摘要
对2003年夏秋季利用机载PMS在北京及周边地区进行的不同天气状况下6次气溶胶粒子探测资料进行了分析。结果表明,北京及周边地区气溶胶粒子的分布,在不同天气背景时有较大差别。粒子平均浓度的最大值为3.46×102cm-3,最大粒子浓度为5.26×103cm-3,相差一个量级;粒子平均最大直径为1.392μm,最大直径为2.75μm。粒子平均浓度的最小值为25.7cm-3。在有雾的天气条件下,气溶胶粒子浓度在近地层基本随高度的增加而减小,粒子尺度变化较为复杂。在阴雨天气情况下,气溶胶粒子浓度和尺度都有增加的现象。另外,逆温层底存在明显的气溶胶粒子累积。0℃层以下气溶胶粒子呈单峰分布,0℃层以上气溶胶出现双峰结构。小云粒子一直是多峰结构,峰值直径分别在3.5μm、12.5μm、23.5μm处。
The aerosol data sampled with an airborne PMS （Particle Measuring System） in six flights under different atmospheric conditions during August to September of 2003 over Beijing and its peripheral areas were analyzed. The results show that due to different atmospheric conditions, the distribution of aerosol particle concentration over Beijing and its peripheral areas is rather different. The maximum of mean number concentration of aerosol particles was 3.46 × 10^2 cm^-3, while the maximum number concentration of particles was 5.26 × 10^3 cm^ -3, therefore the latter is one order of magnitude larger than the former. The maximum of mean diameter of particles was 1. 392 μm, and the maximum diameter of particles was 2. 75 μm. The minimum of mean concentration of particles was 25.7 cm^-3. In the fog condition, aerosol particle number concentration decreased with increasing height near the surface, and change in aerosol particle diameter was complicated. The number concentration and diameter of aerosol particles increased in the overcast and rainy condition. In addition, a distinct accumulation zone of aerosol particles could be found under the weak inversion layers, where were vertically distinct different distributions of aerosol particles. The aerosol particles showed an unimodal distribution below the 0 ℃ layer, and a bimodal distribution above. Cloud droplets exhibited a multimodal distribution with the peak diameters at 3.5 μm,12. 5 μm,and 23.5 μm,respectively.
出处
《南京气象学院学报》
CSCD
北大核心
2007年第3期402-410,共9页
Journal of Nanjing Institute of Meteorology
基金
国家自然科学基金重点资助项目(40333033)
国家科技部十五科技攻关项目(2001BA610-06)
中国科学院知识创新项目(KZCX3-SW-225)
关键词
气溶胶
云滴
北京及周边地区
分布特征
aerosol
cloud droplet
Beijing and its peripheral areas
spectrum property
