Abstract
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 3.9 m 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., −0.95°C to −0.75°C), with topography influencing the discharge periodicity. For increases of ≥0.2°C 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.
Original language | English |
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Article number | e2020GL091790 |
Number of pages | 11 |
Journal | Geophysical Research Letters |
Volume | 48 |
Issue number | 10 |
DOIs | |
Publication status | Published - 28 May 2021 |
Keywords
- ice sheet model
- ocean variability
- Totten Glacier