利用POM模型,以研究海区的海面风应力、温度和盐度资料作为海面边界条件,以与外海界面处的温度和盐度资料作为侧向液边界条件,并考虑长江径流、台湾暖流和东海沿岸流的影响,对长江口及其邻近海区各季节的三维斜压环流和温、盐结构进行了数值模拟。环流的数值结果表明,冬季和秋季研究海区的水平环流主要由长江径流、东海沿岸流、台湾暖流、杭州湾环流和沿岸流与台湾暖流之间的气旋和反气旋涡构成;东海沿岸流与长江径流顺岸南下,随着自北往南岸界地形坡度的增大,其流幅变窄,流速增强;台湾暖流沿陡坡及其外缘蜿蜒北上,随着自南往北水深的变浅,其流幅由宽变窄继而又由窄变宽,流速却一直由强变弱。冬季和秋季海区纬度断面垂直环流的总趋势由近岸向外海流动,海底地形变化缓慢区离岸流产生波动,海底地形变化显著的陡坡区离岸流产生剧烈振荡而生成强升降流。春季和夏季研究海区的水平环流主要由长江径流与东海沿岸流汇合流、台湾暖流、杭州湾环流、舟山群岛附近及长江径流和东海沿岸流汇合流与台湾暖流之间的气旋和反气旋涡构成;长江径流和台湾暖流平行北上并在长江口以北产生顺时针偏转。由海区水平环流特征和变化趋势证实,春季长江冲淡水已开始向东北偏转,夏季冲淡水的偏转程度、伸展距离和扩展范围都更甚于春季;春季在长江口近岸存在弱上升流,夏季长江口外的陡坡区出现下降流,而长江口以北和以南的陡坡区出现上升流。 POM model is used to study the sea surface wind stress, temperature and salinity data as the sea boundary conditions and the temperature and salinity data at the outer sea interface as the lateral liquid boundary conditions, taking into account the runoff of the Yangtze River, the current of Taiwan and the coast of the East China Sea Flow, the three-dimensional baroclinic circulation and temperature and salt structure of the Yangtze River estuary and its adjacent sea areas are numerically simulated. The numerical results of the circulation show that the horizontal circulation in the study area in winter and autumn is mainly composed of the cyclone and anti-cyclone vorticity between the Yangtze River runoff, the East China Sea coast flow, the Taiwan warm current, the Hangzhou Bay circulation and the Taiwan coast warm current, the East China Sea coast flow and the Yangtze River With the increase of the gradient of terrain from north to south, the flow rate narrowed and the velocity increased. The warm current in Taiwan meandered northward along the steep slope and its outer margin. As the depth of water from south to north became shallow, Its flow rate range from narrow to narrow and then from narrow to widen, the flow rate has been weakened from strong. The general trend of the vertical circulation in winter and autumn latitudinal section of the sea area fluctuated from the coast to the open sea. The offshore flow fluctuated slowly in the submarine topography. The offshore terrain in the steep slopes with significant changes in the seafloor produced violent oscillations and formed strong ascending and descending currents. The horizontal circulation in the study area of ​​spring and summer is mainly composed of cyclonic and anti-cyclonic vortices between the confluence of the runoffs of the Yangtze River and the East China Sea, the warm currents of Taiwan, the Hangzhou Bay, the Zhoushan archipelago, the confluence of the Yangtze River runoff and the East China Sea, ; The runoff from the Yangtze River flows warmly along with Taiwan and flows northward parallel to the northward of the mouth of the Yangtze River, causing a clockwise turn. It is confirmed by the horizontal circulation characteristics and trend in the sea area that the spring Yangtze River freshwater red water has started to deflect to the northeast. The degree of deflection, extension distance and extension range of red water in summer are more than those in spring. In spring, there are weak upwelling near the Yangtze River estuary, Downward steep slopes outside the mouth of the Yangtze River occur, while upwelling occurs in the steep slopes north and south of the mouth of the Yangtze River.