GravIS

The Gravity Information Service (GravIS) of the German Research Centre for Geosciences (GFZ) is operated in collaboration with the Alfred-Wegener-Institut (AWI) and Technische Universität Dresden. Data products derived from the gravimetric Earth observation satellite missions GRACE and GRACE-FO are widely used by scientists and other interested users to study mass variations in the Earth system. However, processing of GRACE/GRACE-FO data into user-friendly products for dedicated geophysical applications is nontrivial, neither when starting from original satellite observations nor from the level of gravity field products. In order to enable the usage of satellite gravimetry data for a broader community, user-friendly ('Level-3') products are generated by above institutions.
GravIS visualizes and describes Level-3 products based on the most recent GRACE and GRACE-FO data release from GFZ. In addition, Level-3 products based on the most recent release of combined models of different analysis centers for GRACE and GRACE-FO of the International Gravity Field Service (IGFS) are offered as well. The products provided at GravIS are available for download at GFZ's Information System and Data Center (ISDC).
GRACE/GRACE-FO data processing is structured into sensor data analysis (Level-0 to Level-1), global gravity field estimation (Level-1 to Level-2), and geophysical mass anomaly inversion (Level-2 to Level-3). Level-3 products at GravIS comprise gridded mass anomalies as well as basin average time series and are available for terrestrial water storage over non-glaciated regions, bottom pressure variations in the oceans, and ice-mass changes in both Antarctica and Greenland. Additionally, GravIS also provides products of a prototype for monitoring groundwater storage anomalies which was developed within the EU Horizon 2020 project Global Gravity-based Groundwater Product (G3P). In order to achieve the highest possible accuracy of the mass anomalies, several post-processing steps have been applied to the Level-2 spherical harmonic coefficients before inversion.