杭州城郊大气二氧化硫和气溶胶浓度演变特征及潜在源分析

Evolution characteristics and potential sources of SO_(2) and aerosol concentrations in the urban and suburban atmosphere of Hangzhou

基于2018年1月—2019年10月杭州大气成分监测数据,对杭州城、郊大气SO_(2)和气溶胶的浓度变化特征及其相关性和影响因素进行分析,并探讨不同季节下长距离输送对大气SO_(2)和PM_(2.5)浓度的贡献及潜在源区分布.结果表明:杭州城、郊大气SO_(2)日变化特征均呈单峰型,气溶胶日变化特征均呈双峰型;杭州城区SO_(2)浓度夏季明显低于其他季节,而郊区SO_(2)浓度四季无明显差异,气溶胶浓度城区和郊区均为夏季最低;SO_(2)与气溶胶相关性偏低,城、郊不同粒径的气溶胶之间相关性差异较大;不同季节杭州城区SO_(2)和PM_(2.5)受气团输送的影响具有明显差异,杭州城市高浓度SO_(2)和气溶胶潜在源区主要位于江苏省苏州市、南京市以及浙江省绍兴市、湖州市和杭州市辖区,因而减少或控制这些潜在源区污染物排放将会对杭州大气环境质量改善有积极作用.

Utilizing atmospheric composition monitoring data detected in Hangzhou from January 2018 to October 2019,we examined the characteristics of atmospheric SO_(2) and aerosol concentrations(PM_(2.5) and PM_(10))in urban and suburban areas.Our analysis encompassed the investment in the correlation between the two sites and their corresponding driving factors.Besides,the impacts of long-distance transportation and the potential source areas of SO_(2) and PM_(2.5) were investigated across seasons.The unimodal diurnal pattern of SO_(2) was detected at both sites,contrasting with the bimodal diurnal variations of aerosols.The urban site exhibited a lower SO_(2) in summer compared to the other seasons,with no significant variation observed in the suburban site.The aerosol concentrations were at their lowest in summer in urban and suburban regions.A weak correlation was discovered between SO_(2) and aerosols,but a robust correlation existed between different particle sizes of aerosols.The influences of long-distance transportation differed significantly among seasons,with the potential sources for enhanced concentrations in Hangzhou identified in Suzhou and Nanjing in Jiangsu Province,as well as Shaoxing,Huzhou,and Hangzhou Municipal Districts in Zhejiang Province.Therefore,mitigating pollution emissions from these potential sources could critically improve Hangzhou's atmospheric quality.