渤海的潮汐余流

THE TIDE-INDUCED RESIDUAL CURRENT IN THE BOHAI SEA

本文采用二维非线性潮波微分方程,依据目前的海图对渤海M_2、S_2、K_1、O_1的潮汐余流进行了数值计算,并进一步计算了由这4个分潮组成的总潮汐余流。计算表明,渤海以M_2的潮汐余流占主要地位,S_2、K_1、O_1的潮汐余流具有大约相同的量值。但是,它们比M_2小一个量级。为探讨渤海潮汐余流自30年代以来的变化情况,本文还依据30年代的渤海海图和设想数十年后渤海的海图,对M_2进行数值计算,求得这二个时代的M_2潮汐余流。结果表明,自30年代以来,莱州湾的潮汐余流发生了很大的变化。

In this paper, the tide-induced residual currents of M_2, S_2, K_1 and O_1 and the sum of them in the Bohai Sea are computed using the alternating direction implicit method based on the two-dimesional nonlinear tidal wave equations and the present sea chart. The computation shows that the tide-induced residual current in the Bohai Sea is mainly composed of the M_2 tide-induced residual current and that S_2, K_1 and O_1 tide-induced residual currents are of about same magnitude, but they are about one order of magnitude smaller than that of M_2. In order to study the variations of the tide-induced residual current in the Bohai Sea since 1930s, we also compute the M_2 tide-induced residual current of the 1930s and several decades later in the Bohai Sea using the sea chart of the 1930s and the assumed sea chart of several decades later respectively in the Bohai Sea. The result shows that the tide-induced current of Laizhou Bay has greatly changed since the 1930s.