In this book we have given an overview of the role that ocean waves play in the problem of the interaction of atmosphere and ocean. However, in order to appreciate this role we had to elaborate on how ocean waves evolve in space and time. It was found that ocean waves evolve according to the well-known energy balance equation which states that the wave spectrum changes due to advection with the group velocity, and due to physical processes such as generation by wind, nonlinear transfer by four-wave interactions and dissipation by, for example, white capping. A detailed exposition of the derivation of the physical source functions was given, followed by a study of the impact of ocean waves on the atmospheric circulation and one aspect of the ocean circulation, namely storm surges. It was also pointed out that the study of the effects of ocean waves on ocean circulation is only beginning, but that promising improvements on its wind-driven component are expected in the near future.

This book was concluded by an extensive discussion of the verification of the ECMWF forecast of wave parameters, such as significant wave height. The impression from this verification study is that the quality of the ECMWF wave analysis and wave forecast is high, certainly if the results are put in a historical perspective.