中国大陆精密重力潮汐改正模型

Accurate correction models for tidal gravity in Chinese continent

利用理论和实验重力固体潮模型,充分考虑全球海潮和中国近海潮汐的负荷效应,建立了中国大陆的精密重力潮汐改正模型.结果表明,采用不同的固体潮模型会对重力潮汐结果产生相对变化幅度小于0.06%的差异;在沿海地区海潮负荷的影响约为整个潮汐的4%,而中部地区约为1%,其中中国近海潮汐模型的影响约占整个海潮负荷的1 0%,内插或外推潮波的负荷约占海潮负荷的3%.通过比较实测的重力数据表明,本文给出的重力潮汐改正模型的精度远远优于0.5×10^(-8)m·s^(-2),说明了本文构建的模型的实用性,可为中国大陆高精度重力测量提供有效参考和精密的改正模型.

Accurate correction models for tidal gravity in Chinese continent are developed by using the recent theoretical and experimental models for the Earth＇s tidal gravity, in which the loading effects of the global and local ocean tides are combined. The relative difference of tidal gravity variations induced from different Earth＇s tidal gravity models is less than 0. 06%. The ocean tide loading effects are about 4 % of the total tidal gravity in coastal area while they are about 1 % of the total tidal gravity in inland. The difference between the ocean tide loading effects estimated from global ocean tide models and modified global models with local tides is about 10% of the total ocean tide loading effects. And the interpolated and extrapolated ocean tide loading effects are about 3% of the total ones. Comparison between the observed tidal gravity variations by superconducting gravimeter and the ones calculated through the correction models confirms that the models developed in this study can accurately predict the tidal gravity signatures with a precision much better than 0. 5 ×〈 10^-8 m .s^-2. Consequently, it is expected that the models should provide an effective reference and accurate correction models for gravity measurements.