摘要
特殊深盆地地形背景下,四川盆地呈现独特大气复合污染特征.基于大气污染物观测数据和ERA5气象再分析资料,探究2024年初春四川盆地一次大气复合污染特征及气象成因.结果表明:(1)以宜宾、自贡和泸州为主的川南地区为盆地大气复合污染高发区,并且在3月22~24日期间,这3个城市近地面MDA8O_(3)和PM_(2.5)日均值的平均浓度高达196.3μɡ/m^(3)和66.6μɡ/m^(3),且一致同步变化.川南地区发生了一次以O_(3)和PM_(2.5)“双高”为特征的典型大气复合污染过程.(2)相较于2021~2023年同期,2024年3月22~24日川南地区3个城市平均近地面O_(3)和PM_(2.5)浓度水平异常增加83.4μɡ/m^(3)(99.6%)和26.9μɡ/m^(3)(77.3%),属于初春罕见大气复合污染事件.(3)此次大气O_(3)和PM_(2.5)复合污染受到气象条件变化的显著影响.局地高温、强辐射促进O_(3)的光化学生成和二次PM_(2.5)增加.此外,四川盆地近地层东北风在盆地南缘的川南地区大气辐合,加剧了O_(3)和PM_(2.5)局地累积.此次个例观测研究揭示了四川盆地内独特的大气复合污染特征及气象成因,为区域大气复合污染联防联控提供了科学依据.
Under the unique topographic conditions of a deep basin,the Sichuan Basin was characterized by distinct air pollution complex patterns.A typical air pollution complex event and its meteorological drivers in the Sichuan Basin during spring 2024 were investigated,based on air pollutant monitoring data and ERA5 meteorological reanalysis.The results demonstrate that:(1)The southern part of the basin,particularly the region encompassing Yibin,Zigong,and Luzhou,was identified as a high-incidence area for air pollution complex of O_(3) and PM_(2.5).From March 22 to 24,2024,the average near-surface maximum daily 8-h average(MDA8)O_(3) and daily average PM_(2.5) concentrations in these three cities were measured at 196.3μg/m^(3) and 66.6μg/m^(3),respectively,and synchronous variations in near-surface O_(3) and PM_(2.5) concentrations were observed.This episode was characterized as a typical air pollution complex event in southern Sichuan,with concurrently high levels of both O_(3) and PM_(2.5)(a"dual-high"pattern).(2)Compared to the same period in 2021~2023,the averages of near-surface O_(3) and PM_(2.5) concentrations in these three cities during March 22~24,2024,were found to be abnormally elevated by 83.4μg/m^(3)(99.6%)and 26.9μg/m^(3)(77.3%),respectively,indicating an unusually anomalous spring air pollution complex event.(3)The typical air pollution complex of O_(3) and PM_(2.5) was significantly influenced by meteorological conditions.Local high air temperatures and strong solar radiation were identified as factors that promoted photochemical O_(3) generation and secondary PM_(2.5) formation.Additionally,the convergence of northeasterly surface winds from the basin at the southern edge of the Sichuan Basin was observed to exacerbate the local accumulation of air pollutants.Through this case study,the unique characteristics and meteorological mechanisms of air pollution complex of O_(3) and PM_(2.5) in the Sichuan Basin were elucidated,providing scientific support for regional joint prevention and control strategies.
作者
吴林
张郁青
赵天良
罗悦函
金宇翔
舒卓智
WU Lin;ZHANG Yu-qing;ZHAO Tian-liang;LUO Yue-han;JIN Yu-xiang;SHU Zhuo-zhi(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,CMA Key Laboratory of Aerosol-Cloud-Precipitation,Nanjing University of Information Science and Technology,Nanjing 210044,China;Sichuan Provincial Academy of Environmental Sciences,Chengdu 610041,China)
出处
《中国环境科学》
北大核心
2025年第12期6526-6533,共8页
China Environmental Science
基金
国家重点研发计划项目(2022YFC3701204)
国家自然科学基金资助项目(42275196,42405195)。
