We present a global climatology of aerosol parameters derived recently by optical inversion of extinction profiles measured by the SAGE II experiment. The aerosol parameters of interest are the particle number density and the modal radius and width of the particle size distribution supposed to be lognormal. We further derived the surface area density from those three aerosol parameters and compared our results with data retrieved from in situ measurements. In several cases, we found an underestimation for SAGE II derived values with respect to corresponding in situ values. This discrepancy between both data sets is discussed and interpreted in terms of fundamental limitations of aerosol remote sounding in the UV-Vis range.