ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-7571-2008 Characterizing ozone production and response under different meteorological conditions in Mexico City Lei W. 1 2 Zavala M. 1 2 de Foy B. 1 3 Volkamer R. 2 4 Molina L. T. 1 2 Molina Center for Energy and the Environment, CA, USA Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, MA, USA Department of Earth and Atmospheric Sciences, Saint Louis University, MO, USA Department of Chemistry and Biochemistry, University of Colorado at Boulder, CO, USA 17 12 2008 8 24 7571 7581 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/8/7571/2008/acp-8-7571-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/7571/2008/acp-8-7571-2008.pdf

Photochemistry in polluted atmospheres, particularly the formation of ozone (O<sub>3</sub>), 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</sub> 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 O<sub>3</sub> formation characteristics and sensitivity to emissions change were found to be weakly dependent on the meteorological conditions. The evolution of O<sub>3</sub> formation and its sensitivity to NO<sub>x</sub> and VOC levels were also examined along the photochemical plume transport pathway. The midday O<sub>3</sub> production was found to undergo a rapid increase in a narrow range of chemical aging, while downwind plumes were characterized with low and constant O<sub>3</sub> production, and plumes along their transport pathway were characterized by a combination of the two. The O<sub>3</sub> formation was more VOC sensitive near the source area, but as the plume became chemically aged, O<sub>3</sub> formation became progressively VOC insensitive and more NO<sub>x</sub> sensitive.

 References % vor jede Referenz Baertsch-Ritter, N., Keller, J., Dommen, J., and Prevot, A. S. H.: Effects of various meteorological conditions and spatial emissionresolutions on the ozone concentration and ROG/NO<sub>x</sub> limitationin the Milan area (I), Atmos. Chem. Phys., 4, 423–438, 2004. Byun, D. W.: Dynamically consistent formulations in meteorological and air quality models for multiscale atmospheric studies – Part 1: Governing equations in a generalized coordinate system, J. Atmos. Sci., 56, 3789–3807, 1999. CAM (Comisión Ambiental Metropolitana): Inventario de Emisiones 2002 de la Zona Metropolitana del Valle de México, México, 2004. CAM (Comisión Ambiental Metropolitana): Inventario de Emisiones 2004 de la Zona Metropolitana del Valle de México, México, 2006. Daum, P. H., Kleinman, L. I., Imre, D. G., Nunnermacker, L. J., Lee, Y.-N.: Springston, S. R., Newman, L., and Weinstein-Lloyd, J.: Analysis of the processing of Nashville urban emissions on July 3 and July 18, 1995, J. Geophys. Res., 105, 9155–9164, 2000. Dawson, J. P., Adam, P. J., and Pandis, S. N.: Sensitivity of ozone to summertime climate in the eastern USA: A modeling case study, Atmos. Environ., 41, 1494–1511, 2007. de Foy, B., Caetano, E., Magaña, V., Zitácuaro, A., Cárdenas, B., Retama, A., Ramos, R., Molina, L. T., and Molina, M. J.: Mexico City basin wind circulation during the MCMA-2003 field campaign, Atmos. Chem. Phys., 5, 2267–2288, 2005. de Foy, B., Clappier, A., Molina, L. T., and Molina, M. J.: Distinct wind convergence patterns in the Mexico City basin due to the interaction of the gap winds with the synoptic flow, Atmos. Chem. Phys., 6, 1249–1265, 2006. de Foy, B., Lei, W., Zavala, M., Volkamer, R., Samuelsson, J., Mellqvist, J., Galle, B., Mart\'inez, A.-P., Grutter, M., Retama, A., and Molina, L. T.: Modelling constraints on the emission inventory and on vertical dispersion for CO and SO<sub>2</sub> in the Mexico City Metropolitan Area using Solar FTIR and zenith sky UV spectroscopy, Atmos. Chem. Phys., 7, 781–801, 2007. ENVIRON: User's Guide: Comprehensive Air Quality Model with Extension (CAMx) Version 4.03. ENVIRON International Corporation, Novato, California, 2003. Kleinman, L. I., Daum, P. H., Lee, J. H., Lee, Y.