Premium
Degrading Mountain Permafrost in Southern Norway: Spatial and Temporal Variability of Mean Ground Temperatures, 1999–2009
Author(s) -
Isaksen Ketil,
Ødegård Rune Strand,
Etzelmüller Bernd,
Hilbich Christin,
Hauck Christian,
Farbrot Herman,
Eiken Trond,
Hygen Hans Olav,
Hipp Tobias Florian
Publication year - 2011
Publication title -
permafrost and periglacial processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.867
H-Index - 76
eISSN - 1099-1530
pISSN - 1045-6740
DOI - 10.1002/ppp.728
Subject(s) - permafrost , snow , frost (temperature) , global warming , climate change , thermokarst , physical geography , climatology , geology , hydrology (agriculture) , atmospheric sciences , environmental science , geomorphology , geotechnical engineering , geography , oceanography
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. Copyright © 2011 John Wiley & Sons, Ltd.