渤海潮流、潮能通量和耗散的数值模拟

Numerical Simulation of Tidal Currents, Energy Fluxes and Dissipation in the Bohai Sea

基于渤海最新岸线地形数据,利用有限体积近岸海洋模型(Finite-Volume Coastal Oceon Model, FVCOM)对M_2、S_2、K_1和O_1等4个分潮进行数值模拟,分析渤海潮流的特性,讨论最新岸线地形下渤海各海区的潮能通量和耗散。结果表明:渤海潮流以半日潮流为主,M_2、S_2、K_1和O_1等4个分潮的最大流速分别为120 cm/s、45 cm/s、38 cm/s和30 cm/s;半日潮能输入渤海之后分成3支,向北涌入辽东湾,向西输入渤海湾,向西南传至莱州湾;全日潮能输入渤海之后大致沿逆时针方向传输,在海峡内形成"北进南出"的格局。传入渤海的M_2、S_2、K_1和O_1等4个分潮的净潮能通量分别为4.242 0 GW、0.399 2 GW、0.517 0 GW和0.254 8 GW,其中,输入3个海湾的潮能均以M_2分潮为主,其次为S_2分潮和K_1分潮,O_1分潮的潮能最小。传入渤海的4个主要分潮的总潮能有49.23%耗散在渤海中部海域,27.21%耗散在辽东湾,其次是渤海湾,莱州湾的潮能耗散最少。

A Finite Volume Coastal Ocean Model (FVCOM) is developed based on the new coastline and topography data and used to calculate the tidal currents, energy fluxes and dissipation of the primary tidal constituents (M2, S2, K1, O1) in the Bohai Sea. The accuracy of the model is validated via comparing the simulated tidal amplitudes and phase-lags with observed data. The simulation results demonstrate that semidiurnal currents dominate in the Bohai Sea and the maximum current speeds of the M2, S2, K1 and O1 constituents are 120 cm/s, 45 cm/s, 38 cm/s and 30 cm/s respectively. The semidiurnal tidal energy divides into three branches, one of which turn northward into the Liaodong Bay while the other two westward into the Bohai Bay and southwestward into the Laizhou Bay separately. The diurnal tidal energy cyclonically propagates after entering the Bohai Sea through the northern Bohai Strait while a small portion of the energy flows out across south of the Bohai Strait. The M2, S2, K1 and O1 energy fluxes entering the Bohai Sea are 4.2420 GW, 0.3992 GW, 0.5170 GW and 0.254 8 GW respectively. The energy propagating into the Liaodong, Bohai and Laizhou Bays is related primarily to the M2 constituent followed by the S2, K1 and O1 constituents. Nearly half (49.23%) of the total energy propagated into the Bohai Sea dissipates in the central Bohai Sea, while 27.21% of the energy dissipates in the Liaodong Bay, and only 4.40% dissipates in the Laizhou Bay.