[OPTICAL REVIEW Vol. 17, No. 6 (2010) 507-512]
© 2010 The Japan Society of Applied Physics

Optical Depth and Multiple Scattering Depolarization in Liquid Clouds

Dukhyeon KIM*, Hai Du CHEONG, Yonggi KIM1, Sergey VOLKOV2, and Jeongsoon LEE3

Hanbat National University, Division of Cultural Studies, Daejeon 305-719, Korea
1Kongju National University, Kongju 314-701, Korea
2Institute of Atmospheric Optics, Siberian Branch of the Russsian Academy of Science, Tomsk, Russia
3Environment Measurement Group, Korea Research Institute of Standards and Science (KRISS), 1 Doryong-dong, Yusung-gu, Daejeon 305-600, Korea

(Received March 6, 2010; Accepted October 1, 2010)

In this paper, we calculate multiply scattered lidar signals with Monte Carlo method for measuring optical depth (extinction coefficient), effective size of water droplets, and liquid water content of clouds, and present algorithms that implement our method. We calculated multiply scattered lidar signals for various water droplet sizes and liquid water contents using a Monte Carlo method. A simple correspondence between water droplet optical depth and the degree of polarization in a modified gamma size distribution (C1 cloud) is found. We also calculated the degree of polarization of a lidar signal for a given liquid water content, finding that the degree of polarization is only dependent on optical depth. Since the Raman lidar signal of liquid water depends on the total volume of the water droplet, the effective radius of the water droplet can thus be recovered from the degree of polarization of the lidar signal and the Raman signal of the liquid water.

Key words: multiple scattering, remote sensing, depolarization, optical depth, droplet size

*E-mail address: dhkim7575@paran.com