ABSTRACT
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, 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. Satellite observations of the earth’s time-variable gravity field from the Gravity Recovery and Climate Experiment (GRACE) mission have provided another unique opportunity of monitoring TWS variations from space. This chapter compares GRACE TWS data with other independent estimates of TWS for selected regions and large river basins. The objective is to explore the potential for GRACE to observe TWS variations and to develop a framework for its validation.
