Abstract
Air quality models include representations of pollutant emissions, which necessarily entail spatial averaging to reflect the model grid size; such averaging may result in significant uncertainties and/or systematic biases in the model output. This study investigates such uncertainties, considering ozone concentrations in idealised street canyons within the urban canopy. A photochemical model with grid-averaged emissions of street canyons is compared with a multiple-box model considering each canyon independently. The results reveal that the averaged, ‘one-box’ model may significantly underestimate true (independent canyon mean) ozone concentrations for typical urban areas, and that the performance of the averaged model is improved for more ‘green’ and/or less trafficked areas. Our findings also suggest that the trends of 2005-2020 in emissions, in isolation, reduce the error inherent in the averaged-emissions treatment. These new findings may be used to evaluate uncertainties in modelled urban ozone concentrations when grid-averaged emissions are adopted.
Original language | English |
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Pages (from-to) | 132-143 |
Journal | Environmental Pollution |
Volume | 188 |
Early online date | 2 Mar 2014 |
DOIs | |
Publication status | Published - 2014 |
Keywords
- Segregation Effects
- urban street canyon
- emission heterogeneity
- photochemical box model
- urban ozone concentrations
ASJC Scopus subject areas
- Environmental Science(all)