Hydrology and Land Surface Studies
Basin scale estimates of evapotranspiration using GRACE and other observations
Article first published online: 26 OCT 2004
Copyright 2004 by the American Geophysical Union.
Geophysical Research Letters
Volume 31, Issue 20, October 2004
How to Cite
2004), Basin scale estimates of evapotranspiration using GRACE and other observations, Geophys. Res. Lett., 31, L20504, doi:10.1029/2004GL020873., , , , , , and (
- Issue published online: 26 OCT 2004
- Article first published online: 26 OCT 2004
- Manuscript Accepted: 27 SEP 2004
- Manuscript Revised: 7 SEP 2004
- Manuscript Received: 29 JUN 2004
 Evapotranspiration is integral to studies of the Earth system, yet it is difficult to measure on regional scales. One estimation technique is a terrestrial water budget, i.e., total precipitation minus the sum of evapotranspiration and net runoff equals the change in water storage. Gravity Recovery and Climate Experiment (GRACE) satellite gravity observations are now enabling closure of this equation by providing the terrestrial water storage change. Equations are presented here for estimating evapotranspiration using observation based information, taking into account the unique nature of GRACE observations. GRACE water storage changes are first substantiated by comparing with results from a land surface model and a combined atmospheric-terrestrial water budget approach. Evapotranspiration is then estimated for 14 time periods over the Mississippi River basin and compared with output from three modeling systems. The GRACE estimates generally lay in the middle of the models and may provide skill in evaluating modeled evapotranspiration.