广州番禺大气成分站一次典型光化学污染过程PAN和O3分析

通过对广州番禺大气成分站（GPACS）的光化学相关污染物（O₃、PAN、VOCs、NO₂、NO）以及气象要素进行观测，分析2010~2016年期间发生在广州地区一次典型光化学污染过程.结果表明，该光化学污染过程期间，O₃和PAN总体体积分数比较高，最大O₃小时体积分数为140.6×10^-9，而最大PAN小时体积分数为4.7×10^-9.NO整体体积分数较低，对O₃的化学滴定和PAN的去除影响较小.NO₂整体体积分数较高、辐射较强和风速较低则有利于O₃和PAN的形成和积累.PAN和O₃具有一定的线性关系（R²=0.55），而形成PAN和O₃前体物VOCs物种不完全相同影响着它们的线性关系，在生成PAN的VOCs物种中，乙烯、丙烷、异戊二烯和甲苯所占的比例较大，而对臭氧生成潜势较大的物种有异戊二烯、1，3，5-三甲苯、丙烯、间，对-二甲苯以及甲苯.对PA自由基体积分数进行估算，发现它的日均值体积分数在0.11×10^-12~0.16×10^-12范围变化，远高于其它地区，表明此次发生的光化学反应较为强烈.

Analysis of Peroxyacetyl Nitrate and Ozone During a Typical Photochemical Pollution Process at the Panyu Atmospheric Composition Station

The typical photochemical pollution process in Guangzhou was analyzed from 2010 to 2016 by observing photochemical pollutants (ozone (O₃), peroxyacetyl nitrate (PAN), volatile organic compounds (VOCs), nitrogen dioxide (NO₂), and nitric oxide (NO)) and meteorological factors at the Guangzhou Panyu Atmospheric Composition Station (GPACS). The results showed that during this photochemical pollution process, the average O₃ and PAN concentrations were relatively high:O_3,max 1 h concentration was 140.6×10^-9 and PAN_max 1 h concentration was 4.7×10^-9. The average concentration of NO was low, which had little effect on O₃ titration and PAN elimination. The high NO₂ concentration, strong radiation, and low wind speed all led to the formulation and accumulation of O₃ and PAN. The linear relationship between O₃ and PAN (R²=0.55) was affected by the fact that their precursor VOCs were not similar. Ethene, propane, isoprene, and toluene had a large influence in PAN formation, while isoprene, 1,3,5-trimethylbenzene, propene, m,p-xylene, and toluene had a large influence on O₃ formation potential. When evaluating PA concentration, we found that its daily average concentration ranged from 0.11×10^-12 to 0.16×10^-12, which were higher than many places around the world, indicating that this photochemical process was relatively intensive.