Characterizing ozone production in the Mexico City Metropolitan Area: a case study using a chemical transport model
Item
Title (Dublin Core)
Characterizing ozone production in the Mexico City Metropolitan Area: a case study using a chemical transport model
Description (Dublin Core)
An episodic simulation is conducted to characterize midday (12:00–17:00 CDT) ozone (O<sub>3</sub>) photochemical production and to investigate its sensitivity to emission changes of ozone precursors in the Mexico City Metropolitan Area (MCMA) during an "O<sub>3</sub>-South" meteorological episode using the Comprehensive Air Quality Model with extensions (CAMx). High O<sub>x</sub> (O<sub>3</sub>+NO<sub>2</sub>) photochemical production rates of 10–80 ppb/h are predicted due to the high reactivity of volatile organic compounds (VOCs) in which alkanes, alkenes, and aromatics exert comparable contributions. The predicted ozone production efficiency is between 4–10 O<sub>3</sub> molecules per NO<sub>x</sub> molecule oxidized, and increases with VOC-to-NO<sub>2</sub> reactivity ratio. Process apportionment analyses indicate significant outflow of pollutants such as O<sub>3</sub> and peroxyacetyl nitrate (PAN) from the urban area to the surrounding regional environment. PAN is not in chemical-thermal equilibrium during the photochemically active periods. Sensitivity studies of O<sub>3</sub> production suggest that O<sub>3</sub> formation in the MCMA urban region with less chemical aging (NO<sub>z</sub>/NO<sub>y</sub><0.3) is VOC-limited. Both the simulated behavior of O<sub>3</sub> production and its sensitivities to precursors suggest that midday O<sub>3</sub> formation during this episode is VOC-sensitive in the urban region on the basis of the current emissions inventory estimates, and current NO<sub>x</sub> levels depress the O<sub>3</sub> production.
Creator (Dublin Core)
Lei, W.
Foy, B.
Zavala, M.
Volkamer, R.
Molina, L. T.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-7-1347-2007
https://acp.copernicus.org/articles/7/1347/2007/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
