Multi-Spectral Extinction Measurements to Deduce the Complex Refractive Index and the Size Distribution of Aerosol Particles

Abstract

It is shown that high?precision extinction measurements over a spectral interval can he used to infer aerosol optical parameters including the, heretofore elusive, complex index of refraction, if aerosol particles in the atmosphere are assumed to he spherical Mie scatters with a uniform refractive index over this spectral interval and their sizes are distributed according to the modified gamma function. The error analysis shows that the degree of precision required is attainable, thus making it a viable and unique real?time remote sensing device. No assumptions are made on the vertical profile of aerosols and hence, in a satellite application (occultation experiment), the difficulties due to the sphericity of the medium can be avoided.