Spontaneous near-inertial wave generation from mesoscale eddy: Nonlinear forcing mechanism

The spontaneous generation of near-inertial waves (NIWs) from quasi-geostrophic mesoscale eddies in a stratified fluid is investigated and the process mechanism clarified by numerical modeling theoretical analysis. Mesoscale eddies, as slow balance flows, are inevitably accompanied unbalanced oscillations (NIOs) their long period evolution. A eddy supplies kinetic energy to NIOs through its interaction with perturbations, which exist universally world oceans. Afterward, NIWs generated spontaneously via nonlinear coupling NIOs. baroclinicity an essential condition this NIW mechanism. resonance enables internal wave continuum be dominated NIWs, share same horizontal wavenumbers eddy. After generation, radiate toward center remain stationary whole, relative propagating Generally, anticyclonic can emit much stronger than does cyclonic intensity strengthens exponentially Rossby number. essence between flows accompanying fast motions. It represents effective pathway for sinks makes non-negligible contribution global energy.