Satellite laser ranging mascons: Ice sheet and global ocean mass change from 1993-Present

Abstract:

Satellite laser ranging (SLR) observations have played a critical role in the successes of the GRACE and GRACE-FO missions by providing accurate estimates of the C₂₀ and C₃₀ spherical harmonic coefficients. Recently we have expanded the capabilities of time variable gravity determination with SLR through the estimation of large, regularized mascons from 1993-Present. We validate this new product by comparing to time variable gravity signals derived from GRACE and GRACE-FO during the span of those missions. Additionally, we compare the pre-GRACE estimates to the latest results of the ice sheet mass balance inter-comparison exercise (IMBIE), and to global ocean mass estimates derived from steric-corrected altimetry. This new low-resolution data set is a unique contribution as it extends the global gravimetry record by a decade into the past and bridges the gap between the GRACE and GRACE-FO missions.