Cirrus Optical Properties (COP)

We calculated a large amount of single scattering properties of hexagonal ice crystals with help of a ray tracing model. Part of these data is available on our anonymous ftp server. We created two packages, each containing data for single crystals of different sizes, calculated for different wavelengths, together with a FORTRAN code, which allows mixing of these data of single particles to those of size distributions, i.e. clouds of ice crystals.

• COP contains scattering functions of randomly oriented hexagonal columns and plates in the size range from 2 µm to 2000 µm at 31 wavelengths between 0.28 µm and 3.7 µm. This data set is described in:

Hess, Michael and Matthias Wiegner (1994): COP: a data library of optical properties of hexagonal ice crystals, Appl. Opt.,33, 7740-7746.

• COPE contains the six independent scattering matrix elements of randomly oriented perfect and imperfect hexagonal columns in the size range from 2 µm to 2000 µm at 5 wavelengths of the ATSR-2 instrument. These data are described in:

Hess, M., R.B.A. Koelemeijer, and P. Stammes (1998): Scattering matrices of imperfect hexagonal ice crystals, J. Quant. Spectros. Radiat. Transfer, 60, 301-308.

COPE was made during a working visit of Michael Hess at KNMI, De Bilt, The Netherlands.