气候变化领域集成服务门户(CCPortal): Observed decreases in on-road CO2 concentrations in Beijing during COVID-19 restrictions

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DOI	10.5194/acp-21-4599-2021
	Observed decreases in on-road CO2 concentrations in Beijing during COVID-19 restrictions
	Liu D.; Sun W.; Zeng N.; Han P.; Yao B.; Liu Z.; Wang P.; Zheng K.; Mei H.; Cai Q.
发表日期	2021
ISSN	1680-7316
起始页码	4599
结束页码	4614
卷号	21 期号:6
英文摘要	To prevent the spread of the COVID-19 epidemic, restrictions such as "lockdowns"were conducted globally, which led to a significant reduction in fossil fuel emissions, especially in urban areas. However, CO2 concentrations in urban areas are affected by many factors, such as weather, biological sinks and background CO2 fluctuations. Thus, it is difficult to directly observe the CO2 reductions from sparse ground observations. Here, we focus on urban ground transportation emissions, which were dramatically affected by the restrictions, to determine the reduction signals. We conducted six series of on-road CO2 observations in Beijing using mobile platforms before (BC), during (DC) and after (AC) the implementation of COVID-19 restrictions. To reduce the impacts of weather conditions and background fluctuations, we analyze vehicle trips with the most similar weather conditions possible and calculated the enhancement metric, which is the difference between the on-road CO2 concentration and the "urban background"CO2 concentration measured at the tower of the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences. The results showed that the DC CO2 enhancement was decreased by 41 (±1:3) parts per million (ppm) and 26 (±6:2) ppm compared to those for the BC and AC trips, respectively. Detailed analysis showed that, during COVID-19 restrictions, there was no difference between weekdays and weekends during working hours (09:00-17:00 local standard time; LST). The enhancements during rush hours (07:00-09:00 and 17:00-20:00 LST) were almost twice those during working hours, indicating that emissions during rush hours were much higher. For DC and BC, the enhancement reductions during rush hours were much larger than those during working hours. Our findings showed a clear CO2 concentration decrease during COVID-19 restrictions, which is consistent with the CO2 emissions reductions due to the pandemic. The enhancement method used in this study is an effective method to reduce the impacts of weather and background fluctuations. Low-cost sensors, which are inexpensive and convenient, could play an important role in further on-road and other urban observations. © 2021 Author(s).
语种	英语
scopus关键词	atmospheric chemistry; carbon dioxide; carbon emission; concentration (composition); COVID-19; traffic emission; weather; 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/247027
作者单位	Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Science, Beijing, China; Meteorological Observation Centre, China Meteorological Administration, Beijing, China; Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD, United States; Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, United States; Laboratory for Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Liu D.,Sun W.,Zeng N.,et al. Observed decreases in on-road CO2 concentrations in Beijing during COVID-19 restrictions[J],2021,21(6).
APA	Liu D..,Sun W..,Zeng N..,Han P..,Yao B..,...&Cai Q..(2021).Observed decreases in on-road CO2 concentrations in Beijing during COVID-19 restrictions.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(6).
MLA	Liu D.,et al."Observed decreases in on-road CO2 concentrations in Beijing during COVID-19 restrictions".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.6(2021).