Contribution to the study of the statistical structure and mechanisms of wind wave generation

The main objective of this research is the estimation of 'excitation' functions on which the spectral energy density of the wind wave field depends by the means of the radiative transfer equation. The experimental results presented in this report come from measurements taken in two wind tunnels simulating oceans-atmosphere interactions (respectively 8 m and 40 m in length). The first part of the paper is devoted to a critical review of a number of theoretical data (equations of air and water movements, theoretical models of generation, amplification, saturation of wind waves), which generally serve as a basis for studies on the transfer of mechanical energy between the atmosphere and the ocean. The second part is a brief description of the experimental installations, with particular emphasis on the provisions adopted therein. The methods of acquisition and processing of experimental data are then described, with particular reference to the calculation of errors in the estimation of statistical quantities. In the third part, the obtained results are presented and discussed. If this study is essentially experimental, much of the work, however, has been devoted to the confrontation between measurement results and various theoretical concepts. This confrontation concerns more specifically the results on the statistical structure of the movement of the air-water interface. However, the experience-theory comparison requires the development of numerical methods, which could not be developed in the course of the research project. Therefore, the study was limited to the simplest theoretical models. A special interest was devoted to the possible differences between these experimental results and those from other authors, mainly with observations in natural sites. The last part presents a number of conclusions and suggestions for further researches