NLC particle properties from a five-color lidar observation at 54°N

On June 13/14, 1998, a first simultaneous five-color lidar measurement of a noctilucent cloud was realized. The experiment was made possible by the fact that at the site of our Institute (54 degrees N), dark summer nights allow lidar observations of overhead noctilucent clouds (NLCs) without expensive spectral filters. We determine the size distribution of the NLC particles assuming spherical ice particles with a monomodal, lognormal size distribution. To this end we introduce a new method for calculation of the NLC particle properties. For the latter the following ranges are found: Particle number density N = 260-610 cm(-3), median radius r(m) = 20.2-27.5 nm, and distribution width sigma = 1.5-1.6. Cross checks using different wavelength combinations confirm the robustness of the NLC particle property results. The results are similar to those from recent lidar work on noctilucent clouds, observed at arctic latitudes.