Energy dissipation in the inner surf zone: new insights from LiDAR-based roller geometry measurements

Kevin Martins, Christopher Blenkinsopp, Rolf Deigaard, Hannah E. Power

Research output: Contribution to journalArticle

4 Citations (Scopus)
11 Downloads (Pure)

Abstract

The spatial and temporal variation of energy dissipation rates in breaking waves controls the mean circulation of the surf zone. As this circulation plays an important role in the morphodynamics of beaches, it is vital to develop better understanding of the energy dissipation processes in breaking and broken waves. In this paper we present the first direct field measurements of roller geometry extracted from a LiDAR dataset of broken waves to obtain new insights into wave energy dissipation in the inner surf zone. We use a roller model to show that most existing roller area formulations in the literature lead to considerable overestimation of the wave energy dissipation, which is found to be close to, but smaller than, the energy dissipation in a hydraulic jump of the same height. The role of the roller density is also investigated, and we propose that it should be incorporated into modified roller area formulations until better knowledge of the roller area and its link with the mean roller density is acquired. Finally, using previously published results from deep-water wave breaking studies, we propose a scaling law for energy dissipation in the inner surf zone, which achieves satisfactory results at both the time-averaged and wave-by-wave scales.
Original languageEnglish
Pages (from-to)3386-3407
Number of pages22
JournalJournal of Geophysical Research : Oceans
Volume123
Issue number5
Early online date19 Apr 2018
DOIs
Publication statusPublished - 22 Jun 2018

Fingerprint

surf zone
energy dissipation
geometry
wave energy
breaking wave
water wave
wave breaking
morphodynamics
temporal variation
beach
spatial variation
deep water
hydraulics

Keywords

  • Breaking waves
  • Energy dissipation
  • Inner surf zone
  • LiDAR scanner
  • Surface roller

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Palaeontology

Cite this

Energy dissipation in the inner surf zone: new insights from LiDAR-based roller geometry measurements. / Martins, Kevin; Blenkinsopp, Christopher; Deigaard, Rolf; Power, Hannah E.

In: Journal of Geophysical Research : Oceans, Vol. 123, No. 5, 22.06.2018, p. 3386-3407.

Research output: Contribution to journalArticle

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