Validation of gravity recovery and climate experiment data for assessment of terrestrial water storage variations

Global water cycle directly affects the global circulation of both atmosphere and ocean and, hence, is instrumental in shaping the weather and climate of the earth. However, our quantitative knowledge of the global water cycle is quite poor; large-scale measurements of the states and fluxes of various global reservoirs on time scales appropriate to their dynamics are deficient. Terrestrial water storage (TWS), as a fundamental component of the global water cycle, is of great importance for water resources, climate, agriculture, and ecosystem. TWS controls the partitioning of precipitation into evaporation and runoff and the partitioning of net radiation into the sensible and latent heat fluxes. More importantly, TWS change (TWSC) is a basic quantity in closing terrestrial water budgets (Ngo-Duc et al. 2005; Güntner et al. 2007; Syed et al. 2008; Yeh and Famiglietti 2008).