渤海开边界潮汐的伴随法反演

INVERSION OF THE TIDES ON THE OPEN BOUNDARY OF THE BOHAI SEA BY ADJOINT METHOD

潮汐潮流数值模拟中的一个主要难点在于开边界条件的确定。本文采用伴随法 ,由渤海沿岸 1 9个验潮站的潮汐调和常数来反演渤海海域的开边界条件 ,以实现渤海潮波的数值模拟。计算所得调和常数与实测值之差的绝对平均值 :m1 潮波振幅差为 1 4cm ,迟角差为5 0°;M2 潮波振幅差为 2 4cm ,迟角差为 5 0°。数值模拟结果正确地反映了渤海m1 和M2

A major difficulty faced by numerical models of tidal flows is the treatment of open boundaries. To simulate m 1 and M 2 tides in the Bohai Sea, adjoint method was used to deduce the open boundary conditions of the Bohai Sea by using the harmonic constants at 19 tide gauge stations in the interior of the region. The average absolute differences between the simulated and the observed were computed. For m 1 tide, the average absolute difference of the amplitude is 1.4cm, and the average absolute difference of the phase-lag is 5.0°. For M 2 tide, the average absolute difference of the amplitude is 2.4cm, and the averaged absolute difference of the phase-lag is 5.0°. The results in the numerical simulation coincide with m 1 and M 2 tides observed in the Bohai Sea.