气候变化领域集成服务门户(CCPortal): Volatile organic compounds and ozone at four national parks in the southwestern United States

CCPortal

DOI	10.1016/j.atmosenv.2020.117783
	Volatile organic compounds and ozone at four national parks in the southwestern United States
	Benedict K.B.; Prenni A.J.; El-Sayed M.M.H.; Hecobian A.; Zhou Y.; Gebhart K.A.; Sive B.C.; Schichtel B.A.; Collett J.L.; Jr.
发表日期	2020
ISSN	13522310
卷号	239
英文摘要	The National Park Service is tasked with protecting the lands it oversees, including from impacts from air pollutants. While ozone is regularly monitored in many parks across the United States, precursors to ozone formation are not routinely measured. In this work we characterize volatile organic compounds (VOCs) at four national parks in the southwestern United States: Carlsbad Caverns (CAVE), Great Basin (GRBA), Grand Canyon (GRCA), and Joshua Tree (JOTR). Whole air samples were collected for VOC analysis for five months (mid-April through mid-September) in 2017. Samples were collected from 3 p.m. to 5 p.m. local time, corresponding approximately to the time of expected peak ozone concentrations, and were analyzed using gas chromatography for a variety of compounds including alkanes, alkenes, aromatics, biogenics, and alkyl nitrates. Among the four parks, the total measured VOC mixing ratio was greatest at CAVE, mostly due to an abundance of light alkanes (on average 94% of all VOCs measured) from oil and gas sources. VOC concentrations at the other three parks were similar to each other and approximately 7–10 times lower than at CAVE. While VOC sources varied across sites, VOC-OH reactivity was dominated by biogenic compounds at all sites except CAVE, which had similar contributions from biogenics and from light alkanes. JOTR had the highest levels of ozone, and the highest concentrations of biogenic VOCs among the parks studied. Back trajectory analysis suggests that the high levels of ozone occurred when air flow came from the west, in the direction of the greater Los Angeles area. The two parks most removed from oil and gas and urban sources, GRBA and GRCA, had the lowest concentrations of total VOCs, and were likely influenced by long range transport of pollutants. To better characterize source influences at the park with the highest VOC concentrations, intensive measurements were conducted in and around CAVE for one week in September 2017. These measurements showed an oil and gas influence throughout the region and indicated that the whole air samples collected over the five-month study did not capture the full range of VOC mixing ratios present at other times of the day. © 2020 Elsevier Ltd
英文关键词	Air quality; National parks; VOCs
语种	英语
scopus关键词	Caves; Gas chromatography; Hydrocarbons; Mixing; Ozone; Paraffins; Petroleum transportation; Urban transportation; Volatile organic compounds; Alkyl nitrates; Back trajectory analysis; Biogenic compounds; Intensive measurements; Long range transport; National Park Service; Ozone formation; Peak ozone concentration; Air pollution; alkane derivative; aromatic compound; halocarbon; nitric acid derivative; ozone; volatile organic compound; airflow; alkane; concentration (composition); hydroxide; long range transport; mixing ratio; nitrate; ozone; volatile organic compound; air quality; air sampling; airflow; Article; comparative study; controlled study; flame ionization detection; gas chromatography; humidity; national park; photochemistry; pollution transport; priority journal; retention time; solar radiation; United States; urban area; wind speed; Arizona; California; Carlsbad Caverns; Grand Canyon; Great Basin; Los Angeles [California]; New Mexico; 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/145010
作者单位	Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States; National Park Service, Air Resources Division, Lakewood, CO, United States; Now at Department of Civil Engineering, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114, United States
推荐引用方式 GB/T 7714	Benedict K.B.,Prenni A.J.,El-Sayed M.M.H.,et al. Volatile organic compounds and ozone at four national parks in the southwestern United States[J],2020,239.
APA	Benedict K.B..,Prenni A.J..,El-Sayed M.M.H..,Hecobian A..,Zhou Y..,...&Jr..(2020).Volatile organic compounds and ozone at four national parks in the southwestern United States.Atmospheric Environment,239.
MLA	Benedict K.B.,et al."Volatile organic compounds and ozone at four national parks in the southwestern United States".Atmospheric Environment 239(2020).