The Unique Value of Landsurface Temperature for Mapping Evapotranspiration and Drought

Landsurface temperature (LST) is a diagnostic variable that conveys valuable information about surface moisture status and vegetation health. Retrieved using satellite imagery collected in the thermal infrared (TIR) wavebands, LST is used routinely in constraining surface energy balance models for estimating evapotranspiration (ET) and for monitoring drought-induced stress onset, signaled by anomalous values of actual-to-potential ET ratio. This talk will provide an overview of use of LST collected at multiple spatial and temporal resolutions with polar and geostationary satellites for monitoring ET and drought at field to global scales. The unique value of LST in diagnosing ancillary moisture sources difficult to capture using prognostic water balance models will be highlighted, as well as the use of LST as a fast response variable in detecting rapid onset drought events. The spatial resolution afforded by Landsat TIR imagery allows ET assessments at the sub-field scale, which can be temporally supported by data fusion with MODIS and geostationary based ET retrievals to map daily water use at scales of water management.