-N., Nunnermacker, L. J., Springston, S. R., Newman, L., Weinstein-Lloyd, J., and Sillman, S.: Dependence of ozone production on NO and hydrocarbons in the troposphere, Geophys. Res. Lett., 24, 2299–2302, 1997. Kolb, C. E., Herndon, S. C., McManus, J. B., Shorter, J. H., Zahniser, M. S., Nelson, D. D., Jayne, J. T., Canagaratna, M. R., and Worsnop, D. R.: Mobile laboratory with rapid response instruments for real-time measurements of urban and regional trace gas and particulate distributions and emission source characteristics, Environ. Sci. Technol., 38, 5694–5703, 2004. Lei, W., de Foy, B., Zavala, M., Volkamer, R., and Molina, L. T.: Characterizing ozone production in the Mexico City Metropolitan Area: a case study using a chemical transport model, Atmos. Chem. Phys., 7, 1347–1366, 2007. Liu, S. C., Trainer, M., Fehsenfeld, F. C., Parrish, D. D., Williams, E. J., Fahey, D. W., Hubler, G., and Murphy, P. C.: Ozone production in the rural troposphere and the implications for regional and global ozone distributions, J. Geophys. Res., 92, 4191–4207, 1987. Molina, L. T., Madronich, S., Gaffney, J. S., and Singh, H. B.: Overview of MILAGRO/INTEX-B Campaign, IGAC Newsletter, Issue No. 38, 2–15 April 2008. Molina, L. T., Kolb, C. E., de Foy, B., Lamb, B. K., Brune, W. H., Jimenez, J. L., Ramos-Villegas, R., Sarmiento, J., Paramo-Figueroa, V. H., Cardenas, B., Gutierrez-Avedoy, V., and Molina, M. J.: Air quality in North America's most populous city – overview of the MCMA-2003 campaign, Atmos. Chem. Phys., 7, 2447–2473, 2007. Molina, L. T. and Molina, M. J. (Eds.): Air Quality in the Mexico Megacity: An Integrated Assessment, Kluwer Academy Publishers, 2002. Molina, M. J. and Molina, L. T.: 2004 Critical Review: Megacities and Atmospheric Pollution, J. Air Manage. Assoc., 54, 644–680, 2004. NRC (National Research Council): The effects of meteorology on tropospheric ozone, in: Rethinking the Ozone Problem in Urban and Regional Air Pollution, National Academy Press, Washington, DC, USA, 93–108, 1991. Seaman, N. L.: Meteorological modeling for air-quality assessments, Atmos. Environ., 34, 2231–2258, 2000. Sillman, S: The use of NO<sub>y</sub>, H<sub>2</sub>O<sub>2</sub>, and HNO<sub>3</sub> as indicators for ozone-NO<sub>x</sub>-hydrocarbon sensitivity in urban locations, J. Geophys. Res., 100, 14175–14188, 1995. Sillman, S.: The relation between ozone, NO<sub>x</sub> and hydrocarbons in urban and polluted rural environments, Atmos. Environ., 33, 1821–1845, 1999. SIMAT, Sistema de Monitoreo Atmosferico, Ciudad de Mexico, http://www.sma.df.gob.mx/simat/, last access: 2008. Solomon, P., Cowling, E., Hidy, G., and Furiness, C.: Comparison of scientific findings from major ozone field studies in North America and Europe, Atmos. Environ., 34, 1885–1920, 2000. Stephens, S., Madronich, S., Wu, F., Olson, J. B., Ramos, R., Retama, A., and Muñoz, R.: Weekly patterns of México City's surface concentrations of CO, NO<sub>x</sub>, PM10 and O<sub>3</sub> during 1986-2007, Atmos. Chem. Phys., 8, 5313–5325, 2008. Velasco, E., Lamb, B., Westberg, H., Allwine, E., Sosa, G., Arriaga-Colina, J. L., Jobson, B. T., Alexander, M. L., Prazeller, P., Knighton, W. B., Rogers, T. M., Grutter, M., Herndon, S. C., Kolb, C. E., Zavala, M., de Foy, B., Volkamer, R., Molina, L. T., and Molina, M. J.: Distribution, magnitudes, reactivities, ratios and diurnal patterns of volatile organic compounds in the Valley of Mexico during the MCMA 2002 & 2003 field campaigns, Atmos. Chem. Phys., 7, 329–353, 2007. Volkamer, R., Molina, L. T., Molina, M. J., Shirley, T., and Brune, W. H.: DOAS measurement of glyoxal as an indicator for fast VOC chemistry in urban air, Geophys. Res. Lett., 32, L08806, doi:10.1029/2005GL022616, 2005. Willmott, C. J.: On the validation of models, Phys. Geogr., 2, 184–194, 1981. Zavala, M., Herndon, S. C., Slott, R. S., Dunlea, E. J., Marr, L. C., Shorter, J. H., Zahniser, M., Knighton, W. B., Rogers, T. M., Kolb, C. E., Molina, L. T., and Molina, M. J.: Characterization of on-road vehicle emissions in the Mexico City Metropolitan Area using a mobile laboratory in chase and fleet average measurement modes during the MCMA-2003 field campaign, Atmos. Chem. Phys., 6, 5129–5142, 2006.