气候变化领域集成服务门户(CCPortal): Spatially and temporally resolved measurements of NOxfluxes by airborne eddy covariance over Greater London

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DOI	10.5194/acp-21-15283-2021
	Spatially and temporally resolved measurements of NOxfluxes by airborne eddy covariance over Greater London
	Vaughan A.R.; Lee J.D.; Metzger S.; Durden D.; Lewis A.C.; Shaw M.D.; Drysdale W.S.; Purvis R.M.; Davison B.; Nicholas Hewitt C.
发表日期	2021
ISSN	1680-7316
起始页码	15283
结束页码	15298
卷号	21 期号:19
英文摘要	Flux measurements of nitrogen oxides (NOx) were made over London using airborne eddy covariance from a low-flying aircraft. Seven low-altitude flights were conducted over Greater London, performing multiple overpasses across the city during eight days in July 2014. NOx fluxes across the Greater London region (GLR) exhibited high heterogeneity and strong diurnal variability, with central areas responsible for the highest emission rates (20-30mgm-2h-1). Other high-emission areas included the M25 orbital motorway. The complexity of London's emission characteristics makes it challenging to pinpoint single emissions sources definitively using airborne measurements. Multiple sources, including road transport and residential, commercial and industrial combustion sources, are all likely to contribute to measured fluxes. Measured flux estimates were compared to scaled National Atmospheric Emissions Inventory (NAEI) estimates, accounting for monthly, daily and hourly variability. Significant differences were found between the flux-driven emissions and the NAEI estimates across Greater London, with measured values up to 2 times higher in Central London than those predicted by the inventory. To overcome the limitations of using the national inventory to contextualise measured fluxes, we used physics-guided flux data fusion to train environmental response functions (ERFs) between measured flux and environmental drivers (meteorological and surface). The aim was to generate time-of-day emission surfaces using calculated ERF relationships for the entire GLR; 98% spatial coverage was achieved across the GLR at 400m2 spatial resolution. All flight leg projections showed substantial heterogeneity across the domain, with high emissions emanating from Central London and major road infrastructure. The diurnal emission structure of the GLR was also investigated, through ERF, with the morning rush hour distinguished from lower emissions during the early afternoon. Overall, the integration of airborne fluxes with an ERF-driven strategy enabled the first independent generation of surface NOx emissions, at high resolution using an eddy-covariance approach, for an entire city region. © 2021 Adam R. Vaughan et al.
语种	英语
scopus关键词	atmospheric chemistry; diurnal variation; eddy covariance; emission inventory; flux measurement; nitrogen dioxide; source apportionment; spatiotemporal analysis; England; London [England]; United Kingdom
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/246506
作者单位	Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, United Kingdom; National Centre for Atmospheric Science, University of York, York, YO10 5DD, United Kingdom; Battelle, National Ecological Observatory Network, 1685 38th Street, Boulder, CO 80301, United States; Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, 1225 West Dayton Street, Madison, WI 53706, United States; Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
推荐引用方式 GB/T 7714	Vaughan A.R.,Lee J.D.,Metzger S.,et al. Spatially and temporally resolved measurements of NOxfluxes by airborne eddy covariance over Greater London[J],2021,21(19).
APA	Vaughan A.R..,Lee J.D..,Metzger S..,Durden D..,Lewis A.C..,...&Nicholas Hewitt C..(2021).Spatially and temporally resolved measurements of NOxfluxes by airborne eddy covariance over Greater London.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(19).
MLA	Vaughan A.R.,et al."Spatially and temporally resolved measurements of NOxfluxes by airborne eddy covariance over Greater London".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.19(2021).