The Landsat Collection 2 (C2) Level-3 Provisional Actual Evapotranspiration (ETa) Science Product is now available through the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center Science Processing Architecture (ESPA) on-demand interface globally for Landsat 4–9 scenes that are successfully processed to C2 Level-2 Surface Temperature. ETa is the quantity of water that is removed from a surface due to the processes of evaporation and transpiration and is measured in millimeters. ETa can be fundamental in the understanding of the spatiotemporal dynamics of water use over land surfaces.
Landsat C2 Provisional ETa products are generated by solving the surface energy balance equation for the latent heat flux using a robust model. The surface energy balance model used in this ETa calculation is directly derived from the Operational Simplified Surface Energy Balance (SSEBop) model. The Landsat C2 Level-2 Surface Temperature is input to a SSEBop model with external auxiliary data to retrieve the daily total of ETa.
Note that these data are provisional and subject to revision. They are being provided to meet the need for timely best science. The data have not received final approval by the USGS and are provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the data.
Example of the Landsat Collection 2 Provisional Evapotranspiration science product for agricultural fields on the Fucino plain near San Benedetto dei Marsi, Italy. Left: Landsat 9 Collection 2 Natural Color Surface Reflectance Image; right: Landsat 9 Collection 2 Actual Evapotranspiration Image.
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