Scattering of waves is one of the most general physical phenomena, because the overwhelming part of the information about the surrounding world comes to us in the form of scattered electromagnetic or acoustic waves.
Cirrus clouds form the main source of uncertainty in modern numerical models of long-term weather forecast and global climate change.
Optical models of cirrus clouds developed by some international scientific organizations, in particular, by our group, should remove these uncertainties. In particular, our algorithm for the calculation of matrices of light scattering at ice crystal particles far exceeds all existing analogs in the speed. The results obtained have allowed us to propose some new methods for the optical diagnostics of crystal clouds, in which radiation sources are represented by ground-based or space-borne lidars, projector beams, or the solar radiation.