title: Spatially-varying surface roughness and ground-level air quality in an operational dispersion model.
abstract: Urban form controls the overall aerodynamic roughness of a city, and hence plays a significant role in how air flow interacts with the urban landscape. This paper reports improved model performance resulting from the introduction of variable surface roughness in the operational air-quality model ADMS-Urban (v3.1). We then assess to what extent pollutant concentrations can be reduced solely through local reductions in roughness. The model results suggest that reducing surface roughness in a city centre can increase ground-level pollutant concentrations, both locally in the area of reduced roughness and downwind of that area. The unexpected simulation of increased ground-level pollutant concentrations implies that this type of modelling should be used with caution for urban planning and design studies looking at ventilation of pollution. We expect the results from this study to be relevant for all atmospheric dispersion models with urban-surface parameterisations based on roughness.
authors.affiliation: Lancaster Environment Centre, Lancaster University, LA1 4YW, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Barnes
authors.affiliation: Lancaster Environment Centre, Lancaster University, LA1 4YW, UK.
authors.forename: T K
authors.initials: TK
authors.lastname: Brade
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT, UK. Electronic address: a.r.mackenzie@bham.ac.uk.
authors.forename: A R
authors.initials: AR
authors.lastname: MacKenzie
authors.affiliation: Lancaster Environment Centre, Lancaster University, LA1 4YW, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Whyatt
authors.affiliation: Cambridge Environmental Research Consultants Ltd, 3 Kings Parade, Cambridge CB2 1SJ, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Carruthers
authors.affiliation: Cambridge Environmental Research Consultants Ltd, 3 Kings Parade, Cambridge CB2 1SJ, UK.
authors.forename: J
authors.initials: J
authors.lastname: Stocker
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT, UK.
authors.forename: X
authors.initials: X
authors.lastname: Cai
authors.affiliation: Lancaster Environment Centre, Lancaster University, LA1 4YW, UK.
authors.forename: C N
authors.initials: CN
authors.lastname: Hewitt
mesh_terms: D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D002947:Cities; D002958:City Planning; D006801:Humans; D008956:Models, Chemical
chemical_list: D000393:Air Pollutants
keywords: ADMS-Urban; Aerodynamic roughness; Air quality; Street canyons; Urban breathability