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| Titel |
The Effect of Strong Acids on the Ice – Air Interface Studied by X-Ray Photoelectron Spectroscopy |
| VerfasserIn |
A. Křepelová, M. Amman, J. T. Newberg, H. Bluhm, T. Huthwelker |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020738
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| Zusammenfassung |
| Chemical processes on ice in snow and cirrus clouds are important for atmospheric chemistry,
biogeochemical cycling of trace constituents and archiving of trace species in ice. It has been
suspected since long that trace contaminants affect the thickness of the quasi-liquid layer at
the ice - air interface, which is at the heart of the interactions between snowpacks or cirrus
clouds and the surrounding air.
HNO3 is highly soluble in water and has a strong affinity to ice. It has been suggested to
be a source of NO and NO2 through photolysis. HCl is a key species in stratospheric
ozone depletion through its reaction with chlorine nitrate on ice or within liquid
particles.
Using surface sensitive techniques, X-ray photoelectron spectroscopy (XPS) combined
with near edge X-ray absorption spectroscopy (NEXAFS), performed at equilibrium
pressures in the temperature range of 220 to 250 K, we investigate the effects of HNO3 and
HCl on the local hydrogen bonding environment at the ice surface. These gases were dosed at
concentrations low enough to stay within the ice stability regime of the phase diagram. |
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