德州一次沙尘天气过程成因及气溶胶粒子的输送路径分析

利用NCEP 1°×1°再分析资料分析了2017年5月4日浮尘和5月5日扬沙天气的成因。结果表明：3日20时—4日08时，蒙古气旋在有利的环流背景下迅速发展，配合冷锋在内蒙古中部和东部形成大范围的强沙尘天气；4日20时—5日08时沙尘通过高空气流输送到华北地区，在自身沉降和较强下沉气流的共同作用下，迅速沉降形成华北地区大范围的浮尘天气；5日08—14时由于西北路冷空气影响，横槽转竖，冷锋加速南下，将大量沙源地的沙尘输送到德州造成扬沙天气。通过HYSPLIT模式对本次过程中气团后向轨迹的模拟，证实以上两个阶段沙尘天气过程中的输送方式及路径。通过分析影响系统、物理量和气象要素发现，蒙古国、我国内蒙古中部沙源地天气系统强度、位置的变化直接影响沙尘天气的类型，高层气流变化与沙尘天气的类型有很好的对应关系。

Analysis on the cause of a sand and dust weather process and transportation pathways of aerosol particles in Dezhou

Utilizing the NCEP (1°×1°) reanalysis data, the causes of the floating dust on 4 and the blowing sand weather on 5 May 2017 are analyzed. It shows that the Mongolia cyclone, which rapidly developed under favorable circulations background, together with the cold front, resulted in a wide range of strong sand and dust weather in the middle and east of the Inner Mongolia Autonomous Region from 20:00 on 3 to 08:00 on 4 May. Through the upper air current, the dust was transported to North China from 20:00 on 4 to 08:00 on 5 May. The dustfall and strong downward flow led to a wide range of floating dust weather in North China. Influenced by northwestern cold air, the transversal trough was converted into a vertical one, the cold front speeded up southward, and the sand and dust were transported to Dezhou and hit there from 08:00 to 14:00 on 5 May. Based on the simulation results of backward trajectory of air mass using HYSPLIT model, the transportation modes and pathways of these two kinds of sand and dust weather were clearly verified. Through the analysis of synoptic systems, physical quantities and meteorological factors, the changes of intensity and position of synoptic systems in Mongolia and the central Inner Mongolia Autonomous Region were found to directly affect the types of the sand and dust weather. The change of upper air current was well correspondent to the types of the sand and dust weather.