渤、黄、东海二维潮汐模式底摩擦系数的反演研究

一种新的底摩擦系数处理方法是假定底摩擦系数具有空间分布特征,即在海区中选取一些点作为独立底摩擦系数,计算区域中任意点的底摩擦系数都可由这些独立底摩擦系数通过线性插值得到。采用伴随同化方法对空间分布底摩擦系数的研究表明,与传统的底摩擦系数处理方法相比,空间分布的底摩擦系数模拟精度更高。探讨了根据地形的空间分布特征选取独立底摩擦系数的做法,所做的孪生实验和实际实验均表明,与均匀选取的结果相比,在独立变量个数减少三分之一的情况下,数值模拟的精度反而得以提高。得到的渤、黄、东海底摩擦系数分布表明,东海等深水区及地形复杂的区域底摩擦系数比较大。

Inversion of the bottom friction coefficient in 2D tidal model of the bohai, the yellow and east China seas

The space varying bottom friction coefficient(BFC) is studied with the adjoint assimilation method.In this paper,the BFC at some grid points are chosen as the independent BFC and the BFC at the other grid points can be obtained through linear interpolation with the independent BFC.The results of numerical experiments,including twin and practical experiments,demonstrate that,comparing with the traditional methods,the simulation results of the above method are much better.How to select the independent BFC is also studied and the selection according to the spatial distribution of ocean topography is sampled.Numerical results testify that,with this method,comparing with only uniformly selecting,higher accuracy can be obtained even though the number of independent BFC is reduced from 120 to 80.The BFC distribution of the Bohai Sea,the Yellow Sea and the East China Sea obtained form the practical experiment indicates that,the BFC value are larger where the water is deep,such as in the East China Sea,or where the topography is complicated.