Cooperative Institute for Research in Environmental Sciences

Abstracts: 34

Findings from the Texas 2000 Air Quality Study: Chemical Processes that Control Urban Ozone Production

T.B. Ryerson, M. Trainer, D.K. Nicks Jr.¹, A.J. Neuman¹, J.S. Holloway¹, C.A. Brock¹, R.O. Jakoubek, K.K. Perkins¹, E. Williams¹, D.D. Parrish, D.T. Sueper¹, G.J. Frost¹, S. McCaffrey¹, S. McKeen¹, P. Murphy¹, C. Simons¹, W.C. Kuster, P.D. Goldan, R.W. Dissly¹*, G. Hübler¹, W.M. Angevine¹, and F.C. Fehsenfeld¹ Aeronomy Laboratory [ About this Lab ] , National Oceanic and Atmospheric Administration, Boulder, CO

S.G. Donnelly, S. Schauffler, E.L. Atlas, A.J. Weinheimer, F. Flocke, B.P. Wert, W.T. Potter, A. Fried, and C. Wiedinmyer Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO

C.J. Senff¹, R.M. Banta, L.S. Darby¹, R.J. Alvarez
¹ Environmental Technology Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO ¹also with Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder * now at Ball Aerospace Corporation, Boulder, CO

During summer, the Houston urban area routinely experiences highly elevated levels of ozone exceeding the EPA air quality limits for ozone of 120 ppbv. Airborne measurements obtained in the Houston-Galveston metropolitan area during the 2000 TEXAQS field campaign identify the chemical mechanisms leading to these major ozone exceedences. Petrochemical industrial sources located along the ship channel emit large amounts of highly reactive hydrocarbons and NOx to the atmosphere; in the summertime, such co-located emissions are shown to consistently result in rapid and efficient ozone formation downwind. Routine emissions of the alkenes, propene (C3H6) and ethene (C2H4), by the petrochemical industrial sources result in the high initial hydrocarbon reactivity and, consequently, high ozone formation rates and yields per NOx molecule emitted from petrochemical industrial sources when compared to rates and yields observed in urban or rural power plant plumes. This information will aid state regulators in formulating new control strategies for bringing Houston into compliance with EPA air quality standards.