Semiempirical Dissipation Source Functions for Ocean Waves. Part 1: Definition, Calibration, and Validation
Abstract
New parameterizations for the spectral dissipation of wind-generated waves are proposed. The rates of dissipation have no predetermined spectral shapes and are functions of the wave spectrum and wind speed and direction, in a way consistent with observations of wave breaking and swell dissipation properties. Namely, the swell dissipation is nonlinear and proportional to the swell steepness, and dissipation due to wave breaking is nonzero only when a nondimensional spectrum exceeds the threshold at which waves are observed to start breaking. An additional source of short-wave dissipation is introduced to represent the dissipation of short waves due to longer breaking waves. A reduction of the wind-wave generation of short waves is meant to account for the momentum flux absorbed by longer waves. These parameterizations are combined and calibrated with the discrete interaction approximation for the nonlinear interactions. Parameters are adjusted to reproduce observed shapes of directional wave spectra, and the variability of spectral moments with wind speed and wave height. Some systematic defects are still present, but, overall, the parameterizations probably yield the most accurate estimates of wave parameters to date.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2010
- Accession Number
- ADA536936
Entities
People
- Aaron Roland
- Alexander V. Babanin
- Andre Van Der Westhuysen
- Erick Rogers
- Fabrice Ardhuin
- Fabrice Collard
- Jean-francois Filipot
- Jean-michel Lefevre
- Lotfi Aouf
- Pierre Queffeulou
- Rudy Magne
Organizations
- United States Naval Research Laboratory