SURFACE-ENERGY BALANCE - ANALYSIS OF THE PARAMETERIZATION OF THE GROUND HEAT-FLUX

The parameterization of the surface energy balance in short-range disp ersion models is currently receiving increased attention. Most of the current treatments rely on adaptations of the original schemes of Van Ulden and Holtslag, and Berkovicz and Prahm. These parameterizations a re based on conventional meteorological network measurements of e.g. w ind, temperature and humidity. The ground heat flux is expressed as a constant fraction of the net radiation, as is the sensible heat flux. An alternative approach relates the ground heat flux to the temperatur e gradient within the soil. These schemes are compared with direct mea surements. The aim is to test their ability to simulate the daily heat -flux cycle under various meteorological conditions.