南京夏季清洁与污染区气溶胶微物理特征分析

Analysis of the Micro-physical Characteristics of Aerosol Particles in Clean and Pollution Area in Summer of Nanjing

为研究南京地区大气气溶胶粒子的微物理特征,于2008年8月～2008年9月在南京北郊和南京紫金山对照点进行了大气气溶胶观测,文章分析了气溶胶的浓度、谱分布、日变化特征以及降水对其数浓度的影响。结果表明:南京北郊大气气溶胶日平均数浓度约是紫金山的2.6倍,最大值数量级高达106,比紫金山高出2个量级;南京北郊气溶胶数浓度谱分布呈单峰分布,紫金山观测区呈双峰分布,峰值都集中在爱根核模态;气溶胶的表面积浓度分布集中在积聚模态,质量浓度则主要集中在积聚模态和粗粒子模态;气溶胶表现出明显的日变化,紫金山观测区上午达到全天最大值,南京北郊午后达到全天最大值,受人为活动影响较大;气溶胶的数浓度与降水强度呈负相关性,降水对粒径范围为0.02μm～0.1μm的气溶胶有很强的清除作用。

Using the data of ambient aerosols observed in Nanjing Area in August and September,2008.The concentration,Diurnal variations,spectrum distribution characteristics of Aerosols and the relationship of aerosol particles number concentration with precipitation were analyzed in this paper. The results indicated that the daily average concentration of ambient aerosol in northern suburb of Nanjing was much higher than in Purple Mountain of Nanjing,which were about 2.6 times higher than Purple Mountain,and its quantitative of the aerosols was reached to 106 was more than two quantitative in Purple Mountain;the aerosol spectrum in northern suburb of Nanjing showed a single peak distribution,but a double peak in Purple Mountain,the peak of the aerosol spectrum were both in Aitken mode;The mainly distribution of surface concentration was under the Accumulation mode,and the mass concentration was distributed in the Accumulation and Coarse mode;the number concentration of aerosols in the observation area showed a significant diurnal variation,And the concentration of ambient aerosol reached the maximum in the morning of the day. In the northern suburb of Nanjing,the concentration of ambient aerosol reached the maximum in the afternoon,Human production activities made a greater impact on the change of the concentration of ambient aerosol;the number concentration of aerosols was negatively correlated to the precipitation intensity,the precipitation process on the wiping off action to the particle was obvious,especially to the particle size range of 0.02μm～0.1μm.