Abstract
The scalar roughness for sensible beat can be directly formulated in terms of the surface temperature. Therefore, in the case of an anisothermal vegetation canopy, the concept of a scalar roughness is ill defined and it may vary greatly depending on the method and scale of measurement of the surface temperature. Through an analysis of the turbulent transport phenomena inside the vegetation canopy, it is shown how this uncertainty and variability of the scalar roughness of a vertically anisothermal surface can be reduced by defining a properly weighted average surface temperature. Implications are discussed for the optimal measurement of surface temperature by remote sensing with radiation thermometers.
