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A base case modelling investigation was conducted to explore the chemical and physical behaviour of ground-level ozone (O3) and its precursor nitrogen dioxide (NO2) in Ontario using the U.S. Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) model. Two related studies were completed to evaluate the performance of CMAQ in reproducing the behaviour of these species in both rural and urban environments by comparing to surface measurements collected by the Ontario Ministry of the Environment (MOE) network of air quality stations. The first study was a winter examination and the second study was conducted for a period during the summer of the same year. The municipality of North Bay was used to represent a rural setting given its smaller population relative to the city of Ottawa which was the base of the urban site. Statistical and graphical analyses were used to validate the model output. CMAQ was found to replicate the spatial variation of O3 and NO2 over the domain in both the winter and summer, but showed some difficulty in simulating the temporal allocation of the species. Validation statistics for North Bay and Ottawa showed overall O3 mean biases (MB) of 3.35 ppb and 2.25 ppb, respectively, and overall NO2 MB of -8.75 ppb and -4.37 ppb, respectively for the winter. Summer statistics generated O3 MB of 4.66 ppb (North Bay) and 10.05 ppb (Ottawa) while both MB for NO2 were between -2.20 ppb to -2.55 ppb. Graphical analysis showed that the model was not able to reproduce the lower levels of O3, especially at night, or the higher levels of NO2 during the day at the North Bay site for either season. This was expected since the comparisons were made between point measurements and 36 km grid-averaged model results. The presence of high amounts of NO2 emissions local to the monitoring sites compared to the levels represented in the emissions inventory may also be a contributing factor. The simulations for Ottawa demonstrated better agreement between model results and measurements as CMAQ provided a more accurate reproduction of both the higher and lower mixing ratios of O3 and NO2 during the winter and summer seasons. Results indicate that CMAQ is able to simulate urban environments better than rural ones.

Der Bericht gibt Auskunft über die Luftqualität im Freistaat Sachsen im Jahr 2010. Das 29 Messstellen umfassende stationäre Luftmessnetz misst die Konzentration der Luftschadstoffe Schwefeldioxid, Stickstoffdioxid, Feinstaub-Partikel, Blei, Benzol und Ozon. Die Stickstoffdioxid-Konzentrationen sind an stark befahrenden Straßen weiterhin kritisch. Der Jahresgrenzwert konnte auch 2010 an verkehrsnahen Messstellen in Leipzig, Dresden und Chemnitz nicht eingehalten werden. Der 24-Stunden-Grenzwert der Partikelkonzentration (PM10) wurde an sieben Messstellen überschritten. Betroffen sind verkehrsnahe Messstellen, aber auch Messstellen an der Grenze zu Polen. Keine Probleme gab es dagegen bei der Einhaltung der Jahresgrenzwerte der Partikelkonzentrationen PM10 und PM2,5. In ländlichen Gebieten gab es, wie auch in den Vorjahren, Überschreitungen der Ozon-Zielwerte zum Schutz der menschlichen Gesundheit und der Vegetation. Die Konzentrationen von Schwefeldioxid, Benzol und Blei lagen auf dem Niveau der Vorjahre und damit weit unter den gesetzlichen Grenzwerten.

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Thesis (Ph.D.)--York University, 2006. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 271-296). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR19790

Thesis (M.S.)--University of Nevada, Reno, 2008. / "May 2008." Includes bibliographical references (leaves 44-45). Online version available on the World Wide Web.

Thesis (MTech (Chemistry))--Peninsula Technikon, 1995. / Includes bibliographical references (leaves 85-88). Also available online.

Report (M.S.)--Virginia Polytechnic Institute and State University. M.S. 1993. / Abstract. Includes bibliographical references (leaf 76). Also available via the Internet.

Thesis (Ph. D.)--OGI School of Science & Engineering at OHSU, 2004. / Includes bibliographical references.

Thesis (M.E.S.)--Evergreen State College, 2009. / "June 2009." Title from title screen (viewed 4/8/2010). Includes bibliographical references (leaves 54-56).