Atmospheric Field Measurements in the Mexico City Metropolitan Area

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

This project adds to an existing major international program designed to quantify atmospheric emissions and to understand and improve air quality in a developing mega-city, the Mexico City Metropolitan Area (MCMA). In Spring 2003 an intensive field campaign will be undertaken in the MCMA involving advanced instrumentation deployed aboard both a mobile laboratory and at a major surface site. Specifically, the surface site will be enhanced for the intensive by the addition of research grade visible/near ultraviolet Differential Optical Absorption Spectroscopy (DOAS) and LIght Detection And Ranging (LIDAR) instruments. The currently available mobile laboratory will be enhanced by integrating new instruments to measure key reactive nitrogen species, including gas-phase ammonia and nitric acid, upgrading the current Proton Transfer Reaction Mass Spectrometer (PTR-MS) to allow real-time measurements of selected aromatic and oxygenated hydrocarbons, and developing and deploying an automated sampling system allowing real-time trace gas and fine particle measurements of transient emissions. The investigators will undertake experiments to gain insight into the quantity and identity of gaseous pollutants driving photochemical oxidants and secondary fine aerosol particle production as well as the emission, composition and temporal evolution of the fine aerosol burden. The resulting data sets will be analyzed and integrated into the larger project data archive as well as into ongoing North American Strategy for Tropospheric Ozone (NARSTO) assessment, modeling and policy development activities. Insofar as Mexico City is perhaps representative of other large urban centers this project affords some insight as to air quality of mega-cities in developing countries. The educational and capacity building impacts include extensive and substantive collaborations between Mexican and U.S. researchers in the field, and Mexican student exchange with U.S. institutions during the data analysis phase.