Retrieval of aerosol size distributions by inversion of simulated aureole data in the presence of multiple scattering.

Inversion of solar almucantar data is a simple and practical method of obtaining aerosol size distributions. In this paper, we have inverted a number of sets of simulated data, using the standard single scattering approximation, to test the errors involved in ignoring multiple scattering. We have also inverted the data using two techniques: one, a modification of the method proposed by Deirmendjian and Sekera; and the other that of McPeters and Green. Inversion results strongly suggest that the accuracy of the retrieved size distribution can be significantly improved by use of our modified Deirmendjian-Sekera approach, in which multiple scattering by molecules is included along with single scattering by molecules and aerosols.