Characteristics and Seasonal Variations of the Thermocline and Halocline in the Huanghai Sea and the East China Sea

In this paper, the characteristics of the thermocline and harocline in the Huanghai Sea and the East China Sea in different periods are depicted and analyzed by using the observed CTD data west of 128°E in different seasons from April, 1996 to January, 1999. The results show that (1) thermocline is dominant absolutely in the Huanghai Sea due to the existence of Huanghai bottom cold water mass, while halocline in coastal sea area of the East China Sea is significant due to the influence of Changjiang River runoff; (2) the strength of thermocline is controlled by the different water mass in its corresponding upper and lower layers, and the basic reason for inducing thermocline is the existence of bottom cold water mass; (3) in summer, the double thermoclines in the East China Sea become distinct from Zhejiang coastal area to the area south of Cheju Island, and its distribution area just coincides with the frontier of the Kuroshio water intruding into the continental shelf in winter; (4) the stretching patterns of halocline strength contours in different seasons are similar to the spreading patterns of the Changjiang Diluted Water; (5) there are no thermocline and halocline in the Subei shoal area and the Taiwan Strait all the year round.