New approach to parameterization of physical processes in soil in numerical model

With the high mesh resolution (horizontal grid size down to 2,8 km) used in the current version of COSMO model, the existing soil parameterization schemes have to be significantly improved. Hence in August 2012, IMWM-NRI in collaboration with the Institute of Agrophysics Polish Academy of Science (IA-PAS) started a new project, entitled “New approach to parameterization of physical processes in soil in numerical model”.

Basing on recent theoretical and experimental analysis of the overhaul physical phenomena in soil the new set of parameterizations is being developed, taking into consideration various physical and microphysical processes in soil (including fluid dynamics in porous media, soil dynamics, water cycle in soil and soil–plant–water interaction). At the moment we are working on parameterization of bare soil evaporation, on vertical and horizontal soil water transport and runoff from soil layers. The preliminary results from new mathematical formulation of bare soil evaporation implemented in COSMO model will be presented. We have also improved theoretical description of vertical soil water transport (mainly temperature dependency of hydraulic diffusivity) to test it in next stage of the study.

During the Conference on Agricultural and Forest Meteorology we will present our preliminary results, future plans and directions. While the current results are promising, the additional improvements are still required. In the nearest future it is planned to combine our new approach with TILE and MOSAIC parameterizations available in the TERRA model, and to use data received from IA-PAS field experiments and from Satellite Remote Sensing Center in soil-related COSMO model numerical experiments.