西北太平洋的一种潮汐数值同化模型

An tidal numerical assimilation modeling in northwest Pacific

利用FVCOM海洋数值模式,在球坐标系统下考虑非线性效应和天体引潮力的影响,基于非结构的三角形网格建立了包括中国近海、日本海、鄂霍次科海和部分西北太平洋海域的高分辨率海洋潮汐数值模型,并采用趋近法同化84个沿岸验潮站的观测资料。模拟结果与175个验潮站的实测结果拟合良好,M2,S2,K1,O1四个主要分潮振幅和迟角的绝对平均误差分别为4.0cm和5.6°,2.4cm和7.5°,2.6cm和6.3°,1.5cm和5.0°。依据调和分析结果给出了4个主要分潮的同潮图分布,得到8个半日分潮和5个全日分潮的无潮点,证实了宗谷海峡全日潮无潮点的存在,首次模拟得到津轻海峡的全日潮无潮点;还给出了整个计算海域内最大可能潮差和潮汐余水位的分布特征。

Based on the Finite Volume Coastal and Ocean Model（FVCOM）,an unstructured ocean tidal numerical model with high resolution was built in northwest Pacific,including the marginal seas adjacent to China,Japan/East Sea and Okhotsk Sea.The model was in a spherical coordinate and took into account the effects of non-linear and tide-generating force.The tidal datasets from 84 tide-gauges along the coast were assimilated into the model with Nudging method.Comparing with the other 175 tidal stations which were not assimilated in this model,the simulated results were well agree with the observations,with the absolute mean errors of amplitude and phase-lag 4.0 cm and 5.6° for M2 constituent,2.4 cm and 7.5° for S2 constituent,2.6 cm and 6.3° for K1 constituent,1.5 cm and 5.0° for O1 constituent,respectively.According to the co-tidal charts for the four major constituents by harmonic analysis,8 amphidromic points for the semi-diurnal tides and 5 amphidromic points for the diurnal tides were found.The existence of amphidromic point for the diurnal tides in Soya strait was confirmed by the model results and we documented first an amphidromic point for the diurnal tides in Tsugaru strait.The distribution for the maximum possible tidal ranges and the tide residual water level were obtained in the whole model domain.