ATMOSPHERIC SCATTERING IN THE VISIBLE AND INFRARED

Abstract

The atmospheric aerosol particle-size distribution was examined using experimental spectral scattering coefficients in the wavelength interval 0.40 to 2.27 mu . The results show that the aerosol on a particular day can be represented by a two-component composite distribution, the main component being described by a Junge distribution of the form dN/d log r = Cr/sup -/s and the other by a distribution similar to that of aerosols found in maritime air, or by a relatively monodisperse distribution contained in a narrow radius interval. This study showed that estimates of the aerosol particle size distribution may be in error if based only on attenuation measurements in the visible region. The contribution of the larger particles to the scattering coefficients is not apparent unless the infrared is also investigated. (auth)