台湾海峡西部上升流的生成和长消原因分析

台湾海峡西部海域是上升流多发区,近年来已引起众多海洋学家的重视。我国海洋学家通过对台湾海峡区水团、海流和营养盐等的分析研究,不仅得出了台湾海峡西部海域上升流的分布范围和特征,并对其成因也作了探讨,取得了一些有价值的研究结果。由于这些研究都是采用间接方法,因此对上升流的主要成因尚存在不同的看法。本文通过对引起台湾海峡西部海域上升流的各驱动力因子量级的分析,进而判断出上升流的主要成因。

ANALYSIS ON CAUSES OF GENERATION,EVOLUTION AND DECAY PROCESS OF UPWELLINGS OFF THE WESTERN COAST OF TAIWAN STRAIT

There are several coastal upwelling areas in the Taiwan Strait. The most active and the longest term duration upwelling areas are located at the east side of Haitan Island, south-east side of Dongshan Island and south side of Taiwan Shoal. In this paper, the causes of generation, evolution and decay process of upwellings off the western coast of Taiwan Strait were analysed by using historical weather data, current and seawater temperature data obtained from 1983 to 1989. The influences of dynamical factors (such as currents, monsoon and tide mixture)were evaluated and compared.Results showed that current and monsoon are the main causes of the generation, evolution and decay process of upwellings off the western coast of Taiwan Strait. Because of the instability of monsoon speed and the discontinuity of longshore wind, the main factor influencing the generation and maintainance of coastal upwelling in the research area is current.