The ESA Earth System Model (ESA ESM) provides a synthetic data set of the time-variable global gravity field that includes realistic mass variations in atmosphere, oceans, terrestrial water storage, continental ice sheets, and the solid Earth on a wide set of spatial and temporal frequencies. For more than 10 years already, it is widely applied as a source model in end-to-end simulation studies for future gravity missions, but has been also utilized to study novel gravity observing concepts on the ground. For those purposes, the ESM needs to include a wide range of signals even at very small spatial scales which might not yet have been reliably observed by any active satellite mission.
The updated ESA ESM 3.0 improves upon its predecessor by utilizing ECMWF’s ERA5 atmospheric reanalysis along with dedicated simulated ocean bottom pressure data from the MPIOM ocean model. In addition, it offers a small ensemble of co- and post-seismic earthquake signals, an updated GIA model, additional ice mass balance signals from previously not considered Arctic glaciers, sub-monthly surface-mass balance changes and a more realistic representation of ice sheet dynamics. Extreme hydrometeorological events as well as climate-driven and anthropogenic impacts on continental water storage are represented through an update of the hydrological component. Additionally, the ESM separately includes ocean bottom pressure variations along the western slope of the Atlantic, representing variations in the meridional overturning circulation as a critically important component of the interactively coupled global climate system as well as estimated trend signals from sediment erosion and subsequent marine deposition.
The ESA ESM 3.0 is available with a 6-hourly resolution from January 2007 until December 2020 in the from of Stokes coefficients up to degree and order 180.
Since 2002, time-lapse satellite gravimetry missions have successfully observed global time-variable mass transport. The GRACE (Gravity Recovery And Climate Experiment; Tapley et al., 2004, 2019) mission and its successor, GRACE-FO (GRACE-Follow On; Chen et al., 2022; Landerer et al., 2020), have almost continuously delivered monthly observations of the gravity field for more than two decades. As GRACE-FO approaches the end of its lifetime, new satellite gravity missions are planned for launch. For the continuation of the record, GRACE-C (GRACE-Continuity by NASA and the German Space Agency at DLR with support from GFZ, BMWK, BMFB, HGF and MPG ) is planned to be launched in 2028 in a near-polar orbit at an altitude of ~500 km. GRACE-C will be followed by the Next Generation Gravity Mission (NGGM) launched by the European Space Agency (ESA) in 2032 in an inclined orbit of 65–70 degrees at an altitude of ~400 km. In their overlapping period, these two satellite pairs form the Mass-change And Geoscience International Constellation (MAGIC).
In the frame of the ESA SING (Studying the Impact of the NGGM and MAGIC Gravity missions) project (SING project website, 2026), extensive simulations have been performed to evaluate the added value of extended gravity field measurements in time with enhanced spatial and temporal resolution, and, reduced latency in data availability. Synthetic observations of the gravity field have been generated at Levels 2 and 3 for GRACE-C-like, NGGM and MAGIC satellite configurations using a closed-loop numerical simulator integrating instrument noise, background model errors, and realistic satellite orbits. The simulations utilize target Earth signals from the ESA Earth System Model ESM 2.0 (Dobslaw et al., 2015), including hydrology, ice, and solid Earth components. Two parameterisation strategies used in this study yield simulated gravity solutions of mean fields at 5-day and 30-day resolutions. The other two strategies result in direct estimation of the trend and annual signal (trendannual) and direct estimation of the long-term trend (trendonly). For each parameterisation strategy, the data products are separated into three levels (L2, L2P, and L3). L2 are Stokes coefficients of the simulated Earth’s potential provided separately for each mission scenario and expressed in the spherical harmonic basis in ICGEM format. L2p and L3 synthetic data represent simulated surface mass anomalies provided separately for each mission scenario and expressed in equivalent water heights over regular 1°*1° grids in NetCDF format. The L3 data were corrected for Glacial Isostatic Adjustment (GIA), while the L2p data were not. . The full description of the data and methods is provided in the data description publication (Schlaak et al. in prep.), and the file structure of this data set is fully described in the file inventory.
The resolution of all data products (L2a, L2b, L2P, L3) for each mission scenario (GRACE-C-like, NGGM, MAGIC) depends on the simulation type described in Schlaak et al. (in prep.). For 5-daily solutions, the spatial resolution corresponds to ca. 285 km (d/o 70). For monthly solutions, the temporal resolution is 30 days, with a spatial resolution of ca. 166 km (d/o 120). Trend and annual signals (trend-and-annual solutions) have been estimated simultaneously over a period of 12 years (with 1-year increments) and a spatial resolution of ca. 150 km (d/o 130). For trend-only solutions, the spatial resolution is increased to 125 km, with trend estimates over 5 and 12 years.
Additionally, empirical Variance-Covariance Matrices (VCMs) are provided for L2a and L3b data for the 5-daily and monthly simulation types, computed from Monte Carlo simulations (Schlaak et al., in prep.).
GRACE/GRACE-FO Level-3 products based on GFZ RL06 Level-2B products (Dahle & Murböck, 2019) representing ice-mass changes for the Antarctic Ice Sheet (AIS) and the Greenland Ice Sheet (GIS). The ice-mass changes are provided both as basin average product and as gridded product.
Basin-average ice-mass changes are obtained using the inversion procedure based on a forward modelling approach as described in Sasgen et al. (2013) for the AIS and Sasgen et al. (2012) for the GIS.
Gridded ice-mass changes are provided at polar-stereographic grids with a grid spacing of 50 x 50 km^2. The applied algorithm is based on tailored sensitivity kernels (Döhne et al., 2023; Groh & Horwath, 2021), and has also been used to generate gravimetric mass balance products within the ESA Climate Change Initiative (CCI) projects for the AIS and the GIS.
These Level-3 products are visualized at GFZ's web portal GravIS (https://gravis.gfz.de).
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Version History:
13 March 2026:
Release of Version 0005. This is an update of Version 0004 of the same data set (see changelog).
16 January 2025:
Release of Version 0004. This is an update of Version 0003 of the same data set (see changelog).
21 April 2023:
Release of Version 0003. This is an update of Version 0002 of the same data set (see changelog).
09 June 2020:
Release of Version 0002. This is an update of Version 0001 of the same data set (see changelog).
All changes and updates are documented in the changelog available via the data download section. Previously released versions of this data set are available in the "old_versions" subfolder of the data download folder.