On the Response of Short Ocean Wave Components at a Fixed Wavenumber to Ocean Current Variations

Abstract This paper is concerned with the patterns in the degree of saturation of short wind-generated waves (at scales much smaller than those of the spectral peak but large compared with the capillary scales) that are produced by current variations in the presence of wind energy input and loss by breaking or by the formation of parasitic capillaries. It has two aims: the first is to provide a base for interpretation of patterns observed in synthetic aperture radar imagery in terms of current features. The second is to give analytical expressions for the magnitude of the variations in degree of saturation produced by given current fields so that, when appropriate quantitative measurements become available, better parametric representations of the energy loss rates can be developed. Particular care is taken to provide physically based representations of wind input and loss by wave breaking and a relatively convenient equation (4.2) is derived that specifies the distribution of the degree of saturation in ...