北京一次浮尘事件的沙尘化学特征

Chemical characterization of dust in a floating dust event over Beijing

以2000年4月北京一次浮尘天气完整的观测资料为例,进行元素化学分析.本次浮尘期间20种元素总质量浓度为181.49μg/m3,小于同一监测分析方法下沙尘暴期的总元素质量浓度,浮尘过后与1999年3月非沙尘期的元素总质量浓度相近.浮尘后Al,Fe,K,Ca,Si,Ti,Mn元素质量浓度谱分布图形状发生改变,可能暗示着新一轮的大气污染物积累.浮尘事件中粗细粒子中外来源的贡献量各不相同,分别为82.8%和34.5%.

The chemical characteristics of a floating dust event in April 2000 over Beijing were analyzed based on observation data. The total mass concentration of 20 elements in floating dust period was 181.49μg/m^3 , which is much smaller than that in dust storm with the same measurement and analysis method, bigger than that in non-dust period in Mar 1999. The size distributions of A1, Fe, K, Ca, Si, Ti, Mn were changed after the passage of floating dust, which may imply a new accumulation of atmospheric particles. The contributions of remote sources to coarse and fine particles in this case were 82.8 % and 34.5 %, respectively.