A high level of ozone (O₃) is frequently observed in the suburbs of Shanghai, the reason for this high level remains unclear. To obtain a detailed insight on the high level of O₃ during summer in Shanghai, O₃ and its precursors were measured at a suburban site in Shanghai from July 1, 2016 to July 31, 2016. Using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and concentration weighted trajectories (CWT), we found that Zhejiang province was the main potential source of O₃ in suburban Shanghai. When the sampling site was controlled by south-western winds exceeding 2 m/s, the O₃-rich air masses from upwind regions (such as Zhejiang province) could be transported to the suburban Shanghai. The propylene-equivalent concentration (PEC) and ozone formation potential (OFP) were further calculated for each VOC species, and the results suggested that propylene, (m + p)-xylene, and toluene played dominant roles in O₃ formation. The Ozone Isopleth Plotting Research (OZIPR) model was used to reveal the impact of O₃ precursors on O₃ formation, and 4 base-cases were selected to adjust the model simulation. An average disparity of 18.20% was achieved between the simulated and observed O₃ concentrations. The O₃ isopleth diagram illustrated that O₃ formation in July 2016 was in VOC-sensitive regime, although the VOC/NO_x ratio was greater than 20. By introducing sensitivity (S), a sensitivity analysis was performed for O₃ formation. We found that O₃ formation was sensitive to propylene, (m + p)-xylene, o-xylene and toluene. The results provide theoretical support for O₃ pollution treatment in Shanghai.

在上海郊区经常观察到高浓度的臭氧（O ₃），其高浓度的原因尚不清楚。为了详细了解上海夏季的O ₃含量，于2016年7月1日至2016年7月31日在上海郊区进行了O ₃及其前体的测量。使用混合单粒子拉格朗日积分轨迹（HYSPLIT）模型和浓度加权轨迹（CWT），我们发现浙江省是上海郊区O ₃的主要潜在来源。当采样地点受到西南风超过2 m / s的控制时，O ₃来自上风地区（例如浙江省）的大量空气可以被运输到上海郊区。进一步计算了每种VOC种类的丙烯当量浓度（PEC）和臭氧形成潜能（OFP），结果表明丙烯，（m + p）-二甲苯和甲苯在O ₃形成中起主要作用。臭氧等值线图研究（OZIPR）模型用于揭示O ₃前体对O ₃形成的影响，并选择4个基本案例来调整模型模拟。在模拟和观察到的O ₃浓度之间平均差异为18.20％。O ₃等值线图说明了O ₃尽管VOC / NO _x比率大于20 ，但2016年7月的形成是在VOC敏感的状态下。通过引入敏感度（S），对O ₃形成进行了敏感度分析。我们发现O _3的形成对丙烯，（m + p）-二甲苯，邻二甲苯和甲苯敏感。研究结果为上海O ₃污染治理提供了理论依据。