Open AccessParameterization of the scattering and absorption properties of individual ice crystals
Author(s) -
Yang Ping,
Liou K. N.,
Wyser Klaus,
Mitchell David
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd900755
Subject(s) - ice crystals , scattering , materials science , absorption (acoustics) , extinction (optical mineralogy) , crystal (programming language) , spheres , optics , computational physics , truncation (statistics) , light scattering , molecular physics , physics , mathematics , statistics , astronomy , computer science , programming language
We present parameterizations of the single‐scattering properties for individual ice crystals of various habits based on the results computed from the accurate light scattering calculations. The projected area, volume, and single‐scattering properties of ice crystals with various shapes and sizes are computed for 56 narrow spectral bands covering 0.2–5 μm. The ice crystal habits considered in this study are hexagonal plates, solid and hollow columns, planar and spatial bullet rosettes, and aggregates that are commonly observed in cirrus clouds. Using the observational relationships between the aspect ratios and the sizes of ice crystals, we can define the three‐dimensional structure of these ice crystal habits with respect to their maximum dimensions for light scattering calculations. The volume and projected area of ice crystals, expressed in terms of the diameters of the corresponding equivalent spheres, are first parameterized by employing the ice crystal maximum dimensions. Further, various analytical expressions as functions of the effective dimensions of ice crystals have been developed to parameterize the extinction and absorption efficiencies, asymmetry factor, and the truncation of the forward peak energy in the phase function. The present parameterization scheme provides an efficient approach to obtain the basic scattering and absorption properties of nonspherical ice crystals.