重庆市夏季臭氧污染特征及传输分析

Analysis of Ozone Pollution Characteristics and Transport During Summer in Chongqing

2015年8月27日-9月2日重庆市经历了一次臭氧污染天气,通过分析发现,3个在线站污染时段臭氧平均浓度是清洁时段的1倍左右,浓度峰值有明显升高且日变化更加明显。通过分析3个在线站NO_(2)、O_(3)和总氧化剂O_(x)的浓度发现,南泉站与超级站的臭氧可能是局地化学过程生成与区域传输的共同作用,而缙云山站的臭氧则主要来自区域传输。利用观测值与基于观测的模型结果来分析,发现清晨时重庆市上空边界层以上残留的臭氧向下传输,导致07:00-09:00重庆近地面臭氧浓度的小幅度上升,同时由于近地面风速风向的变化,会导致各站臭氧的输入输出关系发生变化,且该次污染过程中3个在线站之间存在臭氧传输的现象。

During the period from Aug.27 to Sept.2 in 2015,Chongqing experienced ozone polluted weather.The air qual⁃ity monitoring data of the city’s three online stations showed the average ozone concentration during the time was about twice the non-pollution weather,while the peak concentration notably increased and diurnal profile more noticeably.The concentrations of NO_(2),O_(3),and total oxidizer O_(x) at the three online stations was analyzed and found that the ozone detected at Nanquan station and the Super station was likely the combined action of local generation of chemical process and regional transport,while the ozone at Jinyunshan station was mainly attributed to regional transport.Applying the observation data and the modelling result of OBM(observing based-model),it was found that in the morning the residual ozone above the boundary layer transported downward,causing a slight increase in near-surface ozone concentrations during the hours 07:00 to 09:00.Changes in wind speed and direction near the ground would lead to the changes in the input and output of ozone,which were detected in each station,and there would be ozone transport among the areas of three online stations during the pollution period.