Gravitational potential, inertia and Earth rotation

Several satellite missions, devoted to the study of the Earth gravity field, have been launched (like CHAMP, recently). This year, GRACE (Gravity Recovery and Climate Experiment) will allow us to obtain a more precise geoid. But the most important is that they will supply the temporal variations of the geopotential coefficients (called Stokes coefficients). In the poster we show how the Earth gravitational potential is linked to the Earth rotation parameters. Indeed, through the Earth inertia coefficients, we can connect the variation of LOD and Polar Motion with the temporal variations of the Stokes coefficients. We also consider the nutations, that are related to the gravitational geopotential coefficients. We discuss the possibility of using the Stokes coefficients in order to improve our knowledge of the Earth rotation.