The dynamics of internal wave resonance in periodically forced narrow basins

摘要: [1] Laboratory experiments were conducted to determine the steady state internal wave response of a periodically forced, density-stratified, basin characterized by both horizontal and vertical length scales known seiche period. The system was two-layer stratified subjected periodic forcing over wide frequency range. amplitude ratio (σf) mode one (H1) (σ1) governed response. For σf > σ1, higher-mode seiches observed; forσf < nonresonant forced H1 for → resonant observed. this regime, progressive nonlinear waves (NLIWs) formed upon seiche. When NLIWs amplitudes large, Kelvin-Helmholtz instabilities grew within troughs, leading significant diapycnal mixing interior. Resonant amplification most pronounced small because weakly have potential growth prior energy flux ultimate turbulent dissipation mixing. This observation suggests that each has maximum density that, when exceeded, leads cascade. modeled as driven underdamped harmonic oscillator, where damping coefficient interpreted sum effects dissipation.