exist in the whole area in May, namely, the Zhemin Coast Water and the Strait Warm Current Water. From June to August, the whole area is all occupied by the Strait Warm Current Water and according to different temperature and salinity, it can be divided again into two parts, upper water and deep water. 2) The Zhemin Coast Water is of characteristics of lower temperature, lower salinity and higher disolved oxygen. Irs uniformity is poorer and interannual variations are greater. The Strait Warm Current Water is mainly characterized by its higher salinity. And temperature, salinity and disolved oxygen are homogeneously distributed. 3) There are some upwelling phenomena in both east and west sides of the Strait. The upwelliing on the west sides appears between June and August and its centre is in the area near the Haitan Island but the upwelling on the east side is found in the north of the Penghu Islands in July. 4) The Strait WarmCurrent Deep Water (core) mainly goes northwards along the west side of the centreline of the Strait instead of flowing straight to the north closely by the east side of the Strait between June and August.