Inertia-gravity waves generated by near balanced flow in 2 layershallow water turbulence on the beta plane

Using a fine resolution numerical model (2×4000² grid-points) of the two layer shallow-water equations of the mid-latitude beta plane dynamics, it is shown that there is no sudden breakdown of balance in the turbulent enstrophy-cascade but a faint and continuous emission of inertia gravity waves. The wave energy accumulates in the equator-ward region of the domain due to the Coriolis parameter depending on latitude and the dispersion relation of inertia gravity waves.