Strong Interactions in Wind-Wave Fields

Abstract

The theory of weak resonant non-linear interactions among surface wave components has been developed greatly in recent years as several contributions to this symposium have testified. The time scale for these interactions is relatively long, characteristically of the order hundreds of wave periods, but nevertheless in certain circumstances they can be influential in spectral transfers of action and energy and in the progression of the spectral peak towards lower frequencies. At the same time, however, there are also strong interactions among wave groups that can result in rapid and strong modification of the wave characteristics, perhaps sporadically leading to wave breaking and the formation of whitecaps, perhaps more generally on a smaller scale. The theme of this paper is to explore the nature and consequences of some of these processes, particularly as they influence the turbulent fluxes across the sea surface.