Photophoresis of fractal-like soot aggregates: Microphysical model, comparison with experiment, and possible atmospheric manifestations

A microphysical model describing the photophoretic motion of soot aggregates with allowance for their fractal structure is presented. The comparison with known experimental data has been performed and their good qualitative and quantitative agreement has been found. The calculated characteristics of the motion of fractal-like soot aggregates in the atmospheric radiation field are presented. It is shown that photophoretic effects for soot aerosol under conditions of a steady-state atmosphere in the model for fractal-like particles manifest themselves most significantly at heights of the upper troposphere and middle stratosphere.