Abstract:We use more than 5 years continuous data recorded with the observatory superconducting gravimeter(OSG-066) at Lijiang station, Yunnan province, China. High precision tidal parameters are obtained, and the local gravity tide model is established to provide a reference for accurate gravity tide deduction in Lijiang area. The correction effectiveness of gravity influence of ocean tide is computed with 9 new global tide models. In addition, the atmospheric gravity admittance is studied with regression analysis in time domain and wavelet analysis in frequency domain. The parameters of free core nutation are further estimated with the observed tidal parameters. The results show that gravity influence corrections of the 9 different ocean tide models are almost the same at Lijiang station, and correction accuracy of the tide model NAO.99b is slightly higher among them. Results of obtained atmospheric gravity admittance demonstrate that significant seasonal variation characteristics are found in both time domain and frequency domain; significant inverse correlation is found between precipitation data and atmospheric gravity admittance. The eigen period of free core nutation is 431.5(411.2, 454.0) sidereal days, while the quality factor is -2 796.
LIANG Ying,CHEN Xiaodong,SUN Heping et al. Gravity Tide Observation with OSG-066 and Their Applications at Lijiang Station, Yunnan Province, China[J]. jgg, 2020, 40(7): 713-719.