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| Titel |
On the effects of organic matter and sulphur-containing compounds on the CCN activation of combustion particles |
| VerfasserIn |
A. Petzold, M. Gysel, X. Vancassel, R. Hitzenberger, H. Puxbaum, S. Vrochticky, E. Weingärtner, U. Baltensperger, P. Mirabel |
| 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 ; 5, no. 12 ; Nr. 5, no. 12 (2005-12-01), S.3187-3203 |
| Datensatznummer |
250003188
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| Publikation (Nr.) |
 copernicus.org/acp-5-3187-2005.pdf |
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| Zusammenfassung |
| The European PartEmis project (Measurement and prediction of
emissions of aerosols and gaseous precursors from gas turbine engines) was focussed on the characterisation and
quantification of exhaust emissions from a gas turbine engine. The
combustion aerosol characterisation included on-line measurements of mass
and number concentration, size distribution, mixing state, thermal stability
of internally mixed particles, hygroscopicity, cloud condensation nuclei
(CCN) activation potential, and off-line analysis of chemical composition.
Based on this extensive data set, the role of sulphuric acid coating and of
the organic fraction of the combustion particles for the CCN activation was
investigated. Modelling of CCN activation was conducted using microphysical
and chemical properties obtained from the measurements as input data.
Coating the combustion particles with water-soluble sulphuric acid,
increases the potential CCN activation, or lowers the activation diameter,
respectively. The adaptation of a Köhler model to the experimental data
yielded coatings from 0.1 to 3 vol-% of water-soluble matter, which
corresponds to an increase in the fraction of CCN-activated combustion
particles from ≤10−4 to ≌10−2 at a water vapour
saturation ratio Sw=1.006. Additional particle coating by coagulation
of combustion particles and aqueous sulphuric acid particles formed by
nucleation further reduces the CCN activation diameter. In contrast,
particles containing a large fraction of non-volatile organic compounds grow
significantly less at high relative humidity than particles with a lower
content of non-volatile OC. The resulting reduction in the potential CCN
activation with an increasing fraction of non-volatile OC becomes visible as
a trend in the experimental data. While a coating of water-soluble sulphuric
acid increases the potential CCN activation, or lowers the activation
diameter, respectively, the non-volatile organic compounds, mainly found at
lower combustion temperatures, can partially compensate this sulphuric
acid-related enhancement of CCN activation of carbonaceous combustion
aerosol particles. |
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