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| Titel |
Mesoscopic surface roughness of ice crystals pervasive across a wide range of ice crystal conditions |
| VerfasserIn |
N. B. Magee, A. Miller, M. Amaral, A. Cumiskey |
| 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 ; 14, no. 22 ; Nr. 14, no. 22 (2014-11-25), S.12357-12371 |
| Datensatznummer |
250119184
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| Publikation (Nr.) |
 copernicus.org/acp-14-12357-2014.pdf |
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| Zusammenfassung |
| Here we show high-magnification images of hexagonal ice crystals acquired by
environmental scanning electron microscopy (ESEM). Most ice crystals were
grown and sublimated in the water vapor environment of an FEI-Quanta-200
ESEM, but crystals grown in a laboratory diffusion chamber were also
transferred intact and imaged via ESEM. All of these images display
prominent mesoscopic topography including linear striations, ridges,
islands, steps, peaks, pits, and crevasses; the roughness is not observed to
be confined to prism facets. The observations represent the most highly
magnified images of ice surfaces yet reported and expand the range of
conditions in which rough surface features are known to be conspicuous.
Microscale surface topography is seen to be ubiquitously present at
temperatures ranging from −10 °C to −40 °C, in
supersaturated and subsaturated conditions, on all crystal facets, and
irrespective of substrate. Despite the constant presence of surface
roughness, the patterns of roughness are observed to be dramatically
different between growing and sublimating crystals, and transferred crystals
also display qualitatively different patterns of roughness. Crystals are
also demonstrated to sometimes exhibit inhibited growth in moderately
supersaturated conditions following exposure to near-equilibrium conditions,
a phenomenon interpreted as evidence of 2-D nucleation. New knowledge about the
characteristics of these features could affect the fundamental understanding
of ice surfaces and their physical parameterization in the context of
satellite retrievals and cloud modeling. Links to supplemental videos of ice
growth and sublimation are provided. |
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