Open AccessNonlinear generation and loss of infragravity wave energy
Author(s) -
Henderson Stephen M.,
Guza R. T.,
Elgar Steve,
Herbers T. H. C.,
Bowen A. J.
Publication year - 2006
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006jc003539
Subject(s) - infragravity wave , dissipation , energy balance , energy flux , geology , surf zone , physics , nonlinear system , swell , mechanics , wave propagation , mechanical wave , oceanography , longitudinal wave , optics , quantum mechanics , astronomy , thermodynamics
Nonlinear energy transfers with sea and swell (frequencies 0.05–0.40 Hz) were responsible for much of the generation and loss of infragravity wave energy (frequencies 0.005–0.050 Hz) observed under moderate‐ and low‐energy conditions on a natural beach. Cases with energetic shear waves were excluded, and mean currents, a likely shear wave energy source, were neglected. Within 150 m of the shore, estimated nonlinear energy transfers to (or from) the infragravity band roughly balanced the divergence (or convergence) of the infragravity energy flux, consistent with a conservative energy equation. Addition of significant dissipation (requiring a bottom drag coefficient exceeding about 10 −2 ) degraded the energy balance.