AN INVESTIGATION OF OPTICAL AND RADIATIVE PROPERTIES OF DUST AEROSOL

Based on the observational data from the Soviet-American dust research project (Tadjikistan, Sept. 1989), an optical model of the Mid-Asiatic dust aerosol is presented, including spectral dependencies of the single-scattering albedo omega, mean cosine of the scattering phase function g, and possible ranges of the optical thickness variation both for normal conditions and for dust storms. The model is used to study the radiative regime of the dusty atmosphere: modification of the radiative balance at the underlying surface, of the effective flux in the upper atmosphere, and of the vertical profile of the radiative heating rate. The latter agrees reasonably with the data obtained from aerological measurements of the temperature profile during the dust storm of Sept. 17, 1989. Similar computations were made basing on different optical models of dust aerosol for various geographical zones, found in literature.