[OPTICAL REVIEW Vol. 8, No. 6 (2001) 476-479]
Measurement of Water Cloud Particle Size with a Dual-Polarization Pulsed Bistatic Lidar
Nobuo SUGIMOTO*, Ichiro MATSUI and Atsushi SHIMIZU
National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506 Japan
(Received August 21, 2001; Accepted October 19, 2001)
A new bistatic lidar was developed for measuring water cloud particle size at the base of lower clouds. The lidar uses a pulsed Nd:YAG laser at 532 nm and a receiver having a polarization analyzer located at a suitable scattering angle. Cloud particle size (mode radius of the assumed size distribution) was derived from the ratio of the polarization components of the scattered light based on the single scattering Mie theory. The experiment was performed on board the research vessel Mirai in the northwestern Pacific. Particle size at the bottom of maritime cumulus and stratus was measured, and the difference between the internal structures of cumulus and stratus was observed. The effect of multiple scattering was studied by changing the observing scattering angle. The effect was not significant when the penetration depth was less than 50 m.
Key words : lidar, bistatic lidar, cloud, particle size, Mie scattering, aerosols, aerosol cloud interaction