Estimating surface energy fluxes with remotely sensed data

The relationship between modelled and radiometrically observed surface temperature is explored in this paper. Implied in many assimilation attempts is an equivalence in the definition of modelled and observed state variables. We contend and attempt to demonstrate here that this assumption is not of general validity. The analysis is conducted with a Soil-Vegetation-Atmosphere. Transfer model and field data collected during the Southern Great Plains Experiment of 1999 (SGP99). It is shown from supporting equations that the modelled temperature evolves in a dynamic equilibrium with the fluxes, where the radiative flux depends strictly on a radiometric temperature and the sensible and latent heat fluxes depend on an aerodynamic temperature, resulting in a hybrid modelled temperature. It is shown that enforcing an equality between modelled and observed temperatures may result in a logical deterioration in model estimates of latent and sensible heat fluxes.