Internal Wave Breaking From Parametric Subharmonic Instability

Parametric subharmonic instability is an energy transfer mechanism between internal waves from large to small spatial scales. In this type of resonant triad interaction, a parent wave of higher frequency destabilizes leading to the growth of two daughter waves with lower frequencies. In a laboratory experiment, a full-depth wave generator forces a high frequency vertical mode-1 wave and parametric subharmonic instability generates large amplitude, high vertical wave number waves.