Our research involves making measurements of atmospheric aerosol chemistry and developing and using new analytical methods for these measurements. Aerosols occur in the environment in a variety of forms: clouds of ice or water droplets, salt particles from ocean spray, and smoke from a variety of combustion sources. They play an enormous role in our daily lives from affecting visibility and global climate change to endangering our health. Due to applications in research, medicine, and industry, there is great scientific interest in aerosols, however relative to their gas phase counterparts, limited information exists regarding their complex chemistry.

Conventional analytical methods for analyzing aerosols involve isolating particles on filters with subsequent analysis performed in the laboratory. These isolation processes often disturb the aerosol and thus render the data questionable because the particles evaporate or react before analysis. In order to overcome these difficulties, we developed aerosol-time-flight mass spectrometry (ATOFMS). This represented the first analytical technique capable of providing the precise size and chemical composition of individual aerosol particles in real time. Some examples of aerosol systems which we are characterizing in the laboratory using ATOFMS include suspended dust, sea salt, and a variety of combustion particles. Most recently, we developed a much smaller ATOFMS which has been flown over Colorado, northern and southern California, and most recently the Caribbean. In field studies, we strategically position our transportable instruments at sites that allow us to monitor the evolution of single particles in the atmosphere over time. In regional and international studies, these instruments are being used to study the direct effect of aerosols on visibility, pollution levels, cloud formation, and the global radiation balance.