Data from a high resolution radiometer AVHRR (580-680 nm optical lengthwaves) installed on the "NOAA-11" satellite as well as TV (500-700 nm) and IR (8000-12000 nm) equipment of the Russia satellite "Meteor-2/16" were used to study the evolution of dust storms for 1-30 September 1989 in Tajikistan, Uzbekistan, Turkmenistan and Afghanistan. These data help to validate the hypothesis, that long-term dusted boundary layer (duration of the order of a day or more), but of comparatively not high optical density (4-10 km meteorological visibility range at the 20-50 km background), is formed after the northwest intrusions into a region of intensive cold fronts at the surface wind velocities of 7-15 m/s. Stability of dust clouds of vertical power to 3-3.5 km (up to an inversion level) is explained by an action of collective buoyancy factors at heating the dust particles of 2-4 ??m in mean diameter by solar radiation. The more intensive intrusions stimulate a formation of simultaneously dust and water clouds. The last partially reduce the solar radiation (by the calculations of the order of 30-50%) and decrease the role of buoyancy factors. Thus, initiated is the intensive but short-term dusted boundary layer at horizontal visibility of 50-200 m. ?? 1994.
Additional publication details
The origin and evolution of dust clouds in Central Asia