The effect of turbulent motions on the transport of dust and heat in the development stage of dust storms induced by cold front

Abstract

The observation data in the development stage of dust storms induced by cold front were analyzed. The results showed that the contribution of outward and inward interaction to dust and heat transport were less than that of ejection and sweep events. That is, the transportation of dust and heat was not dominated by interactions. In the ejection events, the low- and high-frequency fluctuations dominate the upward transportation of high- and low-concentration dust micro-elements and cold air, respectively. In the sweep events, the low- and high-frequency fluctuations dominate the downward transportation of low- and high-concentration dust micro-elements and hot air. For dust transportation, although the flux directions of the low- and high-frequency fluctuations are opposite, the flux contribution of the low-frequency fluctuation is larger than that of the high-frequency fluctuation. Therefore, directions of dust transportation during dust storms are towards the second-quadrant direction. For heat transport, since the directions of the heat flux of low- and high-frequency fluctuations are the same, the direction of heat transport is towards the fourth quadrant direction.