ESTIMATION OF SURFACE-ENERGY BALANCE FROM RADIANT SURFACE-TEMPERATUREAND NOAA AVHRR SENSOR REFLECTANCES OVER AGRICULTURAL AND NATIVE VEGETATION

A model is developed to evaluate surface heat flux densities using the radiant surface temperature and red and near-infrared reflectances fr om the NOAA Advanced Very High Resolution Radiometer sensor. Net radia tion is calculated from an empirical formulation and albedo estimated from satellite observations. Infrared surface temperature is corrected to aerodynamic surface temperature in estimating the sensible heat fl ux and the latent flux is evaluated as the residual of the surface ene rgy balance. When applied to relatively homogeneous agricultural and n ative vegetation, the model yields realistic estimates of sensible and latent heat flux density in the surface layer for cases where either the sensible or latent flux dominates.