【摘要】 为探究京津冀地区大气污染典型城市保定市PM_2.5和臭氧复合污染现状，文章基于2015-2022年大气污染物浓度及气象参数进行统计分析，探究了保定市PM_2.5和O₃不同时段的浓度变化特征，并运用后向轨迹模型、潜在源贡献因子法和浓度权重轨迹法探究气团传输对PM_2.5和O₃污染的贡献。结果表明：保定市2015-2022年PM_2.5浓度逐年下降，而O₃浓度呈波动上升趋势；季节上PM_2.5浓度表现为冬季高、夏季低的特征，O₃浓度则表现出相反特征。研究期间PM_2.5-O₃复合污染日和PM_2.5单污染日的天数均呈下降趋势，且天数集中出现在4-9月和10月-次年3月，而O₃单污染日天数则呈上升趋势；PM_2.5-O₃复合污染极易出现于温度为20.8～26.7℃、相对湿度为59.0%～77.5%、风速较低的气象条件下。保定市复合污染期间受来自西北方向长距离及偏南方向短距离气流影响显著；复合污染和PM_2.5单污染期间的PM_2.5潜在源区主要集中在保定市周边以及贯穿覆盖内蒙古自治区西部到安徽北部的西北-东南方向的污染区域带上，复合污染状况下O₃和O₃单污染期间主要受到城市周边区域、河南中北部、山东中西部及安徽北部影响。更多还原

【Abstract】 In order to explore the composite pollution status of PM_2.5 and ozone in Baoding City,a typical air polluted city in the Beijing-Tianjin-Hebei region,this study analyzes the variation characteristics at different periods,concentration relation?ships and influencing factors of PM_2.5 and O₃ in Baoding,while investigating the contribution of air mass transport to PM_2.5 and O₃ pollution using trajectory cluster analysis,the potential source contribution function and concentration-weighted trajectory method,based on PM_2.5 and O₃ concentrations as well as meteorological parameters and Global Data Assimilation System data collected from 2015 to 2022.The results show that from 2015 to 2022,the PM_2.5 concentration decreased year by year,with a higher concentration in winter than in summer;the O₃ concentration showed a fluctuating upward trend,with a higher concen?tration in summer than in winter.Both PM_2.5-O₃ composite pollution days and PM_2.5 single pollution days showed a downward trend,with high concentration appearing in April-September and October-March of the following year.PM_2.5-O₃ compos?ite pollution was very likely to occur under the following meteorological conditions:a temperature of 20.8～26.7℃,a humidity of 59.0%～77.5%,and low wind speed.The cluster analysis showed that during the period of composite pollution,Baoding would be significantly affected by the long-distance airflow from the northwest and the short-distance airflow from the south.The PSCF and CWT analysis showed that the potential source areas were mainly concentrated around Baoding and in the northwest-southeast polluted regions,ranging from western Inner Mongolia to northern Anhui,in PM_2.5 composite pollu?tion conditions and during PM_2.5single pollution periods.On the other hand,the pollution was mainly concentrated around the urban surrounding regions,central and northern Henan,central and western Shandong and northern Anhui in O₃ composite pol?lution conditions and during O₃ single pollution periods.更多还原