气候变化领域集成服务门户(CCPortal): Increasing ambient surface ozone levels over the UK accompanied by fewer extreme events

CCPortal

DOI	10.1016/j.atmosenv.2020.117627
	Increasing ambient surface ozone levels over the UK accompanied by fewer extreme events
	Finch D.P.; Palmer P.I.
发表日期	2020
ISSN	1352-2310
卷号	237
英文摘要	We report a statistical analysis of surface ozone (O3) measurements over the UK, 1999–2019. Data are from the Automatic Urban and Rural Network (AURN) that forms the basis of checking nationwide compliance with ambient air quality directives. We determine the mean O3 trend across all AURN sites to be 0.41 ± 0.07 μg m−3yr−1, composed of larger trends in suburban and urban environments (0.36 ± 0.11 μg m−3yr−1–0.75 ± 0.16 μg m−3yr−1) than in the rural environment (0.16 ± 0.07 μg m−3yr−1); consequently the gap between urban and rural surface O3 across the UK has steadily declined from 20 μg m−3 to 12 μg m−3 until 2012 when it has since stalled. These trends in urban surface O3 are coincident with and likely caused by a pronounced decline in surface concentrations of NO2 (proxy for NOx), which we link to reduced emissions from the transport sector. Using a gamma probability distribution to describe changes in surface O3, we find an increase in the probability of high mean O3 and an associated decrease in the probability of extreme (elevated) O3 events. We find no discernible trend in the number of days per year that exceed the 8-h mean O3 value of 100 μg m−3 set by the UK Department for Environment, Food and Rural Affairs (Defra) or a similar metric of 120 μg m−3 set by the EU. These exceedances, typically occurring during summer months across the network, range from 499 exceedances in 2010 to in excess of 2300 exceedances in 2003 and 2006. We find that 50% of these exceedances occur at temperatures greater than 18∘C (21∘C) in rural (urban) environments. With 50% (95%) of the 66 million UK inhabitants living and working within 12 km (50 km) of an AURN site, our analysis is relevant to a large fraction of the UK population. Consequently, we may need to re-prioritize epidemiological studies to understand the impact of chronic exposure to elevated mean O3 concentrations on human health. © 2020
英文关键词	Extreme events; Surface ozone trend; UK air quality
语种	英语
scopus关键词	Air quality; Binary alloys; Compliance control; Nitrogen oxides; Ozone; Probability distributions; Urban transportation; Ambient air quality; Chronic exposure; Department for Environment , Food and Rural Affairs; Epidemiological studies; Rural environment; Surface concentration; Transport sectors; Urban environments; Urban growth
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/129405
作者单位	School of GeoSciences, University of Edinburgh, United Kingdom
推荐引用方式 GB/T 7714	Finch D.P.,Palmer P.I.. Increasing ambient surface ozone levels over the UK accompanied by fewer extreme events[J],2020,237.
APA	Finch D.P.,&Palmer P.I..(2020).Increasing ambient surface ozone levels over the UK accompanied by fewer extreme events.Atmospheric Environment,237.
MLA	Finch D.P.,et al."Increasing ambient surface ozone levels over the UK accompanied by fewer extreme events".Atmospheric Environment 237(2020).