Water Balance Estimates From Time-Variable Satellite Gravity

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

0309678 Wahr Monthly solutions for the Earth's global gravity field, as provided by the GRACE satellite mission, will be used to estimate and interpret month-to-month changes in the vertically-integrated distribution of liquid water and snow stored on land. The spherical harmonic coefficients of the gravity field provided by GRACE will be used to estimate mass variations averaged over continental regions on the Earth's surface. This will involve the construction of averaging functions that are specially tailored for those regions. These variations will be interpreted in terms of changes in the mass of water stored in those regions. Among the things that will be estimated and interpreted are: changes in the total amount of water stored within large regions (greater than 200,000 square km); precipitation minus evaporation averaged over large river basins; changes in snowpack at northern latitudes; and changes in the total water stored in regions with large underground aquifers. This work, which will form the PhD thesis project of a graduate student, will be a first step towards integrating time-variable satellite gravity observations into the hydrological sciences. These observations constitute a new and innovative data type for hydrology, with considerable promise for improved understanding of the global water cycle.