Izvestiya, Atmospheric and Oceanic Physics: Passive Dosimetry of the Natural Ultraviolet Flux in a Snow Cover under Conditions of Different Dustiness of the Surface Atmosphere. M. P. Tentyukov, V. P. Lyutoev, B. D. Belan, E. G. Yazikov, D. V. Simonenkov, I. S. Sobolev, R. Yu. Gavrilov, O. V. Kustov, and V. S. Buchelnikov