Nucleation and Growth of Nanoparticles in the Atmosphere

Recent findings related to nucleation and growth of atmospheric nanoparticles, with an emphasis on the understanding of these processes at a fundamental molecular level, are assessed. A laminar flow chamber with continuous formation of the nucleating vapors has been introduced for studying binary and ternary nucleation of atmospherically important sulfuric acid, which is subject to particularly severe wall loss. Reviews by Curtius, Holmes, and Kulmala and Kerminen provided an update on most recent field studies and also discussed the findings of atmospheric measurements in relation to the current laboratory and modeling work on atmospheric nucleation. Recently, Zhao et al. used a sensitive atmospheric pressure CIMS with two alternative charged/neutral cluster separation methods to measure low concentrations of neutral clusters formed during nucleation events, extending the instrumentation for measuring sulfuric acid in the atmosphere and sulfate clusters in the laboratory.