Nonlinear Dynamical Mechanisms Connecting Ocean Giant Waves and Wave Groups

Abstract

It is well known by direct observations that large ocean waves occur, more frequently among a wave group or group waves, than individually. Several statistical relationships among these two wave features have also been discussed in the past thirty years. However, the dynamical reasons (or mechanisms), why these two ocean wave features are often related, have seldom been discussed in sufficient details. The purpose of this paper are two fold: (1) to review various observations of wave groups and giant waves obtained from deep seas, coastal zones and laboratory experiments, and (2) to provide several significant physical and dynamical mechanisms for explaining the observed close relationship between these two important wave features. (3) to provide an example of a giant wave (called mad-dog waves) event, which resulted in the drowning of fishermen, occurred on the coast of Taiwan.