Characterizing ozone production and response under different meteorological conditions in Mexico City
- ISSN: 1680-7367, 1680-7367
Tropospheric photochemistry, particularly the formation of ozone (O sub(3)), 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 O sub(3) formation and its response to emission reductions under three distinctively different meteorological conditions (QUOTATION_MARKCold SurgeQUOTATION_MARK, QUOTATION_MARKO sub(3)-NorthQUOTATION_MARK and QUOTATION_MARKO sub(3)-SouthQUOTATION_MARK) in the Mexico City Metropolitan Area during the MCMA-2003 field measurement campaign. The O sub(3) formation characteristics and sensitivity to emissions changes were found to be weakly dependent on the meteorological conditions. The evolution of O sub(3) formation and sensitivity were also examined along the photochemical plume transport pathway. The midday O sub(3) 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 O sub(3) production, and plumes along their transport pathway were featured by a combination of the two. The O sub(3) formation was more VOC sensitive near the source area, but as the plume became chemically aged, O sub(3) formation became progressively VOC insensitive and more NO sub(x) sensitive.