Activation and Growth of Newly Formed Atmospheric Particles

California Institute Of Technology, Pasadena CA

Investigators

Abstract

This project is focused on the study of the formation and growth of new particles in the atmosphere. It involves an international collaboration that enables U.S. scientists to work at CERN, the European Organization for Nuclear Research in Switzerland, at the CLOUD (COsmics Leaving Outdoor Droplets) chamber there. The results of this research are expected to have implications that go beyond the atmospheric sciences, to numerous industrial and other natural processes. The objectives of this research are to: (1) advance measurement methods to make it possible to measure the size distribution of freshly nucleated clusters/particles as a function of time as they exist in the atmosphere in which they are formed in order to map their passage through the Kelvin regime, i.e., from near critical, or even sub-critical cluster sizes through to stable particles; (2) measure and model the multicomponent activation kinetics as low volatility organic compounds and extremely low volatility organic compounds condense on inert and sulfuric acid clusters in the Kelvin size regime, varying the temperature and composition of the atmosphere to probe the underlying mechanisms; (3) measure and model new particle formation, secondary activation, and growth in carefully controlled chamber experiments in order to constrain and parameterize new particle formation under a wide range of atmospheric conditions and for key aerosol precursors.