浅水区锋面的流场结构

ON THE FRONT-INDUCED CURRENT STRUCTURE IN SHALLOW SEA

用一垂向二维的诊断模式,研究了浅水区锋面的流场结构。参照James模式并结合杭州湾具体情形来确定垂向涡动粘性系数,得到了与实测结果相一致的浅水区(杭州湾)锋面的流场结构。研究表明,在探讨浅水区锋面流场时必须选取合理的模式;而深水锋面流场结构对所采用的模式依赖性不大;锋面的流场结构不仅与锋面的强度有关,而且与锋面的结构有关。

The front-induced current in shallow sea (Hangzhou Bay) is studied by using a vertical two-dimensional diagnostic model. In determining the model's parameter, a version of James's model was used as reference to derive the value of the eddy viscosity coefficient in our model according to the actual conditions in Hangzhou Bay. The agreement between calculated and observed results is reasonably good. The results indicate that the front-induced current is related to the frontal strength as well as frontal structure. The turbulence closure scheme (TC) is more reasonable than the Munk-Anderson scheme (MA) with regard to shallow water fronts. For deep water fronts, both TC and MA show the same results. The front induced currents are trapped in the frontal zone. Along-frontal current decreases from surface to bottom, where a counter-current exists near the sea bed. Crossfrontal circulation shows one-cell structure for vertically well mixed front and weakly stratified front, and two-cell structure for highly stratified front.