A21A-0059
Understanding ozone formation and the radical budget during oil sands plume transport in the Athabasca region of Alberta
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Samar G. Moussa1, Amy Leithead1, Shao-Meng Li2, Daniel K Wang3, Jason O'brien1, Richard Mittermeier1, Mark Gordon4, Ralf M Staebler2, Peter Liu1 and John Liggio2, (1)Environment Canada, Toronto, ON, Canada, (2)Environment Canada Toronto, Toronto, ON, Canada, (3)Environment Canada Ottawa, Ottawa, ON, Canada, (4)York University, Toronto, ON, Canada
Abstract:
The sources of ozone and hydroxyl radicals (OH) in the Alberta oil sands (OS) region have not previously been well characterized. In the summer of 2013, airborne measurements of various volatile organic compounds (VOCs), nitrogen oxides (NOx = NO2+NO) and ozone were made in the Athabasca OS region between August 13 and September 7, 2013. Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) and whole air samples were used to measure VOCs. A box model incorporating the Master Chemical Mechanism (MCM v3.3), was constrained by measured chemical species and meteorological parameters and used to simulate the evolution of an OS plume. In doing so, an improved understanding of the chemical factors controlling the radical budget and the evolution of ozone in oil sands plumes is achieved. Our results indicate that approximately 20% of the in-plume generated OH radicals are derived from primary sources (HCHO, O3 and HONO photolysis). The remaining OH is derived from the recycling of hydroperoxyl radical (HO2). The HO2 and alkyl peroxyl radical (RO2) chemistry leads to 35% of the ozone formation in the plume, while the main sink for ozone in the plume was via reactions with alkenes (anthropogenic and biogenic). The results of this work will help to characterize ozone formation and the factors influencing its atmospheric fate in the oil sands region.
