Atmospheric evolution of organic aerosol

• Published in: Geophysical research letters Vol. 31; no. 22; pp. L22104 - n/a
• Main Authors: Molina, M. J., Ivanov, A. V., Trakhtenberg, S., Molina, L. T.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01-11-2004; Blackwell Publishing Ltd
• Subjects: Aerosols and particles; Atmospheric Composition and Structure; Chemical kinetic and photochemical properties; Constituent sources and sinks; Pollution—urban and regional; Troposphere—composition and chemistry
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2004GL020910

We report here results of an experimental study of the OH‐initiated oxidation of solid organics in the presence of O2, NOx and H2O, using two kinds of self‐assembled organic monolayers (alkane and aromatic), paraffin and pyrene films as proxies for organic aerosol. We show that the OH‐initiated oxidation of the alkane surfaces leads to rapid volatilization. The gas‐phase products detected include HO2, H2O2, CO, CO2, HCO, CH2O, CH3CHO, CH3OH, and HCOOH. We conclude that volatilization is at least as efficient as wet deposition as a removal process for aliphatic particulates, whereas aromatic particulates show higher stability towards volatilization.