Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 42, 2010
Previous Article Next Article

HOx radical regeneration in isopreneoxidationviaperoxy 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

Article information


Submitted
22 Mar 2010
Accepted
24 Aug 2010
First published
29 Sep 2010

Phys. Chem. Chem. Phys., 2010,12, 14227-14235
Article type
Paper

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

Social activity

Search articles by author

Spotlight

Advertisements