Study of crystalline particles with a pronounced horizontal orientation using a scanning lidar LOSA-M3.

Abstract

The article presents the results of observations of the crystalline cloud polarization structure carried out in Tomsk in April-October 2018. Scanning lidar LOSA-M3 makes it possible to measure the polarization characteristics of backscattering signals from aerosol and clouds at wavelength 532 and 1064 nm. Zenith scanning was carried out at a rate of 0.5 degrees per second, which corresponds to a shift in the direction of sounding by 2 minutes between laser pulses. The results show that the degree of horizontal orientation of the particles can vary significantly in different parts of the cloud. The dependence of the scattering intensity on the inclination angle is well described by the exponential dependence. The values of cross-polarized component in most cases shows a weak decline with the angle, but its change are smaller than the measurement errors. We can conclude that it is practically independent on the inclination angle. The scattering intensity at a wavelength of 532 nm has a wider distribution than at 1064 nm.