AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Role of Sub-2 nm Particles in New Particle Formation
SHANHU LEE, University of Alabama in Huntsville
Abstract Number: 128 Working Group: Aerosol Chemistry
Abstract Atmospheric new particle formation starts with the formation of clusters and the subsequent growth of these clusters. There have been several different theories of the role of these newly formed clusters, and some of the theories even contradict to each other. Direct measurements of atmospheric sub-2 nm particles in various atmospheric environments are also lacking, and this hampers the understanding of the role of these clusters playing in new particle formation processes. Here, we present a series of measurements of sub-2 nm particles made with particle size magnifier (PSM) in several different locations in the United States, including the marine boundary layer, polluted continental sites, and forests that are remote or affected by transported sulfur plumes. Our results show that in these different environments, sub-2 nm particles exist only when there are sufficient sulfuric acid concentrations. Our results are thus different from other observations made in the Finnish boreal forest, which show that sub-2 nm particles are present during day and night, and regardless of sulfuric acid concentrations. This difference indicates that different new particle formation mechanisms, as opposed to a universal mechanism, should be applied in different atmospheric conditions. Our measurements also show that these sub-2 nm particles grow differently, under different atmospheric conditions, depending on available condensable species.