Numerical study of extinction of visible and infrared radiation transformed by preferentially oriented plate crystals

Extinction properties of an ensemble of semi-transparent plate crystals in preferred orientation are studied at wavelengths of visible and infrared ranges using the physical optics method. The work illustrates some calculations of the differential scattering coefficient in the near-forward and the exact forward directions. The features of energy and polarization characteristics of directly transmitted radiation through a set of particles are discussed, as depended on parameters of medium and the incident radiation. It is shown that the effect of polarization on extinction by large plates at certain combination of microphysical parameters of medium and the wavelength can be pronounced even for clean ice. By increasing the real part of complex refractive index, the polarized effect can be increased a few times. It is illustrated as an influence of flutter of plates on the considered characteristics. ► At coherent sum of diffracted and refracted fields, physical optics method is used. ► Pronounced spectral behavior of extinction of optical radiation is analyzed. ► Polarized features of extinction are investigated for set of oriented plates. ► Peculiarities of scattering near the forward direction are shown.