Water lost from the land surface directly into the atmosphere is a key part of the global water cycle. This transfer can come in the form of evaporation and transpiration, the loss of water through the stomates in the leaves of plants.
The combination of these two, evapotranspiration, varies across regions and seasons, and is a significant fraction of the land surface water budget. Accurate forecasts and projections of evapotranspiration have applications in agriculture, water resource management and flood prediction.
This paper combines existing global evapotranspiration estimates to create a new global product with an observationally constrained estimate of uncertainty. It utilises the latest release of ground-based estimates to show that even point-based evapotranspiration estimates have information about much larger spatial scales.