利用伴随法优化非线性潮汐模型的开边界条件Ⅱ.黄海、东海潮汐资料的同化试验

Optimizing open boundary conditions of nonlinear tidal model using adjoint methodⅡ. Assimilation experiment for tide in the Huanghai Sea and the East China Sea

本研究基于最优控制理论 ,采用变分数据同化法 ,通过建立伴随模型 ,把观测资料同化到陆架海域潮汐数值模型中去 ,优化开边界条件 ,以便提高数值预报的精度 .潮汐模型的控制方程为考虑平流项、非线性底摩擦和侧向涡动粘性项的非线性浅水方程组 .在第Ⅰ部分建立伴随模型和进行“孪生”数值试验的基础上 ,给出利用验潮站的水位资料以及TOPEX/Poseidon卫星测高数据在黄海、东海进行变分数据同化试验的数值结果 .

In order to improve the prediction of numerical tidal model in continental shelf, the open boundary conditions are optimized by assimilating the observed data into the model in which the adjoint method, based on optimal control theory, is used. The non linear shallow water equations are considered in which the horizontal kinematic nonlinearities, nonlinear bottom friction and horizontal eddy diffusion are included. On the basis of the establishment of adjoint model and twin experiment (Part Ⅰ), the variational assimilation results obtained by incorporating the data from tide stations with/without TOPEX/Poseidon altimeter data in the Huanghai Sea and the East China Sea for optimizing the open boundary conditions of the model are reported. The deviations of the model results before and after assimilation from the observed demonstrate the applicability of the variational assimilation.