气候变化领域集成服务门户(CCPortal): Thirty years of the Clean Air Act Amendments: Impacts on haze in remote regions of the United States (1990

CCPortal

DOI	10.1016/j.atmosenv.2020.117865
	Thirty years of the Clean Air Act Amendments: Impacts on haze in remote regions of the United States (1990–2018)
	Hand J.L.; Prenni A.J.; Copeland S.; Schichtel B.A.; Malm W.C.
发表日期	2020
ISSN	1352-2310
卷号	243
英文摘要	The Clean Air Act Amendments of 1990 were aimed at reducing major environmental threats in the United States, such as acid rain, urban air pollution, toxic air emissions, and regional haze. To this end, there have been major reductions in anthropogenic gaseous emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx). SO2 and NOx are also major contributors to particulate haze, which affects visibility in both urban and rural environments. The Interagency Monitoring of Protected Visual Environments (IMPROVE) network has tracked trends in haze in remote regions of the United States since the late 1980s by reconstructing total light extinction (bext) from speciated particulate concentrations. Regional trends in bext were examined using aggregated data from individual sites. Regional, annual mean short-term trends analyses (2002–2018) indicated strong reductions in bext associated with reduced SO2 and NOx emissions, especially in the eastern United States (−4.3% yr−1, p < 0.001) where haze historically was dominated by sulfate particles. Less improvement occurred in the Intermountain West/Southwest (−0.9% yr−1, p = 0.03) and trends were negative but insignificant along the West Coast (−1.5% yr−1, p = 0.19). On average, across the continental remote United States, bext has decreased at a rate of −2.8% yr−1 (p < 0.001) from 2002 through 2018 and -1.8% yr−1 (p < 0.001) from 1992 through 2018. The composition of haze has shifted away from being sulfate-dominated to having higher contributions from carbonaceous and crustal aerosols. This shift points to the success of combined regulatory activities aimed at reducing anthropogenic emissions over the last three decades. As emissions from regulated sources of SO2 and NOx continue to decline, the contributions to haze from unregulated sources, both anthropogenic and natural, such as oil and gas extraction, international sources, biomass burning, and dust, have increased in importance. Reducing haze from these sources would require additional mitigation strategies and resource management plans. © 2020 Elsevier Ltd
关键词	Aerosol trends Haze IMPROVE Remote aerosols Visibility
语种	英语
scopus关键词	Acid rain; Air quality standards; Gas emissions; Light extinction; Nitrogen oxides; Particles (particulate matter); Sulfur dioxide; Anthropogenic emissions; Clean air act amendments; Environmental threats; Interagency monitoring of protected visual environments; Mitigation strategy; Resource management plan; Sulfate particles; Urban air pollution; Air pollution; nitric oxide; nitrogen oxide; sulfur dioxide; anthropogenic effect; emission control; environmental impact; haze; pollutant source; pollution control; pollution effect; resource management; temporal analysis; air; Article; biomass; dust; gas; haze; human; priority journal; resource management; rural area; seashore; United States; urban area; visibility; Intermountain West; Pacific Coast [North America]; Pacific Coast [United States]; 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/248908
作者单位	Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO 80523, United States; National Park Service, Air Resources Division, Lakewood, CO 80235, United States
推荐引用方式 GB/T 7714	Hand J.L.,Prenni A.J.,Copeland S.,等. Thirty years of the Clean Air Act Amendments: Impacts on haze in remote regions of the United States (1990–2018)[J],2020,243.
APA	Hand J.L.,Prenni A.J.,Copeland S.,Schichtel B.A.,&Malm W.C..(2020).Thirty years of the Clean Air Act Amendments: Impacts on haze in remote regions of the United States (1990–2018).ATMOSPHERIC ENVIRONMENT,243.
MLA	Hand J.L.,et al."Thirty years of the Clean Air Act Amendments: Impacts on haze in remote regions of the United States (1990–2018)".ATMOSPHERIC ENVIRONMENT 243(2020).