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.

中文翻译：

---

海洋温度变化对托特冰川稳定性和流量的影响

南极洲对未来海平面上升的贡献的主要不确定因素是冰盖对海洋变暖的响应时间表。Totten Glacier流失了一个包含全球海平面3.9 m的区域，并且在最近几十年中一直在减少质量。我们将一个冰盖模型与一个冰架腔组合的海洋箱和羽状流模型耦合使用，以研究托特顿对可变海洋强迫的响应。Totten的接地线可在当前观测值附近的有限海洋温度范围（即-0.95°C至-0.75°C）内保持稳定，并且地形会影响放电周期。如果超出此范围的温度升高≥0.2°C，则会发生接地线后退。相对于恒定的强迫，可变的海洋强迫可以减少后退，并且不同的变化幅度会通过与地形的相互作用而导致退缩的百年尺度延迟。我们的结果强调了对长期海洋状态观测的需求，并且在对未来变化的冰盖模型模拟中包括了强制可变性。