Assessment of atmospheric photochemical reactivity in the Yangtze River Delta using a photochemical box model
Assessment of atmospheric photochemical reactivity in the Yangtze River Delta using a photochemical box model
复制标题
利用光化学盒模型评估长三角地区大气光化学反应性
DOI：
10.1016/j.atmosres.2020.105088
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发表时间：
2020-11-15
影响因子：
5.5
通讯作者：
Ling, Zhenhao
中科院分区：
文献类型：
--
作者：
Huang, Weiwen;Zhao, Qiuyue;Ling, Zhenhao
采用光化学箱模式对长江三角洲南通、徐州和盐城3个城市的臭氧（O-3）及其前体物的变化进行了研究，并分析了它们对光化学反应性的影响。将光化学箱模型与挥发性有机化合物（VOCs）降解的近显式机理（Master Chemical Mechanism，MCM version 3.2）相结合，根据观测数据详细描述了光化学O-3形成的不同途径和相关的大气光化学反应性。烷烃是最重要的挥发性有机化合物组的整体，而芳烃和烯烃的贡献因城市而异。O-3和VOCs浓度最高的城市是南通，表明光化学污染较严重。这导致了更高的贡献，O-3的光解产生的HOx和促进OH-HO 2的传播，导致最大的HOx（OH + HO 2）和更高的O-3的形成率从RO 2 + NO。在阳晨，最高的烯烃的出现导致臭氧分解的最大贡献，HOx的生产。在南通，NO2和HO 2浓度最高时，OH + NO2和HO 2 + HO 2对HOx的破坏贡献最大。而徐州的OH链长度最长，说明徐州的O-3生产效率最高。虽然车辆排放是VOCs的主要来源，南通的工业排放，溶剂使用在徐州和盐城的车辆排放的挥发性有机化合物的O-3形成的最重要的来源。这些结果表明，适当的光化学污染控制措施应考虑排放源和VOCs的光化学反应性。
We investigated variations of ozone (O-3), its precursors, and their influence on photochemical reactivity by applying a photochemical box model to field data from three cities (Nantong, Xuzhou, and Yancheng) in the Yangtze River Delta. The photochemical box model was coupled with the near-explicit mechanism (Master Chemical Mechanism, MCM version 3.2) for the degradation of volatile organic compounds (VOCs), which provided detailed descriptions of different pathways for photochemical O-3 formation and related atmospheric photochemical reactivity based on observed data. Alkanes were the most important VOC group overall, while the contributions of aromatics and alkenes varied by city. The highest levels of O-3 and VOCs (indicating more severe photochemical pollution) were found in Nantong. This induced a higher contribution of O-3 photolysis to HOx production and promoted OH-HO2 propagation, resulting in maximum HOx (OH + HO2) and higher O-3 formation rates from RO2 + NO. In Yangchen, the highest occurrence of alkenes resulted in the maximum contribution of ozonolysis to HOx production. In Nantong, the highest levels of NO2 and HO2 led to the greatest contributions of OH + NO2 and HO2 + HO2 to HOx destruction. However, the longest OH chain length was found in Xuzhou, suggesting that O-3 production was most efficient there. Although vehicular emissions were the dominant sources of VOCs overall, industrial emissions in Nantong, solvent usage in Xuzhou and vehicular emissions in Yancheng were the most important VOC sources for O-3 formation. These results show that appropriate photochemical pollution control measures should consider both the emission sources and photochemical reactivities of VOCs.