C Nicholashewitt
Publications 85
#1Zongbo Shi (TJU: Tianjin University)H-Index: 24
#2Tuan VuH-Index: 1
Last.Mei Zheng (PKU: Peking University)H-Index: 46
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The Atmospheric Pollution and Human Health in a Chinese Megacity (APHH-Beijing) programme is an international collaborative project focusing on understanding the sources, processes and health effects of air pollution in the Beijing megacity. APHH-Beijing brings together leading China and UK research groups, state-of-the-art infrastructure and air quality models to work on four research themes: (1) sources and emissions of air pollutants; (2) atmospheric processes affecting urban air pollution; (...
6 CitationsSource
#1James Brean (University of Birmingham)H-Index: 1
#2Roy M. Harrison (University of Birmingham)H-Index: 92
Last.C Nicholashewitt (Lancaster University)H-Index: 36
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Particle nucleation is one of the main sources of atmospheric particulate matter by number, with new particles having great relevance for human health and climate. Highly oxidised multifunctional organic molecules (HOMs) have been recently identified as key constituents in the growth, and, sometimes, in initial formation of new particles. While there have been many studies of HOMs in atmospheric chambers, flow tubes and clean environments, analyses of data from polluted environments are scarce. ...
#1Ben LangfordH-Index: 20
#2James M. Cash (Edin.: University of Edinburgh)H-Index: 1
Last.Eiko NemitzH-Index: 54
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Biogenic emission algorithms predict that oak forests account for ~ 70 % of the total European isoprene budget. Yet the isoprene emission potentials that underpin these model estimates are calculated from a very limited number of leaf-level observations and hence are highly uncertain. Increasingly, micrometeorological techniques such as eddy covariance are used to measure whole-canopy fluxes directly, from which isoprene emission potentials can be calculated. Here, we review five observational d...
1 CitationsSource
#1Adam R. Vaughan (Ebor: University of York)H-Index: 5
#2James Lee (Ebor: University of York)H-Index: 95
Last.C Nicholashewitt (Lancaster University)H-Index: 36
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Volatile organic compounds (VOCs) originate from a variety of sources, and play an intrinsic role in influencing air quality. Some VOCs, including benzene, are carcinogens and so directly affect human health, while others, such as isoprene, are very reactive in the atmosphere and play an important role in the formation of secondary pollutants such as ozone and particles. Here we report spatially-resolved measurements of the surface-to-atmosphere fluxes of VOCs across London and SE England made i...
3 CitationsSource
#1Adam R. Vaughan (Ebor: University of York)H-Index: 5
#2James Lee (Ebor: University of York)H-Index: 95
Last.Thomas Karl (University of Innsbruck)H-Index: 53
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To date, direct validation of city-wide emissions inventories for air pollutants has been difficult or impossible. However, recent technological innovations now allow direct measurement of pollutant fluxes from cities, for comparison with emissions inventories, which are themselves commonly used for prediction of current and future air quality and to help guide abatement strategies. Fluxes of NOx were measured using the eddy-covariance technique from an aircraft flying at low altitude over Londo...
13 CitationsSource
#1W. Joe F. Acton (Lancaster University)H-Index: 5
#2Simon Schallhart (UH: University of Helsinki)H-Index: 11
Last.Eiko NemitzH-Index: 54
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This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS) and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covarian...
11 CitationsSource
#1Annette Ryan (Lancaster University)H-Index: 9
#2C Nicholashewitt (Lancaster University)H-Index: 36
Last.Ian C. Dodd (Lancaster University)H-Index: 41
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Isoprene protects the photosynthetic apparatus of isoprene-emitting plants from oxidative stress. The role of isoprene in the response of plants to drought is less clear. Water was withheld from transgenic isoprene-emitting and non-emitting tobacco (Nicotiana tabacum) plants, to examine: the response of isoprene emission to plant water deficit; a possible relationship between concentrations of the drought-induced phytohormone abscisic acid (ABA) and isoprene; and whether isoprene affected foliar...
33 CitationsSource
#1Jonathan Strong (Lancaster University)H-Index: 1
#2J. Duncan Whyatt (Lancaster University)H-Index: 15
Last.C Nicholashewitt (Lancaster University)H-Index: 36
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Abstract The Lagrangian tropospheric ozone model ELMO-v2 (Edinburgh Lancaster Model for Ozone) is applied to the intense 2003 ozone episode in SE England. When using model parameters representative of typical episodes, ELMO-v2 was found to underestimate ozone levels substantially during peak ozone days, but, by increasing three parameters (temperature, biogenic and anthropogenic VOC emission rates) to levels close to those observed, good agreement between modelled and observed ozone was achieved...
7 CitationsSource
#1Susan M. OwenH-Index: 29
#2C Nicholashewitt (Lancaster University)H-Index: 36
Last.Clare S. RowlandH-Index: 10
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Agroforestry plantations and urban habitats contribute importantly to atmospheric volatile compound fluxes in densely populated areas. Simulation of emissions from such habitats is associated with several key challenges, including high spatial heterogeneity due to habitat fragmentation and high diversity of planted tree species. On the other hand, plants in urban habitats and in agroforestry plantations commonly receive more nutrients and water than species in natural communities, resulting in h...
9 CitationsSource
#1Reza Ghaffari (Warw.: University of Warwick)H-Index: 3
Last.Jane E. Taylor (Lancaster University)H-Index: 23
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In this paper, we evaluate the use of an electronic nose (EN) containing 13 conducting polymer gas sensors to discriminate between patterns of volatile organic compounds (VOCs) emitted by plants. The VOC patterns examined were produced by tomato, cucumber and pepper plants under both healthy and infected or infested conditions. Leaves from the plants were subjected to mechanical damage or pest and disease attacks (i.e. spider mites infested or mildew infected) and others were judged against unda...
6 CitationsSource