Jump to main content
Jump to site search

Issue 42, 2010
Previous Article Next Article

HOx radical regeneration in isoprene oxidation via peroxy radical isomerisations. II: experimental evidence and global impact

Author affiliations

Abstract

A consistent body of experimental evidence from work of other groups is presented in support of the novel, theoretically based, isoprene oxidation mechanism we recently proposed to rationalize the unexpectedly high OH concentrations observed over areas with high isoprene emissions. Some explicit or implicit criticisms on the new mechanism are addressed. A particular photochemical mechanism is newly proposed for the OH-regenerating photolysis of the crucial hydroperoxy-methyl-butenals (HPALDs), formed by isomerisation of the initial isoprene hydroxy-peroxy radicals, that rationalizes a quantum yield close to 1. A similar photolysis mechanism of the resulting photolabile peroxy-acid-aldehydes (PACALDs) is shown to generate ample additional OH. Global modeling demonstrates the major importance of the new chemistry for the oxidizing capacity of the atmosphere over continents. The globally averaged yield of the HPALDs in the oxidation of isoprene by OH is estimated to be of the order of 0.6. The isomerisation reactions of isoprene peroxy radicals are found to result in modelled [OH] increases in the planetary boundary layer by up to a factor of 3, in agreement with the reported observations as in the Amazon basin.

Graphical abstract: HOx radical regeneration in isoprene oxidation via peroxy radical isomerisations. II: experimental evidence and global impact

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 Mar 2010, accepted on 24 Aug 2010 and first published on 29 Sep 2010


Article type: Paper
DOI: 10.1039/C0CP00811G
Citation: Phys. Chem. Chem. Phys., 2010,12, 14227-14235
  •   Request permissions

    HOx radical regeneration in isoprene oxidation via peroxy radical isomerisations. II: experimental evidence and global impact

    J. Peeters and J. Müller, Phys. Chem. Chem. Phys., 2010, 12, 14227
    DOI: 10.1039/C0CP00811G

Search articles by author

Spotlight

Advertisements