Abstract
SAGE four-channel transmission profiles are inverted to retrieve the extinction profiles from which the aerosol Ångström coefficient α is obtained. The procedure allows one to check the influence of the NO2 absorption profile, which is small below 25 km. The results compare well with those obtained by a completely different procedure at NASA Langley Research Center, and the main features of the α profiles seem to be significant, even considering the rather large error bars. The relation between the retrieved Ångström coefficient, the particle effective radius and the asymmetry factor is considered.