Optical Properties of Secondary Organic Aerosol
Atmospheric aerosols play a significant but poorly understood role in affecting the global radiative balance. Aerosols interact with light indirectly by nucleating clouds or directly by scattering and absorbing incoming light. Predicting the magnitude of the last two effects requires an accurate knowledge of optical properties of aerosols, but there is much uncertainty in this area. A significant fraction of aerosol mass is composed of organic material that entered the atmosphere in the gas phase and was converted into aerosol by various processes. This material is termed secondary organic aerosol (SOA), and measurements of the optical properties of SOA are relatively few.
The Tolbert group has used cavity ring-down aerosol extinction spectroscopy (CRD-AES) to investigate the optical properties of model early Earth and Titan aerosols and the properties of mixed organic/inorganic aerosols. My research uses the CRD-AES to analyze SOA generated by various processes in order to determine the optical properties of the aerosols formed.