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| Titel |
Observations of total peroxy nitrates and aldehydes: measurement interpretation and inference of OH radical concentrations |
| VerfasserIn |
P. A. Cleary, P. J. Wooldridge, D. B. Millet, M. McKay, A. H. Goldstein, R. C. Cohen |
| 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 ; 7, no. 8 ; Nr. 7, no. 8 (2007-04-18), S.1947-1960 |
| Datensatznummer |
250004909
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| Publikation (Nr.) |
 copernicus.org/acp-7-1947-2007.pdf |
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| Zusammenfassung |
| We describe measurements of total peroxy nitrates (ΣPNs), NO2,
O3 and several aldehydes at Granite Bay, California, during the
Chemistry and Transport of the Sacramento Urban Plume-2001 (CATSUP 2001)
campaign, from 19 July–16 September 2001. We observed a strong photochemically
driven variation of ΣPNs during the day with the median of 1.2 ppb
at noon. Acetaldehyde, pentanal, hexanal and methacrolein had median
abundances in the daytime of 1.2 ppb, 0.093 ppb, 0.14 ppb, and 0.27 ppb,
respectively. We compare steady state and time dependent calculations of the
dependence of ΣPNs on aldehydes, OH, NO and NO2 showing that
the steady state calculations are accurate to ±30% between 10:00 and
18:00 h. We use the steady state calculation to investigate the composition
of ΣPNs and the concentration of OH at Granite Bay. We find that PN
molecules that have never been observed before make up an unreasonably large
fraction of the ΣPNs unless we assume that there exists a PAN source
that is much larger than the acetaldehyde source. We calculate that OH at
the site varied between 2 and 7×106 molecule cm−3 at
noon during the 8 weeks of the experiment. |
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