海潮负荷对自由核章动参数拟合的影响  

Influence of the Ocean Tidal Loads on the Fitted Parameters of Free Core Nutation

作　　者：徐建桥[1] 孙和平 罗少聪[1] 

机构地区：[1]中国科学院测量与地球物理研究所,湖北武汉430077

出　　处：《测绘学报》2001年第3期214-219,共6页Acta Geodaetica et Cartographica Sinica

基　　金：中国科学院项目 (K ZCX2 -10 6) ;国家自然科学基金项目 (4992 5 411;497742 2 3 )

摘　　要：基于武汉基准台超导重力仪重力潮汐观测资料 ,利用根据不同海潮模型获得的负荷重力改正值对观测数据作海潮改正 ,拟合了地球自由核章动 ( FCN)共振参数。结果表明 FCN的本征周期为 435 .2恒星日 ,品质因子为 4730 ,复共振强度为 ( - 6.34× 1 0 - 4,- 0 .0 9× 1 0 - 4)°/h。不同的海潮模型对 FCN本征周期和共振强度实部计算结果的影响很小 ,差异分别不超过± 1 .6%和± 7.7% ,对品质因子 Q值和共振强度虚部拟合结果的影响非常显著。基于 Ori96全球海潮模型得到的重力改正值可以很好地解释武汉基准台周日重力潮汐观测残差。After removal of the effects of ocean tidal loads based on various oceanic models, the tidal gravity observations, recorded with a superconducting gravimeter at Wuhan fundamental station, are employed to retrieve the resonance parameters of free core nutation (FCN) of the Earth as of 435.2 sidereal days for the eigenoeriod, 4 730 for the quality factor Q and (-6.34×10 -4 ,-0.09×10 -4 )°/h for the complex resonant strength of the FCN. It is found that the influence of different oceanic models on the fitted eigenperiod and real part of resonant strength of the FCN is very small. The discrepancies are less than ±1.6% for the eigenperiod and ±7.7% for the real part of resonant strength. Meanwhile, the fitted quality factor Q and imaginary part of resonant strength of FCN depend obviously upon the chosen oceanic models, and the influence of different oceanic models on the fitting of these two parameters is very strong. The oceanic corrections to gravity, based on Ori96 global oceanic model, can describe well the diurnal tidal gravity residuals observed at Wuhan.

关 键 词：武汉基准台 超导重力仪 海潮负荷 海潮模型 自由核章动 共振参数 

分 类 号：P312.4[天文地球—固体地球物理学]