VARIATIONS OF LOD INFERRED FROM TEMPORAL GRACE GRAVITY DATA
Chen Wei 1,2) ;Shen Wenbin 1,2,3) ;Li Jin 1) ; and Han Jiancheng 1)
1)Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, Wuhan 430079 2)State Key Laboratory of Information Engineering in Surveying，Mapping and Remote Sensing, Wuhan 4300793)Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,Wuhan 430079
Abstract The impacts of the temporal secondorder potential coefficients on the Earth’s principal axes and moments of inertia as well as variations of length of day (LOD) are studied. By using the wavelet analysis and adoption the monthlyaveraged GRACE gravity model, the secondorder potential coefficients were processed and the jumps and noises presented in these data were removed. After comparing the Earth’s principal axes and moments of inertia obtained from the processed with those from the nonprocessed coefficients, the associated variations of LOD were obtained based on the processed data. Numerical calculation results show that the mass redistribution related to the monthly temporal principal axes and moments of inertia could lead to a decreasing tendency of LOD during the recent 6 years.
