发表机构
University of Exeter; Jagiellonian University（埃克塞特大学; 雅盖隆大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文修正了发散耦合冰流模型的体积守恒误差，通过分岔分析和庞加莱截面揭示频率锁定与混沌，并对比汇聚耦合模型，表明拓扑结构显著影响冰流变率。
AI 中文摘要
快速流动的冰川，即冰流，通过其底部的热机械耦合控制着冰盖质量损失的大部分，这种耦合可诱发基底润滑和高度可变的流动。即使相当简单的模型也能表现出“狂欢-净化”振荡。近期研究强调，发散冰流之间的耦合也能引发混沌变率。本文回归具有发散耦合的冰流模型，以识别并修正一些物理不一致性，最显著的是全局体积守恒误差。我们提出并验证了一个修正的发散耦合（DC）模型，确保严格的质量平衡。分岔分析和庞加莱截面揭示了先前未识别的复杂频率锁定（阿诺德舌头）、周期加级联以及与环面破裂相关的混沌。我们还考虑了一个等效的汇聚耦合（CC）模型，在该模型中未发现混沌变率的证据。这些发现表明特定拓扑结构对冰流变率的重要性。
英文摘要
Fast-flowing glaciers, known as ice streams, control the majority of ice sheet mass loss due to thermomechanical coupling at their base, which can induce basal lubrication and highly variable flow. Even quite simple models can show `binge-purge' oscillations. Recent work has highlighted that coupling between divergent ice streams can also give rise to chaotic variability. In this paper, we return to a model of ice streams with a divergent coupling to identify and correct some physical inconsistencies, most notably a global volume conservation error. We propose and validate a revised Divergent Coupling (DC) model that ensures rigorous mass balance. Bifurcation analysis and Poincaré sections reveal previously unidentified complex frequency-locking (Arnold tongues), a period-adding cascade and chaos associated with torus breakdown. We also consider an equivalent model with a Convergent Coupling (CC), where we find no evidence of chaotic variability. These findings suggest the importance of specific topologies on ice stream variability.
Comments40 pages, 13 Figures
