Non-linear fate of internal wave attractors

Hélène Scolan (1) , E. V. Ermanyuk (2, 1) , Thierry Dauxois (1)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 LIH - Lavrentyev Institute of Hydrodynamics

We present a laboratory study on the instability of internal wave attractors in a trapezoidal fluid domain filled with uniformly stratified fluid. Energy is injected into the system via standing-wave-type motion of a vertical wall. Attractors are found to be destroyed by parametric subharmonic instability (PSI) via a triadic resonance which is shown to provide a very efficient energy pathway from long to short length scales. This study provides an explanation why attractors may be difficult or impossible to observe in natural systems subject to large amplitude forcing.

Mots clés: internal wave; attractors; parametric subharmonic instability

Domaines: Formation de Structures et Solitons [nlin.PS]; Dynamique des Fluides [physics.flu-dyn]; Physique Atmosphérique et Océanique [physics.ao-ph]

Hélène Scolan, E. V. Ermanyuk, Thierry Dauxois. Non-linear fate of internal wave attractors. Physical Review Letters, 2013, 110 (23), pp.234501. ⟨hal-00821714⟩