Spectronephelometric Study of the Aerosol Transformation with Artificial Change of Relative Humidity

Water vapor condensation and evaporation is one of the main processes of the atmospheric aerosoltransformation, significantly affecting its radiative characteristics. Models of the aerosol optical proper-ties are usually based on the assumption of the similar change of the radius of the particles of certainaerosol fraction with relative humidity. Size dependence of the aerosol condensation activity earlier wasstudied using impactors and optical microscope (Meszaros 1971) and photoelectric aerosol counters(Laktionov 1988). Both methods are unsuitable for particles with radii r ≤ 0.2 mcm. In the presentstudy, we made an attempt to investigate the possibility of the evaluation of the dependence of theparticle response on the variation of the relative humidity upon dry particle size with help of thenephelometric and polarimetric measurements.