基于FVCOM的南海北部海域潮汐潮流数值模拟

基于非结构三角形网格的FVCOM(finite-volume coastal ocean model)数值模型,对南海北部海域的潮汐、潮流进行了精细化数值模拟研究,并根据模拟结果详细分析了M2,S2,K1,O1分潮的潮汐和潮流特征。研究结果表明:神泉港到甲子港海域表现为正规全日潮性质,珠江口附近海区潮汐以不正规半日潮为主,其他海域主要表现为不规则全日潮;陆架海域和深水海域主要表现为往复流,陆架坡折区存在较强的旋转流,陆架坡折区为不规则半日潮流和不规则全日潮流的分界线;东沙群岛附近海域以不规则全日潮流为主,旋转方向为顺时针;整个海域的最大流速分布与等深线基本平行,东沙群岛附近速度明显变大,最大值出现在台湾浅滩附近,最大值超过70 cm/s;南海潮波系统以巴士海峡传入的大洋潮波为主,分为三支潮流,以不同的形式进出南海北部海域;余流在台湾浅滩附近达到最大,超过6 cm/s,自南向北进入台湾海峡,近岸余流自东向西沿岸流动。本研究在东沙群岛周边的模拟结果与前人基于实测资料的分析吻合较好,并且由于采用了高精度的三角网格,本文对东沙群岛周边海域的潮汐潮流结构和性质的刻画和分析是迄今为止较为精细的,同时本研究还提高了对沿岸验潮站调和常数的模拟精度。

一种计算斜坡处海流的诊断模式

本文提出一种考虑底斜效应,适合斜坡处海流诊断计算的模式,并且分别计算了日本以南黑潮区部分测线和对马暖流流源区的流速。其结果与实测符合较好。

Estimating open boundary conditions from coastal tidal observations by adjoint approach

A numerical study for estimating the tidal open boundary conditions of a shelf current modrl from tb coastal tidal observations is presented. The method is based on the optimal control/adjoint method. A lrast square fitting of the model state to simulated data is used. Two ideal domains and coastlines are considered. Using the IAP shallow. water model and its adjoint model, some identical twin experiments are carried out to test efficiency and lirnilsd of the method. The results show that the adjoint method can efficiently estimate the open boundary conditions well for gulf/bay like domains. The adjoint method seems to have great potential to improve the accuracy of tide and shelf current modeling in coastal regions.