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英国伯明翰大学环境保护专业留学生硕士论文定制A cluster analysis of long range air transport pathways and associated
pollutant concentrations within the UK
Jacob Baker
Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
a r t i c l e i n f o
Article history:
Received 16 July 2008
Received in revised form
17 October 2009
Accepted 21 October 2009
Keywords:
Cluster analysis
Air pollution
Trajectory sets
Ozone
Midlands
a b s t r a c t
A cluster analysis of four-day back trajectories for January 1998 to December 2001 arriving mid-afternoon inBirmingham, UK at three different within boundary layer arrival heights has been performed in order fora better understanding of the pollution meteorology influencing this region. The time periodwas purposelychosen to encompass the Pollution in the Urban Midlands Atmosphere field campaign. Six natural synoptic
scale transport patterns were identified with three, strong-westerly, westerly and slow-easterly, showingseasonal variation in frequency. Significant differences in air pollutant concentrations and behaviour werefound between air mass cluster types when they were analysed with measurements taken from an urbanbackground site in Birmingham and a rural site in Harwell. Highest concentrations of primary pollutantswere associated with a slow-easterly air mass from mainland Europe, while lowest concentrations wereassociated with south-westerly and strong-westerly air masses passing over the Atlantic Ocean. Thepolluted slow-easterly air mass was associated with highest ozone concentration for the warm season andlowest ozone concentration for the cool season. This could be explained by photochemical ozone productionduring the warm season and NOx titration of background ozone during the cool season, when photochemically“inactive” conditions prevailed. A wealth of informationwas determinable, including influencesof short and long-range transport and photochemical productivity.
2009 Elsevier Ltd. All rights reserved.
1. Introduction
The rationale for the present study was to better understand theconditions for which air pollution, in particular ozone episodes,occurred within the UK Midlands. In addition a better understandingof pollution meteorology was sought for placing the PUMA (Pollutionin the Urban Midlands Atmosphere) field campaign (Harrisonet al., 2006) into its more general context and for gaining insightsthat could lead to improvements in phototrajectory air qualitymodels (Derwent et al., 1996; Walker et al., 2009; Baker, submittedfor publication). This field campaign, which took place during thesummer of 1999 and winter of 1999/2000 was part of the NationalEnvironmental Research Council's Urban Regeneration and the
Environment (URGENT) thematic programme.Ozone in the troposphere is formed from complex reactionsinvolving volatile organic compounds (VOC) and nitrogen oxides(NOx). Its formation may take place over several hours or daysand may be associated with precursor emissions hundreds, or eventhousands of kilometres away. Thus both chemistry and atmospherictransport need to be understood for developing knowledgeof the causes of ozone episodes. With an understanding of thispollution meteorology, the influence of policy on meeting airquality objectives may then be assessed.Back trajectories from trajectory models, which make use ofarchived meteorological data本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。