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Titel |
Collision dynamics and uptake of water on alcohol-covered ice |
VerfasserIn |
E. S. Thomson, X. Kong, N. Markovic, P. Papagiannakopoulos, J. B. C. Pettersson |
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. 4 ; Nr. 13, no. 4 (2013-02-25), S.2223-2233 |
Datensatznummer |
250018433
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Publikation (Nr.) |
copernicus.org/acp-13-2223-2013.pdf |
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Zusammenfassung |
Molecular scattering experiments are used to investigate water interactions
with methanol and n-butanol covered ice between 155 K and 200 K. The
inelastically scattered and desorbed products of an incident molecular beam
are measured and analyzed to illuminate molecular scale processes. The
residence time and uptake coefficients of water impinging on alcohol-covered
ice are calculated. The surfactant molecules are observed to affect water
transport to and from the ice surface in a manner that is related to the
number of carbon atoms they contain. Butanol films on ice are observed to
reduce water uptake by 20%, whereas methanol monolayers pose no
significant barrier to water transport. Water colliding with methanol covered
ice rapidly permeates the alcohol layer, but on butanol water molecules have
mean surface lifetimes of ≲ 0.6 ms, enabling some molecules to
thermally desorb before reaching the water ice underlying the butanol. These
observations are put into the context of cloud and atmospheric scale
processes, where such surfactant layers may affect a range of aerosol
processes, and thus have implications for cloud evolution, the global water
cycle, and long term climate. |
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