Impact of halogen chemistry on summertime air quality in coastal and continental Europe: application of the CMAQ model and implications for regulation
Impact of halogen chemistry on summertime air quality in coastal and continental Europe: application of the CMAQ model and implications for regulation
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DOI：
10.5194/acp-19-15321-2019
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发表时间：
2019-12
影响因子：
6.3
通讯作者：
Qinyi Li;R. Borge;G. Sarwar;D. de la Paz;B. Gantt;Jessica Domingo;C. Cuevas;A. Saiz‐Lopez
中科院分区：
文献类型：
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作者：
Qinyi Li;R. Borge;G. Sarwar;D. de la Paz;B. Gantt;Jessica Domingo;C. Cuevas;A. Saiz‐Lopez
据报道，卤素（Cl、Br和I）化学会影响二次空气污染物的形成。以往的研究主要集中在大空间尺度上氯物种对空气质量的影响。很少有人注意到组合卤素化学对欧洲空气质量的影响及其对控制政策的影响。在本研究中，我们应用广泛使用的区域模型，社区多尺度空气质量模拟系统（CMAQ），结合最新的卤素源和化学，模拟欧洲上空卤素物种的丰度，并研究卤素在形成二次空气污染中的作用。结果表明，CMAQ模型是能够再现的水平的O3，NO2和卤素物种在欧洲。氯化学稍微增加了OH，HO 2，NO3，O3和NO2的水平，并大大提高了Cl自由基的水平。组合卤素化学诱导对OH的复杂作用（范围为-0.023至0.030 pptv）和HO 2（在-3.7至0.73 pptv的范围内），显著降低了NO3的浓度（高达20 pptv）和O3（高达10 ppbv），并在高污染地区减少NO2（高达1.7 ppbv）;在其他地区增加NO2（高达0.20 ppbv）。卤素化学的最大影响发生在海洋和沿海地区，但一些明显的影响也发生在欧洲大陆。卤素化学影响超过欧盟保护人类和植物免受环境O3影响的目标阈值的天数。鉴于卤素化学对空气质量的重大影响，我们建议考虑将卤素化学纳入空气质量政策评估，特别是在沿海城市。
Halogen (Cl, Br, and I) chemistry has been reported to influence the formation of secondary air pollutants. Previous studies mostly focused on the impact of chlorine species on air quality over large spatial scales. Very little attention has been paid to the effect of the combined halogen chemistry on air quality over Europe and its implications for control policy. In the present study, we apply a widely used regional model, the Community Multiscale Air Quality Modeling System (CMAQ), incorporated with the latest halogen sources and chemistry, to simulate the abundance of halogen species over Europe and to examine the role of halogens in the formation of secondary air pollution. The results suggest that the CMAQ model is able to reproduce the level of O3, NO2, and halogen species over Europe. Chlorine chemistry slightly increases the levels of OH, HO2, NO3, O3, and NO2 and substantially enhances the level of the Cl radical. Combined halogen chemistry induces complex effects on OH (ranging from –0.023 to 0.030 pptv) and HO2 (in the range of –3.7 to 0.73 pptv), significantly reduces the concentrations of NO3 (as much as 20 pptv) and O3 (as much as 10 ppbv), and decreases NO2 in highly polluted regions (as much as 1.7 ppbv); it increases NO2 (up to 0.20 ppbv) in other areas. The maximum effects of halogen chemistry occur over oceanic and coastal regions, but some noticeable impacts also occur over continental Europe. Halogen chemistry affects the number of days exceeding the European Union target threshold for the protection of human beings and vegetation from ambient O3. In light of the significant impact of halogen chemistry on air quality, we recommend that halogen chemistry be considered for inclusion in air quality policy assessments, particularly in coastal cities.