Measurement report: Long-term variations in carbon monoxide at a background station in China's Yangtze River Delta region

doi:10.5194/acp-2020-610

GSTDTAP > 地球科学

DOI	10.5194/acp-2020-610
	Measurement report: Long-term variations in carbon monoxide at a background station in China's Yangtze River Delta region
	Yijing Chen, Qianli Ma, Weili Lin, Xiaobin Xu, Jie Yao, and Wei Gao
	2020-07-28
发表期刊	Atmospheric Chemistry and Physics
出版年	2020
英文摘要	This study analyzed the long-term variations in carbon monoxide (CO) mixing ratios from January 2006 to December 2017 at the Lin'an regional atmospheric background station (LAN; 30.3° N, 119.73° E, 138 m a.s.l.) in China's Yangtze River Delta (YRD) region. The CO mixing ratios were at their highest (0.69 ± 0.08 ppm) and lowest (0.54 ± 0.06 ppm) in winter and summer, respectively. The average daily variation of CO exhibited a double-peaked pattern, with peaks in the morning and evening and a valley in the afternoon. A significant downward trend of −11.3 ppb/yr of CO was observed from 2006 to 2017 at the LAN station, which was in accordance with the negative trend of the average CO mixing ratios and total column retrieved from the satellite data (the Measurements Of Pollution In The Troposphere, MOPITT) over the YRD region during the same period. The average annual CO mixing ratio at the LAN station in 2017 was 0.51 ± 0.04 ppm, which was significantly lower than that (0.71 ± 0.12 ppm) in 2006. The decrease in CO levels was largest in autumn (−15.7 ppb/yr), followed by summer (−11.1 ppb/yr), spring (−10.8 ppb/yr), and winter (−9.7 ppb/yr). Moreover, the CO levels under relatively polluted conditions (the annually 95th percentiles) declined even more rapidly (−22.4 ppb/yr, α = 0.05, r = −0.68) from 2006 (0.91 ppm) to 2017 (0.58 ppm) and the CO levels under clean conditions (the annually 5th percentiles) were relatively stable throughout the years. The long-term decline and short-term variations in the CO mixing ratios at the LAN station were mainly attributed to the implementation of the anthropogenic pollution control measures in the YRD region and to the events like Shanghai Expo in 2020 and Hangzhou G20 in 2016. The decreased CO level may influence atmospheric chemistry over the region. The average OH reactivity of CO at the LAN station is estimated to significantly drop from 4.1 ± 0.7 s^-1 in 2006 to 3.0 ± 0.3 s^-1 in 2017.
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/286618
专题	地球科学
推荐引用方式 GB/T 7714	Yijing Chen, Qianli Ma, Weili Lin, Xiaobin Xu, Jie Yao, and Wei Gao. Measurement report: Long-term variations in carbon monoxide at a background station in China's Yangtze River Delta region[J]. Atmospheric Chemistry and Physics,2020.
APA	Yijing Chen, Qianli Ma, Weili Lin, Xiaobin Xu, Jie Yao, and Wei Gao.(2020).Measurement report: Long-term variations in carbon monoxide at a background station in China's Yangtze River Delta region.Atmospheric Chemistry and Physics.
MLA	Yijing Chen, Qianli Ma, Weili Lin, Xiaobin Xu, Jie Yao, and Wei Gao."Measurement report: Long-term variations in carbon monoxide at a background station in China's Yangtze River Delta region".Atmospheric Chemistry and Physics (2020).