Wind waves steepening in coastal areas

The focusing of waves in coastal zones can represent a significant threat to coastal installations and to the residents in these areas. Indeed, a number of incidents related to extreme wave formation in shallow water have been reported lately. The most famous case is the famed “Bondi Black Sunday” event in 1938. During this incident, three rogue waves hit the shore in Bondi Beach washing out up to two hundred swimmers and killing five.

The dynamics of ocean water waves can be described within the context of weakly nonlinear evolution equation such the nonlinear Schrödinger or its extended versions. The advantage in working with such a framework becomes obvious, when performing laboratory and numerical experiments. Due to its integrability it allows to clearly define experimental initial conditions while the numerical simulations are fast. Most importantly, a very good agreement is expected as revealed by the latest laboratory tests.

The research topic proposed aims at understanding the effect of wind and beach geometries in the focusing of nearshore waves. The developed theoretical framework, based on the weakly nonlinear Schrödinger model, will be validated with laboratory experiments that are going to be conducted in the wave flume installed at the School of Civil Engineering at The University of Sydney.

It is expected that the research will have a significant impact in the field of coastal engineering as well as in other interdisciplinary fields of physics such as optics and plasma physics. A long-term goal is to determine specific wave-wind-bottom features responsible for significant wave focusing and to assemble these into a short-term extreme event prediction tool.

Prof Jérôme Kasparian, Non-linearity and Climate Group

Prof Amin Chabchoub, Centre for Wind Waves and Water / School of Civil Engineering / Faculty of Engineering and Information Technologies