Backscatter Lidar Depolarization Study of NLC at Sondrestrom, Greenland

The spherical shape of NLC particles is often an assumed property without much scientific support. Such information would impact our understanding of NLC formation and interpreting backscatter signals. The depolarization lidar technique has been used to characterize the degree of depolarization, and thereby determine the sphericity of ice particles. During the summer of 2003, Sondrestrom Rayleigh lidar system has been operated to make depolarization measurements by discriminating the cross-polarized component from NLC backscatter signals. We will report our initial experimental results and discuss the nonspherical scattering properties of NLC particles using the T-matrix algorithm.