Climate conditions required for re-glaciation of cirques in Rassepautasjtjåkka massif, northern Sweden

• Main Author: Johansson, Margareta
• Format: Other/Unknown Material
• Language: English
• Published: Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap 2000
• Subjects: pedology; geomorphology; physical geography; solar radiation; snow melt; climate change; modelling; cartography; climatology; naturgeografi; geomorfologi; marklära; kartografi; klimatologi; Earth and Environmental Sciences; New Glacier; Northern Sweden
• Online Access: http://lup.lub.lu.se/student-papers/record/1332886

Since the mid 1970s the general retreating trend for glacier in Scandinavian have ceased and some glaciers have even started to advance. This is due to a more maritime influence on the climate, which means increased precipitation in winter and lower summer temperature. A more maritime climate can be said to be favourable for glacier growth. Under such climate conditions is it possible that new glaciers are forming? The aim of this project is to assess the climate conditions that are needed to initiate a glacier in empty cirques in a small mountain massif, the Rassepautasjtjåkka massif, northern Sweden. The study area is of interest since the cirques are located just below the glaciation limit. Since there are no moraines or other signs of glaciation in the area it is still uncertain when the cirques were formed. Using a gridbased temperature index ablation model, that takes into account the topographic effects on melt, the melt during the summer was calculated and the snow that remains at the end of the melt season is what can constitute the ground to a new glacier. Weather data has been collected in the cirques every third hour for the last eight years and this was used as input to the model. The summer mean temperature needs to be lowered between –2 °C and –3 °C from the current climate before snow will remain after a melt season. An increased initial snow cover of today between 100-150% (under otherwise equal conditions) will have the same effect i. e remaining snow at the end of the melt season. When increasing the initial snow cover with 50% and lower the summer mean temperature by –2 °C, snow will be left in the cirques after a melt season. The climate conditions that are required to create a re-glaciation are not met by conditions evaluated from proxy-data from the Holocene. Therefore it can be concluded that glacier has not existed in the Rassepautasjtjåkka massif during the Holocene and that the origin of the cirques extends further back than the Holocene. According to future climate scenarios that ...