Glacier change in Norway since the 1960s – an overview of mass balance, area, length and surface elevation changes

• Published in: Journal of Glaciology
• Main Authors: Andreassen, Liss M., Elvehøy, Hallgeir, Kjøllmoen, Bjarne, Belart, Joaquín M. C.
• Other Authors: Jarðvísindastofnun (HÍ), Institute of Earth Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2020
• Subjects: Earth-Surface Processes; glacier mapping; glacier mass balance; Glacier fluctuations; Jöklafræði; Jöklarannsóknir; Engeset; Etienne; Klingenberg; Norway; Finnmark; glacier; Journal of Glaciology; Lyngen; Troms
• Online Access: https://hdl.handle.net/20.500.11815/2391; https://doi.org/10.1017/jog.2020.10

Publisher's version (útgefin grein) Abstract In this paper, we give an overview of changes in area, length, surface elevation and mass balance of glaciers in mainland Norway since the 1960s. Frontal advances have been recorded in all regions except the northernmost glaciers in Troms and Finnmark (Storsteinsfjellbreen, Lyngen and Langfjordjokelen). More than half of the observed glaciers, 27 of 49, had marked advances in the 1990s. The glaciological mass-balance values for the period 1962-2018, where 43 glaciers have been measured, show great inter-annual variability. The results reveal accelerated deficit since 2000, the most negative decade being 2001-2010. Some years with a positive mass balance (or less negative) after 2010s can be attributed to variations in large-scale atmospheric circulation. A surface elevation change and geodetic mass balance were calculated for a sample of 131 glaciers covering 817 km in the '1960s' and 734 km in the '2010s', giving an area reduction of 84 km, or 10%. The sample covers many of the largest glaciers in Norway, and they had an overall change in surface elevation of -15.5 m for the ~50 year period. Converted to a geodetic mass balance this gives a mean mass balance of -0.27 ± 0.05 m w.e. a-1 The dataset of Norwegian glaciers would not be possible without all the observers who helped collecting them. We thank colleagues at NVE, our front position observers and personnel from hydropower companies. We thank Rune V. Engeset, NVE, for providing input to the manuscript. We thank John Brittain, NVE, for English corrections. We thank two anonymous reviewers for input to the manuscript, and editor C. Schneider for handling the manuscript. Statkraft is thanked for partly funding the laser scannings. We thank Trygve Snøtun and Goeffrey D. Corner for providing information on length change advances and records. Torgeir Ferdinand Klingenberg helped digitising some of the glacier outlines. We thank Etienne Berthier for providing Pléiades (@CNES & Airbus D&S) imagery of ...