The Potential Role of Mexico City Aerosols In Cloud Formation and Evolution

Cloud condensation nuclei (CCN) , precipitation chemistry, and the hygroscopicity of aerosols have been measured in Mexico City during a field project in the wet season (September). The overall goal of this project was to determine the potential impact of urban aerosols on the formation and evolution of clouds in and around the Mexico City basin. The results of these measurements are used in an aerosol model, coupled with a 1-D cloud model to evaluate how cloud formation and development is either enhanced or inhibited.

Preliminary results from the field project will be presented with an emphasis on discussing how the CCN measurements relate to the aerosol hygroscopicity and cloud chemistry. Early results from the aerosol/cloud models will also be presented.