Simulation of Snow Accumulation and Meltin the Votkinsk Reservoir Catchment Usingthe WRF-ARW Model

N. A. Kalinin, A. N. Shikhov, and E. M. Sviyazov

Proposed is the method of computation of snow accumulation using the prognostic fields of precipitation based on the WRF-ARW mesoscale numerical model of the atmosphere that was tested using the data for 2012–2014. The snowmelt intensity in river catchments was computed by the method worked out by P.P. Kuz’min. This method is based on the solution of the equation of snow cover heat balance under assumption that the temperature of melting snow is equal to 0°C. The results of the modeling were validated by comparing the actual and computed snow accumulation and snow-covered area in the catchment under study. It is demonstrated that the proposed method based on prognostic fields of precipitation enables objective retrieving the spatial distribution of snow with the rather high spatial resolution, taking into account the terrain effects. The snow-covered area during the period of spring snowmelt is simulated with higher reliability than snow water equivalent. It is revealed that the difference between the simulated and actual snow accumulation reaching the maximum in spring, is caused both by the overestimation of precipitation amount by the WRF-ARW model and by the effects of local features of snow courses.