干旱区生态环境知识资源中心

A comprehensive experimental plan has been designed to investigate the potential and the limitations associated with the use of a large aperture scintillometer (LAS) to infer path average sensible heat flux over different surfaces in the context of the Semi-Arid Land-Surface-Atmosphere (SALSA) Program. Scintillometer based estimates of sensible heat are compared to those measured by eddy correlation systems over different type of surfaces: sparse healthy grassland and a transect of mesquite and degraded grass. The complexity of the transect is associated with the type and the cover of the vegetation canopy as well as with changes in topography. The issue of validating satellite based (NOAA-AVHRR) estimates of area-averaged surface fluxes is discussed and results are presented. Finally an example of using the LAS to validate aggregation scheme over heterogeneous surfaces is provided.