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| Titel |
Hygroscopic growth and droplet activation of soot particles: uncoated, succinic or sulfuric acid coated |
| VerfasserIn |
S. Henning, M. Ziese, A. Kiselev, H. Saathoff, O. Möhler, T. F. Mentel, A. Buchholz, C. Spindler, V. Michaud, M. Monier, K. Sellegri, F. Stratmann |
| 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 ; 12, no. 10 ; Nr. 12, no. 10 (2012-05-24), S.4525-4537 |
| Datensatznummer |
250011165
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| Publikation (Nr.) |
 copernicus.org/acp-12-4525-2012.pdf |
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| Zusammenfassung |
| The hygroscopic growth and droplet activation of uncoated soot particles and
such coated with succinic acid and sulfuric acid were investigated during the
IN-11 campaign at the Aerosol Interaction and Dynamics in the Atmosphere
(AIDA) facility. A GFG-1000 soot generator applying either nitrogen or argon
as carrier gas and a miniCAST soot generator were utilized to generate soot
particles. Different organic carbon (OC) to black carbon (BC) ratios were
adjusted for the CAST-soot by varying the fuel to air ratio. The hygroscopic
growth was investigated by means of the mobile Leipzig Aerosol Cloud
Interaction Simulator (LACIS-mobile) and two different Hygroscopicity Tandem
Differential Mobility Analyzers (HTDMA, VHTDMA). Two Cloud Condensation
Nucleus Counter (CCNC) were applied to measure the activation of the
particles. For the untreated soot particles neither hygroscopic growth nor
activation was observed at a supersaturation of 1%, with exception of a
partial activation of GFG-soot generated with argon as carrier gas. Coatings
of succinic acid lead to a detectable hygroscopic growth of GFG-soot and
enhanced the activated fraction of GFG- (carrier gas: argon) and CAST-soot,
whereas no hygroscopic growth of the coated CAST-soot was found. Sulfuric
acid coatings led to an OC-content dependent hygroscopic growth of CAST-soot.
Such a dependence was not observed for activation measurements. Coating with
sulfuric acid decreased the amount of Polycyclic Aromatic Hydrocarbons (PAH),
which were detected by AMS-measurements in the CAST-soot, and increased the
amount of substances with lower molecular weight than the initial PAHs. We
assume that these reaction products increased the hygroscopicity of the
coated particles in addition to the coating substance itself. |
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