海洋潮汐模型在浅海区域的应用(英文)

OCEAN TIDE MODELS' PERFORMANCE IN COASTAL REGIONS

海洋潮汐和大气、海洋、海冰之间存在复杂的相互作用,它对地球气候有复杂而深远的影响。海潮对流经大陆沿岸或大陆架的洋流有很强烈的作用。潮汐流产生混合湍动;潮汐耗散和内潮波效应对海洋环流的传输和循环也有一定的影响。1995年前后,使用TOPEX／POSEIDON测高卫星资料。建立了十多个海潮模型。研究表明,1994-1996年期间发展起来的正压波海潮模型在深海的精度为2—3cm,空间分辨率为50km量级,在浅海区域的精度显著下降。近年来运用更加成熟精细的流体动力学理论模型,在数据同化技术中使用时间跨度更长的测高资料,已经建立了一些改进的海潮模型。该文使用验潮站潮汐常数、测高资料以及交叉点资料,评估了6个海潮模型在浅海区域(包括中国海海域)的表现,以应用于今后对海平面的研究。初步分析表明,浅海区域的海平面高度的误差仍然相当显著。要发展海洋潮汐模型需要进一步减小潮汐混淆效应,提高长周期潮汐的精度,尤其在浅海区域。模型的改进必将增进对潮汐现象的认识,促进学科间进行相互融合和相互渗透的研究(例如潮汐摩擦引起的月球自转的长期缓慢减速、地球内部结构的物理学研究等)。

Ocean tides play a significant role in climate due to its complex interactions between ocean, atmosphere, and sea ice. Tides have strong effects on circulations near coastal regions or on continental shelves. Tidal currents create turbulent mixing, tidal dissipation and internal tidal mixing affects general circulation and oceanic transport and thus climate. The first comprehensive ocean tide model is developed in 1980 by E. Schwiderski, the availability of the TOPEX/POSEIDON spaceborne radar altimeter observations has allowed development of more than 10 improved barotropic tide models in 1995, and the same number of further improved models by 2005. The TOPEX/POSEIDON global barotropic ocean tide models developed during 1994 - 1996 have been assessed as with accuracy of 2 - 3 cm rms in the deep ocean, a spatial resolution on the order of 50 km, and with significantly degraded accuracy near coastal regions. The next generations of ocean tide models are now available taking advantage of more than 6 years of TOPEX/POSEIDON ticated hydrodynamical modeling and associated assimilation （T/P） altimeter data and more sophistechniques. Potential improvement in the tide model includes mitigation of tide aliasing, improved accuracy in the long-period tides and in the coastal regions. This study has been conducted to assess the current ocean tide model prediction capability primarily in the global coastal region, especially in the coastal region of China seas. Independent data including pelagic tidal constants from bottom gauges, and radar altimeter and crossover measurements were used. One application of this study is for sea level studies. More than six global ocean tide models have been evaluated and preliminary results indicate significant errors in the coast- al seas still remain. The improved knowledge of tides allows interdis（.iplinary studies including the lunar deceleration caused by tidal frictions as well as geophysical sit,dies of Earth＇s intemal structure.