Photophoretic motion of soot aerosols in field of shortwave solar radiation

Abstract

The results of a theoretical analysis of the photophoretic motion of soot particles in the field of solar radiation under the conditions of stationary atmosphere are presented. In the refined radiation block of the model, integral fluxes of solar radiation were calculated by the Monte Carlo method in the context of the approximation of a plane-parallel horizontally homogeneous atmosphere. An analysis of the obtained results again verifies the possibility of significant photophoretic exhibitions for soot aerosol particles in the stratosphere; solar photophoresis can be considered an efficient mechanism of the vertical transport of absorbing submicron particles up to heights of the middle stratosphere. Forces of solar photophoresis can compete with forces of gravity up to heights of 30–35 km for particles of submicron and micron sizes. At the same time, the estimations again demonstrated the low efficiency of radiometric photophoresis for weakly absorbing, dense, and strongly heat-conducting particles of the atmospheric aerosol. © 2012, Pleiades Publishing, Ltd.