Dynamics of Distribution of Aerosol Fractions in the Surface Air of the Boreal Zone of Western Siberia (Based on Observations at the Fonovaya Observatory)—Part 2. “Snow” Photophoresis

Abstract

Features of the daily dynamics of aerosol fractions in surface air during the generation of a winter aerosol field above the Fonovaya Observatory of V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, (Tomsk, Russia) are studied. The distributions of hourly average particulate count are analyzed along with the spatial distributions of the probability of transport of moisture-bearing air masses taking into account the time intervals of snow accumulation at the observatory in the first half of winter 2022/23 (from November 17, 2022, to January 30, 2023). It is found that the daily variations in hourly average particulate count in the particle size range d = 0.3–2.0 μm are sometimes determined by radiometric forces, that is, “snow” photophoresis caused by and associated with the manifestation of the microphysical properties of aerosol in the field of infrared radiation outgoing from the snow cover. It is reasonable to assume that “snow” photophoresis certainly affects the radiation balance in the winter atmosphere and should be taken into account when modeling vertical transport of aerosols in the lower troposphere.