Accelerated Glacier Mass Loss over Svalbard Derived from ICESat-2 in 2019–2021.

The glaciers in Arctic Archipelago of Svalbard, located in the hotspot of global warming, are sensitive to climate change. The assessment of glacier mass balance in Svalbard is one of the hotspots in Arctic research. In this study, we use the laser altimetry ICESat-2 data to investigate the elevation and mass change of Svalbard from 2019 to 2021 by a hypsometric approach. It is shown that the Svalbard-wide elevation change rate is −0.775 ± 0.225 m yr−1 in 2019–2021, corresponding to the mass change of −14.843 ± 4.024 Gt yr−1. All regions exhibit a negative mass balance, and the highest mass loss rates are observed at Northwestern Spitsbergen. Compared with ICESat/ICESat-2 (2003–2008 to 2019) and Cryosat-2 (2011–2017) periods, the elevation change from 2019 to 2021 has accelerated, with an increase by 158.3% and 31.5%, respectively, leading to equilibrium line altitude increasing to 750 m. Among the seven subregions, four are accelerated. It is shown that the overall accelerated glacier mass loss in Svalbard is expected to be caused by increasing surge events and temperature rise. [ABSTRACT FROM AUTHOR]