Distributions Of Breaking Wave Parameters

Wind wave breaking is an important component in the process of air-sea interaction, playing a primary role in the exchange of mass, momentum and energy between the atmosphere and the ocean. It is also a hot and difficult question of physical oceanography. Because of the complexities of wave breaking, people can not give accurate definition of breaking wave and a uniformly breaking criteria.Wave steep is a frequently-used breaking criteria which has explicit physical meaning. We define wave steep as wave height division by wave length. Therefore, study the distributions of wave parameters, such as wave height, wave length, wave period, are the foundation of building effectively breaking criteria.Based on the lab experiment, this research consists mainly of 3 parts:In the first part , based on the synchronous in situ trigger signal for breaking events,using multi-breaking criterion to classify the breaking and non-breaking waves, the characteristic differences between breaking and non-breaking waves were examined. The results indicate that: distributions of dynamic criterion and kinematic criterion on breakers and non-breakers were well separated which means this two are effective breaking criteria. In second part, the characteristic of wave height ,wave period'distributions between breakers and non breakers were examied. The results indicate that: wave height and wave steep of breaking wave has large value and small variance value compared with non-breaking wave. On the contrary, wave steep of breaking wave has small value. In third part, probability distribution function of breaking wave'height and period are fitted and the availability of the fitting is verified on the base of the reference to others'researches. The results indicate that: Weibull distribution that their parameters are estimated by maximum likelihood estimation could agree well with our experimental wave height distribution. And their shape parameter increases at higher velocity. Adequate distribution to describe breaking wave's period did not find .