Simulation of Snow Water Storage in the Northern Part of the East European Plain in the TerM Land Surface Model

The TerM Land Surface Model (LSM) is based on equations of the land surface block of the INMCM Earth system model. One of the main areas in developing the TerM model is improving the description of hydrological processes. This paper analyzes reproducing the dynamics of snow water storage in the TerM model in the northern part of the East European Plain. The modeled snow water storage is compared with the observational data from snow courses in open terrain (field landscapes). The dynamics of the snow water storage is reproduced using a model configuration with a resolution of 0.5 × 0.5°. The numerical experiments were performed with a time step of 3 h using observational data from weather stations as atmospheric forcing and ERA5 reanalysis data as radiation forcing. The possible sources of modeling errors are analyzed. Based on the results of the analysis, improvements are proposed for the TerM model in terms of the system of equations for snow cover dynamics, parameterization of snow cover roughness, and parameterization of the subgrid distribution of the snow cover. The improved version of the TerM model correctly reproduces the dynamics of the snow water storage in the area under study.