Influence of Thermal Roughness Parameterizations on the Turbulent Fluxes Simulations by Atmospheric Surface Layer Model

Models of the atmospheric surface layer describe the processes of momentum, heat and moisture exchange between the atmosphere and the underlying surface. In the framework of the Monin-Obukhov similarity theory, the height of thermal roughness determines the efficiency of heat transfer in the surface layer. This paper considers different ways of determining this characteristic on the basis of existing parameterizations implemented in the actively developing the surface layer model of the INM RAS Earth System Model. The results obtained using the previously proposed parameterizations were analyzed and compared with observational data for different surface types. The sensitivity of the model reproduction of the heat flux to the choice of the thermal roughness parameterization was evaluated. The obtained significant differences both in the roughness parameter and in the estimates of heat and momentum fluxes obtained in the model depending on the surface type indicate the importance of taking into account the surface type in the schemes for calculating turbulent flows.