中文摘要：

利用美国MSP公司生产的宽范围粒径谱仪（WPS）于2010年5月在石家庄市气象局进行了近地面大气气溶胶数浓度的观测,并结合该市同期的气象资料,分析了该次观测所得的大气气溶胶粒子数浓度和谱的特征及其成因.结果表明,本次观测到的气溶胶以超细粒子（粒径〈0.1μm）为主,各粒径范围内的颗粒物数浓度平均值很高.污染气体和颗粒物排放量高、风速较小以及东南风为主导风向所引起的输送作用是观测期间颗粒物污染严重的主要原因;受太阳辐射、温度、边界层高度和建筑施工的影响,晴天气溶胶粒子数浓度日变化明显,且不同粒径气溶胶粒子数浓度日变化差异显著,气溶胶粒子总数浓度和超细粒子数浓度均在7：00、12：00和21：00达到峰值,而粗粒子（粒径〉0.1μm）数浓度峰值出现时间为7：00和23：00.

英文摘要：

During May,2010,number concentration of atmospheric aerosols near the ground at Shijiazhuang Meteorological Bureau,China were measured using WPS made by MSP Corporation in United States,combined with corresponding meteorological data,to study the characteristics of aerosol number concentration and size distribution in this observation and possible causes that lead to.The spectra of aerosol were mainly occupied by ultrafine particles（DP0.1μm） in this observation.The average particle number concentration was high in all size scales.High emission of pollution gases and particles,weak wind condition and the transport effect when the dominant wind direction was southeast were the primary possible causes of this result.Obvious diurnal variation of aerosol concentration was observed in sunny days,which was mainly controlled by solar radiation,heat condition,the height of the boundary layer and construction,and that between different diameters had significant differences.Both total and ultrafine particles number concentration reached daily peak value at 7：00,12：00 and 21：00,while coarse particles（DP0.1μm） number concentration reached the peak value at 7：00 and 23：00.