Instabilities of Internal Gravity Wave Beams

Abstract

Internal gravity waves play a primary role in geophysical fluids: they contribute significantly to mixing in the ocean and they redistribute energy and momentum in the middle atmosphere. Until recently, most studies were focused on plane wave solutions. However, these solutions are not a satisfactory description of most geophysical manifestations of internal gravity waves, and it is now recognized that internal wave beams with a confined profile are ubiquitous in the geophysical context. We will discuss the reason for the ubiquity of wave beams in stratified fluids, related to the fact that they are solutions of the nonlinear governing equations. We will focus more specifically on situations with a constant buoyancy frequency. Moreover, in light of recent experimental and analytical studies of internal gravity beams, it is timely to discuss the two main mechanisms of instability for those beams. i) The Triadic Resonant Instability generating two secondary wave beams. ii) The streaming instability corresponding to the spontaneous generation of a mean flow.

References in corpus (10)

• A novel internal waves generator
• Energy cascade in internal wave attractors
• New wave generation
• Internal wave attractors examined using laboratory experiments and 3D numerical simulations
• Laboratory experiments on the generation of internal tidal beams over steep slopes
• Quantitative laboratory observations of internal wave reflection on ascending slopes
• Finite-size effects in parametric subharmonic instability
• Experimental observation of a strong mean flow induced by internal gravity waves
• Inherently Unstable Internal Gravity Waves due to Resonant Harmonic Generation
• Boundary streaming with Navier boundary condition

Cited by in corpus (21)

• Damping of quasi-2D internal wave attractors by rigid-wall friction
• Succession of resonances to achieve internal wave turbulence
• Shear-induced breaking of internal gravity waves
• Internal Wave Attractors in 3D Geometries : trapping by oblique reflection
• Scale effects in internal wave attractors
• Internal wave turbulence in a stratified fluid with and without eigenmodes of the experimental domain
• Three-dimensionality of the triadic resonance instability of a plane inertial wave
• On the Holton-Lindzen-Plumb model for mean flow reversals in stratified fluids
• The long view of triadic resonance instability in finite-width internal gravity wave beams
• Energy budget in internal wave attractors experiment
• Particle transport induced by internal wave beam streaming in lateral boundary layers
• Energy spectra of non-local internal gravity wave turbulence
• Mean flow generation by three-dimensional non-linear internal wave beams
• Triadic resonant instability in confined and unconfined axisymmetric geometries
• Variational Mode Decomposition for estimating critical reflected internal wave in stratified fluid
• Lagrangian irreversibility and energy exchanges in rotating-stratified turbulent flows
• Wave-kinetic dynamics of forced-dissipated turbulent internal gravity waves
• Internal waves in aquariums with characteristic corners
• Laboratory observation of internal gravity wave turbulence in a three-dimensional, large-scale facility
• Spontaneous superharmonic internal wave generation by modal interactions in uniform and nonuniform stratifications
• The stability of propagating plane inertial waves in rotating fluids