气候变化领域集成服务门户(CCPortal): Haze pollution under a high atmospheric oxidization capacity in summer in Beijing: Insights into formation mechanism of atmospheric physicochemical processes

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DOI	10.5194/acp-20-4575-2020
	Haze pollution under a high atmospheric oxidization capacity in summer in Beijing: Insights into formation mechanism of atmospheric physicochemical processes
	Zhao D.; Liu G.; Xin J.; Quan J.; Wang Y.; Wang X.; Dai L.; Gao W.; Tang G.; Hu B.; Ma Y.; Wu X.; Wang L.; Liu Z.; Wu F.
发表日期	2020
ISSN	1680-7316
起始页码	4575
结束页码	4592
卷号	20 期号:8
英文摘要	Under a high atmospheric oxidization capacity, the synergistic effect of the physicochemical processes in the atmospheric boundary layer (ABL) caused summer haze pollution in Beijing. The southern and southwestern areas, generally 60 300 km away from Beijing, were seriously polluted in contrast to Beijing, which remained clean. Southerly winds moving faster than 20 30 km h-1 since the early morning primarily caused haze pollution initiation. The PM2.5 (particulate matter with a dynamic equivalent diameter smaller than 2.5 μm) level increased to 75 μgm-3 over several hours during the daytime, which was simultaneously affected by the ABL structure. Additionally, the O3 concentration was quite high during the daytime (250 μgm-3), corresponding to a high atmospheric oxidation capacity. Much sulfate and nitrate were produced through active atmospheric chemical processes, with sulfur oxidation ratios (SORs) up to ~ 0.76 and nitrogen oxidation ratios (NORs) increasing from 0.09 to 0.26, which further facilitated particulate matter (PM) level enhancement. However, the increase in sulfate was mainly linked to southerly transport. At midnight, the PM2.5 concentration sharply increased from 75 to 150 μgm-3 over 4 h and remained at its highest level until the next morning. Under an extremely stable ABL structure, secondary aerosol formation dominated by nitrate was quite intense, driving the haze pollution outbreak. The PM levels in the southern and southeastern areas of Beijing were significantly lower than those in Beijing at this time, even below air quality standards; thus, the contribution of pollution transport had almost disappeared. With the formation of a nocturnal stable boundary layer (NSBL) at an altitude ranging from 0 0.3 km, the extremely low turbulence kinetic energy (TKE) ranging from 0 to 0.05m2 s-2 inhibited the spread of particles and moisture, ultimately resulting in elevated near-surface PM2.5 and relative humidity (~ 90 %) levels. Due to the very high humidity and ambient oxidization capacity, NOR rapidly increased from 0.26 to 0.60, and heterogeneous hydrolysis reactions at the moist particle surface were very notable. The nitrate concentration steeply increased from 11.6 to 57.8 μgm-3, while the sulfate and organics concentrations slightly increased by 6.1 and 3.1 μgm-3, respectively. With clean and strong winds passing through Beijing, the stable ABL dissipated with the potential temperature gradient becoming negative and the ABL height (ABLH) increasing to ~ 2:5 km. The high turbulence activity with a TKE ranging from 3 to 5m2 s-2 notably promoted pollution diffusion. The selfcleaning capacity of the atmosphere is commonly responsi-ble for air pollution dispersion. However, reducing the atmospheric oxidization capacity, through strengthening collaborative control of nitrogen oxide (NOx ) and volatile organic compounds (VOCs), as well as continuously deepening regional joint air pollution control, is urgent. © 2020 IEEE Computer Society. All rights reserved.
语种	英语
scopus关键词	atmospheric chemistry; atmospheric pollution; concentration (composition); formation mechanism; haze; kinetic energy; nitrogen oxides; nocturnal boundary layer; oxidation; physicochemical property; pollutant transport; pollution incidence; summer; turbulence; urban atmosphere; 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/141398
作者单位	State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China; College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, 210044, China; Institute of Urban Meteorology, Chinese Meteorological Administration, Beijing, China
推荐引用方式 GB/T 7714	Zhao D.,Liu G.,Xin J.,et al. Haze pollution under a high atmospheric oxidization capacity in summer in Beijing: Insights into formation mechanism of atmospheric physicochemical processes[J],2020,20(8).
APA	Zhao D..,Liu G..,Xin J..,Quan J..,Wang Y..,...&Wu F..(2020).Haze pollution under a high atmospheric oxidization capacity in summer in Beijing: Insights into formation mechanism of atmospheric physicochemical processes.Atmospheric Chemistry and Physics,20(8).
MLA	Zhao D.,et al."Haze pollution under a high atmospheric oxidization capacity in summer in Beijing: Insights into formation mechanism of atmospheric physicochemical processes".Atmospheric Chemistry and Physics 20.8(2020).