Enhanced secondary organic aerosol formation due to water uptake by fine particles

TitleEnhanced secondary organic aerosol formation due to water uptake by fine particles
Publication TypeJournal Article
Year of Publication2008
AuthorsCJ Hennigan, MH Bergin, JE Dibb, and RJ Weber
JournalGeophysical Research Letters
Volume35
Issue18
Date Published09/2008
Abstract

This study characterizes the partitioning behavior of a significant fraction of the ambient organic aerosol through simultaneous measurements of gas and particle water-soluble organic carbon (WSOC). During the summer in Atlanta, WSOC gas/particle partitioning showed a strong RH dependence that was attributed to particulate liquid water. At elevated RH levels (>∼70%), a significant increase in WSOC partitioning to the particle phase was observed and followed the predicted water uptake by fine particles. The enhancement in particle-phase partitioning translated to increased median particle WSOC concentrations ranging from 0.3-0.9 μg C m-3. The results provide a detailed overview of the WSOC partitioning behavior in the summertime in an urban region dominated by biogenic emissions, and indicate that secondary organic aerosol formation involving partitioning to liquid water may be a significant aerosol formation route that is generally not considered. Copyright 2008 by the American Geophysical Union.

DOI10.1029/2008GL035046
Short TitleGeophysical Research Letters