Utility of remote sensing based two-source energy balance model to estimate land surface fluxes during SMACEX

A two-source(soil+vegetation) energy balance model using radiometric surface temperature as a key boundary condition was applied to remote sensing data collected under a range of crop cover and soil moisture conditions during the Soil Moisture Atmosphere Coupling Experiment(SMACEX). Two formulations of the heat exchange, one allowing interaction between the soil and vegetation(series version) and another neglecting such interaction (parallel version) were evaluated. Comparison of local model output with tower-based flux observations indicated that both the parallel and series resistance formulations produced similar estimates with root-mean-square-differences(RMSD) values ranging from approximately 20 to 50 W m/sup -2/ for net radiation and latent heat fluxes, respectively. Although both the series and parallel versions gave similar results, the parallel resistance formulation was more sensitive to model parameter specification, particularly in accounting for vegetation clumping via row crop planting effects on flux partitioning.