California Institute for Energy and Environment (CIEE)

Atmospheric aerosols have been shown to play an important role in climate by acting as the nuclei for cloud droplet and ice crystal formation. Variations in particle concentration and chemistry can alter a wide range of climate related parameters including: absorbing and scattering solar radiation, changing cloud lifetimes, increasing cloud albedo, and altering precipitation locations and amounts. During this study measurements of both new particle formation (NPF) events as well as measuring particle residues in rainwater allow us to analyze aerosol impacts on climate from two separate, yet important directions. Studying aerosols has traditionally been accomplished through bulk filter measurements, which have provided a great deal of information about bulk particle chemistry and mass concentrations. However, bulk studies have been limited by time resolution, sampling artifacts, and a lack of understanding which species exist together in the same particles (i.e. mixing state). The primary method used in this report, aerosol time-of-flight mass spectrometry (ATOFMS), determines the size and chemical composition of single particles in real-time avoiding many of the limitations of bulk methods.