Studies of the Orientation of Crystalline Particles in Ice Clouds by a Scanning Lidar
Grigorii Kokhanenko, Yu. S. Balin, Anatoli G. Borovoi, Mikhail Novoselov
Abstract
Results of studies of the horizontal orientation of crystalline particles using the LOSA-M3 scanning polarization lidar are presented. In 2018 and 2021, several series of measurements of the crystalline upper cloudiness structure were carried out in the zenith scanning mode. In contrast to sounding only in the vertical direction, observations of the dependence of lidar signal characteristics (intensity and depolarization ratio) on the angle of lidar axis tilt 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 corner reflection in ice clouds.