Accelerated Basal Melt Rates of Ice Shelves in North Greenland From 2013 to 2022 Estimated With the High-Resolution ArcticDEM

Abstract

Basal melting of ice shelves has become one of the main causes of mass loss from the Greenland ice sheet. However, most studies have focused on individual ice shelves, making it difficult to gain a more comprehensive understanding of basal melting across Greenland ice shelves. To address this issue, we utilized timestamped ArcticDEM strip data coregistered with ICESat-2 data to estimate the basal melt rates of the ice shelves in North Greenland at a resolution of 150 m from 2013 to 2022, employing a mass conservation approach within the Lagrangian framework. Additionally, to investigate the influence of temperature on basal melt rates, a basic analysis correlating the basal melt rates with temperatures was conducted. Overall, the mass loss caused by basal melting of the six ice shelves has amounted to 27.86 ± 35.63 Gt yr⁻¹, accounting for approximately 90% of the non-calving mass loss, equivalent to a sea level rise of 0.08 ± 0.10 mm yr⁻¹, far exceeding surface mass loss and glacier calving. The two larger ice shelves, Petermann and 79° North (79N), have contributed to 85% of the basal melt mass loss. Regarding the spatiotemporal distribution, the basal melt rates have gradually decreased from near the grounding line to the ice shelf front. Apart from the Ryder ice shelves, the basal melting of the other ice shelves is in a state of accelerated ablation. Moreover, compared to the skin temperature of the ice shelf, the sea water potential temperature has a greater impact on the basal melt rate.