Alberello Alberto, Părău Emilian, Chabchoub Amin
School of Mathematics, University of East Anglia, Norwich, NR4 7TJ, UK.
School of Civil Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
Sci Rep. 2023 Aug 22;13(1):13654. doi: 10.1038/s41598-023-40696-3.
Wave and sea ice properties in the Arctic and Southern Oceans are linked by feedback mechanisms, therefore the understanding of wave propagation in these regions is essential to model this key component of the Earth climate system. The most striking effect of sea ice is the attenuation of waves at a rate proportional to their frequency. The nonlinear Schrödinger equation (NLS), a fundamental model for ocean waves, describes the full growth-decay cycles of unstable modes, also known as modulational instability (MI). Here, a dissipative NLS (d-NLS) with characteristic sea ice attenuation is used to model the evolution of unstable waves. The MI in sea ice is preserved, however, in its phase-shifted form. The frequency-dependent dissipation breaks the symmetry between the dominant left and right sideband. We anticipate that this work may motivate analogous studies and experiments in wave systems subject to frequency-dependent energy attenuation.
北冰洋和南大洋的海浪及海冰特性通过反馈机制相互关联，因此了解这些区域的海浪传播对于模拟地球气候系统的这一关键组成部分至关重要。海冰最显著的影响是海浪以与其频率成正比的速率衰减。非线性薛定谔方程（NLS）是海浪的一个基本模型，它描述了不稳定模式（也称为调制不稳定性，MI）的完整增长 - 衰减周期。在此，使用具有特征性海冰衰减的耗散NLS（d - NLS）来模拟不稳定海浪的演化。然而，海冰中的MI以其相移形式得以保留。频率依赖的耗散打破了主导的左侧和右侧边带之间的对称性。我们预计这项工作可能会激发在受频率依赖能量衰减影响的波动系统中进行类似的研究和实验。
