In this section, we highlight some of the questions and directions to guide future research into ET, E0, and their roles in monitoring and forecasting drought.
As always, scientists and their products' users clamor for improvements in the spatial and temporal resolutions of data for driving models and of the resulting derived information. This aligns with a call from the agricultural and drought-monitoring communities for an increase in satellite overpass frequency, perhaps by future additional LANDSAT missions. A current drive to improve the estimation of ET from lakes and reservoirs should make significant contributions both to water-resources planning and response to hydrological drought, particularly in the western United States. With all the recent developments in ET- and E0-based drought monitoring, the next steps toward advancing the science of predictions would be to develop real-time forecast products. These would build on the FRET product (Section 11.3.5) and expand to subseasonal and seasonal forecast timescales.