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About 50 % of global mean sea level rise (GMSLR) is caused by changes in global-mean ocean mass which are hydrological variations and melting of land glaciers as well as melting of the major ice sheets in Greenland and Antarctica. Those mass changes are detected by the Gravity Recovery and Climate Experiment (GRACE) mission and its follow-on mission (GRACE-FO). Over ice sheets melting and accumulation of snow and ice leads to geometric surface changes which are observed by high-inclination altimetry missions. Further the solid-earth deformation due to glacial isostatic adjustment (GIA) is of special interest in polar regions, because the signal superimposes ice mass changes.
By combining GRACE and ocean-altimetry data the global fingerprint inversion (Rietbroek et al., 2016) estimates individual mass and steric contributors to the sea-level budget in a joint approach. Here, we present benefits from additionally integrating ice-altimetry data (from ERS-2, Envisat, ICESat, CryoSat-2 missions) to constrain the ice-sheet contributions to GMSLR.

Generally, the inversion accounts for GIA as an a-priori correction from GIA forward modelling. In particular in Antarctica, forward models predict GIA differently. Moreover, the signals due to GIA and ice mass change are in a similar order of magnitude. We demonstrate the potential to parametrize and estimate GIA and ice mass change within a global framework by synthetic experiments. Further we investigate the observational covariance information to account for correlated errors.