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| Titel |
Effect of photochemical ageing on the ice nucleation properties of diesel and wood burning particles |
| VerfasserIn |
C. Chou, Z. A. Kanji, O. Stetzer, T. Tritscher, R. Chirico, M. F. Heringa, E. Weingärtner, A. S. H. Prévôt, U. Baltensperger, U. Lohmann |
| 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 ; 13, no. 2 ; Nr. 13, no. 2 (2013-01-22), S.761-772 |
| Datensatznummer |
250017599
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| Publikation (Nr.) |
 copernicus.org/acp-13-761-2013.pdf |
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| Zusammenfassung |
| A measurement campaign (IMBALANCE) conducted in 2009 was aimed at
characterizing the physical and chemical properties of freshly emitted and
photochemically aged combustion particles emitted from a log wood burner and
diesel vehicles: a EURO3 Opel Astra with a diesel oxidation catalyst (DOC)
but no particle filter and a EURO2 Volkswagen Transporter TDI Syncro without
emission aftertreatment. Ice nucleation experiments in the deposition and
condensation freezing modes were conducted with the Portable Ice Nucleation
Chamber (PINC) at three nominal temperatures, −30 °C,
−35 °C and −40 °C. Freshly emitted diesel particles
showed ice formation only at −40 °C in the deposition mode at
137% relative humidity with respect to ice (RHi) and 92%
relative humidity with respect to water (RHw), and photochemical
ageing did not play a role in modifying their ice nucleation behaviour. Only
one diesel experiment where α-pinene was added for the ageing process,
showed an ice nucleation enhancement at −35 °C. Wood burning
particles also act as ice nuclei (IN) at −40 °C in the deposition
mode at the same conditions as for diesel particles and photochemical ageing
also did not alter the ice formation properties of the wood burning
particles. Unlike diesel particles, wood burning particles form ice via
condensation freezing at −35 °C whereas no ice nucleation was
observed at −30 °C. Photochemical ageing did not affect the ice
nucleation ability of the diesel and wood burning particles at the three
different temperatures investigated but a broader range of temperatures below
−40 °C need to be investigated in order to draw an overall
conclusion on the effect of photochemical ageing on deposition/condensation
ice nucleation across the entire temperature range relevant to cold clouds. |
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