Modeling the Response of Nioghalvfjerdsfjorden and Zachariae Isstrom Glaciers, Greenland, to Ocean Forcing Over the Next Century

Recent studies have shown that the Northeast Greenland Ice Sheet region has been undergoing significant acceleration and dynamic thinning since 2010, and these changes are closely related to regional atmospheric and oceanic warming. Here we model the response of Nioghalvfjerdsfjorden (79North) and Zachariae IsstrOm (ZI) to ocean forcing to investigate their evolution over the coming decades. Our model suggests that 79North will retreat slowly over the next century, whereas ZI will lose its floating ice tongue completely and retreat rapidly for 70 years. After 70 years, ZI will stabilize 30 km upstream of its current position on a topographic ridge. Frontal melt rates need to reach 6 m/d in the summer to dislodge the glacier from this ridge. ZI will then continue a fast and unstoppable retreat, contributing more than 16.2 mm to global sea level rise by 2100.