Relationship between radiative and aerodynamic surface temperature over sparsely vegetated surfaces: estimation of sensible heat flux

Radiative surface temperature has been widely used in past to estimate surface energy balance components from field to regional scales. This approach has been applied successfully over surfaces with near full vegetation cover; however, large discrepancies between measured and simulated surface fluxes have been observed over surfaces with sparse vegetation cover. The reason for these discrepancies is that the assumption that radiative surface temperature can be assimilated to aerodynamic surface temperature is not correct over sparsely vegetated surfaces. In the study an empirical parameterization relating aerodynamic surface temperature to radiative temperature and the leaf area index is used to estimate sensible heat flux over sparse shrub in the central east site during the Hapex Sahel experiment. The result shows that this parameterization leads to reasonable estimates of sensible heat flux, the RMSE was about 50 Wm/sup 2/.