Database of scattering properties of small ice crystals: implications for satellite retrieval algorithms and numerical models

Junshik Um, University of Illinois at Urbana-Champaign

Usage Details

Calculations of single-scattering properties of different idealized models of small ice crystals (i.e., column, droxtal, Gaussian random sphere, and budding Bucky ball) at visible and near-infrared wavelengths are proposed. In particular, we propose to extend the study of Um and McFarquhar (2011; 2013) by computing the single-scattering properties of four different idealized models of small ice crystals. The scattering calculations will be performed for a much larger variety of shapes, sizes, and wavelengths than for previous studies. The generated library of single-scattering properties will be stored together with libraries of microphysical properties acquired from the in situ observations that serve as the basis of the shape models used in the scattering libraries. We will show how the single-scattering properties of natural ice crystals differ from those previously calculated using crude approximations (i.e., due to uncertainties in crystal shapes and calculation methods) in order to develop a guideline on how to determine and achieve the required accuracy in calculations of single-scattering properties. The resulting database on the single-scattering properties of realistically shaped ice crystals can be used to improve cloud property satellite retrieval algorithms and the representation of ice clouds in numerical small- and large-scale models.