| Summary: | The ocean mass budget plays a crucial role in predicting future changes in ocean mass and sea level. In recent efforts to reconcile observations from GRACE and GRACE-Follow On satellites with steric-corrected altimetry and models of contributions from land and ice a discrepancy in the mass budget has been reported (Wang et al, 2022; Barnoud et al, 2022), in particular in the period following the launch of GRACE-Follow On. In this study, we aim to compare 20 years of GRACE-observed mass changes with steric-corrected altimetry and GRD-induced sea level changes resulting from landmass changes. To accomplish this, we produce monthly 3D global mass change products with a spatial resolution of 0.5 degrees, covering the period from 2003 to 2022. We improve the processing steps for steric-corrected satellite altimetry by accounting for ocean bottom deformation, removing the global mean contribution of halosteric sea level change, and replacing the radiometer-based wet tropospheric correction with a model-based correction. Our results indicate that both the steric-corrected altimetry and ocean mass reconstruction from GRD-induced sea level change is in agreement with the GRACE observations on both long-term and seasonal time scales and regional scales. We also find that a recent slowdown in GRACE-observed mass change during the GRACE-FO period can be attributed to terrestrial water storage variability driven by a long phase of La Nina and a deceleration in the mass loss of Greenland and Antarctic ice sheets.
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