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Published February 1997 | public
Journal Article

Formation of Organic Aerosols from the Oxidation of Biogenic Hydrocarbons

Abstract

Measurements of aerosol formation during thephotooxidation of α-pinene, β-pinene,d-3-carene, d-limonene, ocimene, linalool, terpinene-4-ol, andtrans-caryophyllene were conducted in an outdoor smog chamber. Daylight experiments in the presence of NOₓ and dark experiments with elevated ozone concentrations were performed. The evolution of the aerosol was simulated by the application of a gas/particle absorption model in connection with a chemical reaction mechanism. The fractional aerosol yield is shown to be a function of the organic aerosol mass concentration and temperature. Ozone and, for selected hydrocarbons, the NO₃ reaction of the compounds were found to represent efficient routes to the formation of condensable products. For initial hydrocarbon mixing ratios of about 100 ppb, the fractional aerosol yields from daylight runs have been estimated to be ∼5% for open-chain hydrocarbons, such as ocimene and linalool, 5–25% for monounsaturated cyclic monoterpenes, such as α-pinene, d-3-carene, or terpinene-4-ol, and ∼40% for a cyclic monoterpene with two double bonds like d-limonene. For the only sesquiterpene investigated, trans-caryophyllene, a fractional aerosol yield of close to 100% was observed. The majority of the compounds studied showed an even higher aerosol yield during dark experiments in the presence of ozone.

Additional Information

© 1997 Kluwer. (Received: 26 September 1996; in final form: 4 December 1996) This work was supported by U.S. Environmental Protection Agency Exploratory Environmental Research Center on Airborne Organics (R-819714-01-0), National Science Foundation grant ATM-9307603, the Coordinating Research Council (A-5-1), and the Chevron Corporation. T.H. thanks the German Research Association (DFG) for financial support and the BMBF (Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie) for agreeing with the stay at Caltech during his participation in the research programme 'cycles of trace constituents'.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023