中国地壳运动观测网络基准站重力场变化的海潮负荷信号改正问题

CORRECTION PROBLEM OF THE OCEAN LOADING SIGNALS ON GRAVITY MEASUREMENTS AT FUNDAMENTAL STATIONS IN CRUST MOVEMENT OBSERVATION NETWORK IN CHINA

利用最新的全球海潮模型 (Csr3.0 ,Fes95 .2 ,Tpxo2和Csr4 .0 )和原有的Schwiderski海潮模型以及中国近海海潮数据和标准地球模型负荷格林函数 ,采用直接褶积积分方法研究了中国地壳运动观测网络 2 5个基准站重力固体潮观测中的海潮负荷效应问题 ,计算了 8个主要潮汐波的负荷振幅和相位 ,构制了北京和上海等 10个台站重力负荷随时间变化函数。

The main purposes for the observation network of the crust movement in China are to detect and to study the variation laws of the various geophysical fields induced by crust movement, to serve further disaster reduction and environmental protect, to provide important basic observations and background information, therefore the realization of this research project processes very important application prospects. Now it is possible to study the detail structure of the gravity filed due to the improvement of theoretical models and the wide use of the GWR superconducting and of the FG-5 absolute gravimeters with high precision. Researches show that it is obviously important to study the oceanic influence when to determine the Earth's tidal parameters, to study inversely the structure of the crust and upper mantle, to check the movement of the Earth's core, to estimate the resonance parameters of the nearly diurnal free wobble (NDFW) and to study the gravity change due to the Earth's rotation and polar motion. Based on the most recent global ocean tidal maps (Csr 3.0,Fes 95.2,Tpxo 2 and Csr 4.0) and the old Schwiderski (Scw 80) ones, ocean tidal data along the coast of China and the standard Earth model loading Green functions, the influence of the oceanic loading on the tidal gravity measurement at 25 fundamental stations are studied by using a direct convolution technique. The loading amplitudes and phases for 8 main waves are calculated, the temporal variation of the tidal loading at 10 main stations as of Beijing and Shanghai, is constructed in the present study.