Inferring thermodynamic properties from CCN activation experiments: a) single-component and binary aerosols
1School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
2School of Earth and Atmospheric Sciences, Georgia Institute of Technology Atlanta, GA, 30332, USA
*now at: Department of Chemical Engineering, University of Texas, Austin, TX, 78712, USA
Abstract. This study presents a new method, Köhler Theory Analysis (KTA), to infer the molar volume and solubility of organic aerosol constituents. The method is based on measurements of surface tension, chemical composition, and CCN activity coupled with Köhler theory. KTA is evaluated by inferring the molar volume of six known organics (four dicarboxylic acids, one amino acid, and one sugar) in pure form and in mixtures with ammonium sulfate ((NH4)2SO4). Inferred molar volumes are to within 18% of their expected value for organic fractions between 90 and 100%. This suggests that KTA is a powerful and ideal method for determining the CCN characteristic of ambient water soluble organic carbon (WSOC) and provide physically-based constraints for aerosol-cloud interaction parameterizations.