Studies of the orientation of crystalline particles in ice clouds by scanning lidar
G.P. Kokhanenko, Yu.S. Balin, A.G. Borovoi, M.M. Novoselov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: crystal clouds, polarization lidar, depolarization, particle orientation
Abstract
Results of studies of the horizontal orientation of crystalline particles carried out using a scanning polarization lidar LOSA-M3 are presented During 2018-2021, several series of measurements of the structure of high-level crystalline clouds were carried out in the zenith scanning mode. In contrast to sounding only in the vertical direction, observations of the dependence of the lidar signal characteristics (intensity and depolarization ratio) on the angle of lidar axis inclination make it possible to identify the phase composition of clouds (water or crystalline) and measure the distribution of particle deviation relative to the horizontal plane (flutter). In layers with a pronounced specular reflection, the relationship between the signal intensity and the slope of the sounding path at small angles (up to 5°) is well described by an exponential dependence. The results of sounding when scanning up to angles of 45-50° showed a high probability of the existence of a corner reflection in ice clouds.
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