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| Titel |
Diel peroxy radicals in a semi-industrial coastal area: nighttime formation of free radicals |
| VerfasserIn |
M. D. Andrés-Hernández, D. Kartal, J. N. Crowley, V. Sinha, E. Regelin, M. Martinez-Harder, V. Nenakhov, J. Williams, H. Harder, H. Bozem, W. Song, J. Thieser, M. J. Tang, Zeinab Hosaynali Beygi, J. P. Burrows |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 11 ; Nr. 13, no. 11 (2013-06-14), S.5731-5749 |
| Datensatznummer |
250018701
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| Publikation (Nr.) |
 copernicus.org/acp-13-5731-2013.pdf |
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| Zusammenfassung |
Peroxy radicals were measured by a PeRCA (Peroxy Radical Chemical Amplifier)
instrument in the boundary layer during the DOMINO (Diel Oxidant Mechanisms
In relation to Nitrogen Oxides) campaign at a coastal, forested site
influenced by urban-industrial emissions in southern Spain in late autumn.
Total peroxy radicals (RO2* = HO2 + ΣRO2)
generally showed a daylight maximum between 10 and 50 pptv at 13:00 UTC,
with an average of 18 pptv over the 15 days of measurements. Emissions from
the industrial area of Huelva often impacted the measurement site at night
during the campaign. The processing of significant levels of anthropogenic
organics leads to an intense nocturnal radical chemistry accompanied by
formation of organic peroxy radicals at comparable levels to those of summer
photochemical conditions with peak events up to 60–80 pptv. The RO2
production initiated by reactions of NO3 with organic trace gases was
estimated to be significant, but not sufficient to account for the
concentrations of RO2* observed in air masses carrying high
pollutant loading. The nocturnal production of peroxy radicals in those
periods seems therefore to be dominated by ozonolysis of volatile organic
compounds, in particular alkenes of industrial petrochemical origin.
RO2* diurnal variations were consistent with HO2
measurements available at the site. HO2/RO2* ratios
generally varied between 0.3 and 0.6, though on some occasions this ratio
was likely to have been affected by instrumental artifacts (overestimated
HO2) associated with high RO2 loads. |
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