Optical and microphysical parameters of arid dust aerosol

The parameters of heavily dusty air in an aerosol chamber under the conditions of an arid zone are studied. The transmission, optical density, Angstrom parameter, aerosol absorption coefficient, and visibility range are calculated. The temporal and spectral dependences of the optical parameters are analyzed. The regularities of the particle-size distribution function in strongly inhomogeneous dust aerosol are studied for coarsely (with a diameter more than 1 μm) and finely dispersed (with a diameter of less than 1 μm) fractions. The sizes and concentrations of the aerosol particles in air were determined using a photoelectric aerosol counter together with a 15-channel analyzer. We present the absorption spectra of coarsely and finely dispersed dust aerosol collected under different meteorological conditions. The possible mechanisms of variations in the aerosol disperse composition are analyzed.