Towards a global GRACE basin-scale database

Managing water resources is a critical issue because of water scarcity, increased anthropic pressure and reduced reliability related to climate change. The GRACE mission has emerged as the first satellite able to measure total water storage variations and solve water budgets with sufficient accuracy and spatial sensitivity to monitor hydrological systems larger than ~200 000 km2. The objective of this study was to increase access to GRACE water storage variations by providing processed GRACE data for river basins globally. Particular attention was paid to provide unbiased water storage with associated uncertainty estimates, with processing methods validated on the highly instrumented High Plains Aquifer. The global GRACE product includes time series of GRACE total water storage changes (TWSC) from 2002 - 2012 and GLDAS land surface model soil moisture outputs (NOAH, CLM, VIC, and MOSAIC) to estimate GRACE groundwater storage changes. We show how this GRACE product can be used to solve water budgets by applying it to depleted aquifers for irrigation in the Ganges and California Central Valley.