中文摘要：

利用南京北郊2011年春季积分浊度仪的观测资料，结合PM2.5质量浓度、能见度和常规气象资料，分析了南京北郊春季气溶胶散射系数的变化特征、散射系数与PM2.5。质量浓度和能见度的关系。结果表明，观测期间气溶胶散射系数平均值为311．5±173．3Mm^-1，小时平均值出现频率最高的区间为100～200Mm^-1；散射系数的日变化特征明显，总体为早晚大，中午及午后小。散射系数与PM2.5，质量浓度的变化趋势基本一致，但与能见度呈负相关关系。霾天气期间散射系数日平均值为700．5±341．4Mm^-1，最高值达到近1900Mm^-1；结合地面观测资料、NCEP／NCAR再分析资料和后向轨迹模式分析显示，霾期间气块主要来自南京南部和东南方向。

英文摘要：

Based on the aerosol scattering properties observed by the integrating Nephelometer in the north suburb of Nanjing in spring 2011, combined with data of PM2 s mass concentration, visibility and routine weather observation, the variation features of aerosol scattering coefficients and its correlation with PMz 5 mass concentration and visibility were analyzed. Results show that the mean aerosol scattering coefficient is 311.5 ± 173.3 Mm- 1 and the maximum frequency distribution of hourly mean scatter- ing coefficient is 100--200 Mm^-1. The diurnal variation of aerosol scattering coefficient is obvious, and higher（lower） in the morning and evening（ at noon and in the afternoon）. The trend variation of scat- tering coefficient shows an agreement with the mass concentration of PM2. 5, and a negative correlation with the visibility. The daily mean aerosol scattering coefficient in the hazy day is up to 700. 5 ± 341.4 Mm^-1, and the maximum value reaches about 1 900 Mm^-1. The analysis of ground observations, NCEP/NCAR reanalysis data and simulated back trajectories of air parcels shows that the air parcels mainly come from south and southeast of Nanjing in the hazy day.