The Hoffman Glacier in the Subpolar Urals: current state and response to climate change

This paper presents the results of a quantitative assessment of changes of the Hoffman Glacier, the largest glacier in the Subpolar Urals, occurring over the period 1951–2024. Aerial photographs from 1951, current Sentinel-2 satellite images, laser rangefinder data from the ICEsat-2 satellite, as well as historical and modern ground-based photographs were used. The results show that in 1951 glacier area was 0.36±3% km². This value was almost identical to the results of a ground-based phototheodolite survey of the glacier area carried out in 1929. By 2024, the glacier area had decreased by 33% and amounted to 0.24±8% km². The reduction in the glacier area was accompanied by a decrease in its surface height. Over 73 years (1951–2024), the glacier surface elevation on the ICEsat-2 profile decreased by 45±11 m and reached the altitude of 647±11 m. The average rate of the surface lowering amounted to 0.6 m/year. A comparative analysis of the dynamics of changes in the Hoffman Glacier size and climate data in this region suggests that the conditions for the existence of glaciers in this region have significantly worsened at the turn of the centuries. With a relative stability of winter precipitation, the number of years with positive temperature anomalies in summertime has sharply increased (with a continuous series of such anomalies since 2003). In addition, a certain increase in the short-wave radiation caused by reduction in the cloudiness has been observed over the past 20 years. The rise in summer air temperatures and the increase in the shortwave radiation cause the glacier mass balance to become even more negative and the rate of its shrinkage to increase. How long the Hoffman Glacier will remain in its cirque part will depend on the further development of the climate scenario.

glacier shrinkage, historical photographs, remote sensing, Subpolar Urals