Characterizing ozone production and response under different meteorological conditions in Mexico City

W. Lei (1, 2) , M. Zavala (1, 2) , B. de Foy (1, 3) , R. Volkamer (2, 4) , L. T. Molina (1, 2)

1 MCE2 - Molina Center for the Energy and the Environment
2 EAPS - Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
3 Department of Earth and Atmospheric Sciences [Saint Louis]
4 Department of Chemistry and Biochemistry

Tropospheric photochemistry, particularly the formation of ozone (O₃), depends not only on pollutant emissions, but also on meteorological conditions. In this study a 3-D chemical transport model CAMx was employed to investigate the O₃ formation and its response to emission reductions under three distinctively different meteorological conditions ("Cold Surge", "O₃-North" and "O₃-South") in the Mexico City Metropolitan Area during the MCMA-2003 field measurement campaign. The O₃ formation characteristics and sensitivity to emissions changes were found to be weakly dependent on the meteorological conditions. The evolution of O₃ formation and sensitivity were also examined along the photochemical plume transport pathway. The midday O₃ production was found to undergo a rapid increase in a narrow range of chemical aging, while plumes in the downwind were characterized with low and constant O₃ production, and plumes along their transport pathway were featured by a combination of the two. The O₃ formation was more VOC sensitive near the source area, but as the plume became chemically aged, O₃ formation became progressively VOC insensitive and more NO_x sensitive.

Domaines: Océan, Atmosphère

W. Lei, M. Zavala, B. de Foy, R. Volkamer, L. T. Molina. Characterizing ozone production and response under different meteorological conditions in Mexico City. Atmospheric Chemistry and Physics Discussions, 2008, 8 (3), pp.12053-12079. ⟨hal-00304273⟩