北京春季一次沙尘气溶胶污染过程观测
发布时间：2019-08-06 11:27
【摘要】：利用大气物理综合观测资料分析了2013年3月9日北京市一次沙尘过程前后的气溶胶粒径变化情况和垂直分布特性,比较了霾-沙交替的污染特征差异,并对沙尘来源及传输过程进行解析.结果表明:沙尘开始前近地面为细颗粒物主导的干霾气溶胶污染,该过程在污染物出现分层抬升扩散后得到缓解,地面ρ(PM_(2.5))/ρ(PM_(10))最高达0.93.外源输送抵达的浮尘分布在上空800~2500m范围内,退偏振比平均0.35,明显高于霾气溶胶层.沙尘初期的锋前大风使边界层抬升至900m以上,浮尘向下与本地扬尘混合,使近地污染转为以粗颗粒增加为主,扬沙天气爆发,ρ(PM_(10))小时值增至920μg/m~3,退偏振比增至0.4,地面上3000m范围均有沙尘粒子分布.冷锋配合蒙古气旋是造成此次沙尘的主要天气系统,不断加深发展的高空槽和地面气旋上升气流为外蒙沙尘推进和传输提供了动力条件.
[Abstract]:The variation of aerosol particle size and its vertical distribution characteristics before and after a dust process in Beijing on March 9, 2013 are analyzed by using the comprehensive observation data of atmospheric physics. The differences of pollution characteristics between haze and sand are compared, and the source and transmission process of dust are analyzed. The results show that the dry haze aerosol pollution dominated by fine particles is near the surface before the dust begins, and the process is alleviated after the stratification and diffusion of the pollutants, and the highest level of PM_ / PM_ (10) is 0.93%. The results show that the haze aerosol pollution is dominated by fine particles near the ground before the beginning of the dust, and the process is alleviated after the stratification and diffusion of the pollutants. The floating dust reached by exogenous transportation was distributed in the range of 800 m above, and the average depolarization ratio was 0.35, which was significantly higher than that in haze aerosol layer. In the early stage of sand dust, the boundary layer is raised to more than 900 m, and the floating dust is mixed with the local dust, which makes the near-ground pollution mainly increase with the increase of coarse particles, and the PM_ (10) hourly value increases to 920 渭 g / m 鈮，
本文编号：2523524
[Abstract]:The variation of aerosol particle size and its vertical distribution characteristics before and after a dust process in Beijing on March 9, 2013 are analyzed by using the comprehensive observation data of atmospheric physics. The differences of pollution characteristics between haze and sand are compared, and the source and transmission process of dust are analyzed. The results show that the dry haze aerosol pollution dominated by fine particles is near the surface before the dust begins, and the process is alleviated after the stratification and diffusion of the pollutants, and the highest level of PM_ / PM_ (10) is 0.93%. The results show that the haze aerosol pollution is dominated by fine particles near the ground before the beginning of the dust, and the process is alleviated after the stratification and diffusion of the pollutants. The floating dust reached by exogenous transportation was distributed in the range of 800 m above, and the average depolarization ratio was 0.35, which was significantly higher than that in haze aerosol layer. In the early stage of sand dust, the boundary layer is raised to more than 900 m, and the floating dust is mixed with the local dust, which makes the near-ground pollution mainly increase with the increase of coarse particles, and the PM_ (10) hourly value increases to 920 渭 g / m 鈮，
本文编号：2523524
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