Identification of Individual Precipitation Particles Using Particle Polarization Lidar

Tokyo Metropolitan University, 6-6, Asahigaoka, Hino, Tokyo, Japan This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 9 April 2026

Abstract

A particle polarization lidar (PPL) was developed to identify raindrops and snowflakes based on the polarization information of individual precipitation particles. In past polarized lidar observations, temporally and spatially averaged depolarization ratios of snow clouds and snowflakes have been measured. Although individual snowflakes vary in shape and size, investigations into the extent of variability in the depolarization ratios of individual snowflakes have not been conducted. Therefore, we artificially created snowflakes and evaluated their depolarization ratios. Moreover, in an experimental measurement using PPL, a dynamic precipitation process with alternating snowfall and rainfall was observed. The capability of the proposed method to identify raindrops, wet snowflakes, and dry snowflakes based on the depolarization ratio and particle size relationship was demonstrated.