Organic Condensation and Particle Growth to CCN Sizes in the Summertime Marine Arctic Is Driven by Materials More Semivolatile Than at Continental Sites
Por:
Burkart J., Hodshire A.L., Mungall E.L., Pierce J.R., Collins D.B., Ladino L.A., Lee A.K.Y., Irish V., Wentzell J.J.B., Liggio J., Papakyriakou T., Murphy J., Abbatt J.
Publicada:
28 oct 2017
Resumen:
Ship-based aerosol measurements in the summertime Arctic indicate
elevated concentrations of ultrafine particles with occasional growth to
cloud condensation nuclei (CCN) sizes. Focusing on one episode with two
continuously growing modes, growth occurs faster for a large,
preexisting mode (dp approximate to 90 nm) than for a smaller nucleation
mode (dp approximate to 20 nm). We use microphysical modeling to show
that growth is largely via organic condensation. Unlike results for
midlatitude forested regions, most of these condensing species behave as
semivolatile organics, as lower volatility organics would lead to faster
growth of the smaller mode. The magnitude of the CCN hygroscopicity
parameter for the growing particles, similar to 0.1, is also consistent
with organic species constituting a large fraction of the particle
composition. Mixing ratios of common aerosol growth precursors, such as
isoprene and sulfur dioxide, are not elevated during the episode,
indicating that an unidentified aerosol growth precursor is present in
this high-latitude marine environment.
Filiaciones:
Department of Chemistry, University of Toronto, Toronto, ON, Canada
Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States
Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico
Department of Civil and Environmental Engineering, National University of Singapore, Singapore
Department of Chemistry, Faculty of Science, University of British Columbia, Vancouver, BC, Canada
Environment and Climate Change Canada, Toronto, ON, Canada
Department of Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
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