摘要
在华北重度霾过程期间(2013年9月30日),利用夏延ⅢA的飞机观测资料分别对石家庄和邢台的气溶胶粒子谱分布,气溶胶(cloud nuclei,CN)与云凝结核(cloud condensation nuclei,CCN)垂直分布特征进行了分析。研究结果表明,两地的气溶胶数浓度均随着高度的增加而减小,气溶胶粒子有效半径比较接近,积聚模态和粗模态气溶胶粒子有效半径的范围分别在0.05~0.35μm,0.8~2.2μm之间。两地的边界层内和边界层以上均出现了逆温层,且逆温层之下的气溶胶数浓度均出现明显增加现象。对气溶胶后向轨迹的分析结果表明:3 000 m高度处的气溶胶主要是随气团远距离输送而来;1 500 m高度处的气溶胶主要来自南边近地面污染物排放,输送距离较短;500 m高度处的气溶胶受偏南气团的影响,主要由高浓度的气溶胶细粒子组成。云凝结核的垂直分布结果表明,CCN数浓度随高度的增加而减小,逆温层的存在对CCN有一定的累积效应。对石家庄(邢台)市的CCN与气溶胶数浓度做相关性分析,结果表明两地的CCN与气溶胶的总相关系数均在0.95以上,而淡积云内相关系数仅为0.83,且云内的CCN数浓度明显低于云外,因此表明了云滴活化对CCN的消耗作用。云凝结核的数浓度随高度的增加而减小,逆温层的存在对CCN有一定的累积效应。云底以下的气溶胶粒子谱宽较窄,云内和云顶以上的气溶胶粒子谱较宽。
During the period of heavy haze in North China（September 30,2013）,aerosol particle distribution and the vertical distribution characteristics of aerosol and cloud condensing nuclei（CCN） were analyzed by using observational datasets from the aircraft of Cheyenne ⅢA.The results show that the aerosol number concentration in both areas decreases with the increase of height,the effective radius of aerosol particles in both cities is close to each other,the range of aerosol effective radius in the accumulation mode and the coarse mode are 0.05 ~ 0.35 μm and 0.8 ~ 2.2 μm,respectively.Two inversion layers appear in and above the boundary layer,with a significant increase in the aerosol concentration below the inversion layers.The analysis of aerosol back trajectories indicates that the aerosol at the height of 3 000 m is mainly controlled by long transportation of the air mass,the aerosol at1 500 m is mainly from the south side of the ground pollutant with a short transport distance,the aerosol at the height of 500 m is affected by the southern air mass with a high concentration of aerosol fine particles.The profiles of CCN shows that the number concentration of CCN decreases as the height increases,and the presence of inversion layer has a cumulative effect on CCN.Then the relationship between aerosol and CCN in both cities has been studied,the result shows that correlation coefficient of aerosol-CCN in both areas is above 0.95,while the correlation coefficient in clouds is just 0.83,and the number concentration of CCN in clouds is lower than outside,which indicates that the consumption of CCN in the activation of cloud droplets.The width of aerosol particles spectrum is narrow below cloud base,and is large in clouds or above cloud top height.
出处
《科学技术与工程》
北大核心
2018年第2期204-211,共8页
Science Technology and Engineering
基金
河北省气象局科研开发项目(14ky21
15ky36)资助
关键词
霾
气溶胶
CCN
飞机探测
华北
haze aerosol CCN aircraft measurements North China
