Mountain permafrost in Central-Eastern Norway

Earlier studies suggest that the altitudinal permafrost limit decreases from the west to the east in Southern Norway and that the lowermost altitudinal permafrost limit in Southern Scandinavia occurs in the eastern part of Southern Norway. Most investigations on mountain permafrost have been undertaken in Jotunheimen and Dovrefjell further west, and in order to validate this regional pattern, the distribution of permafrost has been mapped on the mountains Sølen and Elgåhogna in the Femunden region, Central-Eastern Norway. Empirical-statistical models based on BTS and logistic regression were developed for each mountain, and validated with DC resistivity measurements. Permafrost was found to be probable down to 1100–1300 m a.s.l., which validates the regional west–east gradient in the altitudinal permafrost limit. Elevation is the main controlling factor for permafrost distribution on both Sølen and Elgåhogna. In addition, potential solar radiation and the surface wetness pattern were significant in the Sølen and Elgåhogna models, respectively. Mean annual ground surface temperatures are high and generally above zero, which contradicts the results from the BTS and DC resistivity. This together with observed air ventilation funnels through the snow cover suggest thermal advection and strong thermal offsets in the openwork blockfields.

Keywords:

• BTS
• DC-resistivity
• permafrost distribution

Acknowledgements

Assistance during fieldwork was given by Jakob Fjellanger, Ole Magnus Tønsberg, Robin Straub, Åse I.F. Heggem, Nina C. Arnesen, Webjørn Finsland, Anders Baumberger, Erik Scavenius, Jon Tolgensbakk, Jenny Rathert, Suha Berberoglu, Henning Urdahl, and Trond Eiken. Martin Hoelzle, University of Zurich, provided sensors and logging equipment for the meteorological station established on Sølen in 2002, and participated in field investigations. Ole Humlum, University of Oslo, contributed valuable discussion and supervision in the field. The municipality of Rendalen and private landowners Jens Tore Løken and Per Ertzaas kindly gave permission to use snow-scooters on their properties during winter fieldwork. Charles Harris and Ketil Isaksen reviewed the article and gave constructive comments.