The mass loss of the Greenland Ice Sheet is nearly equally partitioned between a decrease in surface mass balance from enhanced surface melt and an increase in ice dynamics from the acceleration and retreat of its marine-terminating glaciers. Much uncertainty remains in the future mass loss of the Greenland Ice Sheet due to the challenges of capturing the ice dynamic response to climate change in numerical models. Here, we estimate the sea level contribution of the Greenland Ice Sheet over the 21st century using an ice-sheet wide, high-resolution, ice-ocean numerical model that includes surface mass balance forcing, thermal forcing from the ocean, and iceberg calving dynamics. The model is calibrated with ice front observations from the past eleven years to capture the recent evolution of marine-terminating glaciers. Under a business as usual scenario, we find that northwest and central west Greenland glaciers will contribute more mass loss than other regions due to ice front retreat and ice flow acceleration. By the end of century, ice discharge from marine-terminating glaciers will contribute 50 ± 20% of the total mass loss, or twice as much as previously estimated although the contribution from the surface mass balance increases towards the end of the century.
The long-term response of Greenland’s peripheral glaciers to climate change is widely undocumented. Here we use historical aerial photographs and satellite imagery to document length fluctuations of >1,000 land-terminating peripheral glaciers in Greenland over more than a century. We find that their rate of retreat over the last two decades is double that of the twentieth century, indicating a ubiquitous transition into a new, accelerated state of downwasting.
more » « less- PAR ID:
- 10473446
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Climate Change
- Volume:
- 13
- Issue:
- 12
- ISSN:
- 1758-678X
- Format(s):
- Medium: X Size: p. 1324-1328
- Size(s):
- p. 1324-1328
- Sponsoring Org:
- National Science Foundation
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