Performance of Icelandic jokls 2021-2022

For the glaciological year 2021-22 mass balance was observed at similar to 140 locations in Iceland. At Vatnajokull 67 points were observed, 20 points at Hofsjokull, 25 at Langjokull, four at Myrdalsjokull, five in Tindfjoll, two at Eyjafjallajokull and similar to 15 at Trollaskagi in northern Iceland. Four automatic weather stations (AWSs) were in full-year operation at Vatnajokull but additional 10 AWSs were operated during the melt season. Winter mass balance was above average, due to more winter snow than in an average year, which concurrently with a cold and cloudy summer reduced summer ablation, although fall months (September and October) were quite warm. An extensive dust deposit event at the southwest outlets at Vatnajokull in July enhanced summer ablation by increased radiative forcing. Figure 1 shows the main results for the three largest icecaps in Iceland. At Vatnajokull winter mass balance was 27% above average, average summer ablation was observed (2% above average), resulting in a slightly negative net balance of -0.08 m w. eq. At Hofsjokull winter mass balance has only been observed greater in three years since 1988, about 20% above the long-term average. Summer ablation was below average (92% of 2017-2021 average) resulting in a negative net mass balance of -0.29 m w. eq. Net mass balance at Langjokull was positive, +0.05 m w. eq. Winter mass balance was 41% above long-term average (1.76 m w. eq.) and summer ablation 81% of the long-term average (-2.44 m w. eq. in 2021-22 with long-term average as -3.02 m w. eq.).