Light scattering by large irregular ice crystals of cirrus clouds

Abstract

The scattering matrixes for randomly oriented large particles of faceted shapes have been calculated using both the geometrical optics and physical optics approximations. We showed that the scattering matrixes are different for regular and irregular particle shapes since the corner reflection effect is predominant at the backward direction for the regular shapes. In the case of irregular shapes, the scattering matrixes have the common feature. Namely, the elements of the matrix reveal near the backward scattering direction some typical peaks that are explained by interference of the backscattered waves. In particular, the negative polarization effect known in astrophysics can be explained by the interference.