OPTICAL INVESTIGATIONS OF DUST STORMS DURING USSR-US EXPERIMENTS IN TAJIKISTAN, 1989

The results of studies on dust aerosol optical properties obtained during the U.S.S.R.-U.S. experiment are discussed. The ground-based and aircraft measurements carried out during the experiment allow the estimation of characteristic values of aerosol optical depth, aerosol light-scattering coefficients, the degree of linear polarization, and aureole phase functions for different atmospheric conditions in Central Soviet Asia. Two dust storms were observed for which the recorded aerosol optical depth at lambda = 0.55 mu m {tau(a)(0.55)} reached 1.5 on 16 and 17 September 1989, and 3.5 on 20 and 21 September 1989. The optical characteristics (spectral dependence of the optical depth, degree of linear polarization) were similar for two dust episodes.