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Publications in Scientific Journals:

A. Limbeck, H. Puxbaum:
"Dependence of in-cloud scavenging of polar organic aerosol compounds on the water solubility";
Journal of Geophysical Research-Atmospheres, 105 (2000), 19857 - 19867.



English abstract:
In spring 1997 at the Sonnblick Observatory located at 3106 m elevation in the Austrian Alps, interstitial aerosol and cloud water samples were simultaneously collected in supercooled convective clouds. These samples were analyzed for their polar organic composition using a newly developed analytical method that allows the simultaneous determination of dicarboxylic acids, monocarboxylic acids, and other polar organic constituents. Using the obtained data set, in-cloud scavenging efficiencies for individual polar organic compounds were calculated. For the different organic substances, scavenging efficiencies ranged from 0.16 to 0.98 compared to sulfate which exhibited an average scavenging efficiency of 0.94. For dicarboxylic acids, scavenging efficiencies (average of about 0.8) were in the same order as for sulfate. Distinctly lower values (average of about 0.6) were achieved for polar aromatic compounds like phthalic acid or diisobutylphenol. The lowest scavenging efficiencies (average about 0.4) were found for alcohols and monocarboxylic acids. Thus, we found in the Sonnblick cloud experiment that more polar organic aerosol constituents are more efficiently scavenged into cloud droplets than less polar compounds.
In addition, the scavenging efficiencies exhibited a dependence on the solubilities of the examined compounds. For highly water-soluble compounds (1000 - 1 g/L) a decrease of the water solubility for an individual compound leads to a decrease in the scavenging efficiency for this compound. For "poorly-soluble" substances with water solubilities below 1 g/L, a near constant value for the scavenging efficiency was found, indicating that their scavenging behavior is then dominated by the scavenging of the bulk non-carbonate carbon independent of the physical and chemical properties of the individual substances.

Keywords:
polar organic compounds, atmospheric aerosol, cloud water, scavenging efficiency, oxalic acid, malonic acid, succinic acid

Created from the Publication Database of the Vienna University of Technology.