Schemes for Parameterizing Evaporation from a Non-Plant-Covered Surface and Their Impact on Partitioning the Surface Energy in Land Air Exchange Parameterization

Abstract

The correct simulation of the sensible and latent heat fluxes from a non-plant-covered surface is very important in designing the surface scheme for modeling the processes in the land?air exchange. However, using different bare soil evaporation schemes in land surface parameterization, an error in partitioning the surface fluxes can be introduced. In parameterization of evaporation from a non-plant-covered surface in resistance representation, the α and ? approaches are commonly used in corresponding formulas where the α and ? are functions of soil water content. The performance of different schemes within these approaches is briefly discussed. For that purpose six schemes, based on different dependence α or ? on volumetric soil moisture content and its saturated value, are used. The latent and sensible heat fluxes and the ground temperature outputs were obtained from the numerical tests using the foregoing schemes. The tests were based on time integrations by the bare soil parameterization scheme using real data. The datasets obtained over the experimental site in Rimski ?an?evi, Yugoslavia, on chernozem soil were used. The obtained values of the latent and sensible heat fluxes and the ground temperature were compared with the observed values. Finally, their variability was considered using a simple root-mean-square analysis.