Estimation of heat and momentum fluxes over complex terrain using a large aperture scintillometer

A comprehensive experimental plan has been designed to further investigate the potential and the limitations associated with the use of a large apertu re scintillometer (LAS) to infer path average sensible and momentum fluxes over complex surfaces as part of the Semi-Arid Land-Surface-Atmosphere (SAL SA) program. The complexity of the terrain is associated with the type and the cover of the vegetation canopy as well as with changes in topography. S cintillometer based estimates of sensible heat flux and friction velocity a re compared to those measured by eddy correlation systems over a grassland patch, a mesquite patch, and over a transect spanning both patches. The res ults show that considering the complexity of the surface, the overall perfo rmance of the scintillometer is relatively good. (C) 2000 Elsevier Science B.V. All rights reserved.