Modification and verification of soil-snow module of INM RAS climate model

Abstract This paper describes the new simple parametrization of land snow cover module for INM RAS climate model. The possible liquid water content in the snow layer and refreezing of melt water are taken into account by the proposed parametrization. This is especially important for transition season modelling, because this phenomenon is observed mainly during the formation and melting of the snow cover, when surface temperature fluctuates around 0 °C. Simulation of snow density evolution is also added. This parameterization was implemented in INM-CM snow module and verified on observation data using ESM-SnowMIP-like protocol. As a result, mean climate snowmelting periods according to INM RAS climate model are refined, particularly in middle and high latitudes. Snow covered area reproduction is also improved. Modified version of snow model on the land can be used coupled with albedo model of a snow-covered surface, which takes into account snow metamorphism, and it can be also applied for sea ice case.