伊宁市夏季大气臭氧生成机制及减排策略

为探究我国西北城市地区臭氧（O₃）生成机制及减排策略，2021年夏季在伊宁市开展环境大气加强观测，基于0-D盒子模型（采用MCMv3.3.1化学机制）分析伊宁市大气O₃生成机制并初步探究大气O₃生成敏感性.结果表明：①由O₃生成潜势（OFP）、·OH反应速率（k_·OH）和相对增量反应活性（RIR）这3个指标共同分析可知，烯烃、含氧挥发性有机物（OVOCs）和芳香烃是影响O₃生成的关键人为源挥发性有机物（AVOC）组分，且生物源挥发性有机物（BVOC）对O₃的生成贡献也不容忽视.基于RIR分析发现优控VOCs物种主要为乙醛、乙烯和丙烯等；②由盒子模型模拟可知，伊宁市O₃受到本地光化学生成和区域输出作用共同影响，且HO₂·+NO和·OH+NO₂反应途径分别对本地O₃光化学生成和去除贡献最大；③基于RIR（NO_x）/RIR（AVOC）和EKMA共同表明，伊宁市夏季O₃生成主要处于过渡区且靠近VOCs控制区.不同削减情景模拟表明，AVOC和NO_x协同减排能有效降低当地O₃体积分数，其中AVOC减排效果更为明显.研究结果可为西北区域类似城市大气O₃污染管控提供支持.

Photochemical Mechanism and Control Strategy Optimization for Summertime Ozone Pollution in Yining City

To explore the formation mechanism of the ozone （O₃） and emission reduction strategy in a northwestern city， an extensive field campaign was conducted in summertime in 2021 in Yining City， in which the 0-D box model incorporating the latest explicit chemical mechanism （MCMv3.3.1） was applied for the first time to quantify the O₃-NO_x-VOCs sensitivity and formulate a precise O₃ control strategy in this city. The results showed that： ① the three indicators ［i.e.， O₃ formation potential （OFP）， ·OH reaction rate （k_·OH）， and relative incremental reactivity （RIR）］ jointly indicated that alkenes， oxygenated volatile organic compounds （OVOCs）， and aromatics were the highest contributors among anthropogenic volatile organic compounds （AVOC） to O₃ formation， and the contribution of biogenic volatile organic compounds （BVOC） also could not be ignored. Additionally， the results based on RIR calculation implied that that the acetaldehyde， ethylene， and propylene were the most sensitive individual VOCs species in Yining City. ② The in-situ photochemical O₃ variations were primarily influenced by the local photochemical production and export process horizontally to downwind areas or vertically to the upper layer， and the reaction pathways of HO₂·+ NO and ·OH + NO₂ contributed the most to the gross O_x photochemical production （60%） and photochemical destruction production （53%）， respectively. Hence， the reduction in local emissions for O₃ precursors was more essential to alleviate O₃ pollution in this city. ③ The outcome based on RIR（NO_x） / RIR（AVOC） and EKMA jointly suggested that the photochemical regime in this city can be considered a transitional regime that was also nearly a VOCs-limited regime. Detailed mechanism modeling based on multiple scenarios further suggested that the NO_x and VOCs synergic emission reduction strategies was helpful to alleviate O₃ pollution. These results are useful to provide policy-related guidance for other cities facing similar O₃ pollution in northwest China.