Applied Physics Seminar | Wave Turbulence from a Simple Generic Model and for Understanding of Ocean Mixing

Abstract:
Wave turbulence describes the statistical behavior of a large ensemble of waves. The wave turbulence theory predicts a power-law spectrum as a result of nonlinear wave-wave interactions, which has applications to many physical wave systems. In this presentation, we discuss wave turbulence theory from two aspects. In the first part, we study finite size effect of wave turbulence in the context of a generic wave model Majda-McLaughlin-Tabak (MMT) equation in a two-dimensional periodic setting. We illustrate the dependence of dynamics on
the domain aspect ratio, as well as the turbulence closure model for high-order correlators. In the second part, we study the application of wave turbulence theory to oceanic internal gravity waves (IGWs), and focus on the quantification of downscale energy cascade that drives large-scale energy to ocean mixing. Several outstanding problems in the mechanisms of energy cascade are resolved by a careful calculation of the energy transfer by triad interactions in the
framework of wave kinetic equation.