On Optimal Parameterization for Mascon Solution of Surface Mass Changes From GRACE(‐FO) Satellite Gravimetry

Abstract The Gravity Recovery and Climate Experiment (GRACE) and its successor, GRACE‐Follow On, play an important role in monitoring mass transport across the Earth. Compared to spherical harmonic solutions, mass concentration (mascon) solutions offer less signal leakage and a “higher” spatial resolution. How the shapes, sizes, and positions of mascon are parameterized influences the accuracy of the solutions. In this study, we derive a variable‐sized mascon solution that enhances spatial resolution in polar regions by considering orbital coverage of satellites. To this end, we present a numerical simulation aimed at evaluating the performance of different parameterizations in the mascon solutions. We demonstrate that using variable‐sized mascons reduce parameterization error by up to 17% and improve goodness of fit by up to 34%. The accuracy of signal recovery improves by about 23%, 34%, and 42% for basin scales, respectively, in low‐latitude, mid‐latitude, and high‐latitude zones. When applied to the GRACE (‐FO) data, we see the optimized parameterization scheme reduces noise by up to 1.84 cm in the surface mass change time series. Additionally, the optimally parameterized mascon solution help to enhance signal recovery in mid‐to‐high latitude regions. We discuss and quantify benefits of variable‐sized mason parameterizations for surface mass change recovery and suggest the optimal scheme based on the simulation and real data processing. Overall, the optimized parameterization scheme will benefit finer‐scale mass change signal recovery for mascon solution.