CALCULATION AND ANALYSIS ON SCATTERING CHARACTERISTICS OF NON-SPHERICAL PARTICLES OF HAZE

Abstract. The light scattering characteristics of sulfate, one of the main pollutant particles in haze, are calculated by T-Matrix method at a target wavelength of 550 nm. The variation between shape factors (such as effective radius and aspect ratio) and scattering phase functions with different types and shapes are analysed in small scale range. The influence of shape factors on scattering cross section and depolarization ratio of particles are also discussed. Results show that the shape of particles has great effects on the spatial distribution of scattering energy, and the scattering properties of particles are sensitive to aspect ratio. The depolarization of spherical particles is close to zero, while the difference between ellipsoidal and cylindrical particles reaches several orders of magnitude. When the equivalent radius is larger than 1.0 μm, the mean depolarization ratio of the non-spherical particles is greater than 0.2. The mean depolarization ratio and scattering cross section of non-spherical particle change continuously with a certain aspect ratio and particle size range, and the shape of some particles can be therefore distinguished under certain conditions.