Frontiers_data.zip

Internal solitary waves in polar regions are a developing study that has attracted much interest. It is important to understand how sea ice affects them, as that may have a profound influence on human activities and the environment. In this study, experiments on internal solitary waves and two types of sea ice (ice sheet and ice keel) are presented. After showing that the Korteweg–de Vries (KdV) equation is more suitable than the Benjamin–Ono (BO) equation for simulating the waves studied, this paper presents corresponding simulations using the variable-coefficient Korteweg-de Vries (vKdV) equation, a derivation of the KdV equation. The sharp vertices of the ice result in occasional inconsistency with the vKdV predictions. Nonetheless, the vKdV equation is still suitable for modelling under sea ice, giving generally accurate results that are adequate to assist further studies. Both experiments and simulations provide evidence for wave deformation, oscillation occurring at the back of the wave, and decrease in amplitude, the latter suggesting possibilities of energy dissipation or emission of very small, unobservable linear waves. In fact, this is the first time the vKdV equation is applied to investigate the impacts of sea ice on internal solitary waves.

极地内孤立波是当前广受关注的新兴研究领域。厘清海冰对内孤立波的影响机制至关重要，因为该机制或对人类活动与海洋环境产生深远影响。本研究开展了内孤立波与两类海冰（冰盖（ice sheet）、冰脊（ice keel））的模拟实验。在证实Korteweg-de Vries（KdV）方程相较于Benjamin-Ono（BO）方程更适用于本研究涉及的内孤立波模拟后，本文采用KdV方程的衍生形式——变系数Korteweg-de Vries（vKdV）方程开展了对应模拟实验。海冰尖锐的顶点结构偶尔会导致模拟结果与vKdV方程的预测出现偏差。尽管如此，vKdV方程仍适用于海冰环境下的内孤立波模拟，其整体模拟结果精度较高，足以支撑后续相关研究。实验与模拟结果均证实了内孤立波发生形变、波后出现振荡以及振幅衰减的现象，其中振幅衰减现象暗示了能量耗散或极微小不可观测线性波辐射的可能性。事实上，本研究首次将vKdV方程应用于海冰对内孤立波影响的相关研究中。