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Titel |
Airborne determination of the temporo-spatial distribution of benzene, toluene, nitrogen oxides and ozone in the boundary layer across Greater London, UK |
VerfasserIn |
M. D. Shaw, J. D. Lee, B. Davison, A. Vaughan, R. M. Purvis, A. Harvey, A. C. Lewis, C. N. Hewitt |
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 ; 15, no. 9 ; Nr. 15, no. 9 (2015-05-05), S.5083-5097 |
Datensatznummer |
250119696
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Publikation (Nr.) |
copernicus.org/acp-15-5083-2015.pdf |
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Zusammenfassung |
Highly spatially resolved mixing ratios of benzene and toluene, nitrogen
oxides (NOx) and ozone (O3) were measured in the atmospheric
boundary layer above Greater London during the period 24 June to
9 July 2013 using a Dornier 228 aircraft. Toluene and benzene were
determined in situ using a proton transfer reaction mass spectrometer
(PTR-MS), NOx by dual-channel NOx chemiluminescence and O3 mixing
ratios by UV absorption.
Average mixing ratios observed over inner London at 360 ± 10 m a.g.l.
were 0.20 ± 0.05, 0.28 ± 0.07, 13.2 ± 8.6, 21.0 ± 7.3
and 34.3 ± 15.2 ppbv for benzene, toluene, NO, NO2 and NOx
respectively. Linear regression analysis between NO2, benzene and
toluene mixing ratios yields a strong covariance, indicating that these
compounds predominantly share the same or co-located sources within the
city.
Average mixing ratios measured at 360 ± 10 m a.g.l. over outer London
were always lower than over inner London. Where traffic densities were
highest, the toluene / benzene (T / B) concentration ratios were highest
(average of 1.8 ± 0.5 ppbv ppbv-1), indicative of strong local
sources. Daytime maxima in NOx, benzene and toluene mixing ratios were
observed in the morning (~ 40 ppbv NOx, ~ 350 pptv toluene and ~ 200 pptv benzene) and in the
mid-afternoon for ozone (~ 40 ppbv O3), all at 360 ± 10 m a.g.l. |
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