A Resistance Representation of Schemes for Evaporation from Bare and Partly Plant-covered Surfaces for Use in Atmospheric Models

Abstract

In the parameterization of land surface processes, attention must be devoted to surface evaporation, one of the main processes in the air-land energy exchange. One of the most used approaches is the resistance representation which requires the calculation of aerodynamic resistances. These resistances have been calculated using K theory for different morphologies of plant communities, then the performance of the evaporation schemes within the ?α?, ???, and their combination approaches that parameterize evaporation from bare and partly plant-covered soil surfaces are discussed. Additionally, a new ?α? scheme is proposed based on an assumed power dependence α on volumetric soil moisture content and its saturated value. Finally, the performance of the considered and the proposed schemes is tasted based on time integrations using real data. The first set was for 4 June 1982, and the second for 3 June 1981 at the experimental site in Rimski ?an?evi, Yugoslavia, on chernozem soil, as representative for a bare, and partly plant-covered surface, respectively. The accuracy of the schemes was compared with the observations using a root-mean-square error and the factor-of-deviation analyses.