Turbulence and columnar vortex formation through inertial-wave focusing.

In this experimental and numerical study, we consider the role of inertial waves in the inverse energy cascade and the transfer of momentum in a rotating fluid. An oscillating torus generates two inertial-wave cones with their energy focusing at their apex. For high wave amplitudes, turbulence is generated locally around the focal point, resulting in angular momentum mixing and the generation of a columnar cyclonic vortex. The results suggest that nonlinear dynamics is essential for the wave induced momentum transport towards columnar vortices in rotating turbulence.