Globally Gridded Mass Distributions from GRACE and GRACE-FO

Satellite-based GRACE and GRACE-FO monthly gravity fields are conventionally provided in terms of spherical harmonic coefficients that are difficult to process by potential users with non-geodetic scientific background. We therefore post-process Level-2 gravity fields into globally gridded estimates of terrestrial water storage and ocean bottom pressure (Fig. 1). Post-processing includes replacement of certain low-degree spherical harmonic coefficients that are not or not well determined from GRACE alone; the reduction of correlated errors via anisotropic filtering; and the reduction of geophysical mass anomalies unrelated to the water cycle, as e.g., atmospheric masses, co- and post-seismic deformations, and deformations of the solid Earth related to glacial isostatic adjustment. 

Variability of Ocean Bottom Pressure as calculated from GRACE Level-3 products derived from GFZ RL05a.
Variability of Terrestrial Water Storage (right) as calculated from GRACE Level-3 products derived from GFZ RL05a.

Reference Paper

Zhang, L., Dobslaw, H., and Thomas, M. (2016): Globally gridded terrestrial water storage, variations from GRACE satellite gravimetry for hydrometeorological applications. - Geophysical Journal International, 206 (1), pp. 368 – 378. doi: 10.1093/gji/ggw153.