Computing predictions of future sea level that include well-defined uncertainty bounds requires models that are capable of robustly simulating the evolution of ice sheets and glaciers. Ice flow behaviour is known to be sensitive to the location and geometry of dynamic ice boundaries such as the grounding line (GRL), terminus position and ice surface elevation, so that any such model should track these interfaces with a high degree of accuracy. To address this challenge, we implement a numerical approach that uses the level-set method (LSM) that accurately models the evolution of the ice–air and ice–water interface as well as capturing topological changes in ice-sheet geometry. This approach is evaluated by comparing simulations of grounded and marine-terminating ice sheets to various analytical and numerical benchmark solutions. A particular advantage of the LSM is its ability to explicitly track the moving margin and GRL while using a fixed grid finite-difference scheme. Our results demonstrate that the LSM is an accurate and robust approach for tracking the ice surface interface and terminus for advancing and retreating ice sheets, including the transient marine ice-sheet interface and GRL positions.

中文翻译：

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使用水平集方法模拟动态冰盖边界和接地线迁移

计算包括明确定义的不确定性界限的未来海平面预测需要能够稳健地模拟冰盖和冰川演变的模型。众所周知，冰流行为对动态冰边界的位置和几何形状很敏感，例如接地线 (GRL)、终点位置和冰面高程，因此任何此类模型都应以高精度跟踪这些界面。为了应对这一挑战，我们实施了一种数值方法，该方法使用水平集方法 (LSM)，该方法可以准确地模拟冰-空气和冰-水界面的演变，并捕捉冰盖几何形状的拓扑变化。通过将接地和海洋终止冰盖的模拟与各种分析和数值基准解决方案进行比较来评估这种方法。LSM 的一个特殊优势是它能够在使用固定网格有限差分方案的同时显式跟踪移动边距和 GRL。我们的研究结果表明，LSM 是一种准确且稳健的方法，用于跟踪冰面界面和前进和后退冰盖的终点，包括瞬态海洋冰盖界面和 GRL 位置。