渤、黄海的底摩擦系数

利用伴随法，根据32个验潮站的水位观测资料来优化渤、黄海的底摩擦系数．所作的一系列数值模拟实验表明；利用伴随方法优化渤、黄海的底摩擦系数能够有效地减少数值模拟结果与观测结果的差异．

THE BOTTOM FRICTION COEFFICIENTS OF THE BOHAI SEA AND THE HUANGHAI SEA

In the numerical models of tidal flows, the correct choice of the bottom friction coefficient is an important problem, and the problem has not been solved by now. In the traditional numerical simulation, the bottom friction coefficient is treated as a constant or different constant in different region. And the treatment of the bottom friction coefficient depends on the experiences and subject estimation, too much work to be done for the satisfied results. Adjoint method could change the treatment of the bottom friction coefficient to a process of the numerical iteration which depending on the results of the observation. It realizes the automation of the treatment of the bottom friction coefficient. In this paper, under the conditions that the M2 tidal harmonic constants on the open boundaries having not been changed, adjoint method was used to optimize the prescribed bottom friction coefficients of the Bohai Sea and the Huanghai Sea by using M2 tidal harmonic constants in the interior region: harmonic constants at 32 tidal stations. In the numerical simulation, the bottom friction coefficients are supposed to be different in different points. The similar treatments have not been seen in the literature. By using the adjoint method to inverse the bottom friction coefficients, the precision of the numerical simulation is efficiently increased. The results of the experiments coincide with the observed M2 tide in the Bohai Sea and the Huanghai Sea fairly well.