“Pochva”: a new hydro-thermal process model in soil, snow, vegetation for application in atmosphere numerical models

Abstract. This work presents the land model “Pochva”. “Pochva” is a model of hydro-thermal processes at the Earth surface and in the underlying medium. The model simulates the main hydro-thermal parameters of the surface, soil layer, vegetation and snow layer. Its soil process scheme allows to use physical parameters having vertical variations along the soil profile. Its snow processes scheme is a multiple layer scheme and has a numerical algorithm allowing to solve both cases of extremely thin and extremely thick layer. The model is marked by a particular accuracy in simulating the water phase transitions in soil and snow, and by the autonomy in the determination of the lower boundary condition in the soil column. The model can be used as a stand-alone land-surface model driven by observed or analytical forcing data, or coupled to an atmospheric model, either global or limited-area, either in forecast regime or climatic (hindcast) regime. The results of coupling “Pochva” to the numerical weather prediction limited-area model “Bolam” are presented in this article.