Negative mass balances at Austdalsbreen and Nigardsbreen in 2022/2023

by Hallgeir Elvehøy, February 5, 2024

After a fairly dry winter at Jostedalsbreen, the 2023 summer was warmer than average and consequently the annual balances were more negative than average.

The winter balances at Austdalsbreen and Nigardsbreen were 77% and 98% of the 1991-2020 averages, and the summer balances were 116% and 115% of the 1991-2020 averages, respectively.

At Austdalsbreen, all the winter snow melted during the summer, resulting in an equilibrium line altitude (ELA) above the top of the glacier. The annual balance for 2022/23 was -1.5 m w.e., well below the 1991-2020 average of -0.6 m w.e. per year.

At Nigardsbreen, the equilibrium line altitude (ELA) was around 1635 m a.s.l., resulting in an accumulation area ratio of ca. 50%. The annual balance for 2022/23 was -0.4 m w.e., slightly below the 1991-2020 average of 0.0 m w.e. per year.

The outlet glaciers from Jostedalsbreen are retreating. In 2023, the average terminus retreat for six measured outlet glaciers was -28 meters. The observed retreat varied between -7 meters for Stigaholtbreen in Jostedalen and -73 meters for Vetle Supphellebreen in Fjærland. The six outlet glaciers have retreated on average 273 meters during the last 10 years.

The autumn measurements were performed on 22 September 2023. All the winter snow had melted on Austdalsbreen this summer (photo: Emma Barfod/NVE).