Land-ocean leakage errors in satellite gravity measurements using forward modeling

The Gravity Recovery and Climate Experiment (GRACE) satellite launched in 2002 can offer high-precision time-varying gravity field and the changes of Earth´s surface mass, which has been widely used in geodesy, hydrology, oceanography and glaciology. However, one of larger errors in GRACE measurements, land-ocean leakage error restricts high accuracy retrieval of ocean mass and terrestrial water storage along the coasts. The land signals will contaminate the ocean signals with significant signal attenuation, particularly ocean coast leakage errors. In this paper, global land-ocean leakage errors from GRACE are investigated using the forward gravity modeling. The effects on global ocean mass variations are further assessed. Results show that the forward gravity modeling will greatly reduce the continent-ocean leakage errors, especially oceanic leakage effects.