Estimating geocenter motion and changes in the Earth’s dynamic oblateness from GRACE and geophysical models

Geocenter motion and changes in the Earth’s dynamic oblateness (J2) are of great importance in many applications. Among others, they are critical indicators of largescale mass redistributions, which is invaluable to understand ongoing global climate change. The revolutionary Gravity Recovery and Climate Experiment (GRACE) satellite mission enables a constant monitoring of redistributing masses within the Earth’s system. However, it still cannot provide reliable time variations in degree-1 coefficients and degree-2 zonal coefficients, which are directly related to geocenter motion and J2 variations