Combining the Penman-Monteith equation with measurements of surface temperature and reflectance to estimate evaporation rates of semiarid grassland

Remote sensing in hydrology

“…Moran et al [70] have compared the method for estimating relative rates of ET with observations over agricultural fields and showed it could be used for irrigation scheduling purposes. More recently, Moran et al [71] have shown the technique has potential for computing ET over natural grassland ecosystems.…”

Assessing eddy-covariance flux tower location bias across the Fluxnet-Canada Research Network based on remote sensing and footprint modelling

“…Moran et al, 1997;Running et al, 2004). Studies on the use of satellite-derived vegetation reflectance indices have shown that these indices are significantly correlated with carbon or water flux strength (Moran and Jackson, 1991;Moran et al, 1994Moran et al, , 1995Moran et al, , 1996Nouvellon et al, 2001;Holifield et al, 2003;Bergheime et al, 2006), and as a result remotely sensed vegetation indices can provide a surrogate of the surface flux source strength. Therefore, the combination of footprint climatology modelling and remotely sensed moderate-resolution image data can potentially be used to assess the representativeness, more formally the sensor location bias (SLB), of an EC flux tower over a heterogeneous surface area (Kim et al, 2006;Chen et al, 2009a).…”

Regional estimation and validation of remotely sensed evapotranspiration in China

“…However, the use of radiometric surface temperature as a substitute for the aerodynamic temperature in the original Penman-Monteith model leads to substantial error, especially over partial vegetation cover, because the radiometric surface temperature is a composite temperature consisting of soil and vegetation temperatures. Yet such error can be reduced in several ways: through an introduction of an extra-resistance (Kustas and Norman, 1996;Kustas et al, 1989), by switching from singleresistance models to a two-source model, by using more complicated multilayer models (Choudhury and Monteith, 1988;Lhomme et al, 1994a,b;Norman et al, 1995), by developing an empirical formula to estimate the aerodynamic temperature (Huang et al, 1993) and by incorporating a vegetation index within the model (Moran et al, 1994(Moran et al, , 1996. A Surface Energy Balance System (SEBS) for the estimation of atmospheric turbulent fluxes and surface evaporation using satellite earth observation data in the visible, near infra-red and thermal infrared frequency range has been designed for composite terrain with heterogeneous surfaces at a larger scale (Su, 2002).…”