海潮模型的比较及海潮对地球自转变化的影响

近年来，由于卫星测高工作的开展，提供了丰富准确的观测资料，产生出许多新的海潮模型。这些海潮模型的相互比较为研究海洋的精细结构、海潮的动力学、地球动力学提供了依据。另一方面，由现代空间技术和新方法来监测地球自转中的高频变化研究领域也有长足的进展。用这些技术可检测出地球自转中的周日和半日变化，从而激发地球自转的变化。一般来说，海潮影响地球自转的高频变化有两种不同的激发机制。地球的惯性张量的变化即质量项

The Comparison among Ocean Tide Models and the Ocean Tide Effect on the Earth Rotation

In recent years, the more precise and rich observational data have been contributed and a number of new ocean tide models have been produced with development of the satellite altimetry technique. The comparison of the different ocean tide models should provide a base to the study of ocean structure, ocean tide dynamics and geodynamics. On the other hand, a remarkable progress of monitoring high-frequency variation in earth rotation from both modern space techniques and new methods has been made. The daily and subdaily variatons of earth rotation are detected with these techniques. The dominant reason of high frequency variation in earth rotation comes from the ocean tide, which produces the variation of both tidal height and velocity of tidal current generated by the tidal potential to excitate a changes in Earth rotation. In general, the oceanic tides induce the earth rotation variation with high-frequency in two different excitation mechnisms: one is the change of the inertia tensor of the Earth , which corresponds the tidal height, the other is the motion term, which corresponds the tidal current. It is shown that the high frequency variation of earth rotation detected from space geodetic techniques agrees well with daily and subdaily variation predicted from the ocean tide model. Recent progress in the study of the influence of ocean tide on earth rotation below daily time scales , which are obtained from the different space observations, is reviewed. Meantime the comparison between observational results and values from theoretical ocean tide models in daily and subdaily terms is introduced.In addition, some unresolved problems on the subject are also outlined.