Extreme waves induced by localized frequency and amplitude modulations in a random sea: an experimental study
- 1School of Civil Engineering, The University of Sydney, Sydney, Australia
- 2Department of Engineering, University of Ferrara, Ferrara, Italy
- 3Hakubi Center for Advanced Research, Kyoto University, Kyoto, Japan
- 4Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan
- 5Dynamics Group, Hamburg University of Technology, Hamburg, Germany
- 6Department of Mechanical Engineering, Imperial College London, London, United Kingdom
It is known that the modulation instability (MI) is a focusing mechanism responsible for the formation of rogue waves (RWs). Such dynamics are initiated from the injection of sidebands, which translates into an amplitude modulation (AM) of the wave field. The nonlinear stage of unstable wave evolution can be described by exact breather solutions of the nonlinear Schrödinger equation (NLSE). In fact, the amplitude modulation of such coherent RW structures is connected to a particular phase-shift seeded in the carrier wave, i.e. a particular form of localized frequency modulation (FM). By seeding only the local FM information of a deterministic breather to a regular wave train, our experiments show that such an FM localization can indeed trigger pure breather-type RW dynamics. Results of an experimental study on identifying spontaneous RWs in a random wave field by isolating the respective FM and AM dynamics will also be discussed.
How to cite: He, Y., Trillo, S., Chabchoub, A., Witt, A., and Hoffmann, N.: Extreme waves induced by localized frequency and amplitude modulations in a random sea: an experimental study, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11963, https://doi.org/10.5194/egusphere-egu23-11963, 2023.
