Abstract:

Scattering matrices of perfect and imperfect hexagonal ice crystals are presented and compared to those of so-called polycrystals, proposed by Macke et al. Scattering properties of imperfect hexagonal crystals are calculated using statistical deviations of ray paths during the ray tracing in perfect hexagonal crystals. At a certain degree of deviation, the resulting scattering matrix becomes similar to that of polycrystals. Therefore, this method forms a link between perfect hexagonal columns and polycrystals. The optical properties of these imperfect crystals are sensitive to the aspect ratio (and thus to particle size) as well as to the allowed deviation from the perfect shape. This approach to simulate imperdect ice crystals introduces new possibilities for interpretation of satellite measurements.