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| Titel |
Exploring the nature of air quality over southwestern Ontario: main findings from the Border Air Quality and Meteorology Study |
| VerfasserIn |
J. R. Brook, P. A. Makar, D. M. L. Sills, K. L. Hayden, R. McLaren |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 20 ; Nr. 13, no. 20 (2013-10-29), S.10461-10482 |
| Datensatznummer |
250085773
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| Publikation (Nr.) |
 copernicus.org/acp-13-10461-2013.pdf |
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| Zusammenfassung |
| This paper serves as an overview and discusses the main findings from the
Border Air Quality and Meteorology Study (BAQS-Met) in southwestern Ontario
in 2007. This region is dominated by the Great Lakes, shares borders with
the United States and consistently experiences the highest ozone (O3)
and fine particulate matter concentrations in Canada. The purpose of BAQS-Met was to
improve our understanding of how lake-driven meteorology impacts air quality
in the region, and to improve models used for forecasting and policy
scenarios. Results show that lake breeze occurrence frequencies and inland
penetration distances were significantly greater than realized in the past.
Due to their effect on local meteorology, the lakes were found to enhance
secondary O3 and aerosol formation such that local anthropogenic
emissions have their impact closer to the populated source areas than would
otherwise occur in the absence of the lakes. Substantial spatial
heterogeneity in O3 was observed with local peaks typically 30 ppb
above the regional values. Sulfate and secondary organic aerosol (SOA)
enhancements were also linked to local emissions being transported in the
lake breeze circulations. This study included the first detailed evaluation
of regional applications of a high-resolution (2.5 km grid) air quality
model in the Great Lakes region. The model showed that maxima in secondary
pollutants occur in areas of convergence, in localized updrafts and in
distinct pockets over the lake surfaces. These effects are caused by lake
circulations interacting with the synoptic flow, with each other or with
circulations induced by urban heat islands. Biogenic and anthropogenic
emissions were both shown to play a role in the formation of SOA in the
region. Detailed particle measurements and multivariate receptor models
reveal that while individual particles are internally mixed, they often
exist within more complex external mixtures. This makes it difficult to
predict aerosol optical properties and further highlights the challenges
facing aerosol modelling. The BAQS-Met study has led to a better
understanding of the value of high-resolution (2.5 km) modelling for air
quality and meteorological predictions and has led to several model
improvements. |
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