Nonlinear deep water waves: Theory and experiment

The evolution and interaction of nonlinear wavepackets on deep water is studied both theoretically and experimentally. The nonlinear Schrödinger equation, first derived in this context by Hasimoto and Ono, is shown to be a special case of Whitham's theory. The exact solution to this equation predicts the existence of stable envelope solitons, which is indeed verified by laboratory experiments. A comparison between laboratory data and a numerical solution of the nonlinear Schrödinger equation is also given.