摘要
二次气溶胶是大气气溶胶的重要组成,量化二次气溶胶贡献是认识PM_(2.5)污染成因的关键.本研究通过近似包络法(AEM)估算了随州2015—2020年冬季的一次气溶胶和二次气溶胶浓度,分析了二次气溶胶对PM_(2.5)贡献的变化特征及其可能的影响因素,得到以下主要结论:①随州冬季PM_(2.5)及其一次和二次组分均呈逐年下降趋势,分别为5.8、3.8和1.7μg·m^(-3)·a^(-1),而二次气溶胶对PM_(2.5)贡献呈逐年上升趋势(2.1%a^(-1)),反映了减排进程中二次气溶胶对空气质量变化的重要贡献.②人为活动和化学转化分别影响了一次和二次PM_(2.5)日变化分布.一次PM_(2.5)双峰结构(09:00和21:00)对应了早晚人为活动高峰,二次气溶胶在午后(13:00—15:00)和凌晨(03:00—06:00)对PM_(2.5)贡献最大;PM_(2.5)正午峰值可能与当地二次污染生成密切相关.③二次气溶胶对随州冬季PM_(2.5)平均贡献为60.0%;随着PM_(2.5)污染程度加重,二次气溶胶对PM_(2.5)贡献明显增加,从清洁条件的29%上升到重污染条件的72%,表明二次气溶胶对重污染事件的显著贡献.④二次气溶胶贡献与污染物浓度及气象条件的关系分析表明,相对高温高氧化条件下的光化学氧化作用加速了气态前体物的消耗,明显促进了二次气溶胶的形成.特定气象条件驱动下的大气污染物区域传输也可能对二次气溶胶生成有一定的贡献.因此,未来需要坚持以PM_(2.5)和O_(3)协同控制为核心,强化区域协同减排,做好对二次污染源的控制,加强对二次污染的针对性治理措施.
Secondary aerosols are an important component of atmospheric aerosols,and quantifying the contribution of secondary aerosols is the key to understanding the causes of PM_(2.5) pollution.In this study,the approximate envelope method(AEM)was used to estimate the primary and secondary aerosol concentrations in Suizhou in winter from 2015 to 2020,as well as the variation characteristics of the contribution of secondary aerosols to PM_(2.5).The following main conclusions were obtained:①PM_(2.5) and its primary and secondary components in Suizhou in winter showed a decreasing trend year by year,which were 5.8,3.8 and 1.7μg·m^(-3)·a^(-1) respectively,while the contribution of secondary aerosols to PM_(2.5) is increasing year by year(2.1%a^(-1)),reflecting the important contribution of secondary aerosols to air quality changes in the process of emission reduction.②Human activities and chemical transformations affected the diurnal distribution of primary and secondary PM_(2.5),respectively.The primary PM_(2.5) double-peak structure(09:00 and 21:00)corresponds to the peak of anthropogenic activity in the morning and evening,and the secondary aerosols in the afternoon(13:00—15:00)and early morning(03:00—06:00)contributed the most;PM_(2.5) peak at noon may be closely related to local secondary pollution.③The average contribution of secondary aerosols to PM_(2.5) in Suizhou in winter is 60.0%;with the increase of PM_(2.5) pollution,the contribution of secondary aerosols to PM_(2.5) increases significantly,from 29%in clean conditions to 72%under heavy pollution conditions,indicating a significant contribution of secondary aerosols to heavy pollution events.④Analysis of the relationship between the contribution of secondary aerosols and pollutant concentrations and meteorological conditions showed that photochemical oxidation under relatively high temperature and high oxidation conditions accelerated the consumption of gaseous precursors and significantly promoted the formation of secondary aerosols.Regional tran
作者
郝元甲
白永清
朱燕
岳岩裕
杨涛
贺晓露
赵天良
秦幼文
李艳婕
HAO Yuanjia;BAI Yongqing;ZHU Yan;YUE Yanyu;YANG Tao;HE Xiaou;ZHAO Tianiang;QIN Youwen;LI Yanjie(Suizhou Meteorological Bureau,Suizhou 441300;Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,China Meteorological Administration,Wuhan430205;Hubei Meteorological Service Center,Wuhan 430205;Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,Nanjing University of Information Science and Technology,Nanjing 210044;Wuhan Regional Climate Center,Wuhan 430074)
出处
《环境科学学报》
CAS
CSCD
北大核心
2023年第3期333-342,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.42075186,41830965)
湖北省气象局科技课题(No.2021Q16,2021Z05)。
