Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 8 12 2008 10.5194/acp-8-3061-2008 http://www.atmos-chem-phys.net/8/3061/2008/ http://www.atmos-chem-phys.net/8/3061/2008/acp-8-3061-2008.html http://www.atmos-chem-phys.net/8/3061/2008/acp-8-3061-2008.pdf 3061 3079 2008-06-20 Vertical distribution of ozone and VOCs in the low boundary layer of Mexico City E. Velasco evelasco@mce2.org C. Márquez E. Bueno R. M. Bernabé A. Sánchez O. Fentanes H. Wöhrnschimmel B. Cárdenas A. Kamilla S. Wakamatsu L. T. Molina Molina Center for Energy and the Environment (MCE2), La Jolla, CA, USA Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA Centro Nacional de Investigación y Capacitación Ambiental del Inst. Nacional de Ecología (CENICA-INE), D.F., Mexico Japanese International Cooperation Agency (JICA), Tokyo, Japan Atmospheric Environmental Science Laboratory, Faculty of Agriculture, Ehime University, Ehime, Japan The evolution of ozone (O₃) and 13 volatile organic compounds (VOCs) in the boundary layer of Mexico City was investigated during 2000–2004 to improve our understanding of the complex interactions between those trace gases and meteorological variables, and their influence on the air quality of a polluted megacity. A tethered balloon, fitted with electrochemical and meteorological sondes, was used to obtain detailed vertical profiles of O₃ and meteorological parameters up to 1000 m above ground during part of the diurnal cycle (02:00–18:00 h). VOCs samples were collected up to 200 m by pumping air to canisters with a Teflon tube attached to the tether line. 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