Influence of parameterization of soil processes on numerical forecasts of vertical profiles of air potential temperature

Abstract

Very complex physical processes occurring in the soil have an influence on the structure of the atmospheric boundary layer. These processes, together with sub-grid processes, in general, must be parameterized. A good description of soil (micro)physics, fluid dynamics in porous media, soil dynamics, the water and thermal cycle in soil, and the soil–plants–water–atmosphere relation affects the quality of numerical weather forecasts. The current parameterization of soil's physical processes in the COSMO meteorological model was initially prepared 40 years ago for numerical models with a poor resolution of several kilometres. Nowadays, operational numerical models work with a resolution that has been enhanced significantly. In order to improve the quality of numerical weather prediction, existing parameterizations should be adequately changed. This research was focused on the case of ‘bare soil’. The influence of the changed parameterization of water flux through the soil on forecasts of vertical profiles of potential temperature for the dry and moist cases is presented.