Computation of a global mascon solution from satellite gravimetry data

We present an innovative global mass concentration (mascon) solution, "GCL-Mascon2024", derived using the short-arc approach to estimate spatially enhanced mass variations on the Earth's surface. This monthly solution is based on K-/Ka-band ranging (KBR) satellite-to-satellite tracking data from the Gravity Recovery and Climate Experiment (GRACE) mission. Compared to contemporary GRACE mascon solution computations, we introduce three key advancements: (1) a frequency-dependent data weighting strategy to mitigate low-frequency noise in the satellite observations; (2) a variable-shaped mascon geometry incorporating physical constraints such as coastlines and river basin boundaries to reduce signal leakage and better capture temporal gravity variations; and (3) a regularization scheme integrating climate factors and cryospheric elevation models to address the ill-posed nature of mascon estimation. Temporal signals from GCL-Mascon2024 show 7% to 20% lower residuals over continental regions compared to Release-06 (RL06) mascon solutions from GSFC, CSR, and JPL. For various river basins, GCL-Mascon2024 solutions reduce random noise over non-humid river basins by 37% relative to contemporary mascon products. In desert regions, residual analyses after removing climatological components reveal that GCL-Mascon2024 and JPL RL06 solutions are roughly equivalent in accuracy, with a 28% noise reduction compared to GSFC and CSR RL06 solutions. This study underscores the potential of GCL-Mascon2024 to enhance the accuracy of gravity field solutions, offering valuable insights into global mass variations, which is of importance for various geoscience applications.