Remote sensing and modeling of global evapotranspiration

Terrestrial water cycle is of critical importance to a wide array of Earth system processes. It plays a central role in climate and meteorology, plant community dynamics, and carbon and nutrient biogeochemistry (Vörösmarty et al. 1998). Evapotranspiration (ET) is an important component of the terrestrial water cycle. At the global scale, it represents more than 60% of precipitation inputs (L’vovich and White 1990), thereby conveying an important constraint on water availability at the land surface. Through links between stomatal conductance, carbon exchange, and water use efficiency in plant canopies (e.g., Hari et al. 1986; Raich et al. 1991; Woodward and Smith 1994; Sellers et al. 1996; Farquhar et al. 2002), ET serves as a regulator of key ecosystem processes. This, in turn, controls the large areal distribution of plant communities and net primary production of vegetation (e.g., Dang et al. 1997; Oren et al. 1999; Misson et al. 2004; Zhao and Running 2010).