Modeling of scattering properties of mineral aerosols using modified beta function

Abstract

[1] In the combined experiment from Amsterdam and modeling study, the spheroid is applied to represent the real mineral aerosols, and the single scattering properties of spheroids are computed using the T matrix combined with the improved geometric optical method in the wider size range and aspect ratio range. After that a modeling method for the scattering matrices of the feldspar, quartz, and red clay is proposed. In this approach, the ensemble-average scattering matrix is calculated by using the number density distribution deduced from the fit of the measured normalized projected surface area distribution with the modified beta function and the shape distribution obtained by the least squares fit of all the six measured scattering elements. On the other hand, the models of scattering matrices using the lognormal function to fit the measured normalized number distribution and fit the measured normalized projected surface area distribution are also conducted as comparison. Furthermore, the asymmetry parameter is calculated in order to further verify the reliability of the proposed method. Simulation experiments indicate that the simulated scattering matrices with the proposed method are rather close to the measured scattering matrices for the three mineral aerosols, and this proposed numerical model can provide a simple, reliable, and efficient method to reproduce the scattering properties of the mineral aerosols based on the Amsterdam database.