What the study found
Small differences in synthetic bed topography can lead to noticeable differences in projected Antarctic ice mass loss and in the timing and extent of grounding line retreat. The study found that sea-level rise estimates varied depending on how the synthetic bed was generated and whether basal friction coefficients were optimized for each bed.
Why the authors say this matters
The authors conclude that relatively small bed variations matter for decadal- to centennial-scale sea-level projections, and they say the findings indicate a need for process-informed representation of basal friction in ice sheet models. Here, basal friction means the resistance to ice sliding over the ground beneath it.
What the researchers tested
The researchers reviewed commonly used methods for generating synthetic gridded bed topography datasets and their uncertainties. They used the Aurora Subglacial Basin in East Antarctica as a case study and compared five synthetic bed generation methods in ice sheet modeling under high-emission forcing scenarios.
What worked and what didn't
When basal friction coefficients were optimized for each bed, sea-level rise estimates at 2300 CE varied by up to 11% under SSP5-8.5 forcing and 32% under RCP2.6. When non-optimized coefficients were used, the variation increased to up to 23% under SSP5-8.5 and 51% under RCP2.6.
What to keep in mind
The abstract does not describe all model details or provide broader validation beyond the Aurora Subglacial Basin case study. It also does not give a full account of the uncertainties for each synthetic bed method, only that the methods and their associated uncertainties were reviewed.
Key points
- Synthetic Antarctic bed topography can affect projected ice mass loss and grounding line retreat.
- Five synthetic bed generation methods were compared using the Aurora Subglacial Basin in East Antarctica.
- Sea-level rise estimates at 2300 CE varied by up to 11% to 51%, depending on scenario and friction treatment.
- Optimizing basal friction coefficients reduced the range of projected sea-level rise differences compared with non-optimized coefficients.
- The authors say small bed variations matter for decadal- to centennial-scale sea-level projections.
Disclosure
- Research title:
- Synthetic bed choices affect Antarctic ice-loss projections
- Authors:
- Felicity S. McCormack, Tobias Stål, Niya Shao, Emma MacKie, Ana Fabela Hinojosa, Mareen Lösing, Jason Roberts, Shivani Ehrenfeucht, Christine Dow
- Institutions:
- Monash University, University of Tasmania, Australian Antarctic Division, University of Florida, Florida College, The University of Western Australia, Potsdam Institute for Climate Impact Research, University of Waterloo
- Publication date:
- 2026-04-23
- OpenAlex record:
- View
- Image credit:
- Photo by ArcticDesire.com Polarreisen on Pexels · Pexels License
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