Vendredi 9 juin 2023 de 11h30 à 12h30 – Amphi. du LCI

Ocean Exploration: Energetics, Acoustic Effects, and Imaging of Internal Waves

Likun Zhang

National Center for Physical Acoustics and Department of Physics and Astronomy
University of Mississippi, USA

Ocean exploration plays a vital role in climate studies. In particular, oceanic internal waves are waves in the ocean interior that transfer heats and lead to ocean mixing. These waves also affect the fidelity of acoustic signals used in communication and imaging in the oceans. With the aid of knowledge in fluid dynamics and acoustics, we take the approaches of simulations, laboratory measurements, and field data analysis to investigate dynamics and energetics of oceanic internal waves and their effects on underwater sound propagation. The investigations also improve our ability of using acoustic signals to image ocean dynamics. This talk will report our simulations on generation of internal waves by tidal flow over submarine topography such as ridges and seamounts, our laboratory experiments on sound propagation through internal waves produced by a wave generator placed in a density-stratified fluid, and our analysis of acoustic signals in existing marine seismic dataset to study the temporal evolution of internal wave fields in high-resolution acoustic images.