Expérimental
Internal gravity waves are mechanical waves that propagate in the bulk of stratified fluids, such as the ocean or the atmosphere. When the density stratification is not uniform, internal waves can exhibit resonances, tunneling, and frequency-dependent transmissions. In the Arctic Ocean, global warming has been driving rapid ice cover loss, and led to an increase of seasonal internal gravity wave activity. In this region, intriguing structures known as thermohaline staircases form spatially periodic density profiles. Recently, laboratory experiments in periodic stratifications have shown the appearance of internal wave band gaps and surface states. The occurrence of such banded wave transmission through periodic thermohaline structures could profoundly affect energy transfer processes in the ocean, yet their modeling poses a fundamental challenge that requires the development of pluri-disciplinary approaches. During this internship, we will identify the characteristics of periodic stratification profiles that produce band gap opening. By drawing analogies from a variety of systems describing wave-matter interactions, such as multi-layered photonic materials and topological insulators, we will investigate the physical mechanisms that govern internal wave surface states formation. The internship can lead to an ANR funded PhD thesis focusing on energy transport in nonlinear regimes and internal wave localization-like phenomena with applications in geophysical fluids.