Absorption of waves by large scale winds in stratified turbulence

Abstract

The atmosphere is a nonlinear stratified fluid in which internal gravity waves are present. These waves interact with the flow, resulting in wave turbulence that displays important differences with the turbulence observed in isotropic and homogeneous flows. We study numerically the role of these waves and their interaction with the large scale flow, consisting of vertically sheared horizontal winds. We calculate their space and time resolved energy spectrum (a four-dimensional spectrum), and show that most of the energy is concentrated along a dispersion relation that is Doppler shifted by the horizontal winds. We also observe that when uniform winds are let to develop in each horizontal layer of the flow, waves whose phase velocity is equal to the horizontal wind speed have negligible energy. This indicates a nonlocal transfer of their energy to the mean flow. Both phenomena, the Doppler shift and the absorption of waves traveling with the wind speed, are not accounted for in current theories of stratified wave turbulence.

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• Hamiltonian formalism and the Garrett-Munk spectrum of internal waves in the ocean
• Geophysical turbulence and the duality of the energy flow across scales
• Quantification of the strength of inertial waves in a rotating turbulent flow
• Large-scale anisotropy in stably stratified rotating flows
• Helicity dynamics in stratified turbulence in the absence of forcing
• Restricted Equilibrium and the Energy Cascade in Rotating and Stratified Flows

Cited by in corpus (11)

• Dual constant-flux energy cascades to both large scales and small scales
• Waves and vortices in the inverse cascade regime of stratified turbulence with or without rotation
• Interplay of waves and eddies in rotating stratified turbulence and the link with kinetic-potential energy partition
• Succession of resonances to achieve internal wave turbulence
• Interplay between Alfvén and magnetosonic waves in compressible magnetohydrodynamics turbulence
• Inverse cascades and resonant triads in rotating and stratified turbulence
• Internal gravity waves in the energy and flux budget turbulence-closure theory for shear-free stably stratified flows
• Spatio temporal analysis of waves in compressively driven magnetohydrodynamics turbulence
• Single-particle dispersion in stably stratified turbulence
• Vertical dispersion of Lagrangian tracers in fully developed stably stratified turbulence
• 2D Internal Gravity Wave Turbulence