HR: 0800h
AN: A51E-0834    [Abstracts]
TI: The Deliquescence Behavior of Internally Mixed NaCl/Dicarboxylic Acid Aerosols in the Kelvin Regime
AU: * Oatis, S J
EM: Susan.Oatis@liu.edu
AF: Southampton College, Department of Natural Sciences 239 Montauk Highway, Southampton, NY 11968 United States
AU: Reid, W L
EM: WReid@southampton.liu.edu
AF: Southampton College, Department of Natural Sciences 239 Montauk Highway, Southampton, NY 11968 United States
AU: Reaney, B
EM: BReaney@southampton.liu.edu
AF: Southampton College, Department of Natural Sciences 239 Montauk Highway, Southampton, NY 11968 United States
AB: Organic compounds have been shown to contribute significantly to the mass fraction ( 10-70%\ ) of fine particulate matter in the troposphere. Low molecular weight dicarboxylic acids, formed by oxidative processes in the atmosphere, constitute a substantial portion of the organic component. Investigations have shown the organic component often modifies the hygroscopic behavior and cloud nucleating ability of an inorganic aerosol, thus having implications for both direct and indirect radiative forcing. Most laboratory studies of internally mixed inorganic/organic aerosols have focused on dicarboxylic acids. The deliquescence behavior of these mixed aerosols has been suggested to be primarily dependent upon the organic component's water solubility. The hygroscopic behavior of 5 nm NaCl and three internally mixed NaCl/dicarboxylic acid aerosols (NaCl/oxalic acid, NaCl/malonic acid, and NaCl/succinic acid) were observed. The motivation for this work was to investigate the thermodynamic properties of aerosols at the beginning of their life cycle. A limited number of studies have been reported for aerosols with diameters less than 30nm where the Kelvin effect is expected to be significant. In this work, an increase in the deliquescence relative humidity relative to bulk measurements was observed for 5 nm NaCl aerosols. The presence of a dicarboxylic acid was shown to modify the deliquescence behavior of pure NaCl in all three cases. The deliquescence behavior of these internally mixed particles will be compared to the behavior observed and modeled for the corresponding bulk systems.
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting