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| Titel |
Influence of aerosol chemical composition on N2O5 uptake: airborne regional measurements in northwestern Europe |
| VerfasserIn |
W. T. Morgan, B. Ouyang, J. D. Allan, E. Aruffo, P. Di Carlo, O. J. Kennedy, D. Lowe, M. J. Flynn, P. D. Rosenberg, P. I. Williams, R. Jones, G. B. McFiggans, H. Coe |
| 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. 2 ; Nr. 15, no. 2 (2015-01-28), S.973-990 |
| Datensatznummer |
250119350
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| Publikation (Nr.) |
 copernicus.org/acp-15-973-2015.pdf |
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| Zusammenfassung |
| Aerosol chemical composition was found to influence nighttime atmospheric chemistry during
a series of airborne measurements in northwestern Europe in summer conditions, which has
implications for regional air quality and climate. The uptake of dinitrogen pentoxide, γ
(N2O5), to particle surfaces was found to be modulated by the amount of water
content and ammonium nitrate present in the aerosol. The conditions prevalent in this study
suggest that the net uptake rate of N2O5 to atmospheric aerosols was relatively
efficient compared to previous studies, with γ (N2O5) values in the range
0.01–0.03. This is likely a consequence of the elevated relative humidity in the region, which
promotes greater aerosol water content. Increased nitrate concentrations relative to particulate
water were found to suppress N2O5 uptake. The results presented here contrast with
previous ambient studies of N2O5 uptake, which have generally taken place in
low-nitrate environments in the USA. Comparison of the N2O5 uptake derived from the
measurements with a parameterised scheme that is based on the ratio of particulate water to
nitrate yielded reasonably good agreement in terms of the magnitude and variation in uptake,
provided the effect of chloride was neglected. An additional suppression of the parameterised
uptake is likely required to fully capture the variation in N2O5 uptake, which could
be achieved via the known suppression by organic aerosol. However, existing parameterisations
representing the suppression by organic aerosol were unable to fully represent the variation in
N2O5 uptake. These results provide important ambient measurement constraint on our
ability to predict N2O5 uptake in regional and global aerosol
models. N2O5 uptake is a potentially important source of nitrate aerosol and a sink
of the nitrate radical, which is the main nocturnal oxidant in the atmosphere. The results further
highlight the importance of ammonium nitrate in northwestern Europe as a key component of
atmospheric composition in the region. |
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