The data set provides surface water storage (SWS) and groundwater storage (GWS) data for the Northern East African Rift region.
SWS is estimated from a combination of lake water levels observed with satellite altimetry and water surface area derived from the water occurrence maps. The truncated pyramid formula estimates water volume change from these two data sets. The volume change is then converted to surface water storage and uniformly distributed over the lake surface, leading to SWS. To match the spatial resolution of SWS with the spatial resolution of terrestrial water storage (TWS), the resulting maps are spatially Gaussian filtered, half-width 250km.
TWS, as observed with the GRACE and GRACE-FO satellite mission, monitors the sum of changes in the water storage compartments SWS, GWS, snow and ice, and root-zone soil moisture (RZSM). Thus, to estimate GWS for this data set, the water storage compartments are subtracted from TWS. Here, we neglect snow and ice.
The temporal coverage of the data is from April 2020 to May 2023.
In Irrgang et al. (2020), we have trained a convolutional neural network to perform a so-called downscaling task. This downscaling aims to recover the fine-structure continental water storage distribution on the South American continent from coarse-resolution space-borne gravimetry observations. Here, we share data sets that were used for training the neural network, namely (1) monthly pairs of gridded terrestrial water storage anomalies (TWSA) of the South American continent and (2) surface water storage anomalies (SWSA) in the Amazonas region for the time period 2003-2019. TWSAs were used as target (output) values of the neural network and were derived from the Land Surface Discharge Model (LSDM, Dill, 2008). The corresponding input values were calculated by spatially smoothing the TWSA fields with a 600 km Gaussian filter. After training the neural network over the time period of 2003 to 2018, its performance was tested and compared to LSDM for the subsequent year 2019.
The Global Gravity-based Groundwater Product (G3P) provides groundwater storage anomalies (GWSA) from a cross-cutting combination of GRACE/GRACE-FO-based terrestrial water storage (TWS) and storage compartments of the water cycle (WSCs) that are part of the Copernicus portfolio. The data set comprises gridded anomalies of groundwater, TWS, and the WSCs glacier, snow, soil moisture and surface water bodies plus layers containing uncertainty information for the individual data products. All WSCs are spatially filtered with a Gaussian filter to be compatible with TWS. Spatial coverage is global, except Greenland and Antarctica, with 0.5-degree resolution. Temporal coverage is from April 2002 to September 2023 with monthly temporal resolution. Gridded data sets are available as NetCDF files containing variables for the parameter value as anomaly in mm equivalent water height and the parameter’s uncertainty as mm equivalent water height.
The latest version of the data is visualized at the GravIS portal: https://gravis.gfz-potsdam.de/gws. From GravIS, the data is also available as area averages for several large river basins and aquifers, as well as for climatically similar regions.
G3P was funded by the EU Horizon 2020 programme in response to the call LC-SPACE-04-EO-2019-2020 “Copernicus evolution – Research activities in support of cross-cutting applications between Copernicus services” under grant agreement No. 870353.
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Version History:
10 March 2023: Release of Version v1.11. That version is the initial release of the data (Güntner et al., 2023; https://doi.org/10.5880/G3P.2023.001)
(DATE TO BE ADDED) Release of Version v1.12. Temporal coverage has been extended until September 2023.
The Global Gravity-based Groundwater Product (G3P) provides groundwater storage anomalies (GWSA) from a cross-cutting combination of GRACE/GRACE-FO-based terrestrial water storage (TWS) and storage compartments of the water cycle (WSCs) that are part of the Copernicus portfolio. The data set comprises gridded anomalies of groundwater, TWS, and the WSCs glacier, snow, soil moisture and surface water bodies plus layers containing uncertainty information for the individual data products. All WSCs are spatially filtered with a Gaussian filter to be compatible with TWS. Spatial coverage is global, except Greenland and Antarctica, with 0.5-degree resolution. Temporal coverage is from April 2002 to December 2020 with monthly temporal resolution. Gridded data sets are available as NetCDF files containing variables for the parameter value as anomaly in mm equivalent water height and the parameter’s uncertainty as mm equivalent water height.
The latest version of the data is visualized at the GravIS portal: https://gravis.gfz-potsdam.de/gws. From GravIS, the data is also available as area averages for several large river basins and aquifers, as well as for climatically similar regions.
G3P was funded by the EU Horizon 2020 programme in response to the call LC-SPACE-04-EO-2019-2020 “Copernicus evolution – Research activities in support of cross-cutting applications between Copernicus services” under grant agreement No. 870353.
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Version History:
10 March 2023:
Release of Version v1.11. This is the initial release of the data.