The technology is described for constructing the set of the initial data using the technique of eliminating the model’s bias for seasonal experiments with a numerical climate model of the Institute of Numerical Mathematics of the Russian Academy of Sciences (INM RAS), which was originally developed for multi-annual experiments. A comparative analysis of the multiyear mean correlation coefficients of the anomalies for different meteorogical fields and regions in winter seasons with similar results of the SLAV model is carried out. The presence of an increase in the correlation coefficients of anomalies in the years of the El Niño and La Niña phenomena is revealed. The coincidence of the phases of the quasi-biennial oscillation is shown. The model anomalies of sea-level pressure, the amount of precipitation, and the surface temperature are compared with the anomalies of the reanalysis and the similarity is shown.

The first empirical orthogonal function (EOF) of intraannual evolution of temperature averaged along the circle of latitude in the 0-60-km layer is calcul ated using the data of the 500-year...

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