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| Titel |
Modeling near-surface firn temperature in a cold accumulation zone (Col du Dôme, French Alps): from a physical to a semi-parameterized approach |
| VerfasserIn |
A. Gilbert, C. Vincent, D. Six, P. Wagnon, L. Piard, P. Ginot |
| 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 ; 8, no. 2 ; Nr. 8, no. 2 (2014-04-17), S.689-703 |
| Datensatznummer |
250116095
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| Publikation (Nr.) |
 copernicus.org/tc-8-689-2014.pdf |
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| Zusammenfassung |
| Analysis of the thermal regime
of glaciers is crucial for glacier hazard assessment, especially in the
context of a changing climate. In particular, the transient thermal regime of
cold accumulation zones needs to be modeled. A modeling approach has
therefore been developed to determine this thermal regime using only
near-surface boundary conditions coming from meteorological observations. In
the first step, a surface energy balance (SEB) model accounting for water
percolation and radiation penetration in firn was applied to identify the
main processes that control the subsurface temperatures in cold firn. Results
agree well with subsurface temperatures measured at Col du Dôme (4250 m
above sea level (a.s.l.)), France. In the second step, a simplified model
using only daily mean air temperature and potential solar radiation was
developed. This model properly simulates the spatial variability of surface
melting and subsurface firn temperatures and was used to accurately
reconstruct the deep borehole temperature profiles measured at Col du
Dôme. Results show that percolation and refreezing are efficient
processes for the transfer of energy from the surface to underlying layers.
However, they are not responsible for any higher energy uptake at the
surface, which is exclusively triggered by increasing energy flux from the
atmosphere due to SEB changes when surface temperatures reach 0 °C.
The resulting enhanced energy uptake makes cold accumulation zones very
vulnerable to air temperature rise. |
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