G3P - The Global Gravity-based Groundwater Product

Groundwater is one of the most important freshwater resources for mankind and for ecosystems. Due to its fundamental role in the Earth’s water and energy cycles, groundwater has been declared as an Essential Climate Variable (ECV) by GCOS, the Global Climate Observing System. The Copernicus Services, however, do not yet deliver data on this fundamental resource, nor is there any other data source worldwide that operationally provides information on changing groundwater resources in a consistent way, observation-based, and with global coverage. This gap will be closed by G3P, the Global Gravity-based Groundwater Product, a European Union’s Horizon 2020 project.

Setting-up the groundwater product as a new ECV of the existing product portfolio of three Copernicus core services, i.e., combining products of the Global Land Monitoring Service (snow water equivalent, soil water index, river water levels), the Copernicus Climate Change Service (C3S) (surface soil moisture, glacier mass changes, lake water level), and the Emergency Management Service (river discharge and simulated storage compartments).

G3P aims at developing a product of groundwater storage variations with global coverage and monthly resolution from 2002 until present by a cross-cutting combination of Total Water Storage data by GRACE and GRACE-FO satellite gravity measures with water storage data that are based on the existing portfolio of the Copernicus services.

Find more details at G3P&rsguo;s project webpage

FMI Arctic Space Centre provides first-hand information about the cryosphere via space-borne observations of the Earth. To resolve for groundwater changes, variations in the various water storage compartments, including snow, have to be quantified and subtracted from the total water storage. Within G3P, FMI provides Snow Water Equivalent (SWE), a measure for the water column height of a snow layer, if it would be melted completely. In order to ensure a spatial and temporal continuous product for G3P groundwater processing, remote sensed SWE, by FMI’s Copernicus Global Land service (CGLS) and the Globsnow project, are gap-filled and globally expanded with a combination of model-based SWE estimates from MERRA2 and ERA5-Land reanalysis.

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Project consortium
Horizon_EU_flag This project has received funding from
the European Union’s Horizon 2020 research and innovation programme
under grant agreement No 870353.