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dc.contributor.authorMüller, J.-F.
dc.contributor.authorPeeters, J.
dc.contributor.authorStavrakou, T.
dc.date2014
dc.date.accessioned2016-03-25T09:42:10Z
dc.date.available2016-03-25T09:42:10Z
dc.identifier.urihttps://orfeo.belnet.be/handle/internal/2842
dc.descriptionPhotolysis is shown to be a major sink for isoprene-derived carbonyl nitrates, which constitute an important component of the total organic nitrate pool over vegetated areas. Empirical evidence from published laboratory studies on the absorption cross sections and photolysis rates of α-nitrooxy ketones suggests that the presence of the nitrate group (i) greatly enhances the absorption cross sections and (ii) facilitates dissociation to a point that the photolysis quantum yield is close to unity, with O–NO2 dissociation as a likely major channel. On this basis, we provide new recommendations for estimating the cross sections and photolysis rates of carbonyl nitrates. The newly estimated photo rates are validated using a chemical box model against measured temporal profiles of carbonyl nitrates in an isoprene oxidation experiment by Paulot et al. (2009). The comparisons for ethanal nitrate and for the sum of methacrolein- and methyl vinyl ketone nitrates strongly supports our assumptions of large cross-section enhancements and a near-unit quantum yield for these compounds. These findings have significant atmospheric implications: the photorates of key carbonyl nitrates from isoprene are estimated to be typically between ~ 3 and 20 times higher than their sink due to reaction with OH in relevant atmospheric conditions. Moreover, since the reaction is expected to release NO2, photolysis is especially effective in depleting the total organic nitrate pool.
dc.languageeng
dc.titleFast photolysis of carbonyl nitrates from isoprene
dc.typeArticle
dc.subject.frascatiChemical sciences
dc.audienceScientific
dc.source.titleAtmospheric Chemistry and Physics
dc.source.volume14
dc.source.issue5
dc.source.page2497-2508
Orfeo.peerreviewedYes
dc.identifier.doi10.5194/acp-14-2497-2014
dc.identifier.scopus2-s2.0-84896753330


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