Significant concentrations of nitryl chloride sustained in the morning: investigations of the causes and impacts on ozone production in a polluted region of northern China

doi:10.5194/acp-16-14959-2016

GSTDTAP > 地球科学

DOI	10.5194/acp-16-14959-2016
	Significant concentrations of nitryl chloride sustained in the morning: investigations of the causes and impacts on ozone production in a polluted region of northern China
	Yee Jun Tham, Zhe Wang, Qinyi Li, Hui Yun, Weihao Wang, Xinfeng Wang, Likun Xue, Keding Lu, Nan Ma, Birger Bohn, Xin Li, Simonas Kecorius, Johannes Größ, Min Shao, Alfred Wiedensohler, Yuanhang Zhang, and Tao Wang
	2016-12-05
发表期刊	Atmospheric Chemistry and Physics
出版年	2016
英文摘要	Nitryl chloride (ClNO₂) is a dominant source of chlorine radical in polluted environment, and can significantly affect the atmospheric oxidative chemistry. However, the abundance of ClNO₂ and its exact role are not fully understood under different environmental conditions. During the summer of 2014, we deployed a chemical ionization mass spectrometer to measure ClNO₂ and dinitrogen pentoxide (N₂O₅) at a rural site in the polluted North China Plain. Elevated mixing ratios of ClNO₂ (> 350 pptv) were observed at most of the nights with low levels of N₂O₅ (< 200 pptv). The highest ClNO₂ mixing ratio of 2070 pptv (1 min average) was observed in a plume from a megacity (Tianjin), and was characterized with a faster N₂O₅ heterogeneous loss rate and ClNO₂ production rate compared to average conditions. The abundant ClNO₂ concentration kept increasing even after sunrise, and reached a peak 4 h later. Such highly sustained ClNO₂ peaks after sunrise are discrepant from the previously observed typical diurnal pattern. Meteorological and chemical analysis shows that the sustained ClNO₂ morning peaks are caused by significant ClNO₂ production in the residual layer at night followed by downward mixing after breakup of the nocturnal inversion layer in the morning. We estimated that ∼  1.7–4.0 ppbv of ClNO₂ would exist in the residual layer in order to maintain the observed morning ClNO₂ peaks at the surface site. Observation-based box model analysis show that photolysis of ClNO₂ produced chlorine radical with a rate up to 1.12 ppbv h⁻¹, accounting for 10–30 % of primary RO_x production in the morning hours. The perturbation in total radical production leads to an increase of integrated daytime net ozone production by 3 % (4.3 ppbv) on average, and with a larger increase of 13 % (11 ppbv) in megacity outflow that was characterized with higher ClNO₂ and a relatively lower oxygenated hydrocarbon (OVOC) to non-methane hydrocarbon (NMHC) ratio.
领域	地球科学
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/287918
专题	地球科学
推荐引用方式 GB/T 7714	Yee Jun Tham, Zhe Wang, Qinyi Li, Hui Yun, Weihao Wang, Xinfeng Wang, Likun Xue, Keding Lu, Nan Ma, Birger Bohn, Xin Li, Simonas Kecorius, Johannes Größ, Min Shao, Alfred Wiedensohler, Yuanhang Zhang, and Tao Wang. Significant concentrations of nitryl chloride sustained in the morning: investigations of the causes and impacts on ozone production in a polluted region of northern China[J]. Atmospheric Chemistry and Physics,2016.
APA	Yee Jun Tham, Zhe Wang, Qinyi Li, Hui Yun, Weihao Wang, Xinfeng Wang, Likun Xue, Keding Lu, Nan Ma, Birger Bohn, Xin Li, Simonas Kecorius, Johannes Größ, Min Shao, Alfred Wiedensohler, Yuanhang Zhang, and Tao Wang.(2016).Significant concentrations of nitryl chloride sustained in the morning: investigations of the causes and impacts on ozone production in a polluted region of northern China.Atmospheric Chemistry and Physics.
MLA	Yee Jun Tham, Zhe Wang, Qinyi Li, Hui Yun, Weihao Wang, Xinfeng Wang, Likun Xue, Keding Lu, Nan Ma, Birger Bohn, Xin Li, Simonas Kecorius, Johannes Größ, Min Shao, Alfred Wiedensohler, Yuanhang Zhang, and Tao Wang."Significant concentrations of nitryl chloride sustained in the morning: investigations of the causes and impacts on ozone production in a polluted region of northern China".Atmospheric Chemistry and Physics (2016).