A numerical simulation of the water and sea ice dynamics of the Arctic Ocean was carried out to identify the physical mechanisms that determine the variability of the state of the ice cover. For the research, we used the coupled ocean-ice regional numerical model of the North Atlantic and the Arctic SibCIOM, developed at the ICMMG SB RAS. In the coarse of this study, heat fluxes on the ice boundary from the ocean and the atmosphere were analyzed, and the correlation coefficients of these fluxes with the volume of ice in the region in question were calculated. The results obtained indicate to a significant effect on the Arctic ice of the heat coming from the ocean along the trajectory of the warm Atlantic water.