基于长期观测的淮河流域农田背景区灰霾污染气溶胶光学特性和类型分析

Haze optical properties and types from long-term measurements on farmland background area of Huai River Basin

利用2015—2019年寿县国家气候观象台的CE-318型太阳光度计观测数据,比较分析了淮河流域农田背景区及其灰霾污染日、非灰霾污染日的气溶胶光学特性和类型的差异和联系.结果表明:①淮河流域农田背景区及其灰霾污染日、非灰霾污染日的AOD_(440)平均值为0.60~0.86,以细粒子气溶胶为主,气溶胶散射能力强,吸收能力弱;②细粒子气溶胶增加在淮河流域农田背景区灰霾污染中占主导作用,灰霾污染发生时,AOD_(440)平均值增大0.26,散射能力增强,吸收能力减弱,污染的气溶胶类型占比增加17.79%;③2015—2019年,淮河流域农田背景区及其灰霾污染日、非灰霾污染日的气溶胶光学厚度、细模态粒子体积浓度整体呈减小趋势,气溶胶散射能力逐年增强,吸收能力逐年减弱;④淮河流域农田背景区及其灰霾污染日,随着污染等级的增加,气溶胶光学厚度和污染的气溶胶类型占比增大,重度污染时颗粒物向大粒径方向移动,但仍为细粒子;⑤受气溶胶来源、吸湿增长和高温的影响,春夏季气溶胶光学厚度和单次散射反照率较高,秋冬季主要由雾霾污染造成,细粒子比例高,气溶胶光学厚度和单次散射反照率较低.

The optical properties and types of aerosol in farmland background area of Huai River Basin and the haze and non-haze pollution days were comparatively analyzed,based on CE-318 sun photometer measurements in Shouxian National Climatology Observatory from 2015 to 2019.The results indicate:①The average AOD_(440) values were between 0.60 and 0.86 on farmland background area of Huai River Basin during haze and non-haze pollution days.The aerosol was mainly fine particle,which has strong scattering ability but weak absorption ability.②The increase of fine particle aerosol played a dominant role in haze pollution on farmland background area of Huai River Basin.When the haze pollution occurred,the average AOD_(440) increased by 0.26,with stronger scattering ability but weaker absorption ability,and the proportion of aerosol pollution increased by 17.79%.③Aerosol optical depth and volume concentration of fine particle showed a decreasing trend,and aerosol scattering ability gradually increased,while absorption ability decreased from 2015 to 2019.④Aerosol optical depth and the proportion of pollution aerosol type increased with the pollution level on farmland background area of Huai River Basin and its haze pollution days.In the heavy pollution,the particle size increased,but were still fine particles.⑤The aerosol optical depth and single scattering albedo were higher in spring and summer due to the influence of aerosol source,hygroscopic growth and high temperature,while the aerosol optical depth and single scattering albedo were lower in autumn and winter due to haze pollution with high proportion of fine particles.