Our research involves investigations of chemical and physical processes in the atmosphere and of the processing of advanced materials and devices. The common thread through this work is aerosols, suspensions of small solid or liquid particles in gas. Atmospheric Research Atmospheric aerosols include particles that are emitted directly to the atmosphere and those that are formed in the atmosphere by the reactions of gaseous pollutants and certain natural compounds. At high concentrations, they become the haze that reduces visibility and becomes a health hazard.
Aerosols also play an important role in the global atmosphere.
They scatter sunlight back to space, producing a cooling effect that partially offsets the warming induced by greenhouse gases such as CO 2 . The geographical extent of this cooling effect of aerosols is limited, however, due to the relatively short life of aerosol particles in the atmosphere. Aerosol particles also form the seeds on which cloud droplets form, leading to an even greater and more uncertain cooling effect. We are conducting both laboratory and field investigations aimed at understanding the nature and dynamics of atmospheric aerosols. Over the years we have used an outdoor chamber facility to probe atmospheric reaction mechanisms driven by solar radiation, and to study the yield of secondary organic aerosols from a wide range of anthropogenic and biogenic hydrocarbons.