Evaluation of Atmospheric Aerosol Particle Size Distribution from Scattering Measurements in the Visible and Infrared

The atmospheric aerosol particle size distribution was examined using measured spectral scattering coefficients in the wavelength region 0.40–2.27 μ. It was found that the aerosol on a particular day can be represented by a two-component composite, the main component having a Junge distribution of the form dN/d logr = Cr−n and the other having either a distribution of larger particles similar to that of aerosols found in maritime air or a relatively monodisperse distribution contained in a narrow radius interval. This study shows that estimates of aerosol size distribution may be in error if based only on attenuation measurements in the visible region.