The results of theoretical analysis of photophoretic motion of soot particles in the field of the Earth' thermal radiation in a stationary atmosphere are presented. In calculations the up- and downfluxes of thermal radiation are taken into account. It is shown that positive "thermal" photophoresis potentially can be the effective mechanism of vertical transport for micron-sized soot particles at stratospheric altitudes.
aerosol, photophoresis, thermal radiation, soot particles