A Hamiltonian formulation for long internal waves

A novel canonical Hamiltonian formalism is developed for long internal waves in a rotating environment. This includes the effects of background vorticity and shear on the waves. By restricting consideration to flows in hydrostatic balance, superimposed on a horizontally uniform background of vertical shear and vorticity, a particularly simple Hamiltonian structure arises, which can be thought of as describing a nonlinearly coupled infinite collection of shallow water systems. The kinetic equation describing the time evolution of the spectral energy of internal waves is subsequently derived. In the high-frequency limit, the Coriolis effects may be neglected, and a family of stationary Kolmogorov solutions can be found, which includes the Garrett–Munk spectrum of oceanic internal waves.