UCMEXUS FINAL PROJECT REPORT Collaborative Environmental Chamber and Modeling Studies for Evaluating Effects of Emissions on Air Quality in Mexico City

CERT) and the Mexican Petroleum Institute (IMP) have been carried out. The areas of collaboration were in air quality modeling simulation, environmental chamber experimentation, and chemical reaction mechanisms. During the two-year UCMEXUS project the IMP researchers visited CE-CERT on two separate occasions. Extensive discussions concerning these research areas were held and direct participation on experiments and training courses were undertaken. The bilateral technical effort between IMP and CE-CERT resulted in a number of achievements. Input was obtained on the design of an indoor environmental gas chamber laboratory to conduct reactivity studies of Volatile Organic Compounds (VOC) at IMP. This effort materialized in the construction of a smog chamber facility designed to operate as a Dividable Teflon Chamber (DTC), similar to the gas chambers employed at CE-CERT. The second important area of collaboration focused on air quality modeling using the most recent atmospheric modeling system developed by the USEPA, known as Models-3/CMAQ. New meteorological and air quality data for the Mexico City valley that have become available will be used to conduct collaborative efforts on ozone and aerosol formation with CE-CERT researchers by October of this year. A third important area of interaction concerns the application of the SAPRC-99 chemical mechanism for model evaluation. SAPRC-99 is one of the most advanced explicit photochemical mechanisms developed by CE-CERT that can be used to study VOC reactivity in the airshed. The chamber database from the indoor environmental gas chamber simulations will be used to evaluate the SAPRC-99 chemical mechanism for predicting the effects of VOCs on ozone formation in Mexico City. Acknowledgements The investigators want to thank UCMEXUS for the financial support received for this project. We also thank Ms. for valuable assistance and helpful discussions on air quality modeling.