Spectral energy balance of waves in the surf zone
By: Noel R. Russnogle
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1998
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 31
Description: The spectral energy balance of waves in the surf zone is examined with extensive measurements from the      Duck94 experiment. Cross-shore energy flux gradients are estimated from spectra observed with closely      spaced pressure sensors. Nonlinear energy exchanges between different wave components in the spectrum are      estimated from observed bispectra based on Boussinesq theory for near-resonant triad interactions. Dissipation      of wave energy in file poorly understood breaking process is inferred as the residual term in the spectral energy      balance. Analysis of the spectral energy balance shows that large decreases in energy flux observed at the      dominant wave frequencies as waves break over a sand bar are closely balanced by nonlinear energy transfers      to higher frequencies. That is, the decay of the spectral peak within the surf zone is a result of nonlinear energy      transfers rather than direct dissipation. At higher frequencies, observed energy flux gradients are small and do      not balance the nonlinear transfers of energy to high frequency components of the spectrum. This analysis      suggests that the spectrum is saturated at high frequencies, and thus, file energy that cascades through nonlinear      interactions to higher frequencies is dissipated in the high-frequency tail of file spectrum.
Notes: "March 1998."

Thesis advisor(s): Thomas H.C. Herbers.

Thesis (M.S. in Physical Oceanography) Naval Postgraduate School, March 1998.

Includes bibliographical references (p. 29-30).

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat Reader 7.0.

US Navy (USN) author.

dk/dk cc:9116 8/4/98.