The USGS has released an on-demand Landsat Provisional Actual Evapotranspiration (ETa) Science Product that will be useful in understanding the spatiotemporal dynamics of water use over land surfaces and for monitoring hydrologic, agricultural, and environmental systems.
ETa is generated by calculating the latent heat flux based on surface energy balance principles using a robust model and provides an estimate of the quantity of water that is removed from a surface due to the processes of evaporation and transpiration.
ETa is scene-based and derived from the Landsat Collection 1 Level-2 Provisional Surface Temperature product. Landsat Provisional Surface Temperature is input to the Operational Simplified Surface Energy Balance (SSEBop) model along with external auxiliary data to quantify daily total ETa (Senay et al., 2013; Senay, 2018).
ETa is currently available for Landsat 4-5 Thematic Mapper, Landsat 7 Enhanced Thematic Mapper Plus, and Landsat 8 Operational Land Imager/Thermal Infrared Sensor scenes acquired over the conterminous United States from 1982-present through the USGS EROS Center Science Processing Architecture (ESPA) on-demand interface.
For more information please visit the Landsat Provisional Actual Evapotranspiration product page.
ETa belongs to a suite of USGS research-quality, applications-ready, Landsat-derived science products aimed at reducing the burden of data processing for the user community. Visit the Landsat Science Products web page to learn more about the types of products available and how to download them.