Deduction of aerosol concentrations from 1.06-microm lidar measurements

A theoretical study has been made of the problem of deducing tropospheric aerosol mass concentrations from lidar observations at 1.06 microm. Brief results of calculations at other wavelengths are also presented. Experimentally measured aerosol distributions have been used and also simulated by a model, in which lognormal functions are fitted to individual distribution modes. The errors contained in this simple model are shown to be much less than the variations observed in backscattering cross sections. The problem of determination of the accumulation mode concentration, for a pollution aerosol, is analyzed in some detail. Calculations have also been made of the effects of humidity on backscattering cross sections and the results compared with experimental measurements.