Modeling the radiative transfer properties of media containing particles of moderately and highly elongated shape

The transfer of polarized radiation in a medium containing size-shape distr ibutions of randomly oriented nonspherical particles is modeled by employin g a prolate spheroidal particle model. The parameter characterizing the mea n departure from sphericity of the shape-distribution is the effective aspe ct ratio of the particle ensemble. The radiance, the degree of linear polar ization and the degree of circular polarization are strongly sensitive to a variation of the effective aspect ratio. This shape-sensitivity is observe d consistently from size-shape distributions containing mainly moderately a spherical particles to those containing predominantly highly aspherical par ticles. When the effective aspect ratio varies between 4 and 12, the degree of linear polarization changes by as much as 0.15. At certain angles from the sun, the radiance changes by as much as 60% within the same range of ef fective aspect ratios.