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

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.