Degrading mountain permafrost in southern Norway: spatial and temporal variability of mean ground temperatures, 1999–2009
- Isaksen, Ketil Norwegian Meteorological Institute, Oslo, Norway
- Ødegård, Rune Strand Gjøvik University College, Gjøvik, Norway
- Etzelmüller, Bernd Department of Geosciences, University of Oslo, Norway
- Hilbich, Christin Department of Geography, University of Zurich, Switzerland
- Hauck, Christian Department of Geosciences, University of Fribourg, Switzerland
- Farbrot, Herman Department of Geosciences, University of Oslo, Norway
- Eiken, Trond Department of Geosciences, University of Oslo, Norway
- Hygen, Hans Olav Norwegian Meteorological Institute, Oslo, Norway
- Hipp, Tobias Florian Department of Geosciences, University of Oslo, Norway
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04.10.2011
Published in:
- Permafrost and Periglacial Processes. - 2011, vol. 22, no. 2, p. 361–377
warming permafrost
permafrost degradation
mean ground surface temperature
seasonal frost
repeated electrical resistivity tomography (ERT)
long-term monitoring
English
A ten-year record (1999–2009) of annual mean ground surface temperatures (MGSTs) and mean ground temperatures (MGTs) was analysed for 16 monitoring sites in Jotunheimen and on Dovrefjell, southern Norway. Warming has occurred at sites with cold permafrost, marginal permafrost and deep seasonal frost. Ongoing permafrost degradation is suggested both by direct temperature monitoring and indirect geophysical surveys. An increase in MGT at 6.6–9.0-m depth was observed for most sites, ranging from ~0.015 to ~ 0.095°C a-1. The greatest rate of temperature increase was for sites having MGTs slightly above 0°C. The lowest rate of increase was for marginal permafrost sites that are affected by latent heat exchange close to 0°C. Increased snow depths and an increase in winter air temperatures appear to be the most important factors controlling warming observed over the ten-year period. Geophysical surveys performed in 1999 to delineate the altitudinal limit of mountain permafrost were repeated in 2009 and 2010 and indicated the degradation of some permafrost over the intervening decade.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Géosciences
- Language
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- English
- Classification
- Meteorology, climatology
- License
- License undefined
- Identifiers
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- RERO DOC 28729
- DOI 10.1002/ppp.728
- Persistent URL
- https://folia.unifr.ch/unifr/documents/302428
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