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Titel |
Methyl hydroperoxide (CH3OOH) in urban, suburban and rural atmosphere: ambient concentration, budget, and contribution to the atmospheric oxidizing capacity |
VerfasserIn |
X. Zhang, S. Z. He, Z. M. Chen, Y. Zhao, W. Hua |
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 ; 12, no. 19 ; Nr. 12, no. 19 (2012-10-01), S.8951-8962 |
Datensatznummer |
250011487
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Publikation (Nr.) |
copernicus.org/acp-12-8951-2012.pdf |
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Zusammenfassung |
Methyl hydroperoxide (MHP), one of the most important
organic peroxides in the atmosphere, contributes to the tropospheric
oxidizing capacity either directly as an oxidant or indirectly as a free
radical precursor. In this study we report measurements of MHP from seven
field campaigns at urban, suburban and rural sites in China in winter 2007
and summer 2006/2007/2008. MHP was usually present in the order of several
hundreds of pptv level, but the average mixing ratios have shown a wide
range depending on the season and measuring site. Primary sources and sinks
of MHP are investigated to understand the impact of meteorological and
chemical parameters on the atmospheric MHP budget. The
MHP/(MHP+H2O2) ratio is also presented here to examine different
sensitivities of MHP and H2O2 to certain atmospheric processes.
The diurnal cycle of MHP/(MHP+H2O2), which is out of phase with
that of both H2O2 and MHP, could imply that MHP production is more
sensitive to the ambient NO concentration, while H2O2 is more
strongly influenced by the wet deposition and the subsequent aqueous
chemistry. It is interesting to note that our observation at urban Beijing
site in winter 2007 provides evidence for the occasional transport of
MHP-containing air masses from the marine boundary layer to the continent.
Furthermore, the contribution of MHP as an atmospheric oxidant to the
oxidizing capacity of an air parcel is assessed based on the "Counter
Species" concept. |
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