苏州市气溶胶消光特性及其对灰霾特征的影响  

Aerosol Extinction Characteristics and Analysis of Haze Formation in Suzhou City

作　　者：杨康[1] 刘红年[1] 朱焱[2] 王学远[1] 林惠娟[2] 

机构地区：[1]南京大学大气科学学院,江苏南京210093 [2]苏州市气象局,江苏苏州215131

出　　处：《环境科学研究》2015年第6期848-854,共7页Research of Environmental Sciences

基　　金：国家重点基础研究发展计划(973)项目(2014CB441203);国家环境保护公益性行业科研专项(GYHY201206011);江苏省自然科学基金项目(BK2012314)

摘　　要：为研究气溶胶消光特性对城市灰霾特征及形成的影响机制,采用2010年1月─2013年12月4 a的苏州市逐时散射系数、能见度、颗粒物质量浓度以及风速、风向、气温、气压、相对湿度等数据,对该市气溶胶散射系数、消光特性及影响因子进行了研究.结果表明：苏州市气溶胶散射系数为（301.1±251.3）Mm^-1,日变化呈双峰型,早高峰出现在07：00─08：00,晚高峰出现在20：00─21：00;其年内变化呈夏季低、冬季高.气溶胶散射系数与ρ（PM2.5）的相关系数为0.77,高于与ρ（PM1）和ρ（PM10）的相关性,PM2.5散射效率为6.08 m^2/g.气溶胶散射系数受风速、风向等气象要素的影响：风速〈4 m/s时,气溶胶散射系数下降迅速;风速在4-6 m/s时,气溶胶散射系数随风速下降缓慢.苏州市气溶胶单次散射反照率平均值为0.84,散射消光比平均值为0.79,说明该地区气溶胶消光以散射性气溶胶为主.气溶胶散射消光、气溶胶吸收消光、空气分子散射消光、NO2吸收消光分别占大气消光的82.33%、13.63%、2.72%和1.32%.研究表明,对气溶胶散射消光贡献最大的非吸收性PM2.5是苏州市能见度下降、灰霾增加的最重要原因.Hazy weather is a heavy pollution phenomenon in urban areas of China. The primary cause of the deterioration of visibility and the increase of haze is the enhancement of aerosol extinction caused by the increase of particle pollution in urban areas. Based on hourly observation data （including scattering coefficient, visibility, particle concentration, wind velocity and direction, temperature, pressure and humidity） from January 2010 to December 2013 in Suzhou City, aerosol scattering coefficient, extinction coefficient and their impact factors were analyzed. The results show that the average scattering coefficient in Suzhou City was （301.1 ± 251.3 ） Mm^-1 , and there were two peaks in daily variation, one at 07：00-08：00 and the other at 20：00-21：00. The seasonal variation of scattering coefficient was also obvious： the highest one was in winter while the lowest one was in summer. The correlation coefficient between scattering coefficient and p（PM2,s） was 0.77, higher than those of ρ（ PM10 ） and ρ（ PM1 ）. The mass scattering efficiency of PM2.5 was 6.08 m^2/g. The relationship between scattering coefficient and some meteorological elements, such as wind direction and velocity, was also significant. When the wind velocity was less than 4 m/s, the scattering coefficient decreased rapidly with increasing wind velocity. When the wind velocity was between 4 and 6 m/s, the scattering coefficient decreased slowly with increasing wind velocity. The average single-scattering albedo and scattering-to-extinction ratios were 0.84 and 0. 79, respectively, which showed that the aerosol extinction of Suzhou City was based on scattering of aerosol. The contribution to light extinction of aerosol scattering, aerosol absorbing, air molecules scattering and NO2 absorption were 82. 33% , 13.63% , 2. 72% and 1.32% , respectively. The most important reason for the deterioration of visibility and the increase of haze in Suzhou City was the nonabsorbable PM2.5 , which contributed the most to the aerosol s

关 键 词：散射系数 消光系数 单次散射反照率 散射消光比 苏州市 

分 类 号：X51[环境科学与工程—环境工程]