Dynamics of fractional of aerosol in the surface air of the boreal zone of Western Siberia (based on observational at the Fonovaya observatory). Part 2. “Snow" photophoresis
M.P. Tentyukov1,2, D.A. Timushev3, D.V. Simonenkov1, B.D. Belan1, K.A. Shukurov4, A.V. Kozlov1
1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
2Pitirim Sorokin Syktyvkar state University, Syktyvkar, Russia
3Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, Physics and Mathematics Institute, Syktyvkar, Russia
4A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Moscow, Russia
Keywords: atmospheric aerosol, aerosol lifetime, levitation, microphysical properties of aerosols, snow photophoresis, photophoretic force, infrared radiation
Abstract
The features of the intra-day dynamics of fractionation of aerosol particles in surface air during the formation of a winter aerosol field above the Fonovaya observatory of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, (Tomsk Region) are studied. The distributions of hourly average count concentrations of aerosol particles 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 was found that intra-day variations in hourly average count concentrations of aerosol particles in the size range d = 0.3-2.0 mm in some cases are determined by the action of radiometric forces - “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 reasonably assumed that “snow” photophoresis certainly affects the radiation balance of the winter atmosphere and should be taken into account when modeling vertical transport of aerosols in the lower troposphere.
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