蒙古气旋引发的一次山西沙尘天气分析

Analysis of a Sandstorm in Shanxi Caused by Mongolia Cyclone

利用常规气象观测资料和NECP再分析资料，对2013年3月9日出现在山西的沙尘天气进行了分析。结果表明：①前期降水偏少、气温偏高是此次沙尘天气发生的有利背景，蒙古气旋、冷锋、副冷锋是此次沙尘天气的主要影响系统。②地面3h变压的正的大值区和强的阵风发生区域有很好的对应关系。③500hPa的水平螺旋度正值对地面气旋的移动有指示意义；沙尘天气出现在500hPa水平螺旋度正值范围偏西、偏西南区域。④300hPa以上的高空急流为双急流型，急流中心风速相对较小、垂直运动相对较弱以及混合层高度相对较低是没有发生大范围沙尘暴的主要原因。

Based on NCEP reanalysis data and ordinary observation data, the sand storm occurred in Shanxi province on 9 March 2013 was analyzed. The results show that there were several advantageous for the dust weather, such as the less rainfall in the prior period and the higher temperature ; the main impact system of the storm were Mongolia cyclone, cold front, secondary cold front; the strong wind area was corresponded with the greater value of the 3h allobaric field; the relatively small wind speed of the double jet above 300hPa , the relatively weak vertical movement and the relatively low mixing layer height were the adverse conditions of the large - scale sandstorm; the horizontal spiral degrees on 500hPa was a syndicate of the cyclone movement on the ground; the sand and the dust weather was occurred on the west or the southwest side of the horizontal spiral degrees on 500hPa