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Titel |
The influence of surface characteristics, topography and continentality on mountain permafrost in British Columbia |
VerfasserIn |
A. Hasler, M. Geertsema, V. Foord, S. Gruber, J. Noetzli |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 9, no. 3 ; Nr. 9, no. 3 (2015-05-20), S.1025-1038 |
Datensatznummer |
250116799
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Publikation (Nr.) |
copernicus.org/tc-9-1025-2015.pdf |
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Zusammenfassung |
Thermal and surface offsets describe mean annual ground temperature
relative to mean annual air temperature, and for permafrost modelling they
are often predicted as a function of surface characteristics and topography.
As macroclimatic conditions influence the effectiveness of the underlying
processes, knowledge of surface- and topography-specific offsets is not
easily transferable between regions, limiting the applicability of empirical
permafrost distribution models over areas with strong macroclimatic
gradients.
In this paper we describe surface and thermal offsets derived from
distributed measurements at seven field sites in British Columbia. Key
findings are (i) a surprisingly small variation of the surface offsets
between different surface types; (ii) small thermal offsets at all sites
(excluding wetlands and peat); (iii) a clear influence of the
micro-topography at wind exposed sites (snow-cover erosion); (iv) a
north–south difference of the surface offset of 4 °C in vertical
bedrock and of 1.5–3 °C on open (no canopy) gentle slopes; (v)
only small macroclimatic differences possibly caused by the inverse
influence of snow cover and annual air temperature amplitude. These findings
suggest that topoclimatic factors strongly influence the mountain
permafrost distribution in British Columbia. |
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