ECOMSED模式在杭州湾海域流场模拟中的应用

Application of ECOMSED model to the simulation of Hangzhou Bay tide current

针对杭州湾独特的喇叭型强潮河口湾的特点,基于Blumberg等(1996)的ECOMSED模式,引入动边界技术,建立杭州湾三维动边界的潮流模型.模型以正交曲线坐标下三维非线性水动力方程为基本方程,应用Mellor和Yamada的2.5阶湍流闭合模型计算紊动黏滞系数,嵌入Grant和Madsen的底边界层模型考虑波浪对底部应力的作用,采用干湿网格法模拟潮流漫滩过程;综合考虑径流,风应力,密度流和M2,S2,K1,O1四个主要分潮和M4,S4,MS4三个浅水分潮的作用,从而提高杭州湾潮流模拟的精度.通过验潮站调和常数和多次海流连续观测资料的验证,表明该文建立的模型可以更好的用于杭州湾流场的预报模拟.

A 3-D variable boundary numerical tidal model for the Hangzhou Bay is established. The model is based on ECOMSED model （Blumberg et al. , 2002） ,and is modified by introducing Drying and Wetting scheme technology. A a-coordinate transformation in vertical and a curvilinear coordinate in horizontal are used. The level 2.5 turbulence closure model is also used to give more reasonable vertical eddy viscosity coefficient. A Grant and Madsen model is used to calculate the shear stress of wave and current. A drying and wetting scheme technology is used to treat the tidal flood-ebb in tidal flat areas. An application of the model to the Hangzhou Bay grasps the tidal characterstics well. the computed result in the Hangzhou Bay agrees with the observation well . In order to improve the accuracy of the baroclinic pressure gradient, the impacts of river flow, wind, baroclinic pressure induced by salinity and tide （including M2 ,S2 ,K1 ,O1 ,M4, Ms4 and S4） are taken into account. The simulated results are fairly consistent with observations.