气候变化领域集成服务门户(CCPortal): Photochemical impacts of haze pollution in an urban environment

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DOI	10.5194/acp-19-9699-2019
	Photochemical impacts of haze pollution in an urban environment
	Hollaway M.; Wild O.; Yang T.; Sun Y.; Xu W.; Xie C.; Whalley L.; Slater E.; Heard D.; Liu D.
发表日期	2019
ISSN	16807316
起始页码	9699
结束页码	9714
卷号	19 期号:15
英文摘要	Rapid economic growth in China over the past 30 years has resulted in significant increases in the concentrations of small particulates (PM2,5) over the city of Beijing. In addition to health problems, high aerosol loading can impact visibility and thus reduce photolysis rates over the city, leading to potential implications for photochemistry. Photolysis rates are highly sensitive not only to the vertical distribution of aerosols but also to their composition, as this can impact how the incoming solar radiation is scattered or absorbed. This study, for the first time, uses aerosol composition measurements and lidar optical depth to drive the Fast-JX photolysis scheme and quantify the photochemical impacts of different aerosol species during the Air Pollution and Human Health (APHH) measurement campaigns in Beijing in November-December 2016 and May-June 2017. This work demonstrates that severe haze pollution events (PM2,5 > 75 μgm-3) occur during both winter and summer, leading to reductions in O3 photolysis rates of 27 %-34% (greatest in winter) and reductions in NO2 photolysis of 40 %-66% (greatest in summer) at the surface. It also shows that in spite of much lower PM2,5 concentrations in the summer months, the absolute changes in photolysis rates are larger for both O3 and NO2. In the winter, absorbing species such as black carbon dominate the photolysis response to aerosols, leading to mean reductions in J [O1D] and J[NO2] in the lowest 1 km of 24% and 23 %, respectively. In contrast, in the summer, scattering aerosol such as organic matter dominate the response, leading to mean decreases of 2 %-3% at the surface and increases of 8 %-10% at higher altitudes (3-4 km). During these haze events in both campaigns, the influence of aerosol on photolysis rates dominates over that from clouds. These large impacts on photochemistry can have significant implications for concentrations of important atmospheric oxidants such as the hydroxyl radical. Idealized photochemical box model studies show that such large impacts on photochemistry could lead to a 12% reduction in surface O3 (3% for OH) due to haze pollution. This highlights that PM2,5 mitigation strategies could have important implications for the oxidation capacity of the atmosphere both at the surface and in the free troposphere. © 2019 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	aerosol; aerosol composition; air quality; atmospheric pollution; concentration (composition); haze; photochemistry; photolysis; urban area; urban pollution; Beijing [Beijing (ADS)]; Beijing [China]; China
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144241
作者单位	Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, United Kingdom; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China; University of Chinese, Academy of Sciences, Beijing, 100049, China; School of Chemistry, University of Leeds, Leeds, United Kingdom; National Centre for Atmospheric Science, University of Leeds, Leeds, United Kingdom; Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang, 310027, China; Centre for Atmospheric Sciences, School of Earth and Environmental Sciences, University of Manchester, Manchester, United Kingdom; Centre for Ecology and Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster, United Kingdom
推荐引用方式 GB/T 7714	Hollaway M.,Wild O.,Yang T.,et al. Photochemical impacts of haze pollution in an urban environment[J],2019,19(15).
APA	Hollaway M..,Wild O..,Yang T..,Sun Y..,Xu W..,...&Liu D..(2019).Photochemical impacts of haze pollution in an urban environment.Atmospheric Chemistry and Physics,19(15).
MLA	Hollaway M.,et al."Photochemical impacts of haze pollution in an urban environment".Atmospheric Chemistry and Physics 19.15(2019).