Skip to Main content Skip to Navigation
Journal articles

On the Unsteady Steepening of Short Gravity Waves Near the Crests of Longer Waves in the Absence of Generation or Dissipation

Abstract : The wave action equation provides a general framework that has been applied to the conservative hydrodynamic interactions between short and long surface waves. So far, only a limited range of solutions have been investigated. Here, we show that the wave action equation predicts that groups of short waves propagating over long monochromatic waves are unstable. We demonstrate theoretically and numerically, a new ratchet-type instability that progressively condenses short wave action around the long wave crests due to the correlation of phase speed and action fluctuations. This instability is of particular interest because it may lead to a higher probability of breaking for short waves propagating in directions within ±35 degrees of the dominant waves direction. This preferred breaking could has a strong impact on cross- and down-wind slope statistics and thus air-sea exchanges and remote sensing.
Document type :
Journal articles
Complete list of metadata

https://hal.univ-brest.fr/hal-03181322
Contributor : Laurent Hedoin Connect in order to contact the contributor
Submitted on : Thursday, March 25, 2021 - 3:13:34 PM
Last modification on : Monday, October 11, 2021 - 2:23:58 PM

Links full text

Identifiers

Collections

Citation

Charles Peureux, Fabrice Ardhuin, Pedro Veras Guimarães. On the Unsteady Steepening of Short Gravity Waves Near the Crests of Longer Waves in the Absence of Generation or Dissipation. Journal of Geophysical Research. Oceans, Wiley-Blackwell, 2021, 126 (1), ⟨10.1029/2020JC016735⟩. ⟨hal-03181322⟩

Share

Metrics

Record views

36