CAREER: Multi-Generational Aging of Atmospheric Organic Mixtures

This CAREER project focuses on long-term chemical changes that take place in mixtures of atmospheric organic aerosol. Organic molecules in the atmosphere can have large impacts on climate, air quality, and on human health and the environment. One of the goals of this research is to develop a more accurate way to estimate the fraction of carbon emitted into the atmosphere that stays in the condensed phase, both in aerosol and in surface films, as the aerosol ages. Knowledge about the types and extents of slower aging reactions is key to understanding and predicting the behaviors of carbon mixtures in the atmospheric aerosols. The central hypothesis of this research is that when organic mixtures are aged, functional group distributions change, enabling subsequent accretion reactions. The hypothesis is based on prior work by this investigator who has found that both a-pinene and food cooking organic aerosol films show evidence of oligomerization with long aging times (days to weeks). The objectives of this research are to: (1) investigate the impact of water vapor on the multi-generational aging of secondary organic aerosol, (2) investigate the aging process for components of urban grime, including food cooking organic aerosol and ambient surface films, and (3) help attract and retain students in the atmospheric sciences by partnering with local high schools to develop learning experiences related to air pollution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.