The impact of variable ocean temperatures on Totten Glacier stability and discharge
A major uncertainty in Antarctica's contribution to future sea-level rise is the ice sheet response timescales to ocean warming. Totten Glacier drains a region containing 3.9m global sea level equivalent and has been losing mass over recent decades. We use an ice sheet model coupled to an ice-s...
| Published in: | Geophysical Research Letters |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Amer Geophysical Union
2021
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| Subjects: | |
| Online Access: | https://doi.org/10.1029/2020GL091790 http://ecite.utas.edu.au/151704 |
| Summary: | A major uncertainty in Antarctica's contribution to future sea-level rise is the ice sheet response timescales to ocean warming. Totten Glacier drains a region containing 3.9m global sea level equivalent and has been losing mass over recent decades. We use an ice sheet model coupled to an ice-shelf cavity combined ocean box and plume model to investigate Totten's response to variable ocean forcing. Totten's grounding line is stable for a limited range of ocean temperatures near current observations (i.e., −0.95C to −0.75C), with topography influencing the discharge periodicity. For increases of ≥0.2C in temperatures beyond this range, grounding line retreat occurs. Variable ocean forcing can reduce retreat relative to constant forcing, and different variability amplitudes can cause centennial-scale delays in retreat through interactions with topography. Our results highlight the need for long-term ocean state observations and to include forcing variability in ice sheet model simulations of future change. |
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