Optical characteristics of irregular atmospheric ice columns
A.V. Konoshonkin1,2
1National Research Tomsk State University, 36, Lenin Avenue, Tomsk, 634050,Russia
2V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: деформированный ледяной столбик, перистые облака, физическая оптика, рассеяние света, ледяные кристаллы, irregular ice columns, cirrus clouds, physical optics, light scattering, ice crystals
Abstract
The study of cirrus clouds, which significantly affect the climate, is carried out using lidars. Interpretation of the lidar data is based on the direct solution of the problem of light scattering by particles of crystal clouds. Optical characteristics of perfect ice hexagonal columns, obtained previously, poorly agree with the lidar observation results. The work describes calculations of the optical characteristics of irregular hexagonal ice columns, which are in a good agreement with the experimental results. The calculations for particles with deformation of a dihedral angle of 90° are presented. It is shown that the logarithm of the scattering matrix can be well linearly approximated by the logarithm of the particle size. This can significantly speed up the calculations of the optical characteristics of clouds. It is ascertained that the optical characteristics are in a good agreement with the lidar observation results throughout the entire range of sizes calculated even at deformation angles of a few degrees.
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