The Interaction of Wind Waves and Internal Waves: Theoretical Analysis,
Abstract
A theoretical description is given of the behaviour of a broadband, small-amplitude wind-wave field to a perturbing internal wave velocity pattern. The theory includes the effect of the local wind. Specific predictions are made for the case of weak internal wave currents, and these predictions are compared to measurements. The theory predicts the magnitude of the mean-square-slope changes reasonably well, and it predicts the quadrant of the phases correctly. General features of the perturbed surface-wave energy spectrum integrated in an angle are also predicted reasonbly well, and comparisons are made of the theoretical and measured local integrated spectrum at roughened areas and at slick areas. Various conditions for two theoretical wind-wave spectra are used to predict the sensitivity (or magnitude of mean-square-slope change per unit-current change, suitably normalized) and phase of the slope field as functions of the wind. Representative calculations are also made to provide sensitivity and phase of mean-square height and mean-square curvature as functions of the wind. It is shown that the 'weak internal wave' analysis leads to a singular perturbation series, and a method for obtaining a uniformly valid expansion is given and explored in detail.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1975
- Accession Number
- ADA016648
Entities
People
- B. A. Hughes