山西夏季气溶胶空间分布飞机观测研究

以搭载了多种气溶胶观测仪器的飞机为观测平台,在2013年夏季首次对山西中部地区霾日及晴空大气气溶胶空间分布特性进行了观测,得到气溶胶粒子数浓度和尺度的垂直分布廓线以及不同高度气溶胶粒子谱分布特征.研究发现,山西夏季非降水天气条件下气溶胶粒子以核模态和积聚模态的细粒子为主,粗粒子很少.霾日气溶胶数浓度是晴空的2~3倍,主要是核模态的小粒子;气溶胶粒子数浓度随着高度逐渐减小,低空存在气溶胶累积区,逆温层的存在是导致气溶胶累积区形成的主要原因;气溶胶粒子尺度随高度增加,大粒子主要分布在2500m以上的高空;不同高度上的气溶胶粒子谱均呈双峰或三峰分布,谱型基本一致,从近地面到5000m高空,气溶胶粒子谱随高度的增加略有展宽.观测区域气团后向轨迹模拟结果显示,4000m以上高空气溶胶粒子主要是从中国西北地区远距离输送而来,3000m以下气溶胶粒子则主要来源于近地面排放.

Aircraft measurements of aerosol spetial distribution properties in Shanxi Province in summer.

Aircraft Measurements of aerosol spatial distribution properties in the central region of Shanxi Province were carried out in summer, 2013. The vertical distribution characteristics of aerosol number concentration and size were observed and analyzed, and the spectrum properties of aerosol particles in different height were studied. The results show that most aerosol particles were nucleation mode and accumulation mode on non-precipitation days in Shanxi Prov. in summer. Aerosol number concentration on haze day was 2 or 3 times larger than that on clear days. Aerosol number concentration decreased with altitude. A low-level aerosol accumulation zone was present due to the existence of temperature inversion layer. The mean aerosol particle size increased with height with the larger particles mainly distributed above 2500m. The aerosol particles spectrum usually showed a bimodal or three-modal type. The width of aerosol particles spectrum broadened slightly from ground surface to 5000m. The air mass back trajectory in observation days showed aerosol particles in high level was transported from north-west China over long distance, and aerosol particles below 3000m mainly came from the ground emissions.