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.