关键词: 沙尘, 颗粒物浓度, 消光系数, 金属元素, 天气分析

Abstract:

The dust event on May 25–26, 2014 in Wuhan Hubei province was studied by integrating multiplex information including mass concentration, metal element contents of atmospheric particle, vertical particle extinction, backward trajectory, surface meteorological parameters and synoptic analysis. The results show that the dust came from the sandstorm occurred in southern Xinjiang Taklamakan desert and Inner Mongolia Badan Jaran desert and Teng Ko Erh desert and then transported to east and south of China with cold air blowing. The PM₁₀ mass concentration decried along the trajectory, with hourly average exceeding 2000 μg/m³, 1000 μg/m³ and 500 μg/m³ in Lanzhou, Yinchuan and Wuhan respectively. During the dust event, coarse particle was dominant, PM₁₀ concentration increasing rapidly, and proportion of PM_2.5 to PM₁₀ decreased to about 35%. The concentrations of dust trace element Ca, V, Ba and Fe increased by about 4 times, percentages of the total element concentration doubled and the concentrations of As, Se, Cr, Cu, Zn and Pb from local anthropogenic sources were 1/5–2/5 of previous levels, percentages of the total element concentration decreasing significantly. Two evident dust deposition processes were recorded by Lidar, and the maximum area of extinction appeared near surface around 500 m with the max value at 0.086 km^-1. This paper pilots the analysis method of transporting air pollution using combination of meteorological and environmental measurements.

Key words: dust, particle concentration, particle extinction coefficient, metal element, synoptic analysis