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Prof. Geoff Smith, University of Georgia
Laboratory Studies of the Chemical and Optical Transformations of Organic Aerosols in the Atmosphere
Physical Chemistry Seminar Series
Aerosol particles ranging in size from a few nanometers to several microns in size play many roles in the atmosphere. Among other things, they influence global warming, climate change and human health. While they are composed of many things, including inorganic species such as ammonium sulfate and other salts, organic species comprise a large fraction of the particles in many environments. Despite their importance in determining how particles evolve chemically in the atmosphere, how they take up water, how they interact with clouds and how they scatter or absorb sunlight, much is still not known about these organic aerosols.
This presentation will highlight recent findings from two projects in my lab designed to learn more about how organic aerosols evolve in the atmosphere. In the first project, the rates of oxidation in particles by gas-phase species such as O3, OH, NO3 and Cl are measured using the Aerosol Chemical Ionization Mass Spectrometer (CIMS) developed in our lab. In the second project, the efficiencies with which oxidized organic particles scatter and absorb UV light are determined using Cavity Ring-Down Spectroscopy. These results will be discussed in the context of how ambient aerosols are âagedâ chemically and how their optical properties evolve over time as a result.
For more information contact Prof. Paul Wine (404-894-3425).
