Articles | Volume 8, issue 24
Atmos. Chem. Phys., 8, 7571–7581, 2008

Special issue: Mexico City Metropolitan Area Field Campaign 2003...

Atmos. Chem. Phys., 8, 7571–7581, 2008

  17 Dec 2008

17 Dec 2008

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

W. Lei1,2, M. Zavala1,2, B. de Foy1,3, R. Volkamer2,4, and L. T. Molina1,2 W. Lei et al.
  • 1Molina Center for Energy and the Environment, CA, USA
  • 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, MA, USA
  • 3Department of Earth and Atmospheric Sciences, Saint Louis University, MO, USA
  • 4Department of Chemistry and Biochemistry, University of Colorado at Boulder, CO, USA

Abstract. Photochemistry in polluted atmospheres, 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 emissions reduction under three distinctively different meteorological conditions in the Mexico City Metropolitan Area during the MCMA-2003 field measurement campaign. The O3 formation characteristics and sensitivity to emissions change were found to be weakly dependent on the meteorological conditions. The evolution of O3 formation and its sensitivity to NOx and VOC levels 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 downwind plumes were characterized with low and constant O3 production, and plumes along their transport pathway were characterized 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 NOx sensitive.

Final-revised paper