山东农村和背景地区雾霾天与清洁天气溶胶光学特性

Aerosol optical properties on hazy days and clear days at rural and background sites in Shandong Province of China

为了解山东省农村和背景地区的气溶胶光学特性,2014年6月至8月先后在禹城和泰山进行气溶胶采集。利用浊度计、黑碳仪测得气溶胶散射系数和吸收系数,分析雾霾天和清洁天散射系数和吸收系数的日变化,并利用HYSPLIT模型分析了两地的气团来源。结果表明,禹城和泰山雾霾天的单次散射反照率均高于清洁天,这可能与雾霾天硫酸盐和硝酸盐气溶胶的大量形成有关。禹城的散射系数和吸收系数日变化均呈现双峰分布,这归因于当地的早、晚交通峰;而泰山散射系数和吸收系数日变化呈单峰模式,归因于大气边界层的日变化。后向气流轨迹分析结果显示,禹城雾霾时期的气团主要来自东南方向,途经济南等重污染城市,同时计算出气团穿过密集火点,表明生物质的燃烧影响了禹城的雾霾形成;在泰山雾霾期间,气团移动缓慢,可被认作本地源。

To study the aerosol optical properties of rural and background areas in Shandong Province,aerosol was collected from June,2014 to August,2014 in Yucheng and Mt.Tai.We measured aerosol scattering coefficient and absorption coefficient by nephelometer and aethalometer.It was shown that the average of the single scattering albedo(ω)of haze days in Yucheng and Mt.Tai were both higher than that in clean days,which could be caused by the formation of sulphate and nitrate aerosols.The diurnal variation of scattering coefficient and absorption coefficient of Yucheng showed two peak patterns,which were mainly caused by morning and evening rush hour.However,the diurnal variation of scattering coefficient and absorption coefficient of Mt.Tai showed a unimodal pattern,which was attributed to the diurnal evolution of the atmospheric boundary layer.Indicated by the 48 h backward trajectories,long-distance transmission from the southeast coastal areas via polluted cities such as Jinan,as well as local biomass burning emissions had an important influence on the formation of haze at Yucheng.However,during haze periods at Mt.Tai,the most frequently observed cluster moved slowly and could be considered a local source.