气候变化领域集成服务门户(CCPortal): Using near-road observations of CO, NOy, and CO2 to investigate emissions from vehicles: Evidence for an impact of ambient temperature and specific humidity

CCPortal

DOI	10.1016/j.atmosenv.2020.117558
	Using near-road observations of CO, NOy, and CO2 to investigate emissions from vehicles: Evidence for an impact of ambient temperature and specific humidity
	Hall D.L.; Anderson D.C.; Martin C.R.; Ren X.; Salawitch R.J.; He H.; Canty T.P.; Hains J.C.; Dickerson R.R.
发表日期	2020
ISSN	1352-2310
卷号	232
英文摘要	Vehicles are a significant source of carbon monoxide (CO) and nitrogen oxides (NOx), two harmful pollutants and precursors to ozone formation. Previous studies have shown that emissions of NOx in the US EPA's National Emissions Inventory (NEI) are overestimated relative to observations in the summer and possibly for an annual average. Here we use measurements of CO, NOx, carbon dioxide (CO2), and meteorological variables collected at a near-road (NR) site along I-95 in Howard County, Maryland, during the cold months of 2016 and 2017, to infer ΔCO/ΔNOx, ΔCO2/ΔNOx, and ΔCO2/ΔCO emission ratios from vehicular running exhaust and their sensitivity to temperature and specific humidity. We also use aircraft observations of CO, NOx, and meteorological variables collected during the 2011 summertime DISCOVER-AQ campaign over the Baltimore-Washington region to analyze the impact of temperature and humidity on ΔCO/ΔNOx ratios, which integrate anthropogenic and biogenic sources in the urban area. Overall, we find a strong, statistically significant increase of 113% in ΔCO/ΔNOx and of 112% in ΔCO2/ΔNOx from −5 to 25 °C at the I-95 NR site, indicating a decrease of approximately 50% in emissions of NOx as air warms, linked primarily to diesel-powered trucks. Temperature sensitivity of pollution control equipment on diesel vehicles may contribute to this trend. Results are robust when using several different techniques for calculating emission ratios. The sensitivity of vehicular emissions of NOx to specific humidity is much weaker and cannot solely explain the trend with temperature. The aircraft data show a similar increase of 114% in ΔCO/ΔNOx from 25 °C to 34 °C, with a weaker sensitivity to specific humidity. In comparison to the NR observations, ΔCO/ΔNOx output from the MOtor Vehicle Emission Simulator (MOVES) with default settings, used to simulate mobile emissions for air quality models and in the NEI, showed a smaller increase for ΔCO/ΔNOx of 41% over the temperature range −5 to 25 °C. The increase in ΔCO/ΔNOx from MOVES is due to an increase in emissions of CO by 23% and a decrease in emissions of NOx by 11% over −5 to 25 °C, which is less than the observed decrease in NOx. Our study suggests that the overestimate in emissions of NOx in the NEI previously reported using summertime observations may be corrected in part by accounting for the temperature sensitivity of mobile NOx running emissions within MOVES. Future work will focus on improving MOVES by adjusting parameters controlling the impact of temperature and humidity on emissions to better represent the behavior of real-world vehicular emissions. © 2020 Elsevier Ltd
英文关键词	Air quality; Ambient temperature; CO; CO2; Emission model; National emissions inventory; NOx; On-road emissions
语种	英语
scopus关键词	Air quality; Aircraft; Carbon dioxide; Carbon monoxide; Diesel engines; Humidity control; Nitrogen oxides; Pollution control; Pollution control equipment; Roads and streets; Vehicles; Aircraft observations; Diesel-powered trucks; Impact of temperatures; Meteorological variables; Motor vehicle emissions; National emissions inventories; Sensitivity to temperatures; Temperature sensitivity; Atmospheric temperature; carbon dioxide; carbon monoxide; nitrogen oxide; ozone; air quality; carbon dioxide; carbon monoxide; emission inventory; humidity; nitrogen oxides; pollutant source; roadside environment; temperature effect; traffic emission; urban area; air pollution control; air quality; aircraft; Article; cold; environmental temperature; humidity; Maryland; meteorology; motor vehicle; pollution control; priority journal; temperature sensitivity; trend study; Baltimore; Howard County [Maryland]; Maryland; United States; Washington [United States]
来源期刊	Atmospheric Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129467
作者单位	Department of Atmospheric and Oceanic Science, University of Maryland, College ParkMD, United States; Universities Space Research Association, Columbia, MD, United States; NASA Goddard Space Flight Center, Greenbelt, MD, United States; RedLine Performance Solutions LLC, Rockville, MD 20850, United States; Environmental Modeling Center, National Centers for Environmental Prediction, National Oceanic and Atmospheric Administration, College ParkMD 20740, United States; Air Resources Laboratory, National Oceanic and Atmospheric Administration, College ParkMD, United States; Cooperative Institute for Satellite Earth System Studies, University of Maryland, College ParkMD, United States; Department of Chemistry and Biochemistry, University of Maryland, College ParkMD, United States; Earth System Science Interdisciplinary Center, University of Maryland, College ParkMD, United States; Minnesota Department of Health, St. PaulMN, United States; Maryland Department of the Environment, Baltimore, MD, United States
推荐引用方式 GB/T 7714	Hall D.L.,Anderson D.C.,Martin C.R.,et al. Using near-road observations of CO, NOy, and CO2 to investigate emissions from vehicles: Evidence for an impact of ambient temperature and specific humidity[J],2020,232.
APA	Hall D.L..,Anderson D.C..,Martin C.R..,Ren X..,Salawitch R.J..,...&Dickerson R.R..(2020).Using near-road observations of CO, NOy, and CO2 to investigate emissions from vehicles: Evidence for an impact of ambient temperature and specific humidity.Atmospheric Environment,232.
MLA	Hall D.L.,et al."Using near-road observations of CO, NOy, and CO2 to investigate emissions from vehicles: Evidence for an impact of ambient temperature and specific humidity".Atmospheric Environment 232(2020).