关键词: 毛乌素沙地, 位涡, Q矢量, 沙尘天气

Abstract: Based on the routine synoptic chart,satellite nephogram, wet potential vortex and Q vector and some other data, comprehensive analysis for the two cases of dust storms happened on April 30, 2007 and May 2, 2007 respectively over Mu Us Desert are presented in the paper. The results show: the generation of mesoscale convection instability in the low troposphere with MPV1 < 0 provides the instability energy for the generation of the dry convection; the dry intrusion and turbulence intrusion which come from the upstream area in the middle and high layers of troposphere play a very important role in the formation of the dust storm weather; sub-circulation triggered by the divergence and convergence of Q vector in the low troposphere provides the dynamic mechanism for the generation, development and maintenance of the dust storm weather. The effect of downward convection capable potential energy should be considered in the β scale dust storm forecasting and warning in Mu Us Desert.

Key words: Mu Us Desert, potential vortex, Q vector, dust storm weather