渤、黄、东海夏季环流的三维斜压模型

基于拉格朗日时均观点描述环流，建立起潮流与准定常流共同占优势系统中的陆浅海环流模型，并诊断计算了夏季渤、黄、东海的三维环流图。模拟结果较好地再现了渤、黄、东海主要流系的特征。对照冬季结果，对渤、黄、东海环流的季节变化做了阐述。从环流垂向分量的分布图上，可发现渐闽近海、长江口外存在较明显的上升流区。另外，对夏季渤、黄、东海的热盐环流和潮致余流分别进行了模拟，发现它们均能在黄海构成一逆时针向的五流系统，这对形成和维持夏季黄海冷水团的存在有重要作用。热盐环流的模拟结果表明，黄海冷水团环流含有“热成流”的成分；通过Lagrange余流的计算发现环绕黄河冷水团的环流还含有“潮成流”的成分。

A 3-D BAROCLINIC MODEL OF SUMMER CIRCULATION IN THE BOHAI, YELLOW AND EAST CHINA SEAS

Based on the idea of Lagrangian time-average residual current, a coastal water circulation model which can describe the circulation in a coastal water-shelf s ea system where tidal currents and some quasi-steady flows, such as the Kuroshi o in the East China Sea, are of the same order and dominant in the observable fl ow field, is developed. In this paper, the summer circulations in the Bohai, Yel low and East China Seas are diagnostically simulated by a sigma coordinate semi -implicit numerical scheme using the time-splitting scheme. The numerical resu lt show the summer character circulation pattern over the Yellow and East China Seas, such as the Kuroshio, the Taiwan Warm Current, the Tsushima Warm Current, the Yellow Sea Warm Current and coastal circulation systems (current along the c oastline of Shandong Province, Jiangsu Province). The thermal stratification is strong in summer over the computational domain, especially the appearance of the Yellow Sea Cold Water Mass (YSCWM). And thermocline layer appears mostly in sea area except the coastal zone. The inflow and outflow currents are altered from wintertime. The seasonal change of circulation patterns is discussed by comparin g the numerical results of summer and that of winter. The vertical component of circulation in summer is also illustrated, and the numerical results show that t he main upwelling areas in the East China Sea are located in the coastal off Zhe jiang Province and Fujian Province and the outside of Changjiang River mouth. Fu rther more, the thermohaline circulation and M 2 tide-induced Lagrange res idua l current is simulated respectively. In both numerical experiments, an anticlock wise gyre appears in the Yellow Sea. The thermohaline numerical experiment indic ates that the circulation surrounding the YSCWM is partly due to thermal effect. Meanwhile, the circulation encircling the YSCWM is also partly due to tide-ind uced residual current.