中文摘要：

于2015年12月采用三波长光声黑碳光度仪（PASS-3）对PM_（2.5） 光学特性进行实时在线观测,同时采用大气粒子检测仪（BAM-1020）和扫描电迁移率粒径谱仪（SMPS）分别在线测量PM_（2.5） 和PM_（0.3）质量浓度.结果表明,观测期间南京北郊的气溶胶在532 nm波段的吸收、散射和消光系数分别为（56.34±27.09）Mm-1、（461.68±267.97）Mm^-1和（518.02±290.94）Mm^-1,其中,散射系数高于上海、广州等地的观测值,明显低于西安、沈阳等地的观测值,而吸收系数均低于其他城市.气溶胶散射和吸收系数的日变化呈双峰特性,且与NOx和CO日变化趋势一致,说明其主要受交通排放影响.气溶胶消光系数与ρ（PM_（2.5） ）呈显著的线性正相关,与大气能见度呈反比例负相关.PM_（2.5） 的质量消光效率为4.43 m~2·g^-1.ρ（PM_（0.3））占ρ（PM_（2.5） ）的质量百分比越高,其质量消光效率越大.

英文摘要：

A three-wavelength photoacoustic soot spectrometer（ PASS-3） was used for on-line measurement of PM_（2.5） optical properties in December,2015 in north suburban Nanjing. The mass concentrations of PM_（2.5） and PM_（0.3） were monitored by continuous particulate monitor and scanning mobility particle sizer, respectively. The results showed that the aerosol scattering coefficient,absorption coefficient and extinction coefficient at 532 nm were（ 461.68 ± 267.97） Mm^-1,（ 56.34 ±27.09） Mm^-1 and（ 518.02 ± 290.94） Mm^-1 respectively during the observation period. Compared with other cities,the scattering coefficient in Nanjing was higher than Shanghai and Guangzhou,but lower than Xi＇ an and Shenyang. However,the absorption coefficient in Nanjing was lower than others. Thediurnal variation of absorption and scattering coefficients was bimodal,consistent with that of NOx and CO, suggesting the contribution of traffic emissions. In addition, the aerosol extinction coefficient was linearly correlated with ρ（ PM_（2.5） ）,negatively correlated with atmospheric visibility,and the mass extinction efficiency was 4. 43 m2·g-1. The higher proportion of ρ（ PM_（0.3）） inρ（ PM_（2.5） ）,the greater the extinction efficiency.