Interaction between torsional Alfvén and QG-MC waves

Determine whether axisymmetric torsional Alfvén waves and non-axisymmetric quasi-geostrophic Magneto-Coriolis waves interact in the rapidly rotating, electrically conducting spherical shell configuration considered here, where waves are triggered by a super-rotating impulse of the inner core and propagate over a steady non-axisymmetric poloidal background magnetic field with insulating outer boundary and conducting inner core conditions.

Background

The paper investigates hydromagnetic wave dynamics in a rapidly rotating spherical shell representative of Earth’s outer core, linearized around a steady non-axisymmetric poloidal background magnetic field with zero base flow. An inner-core super-rotation impulse triggers multiple wave types, including torsional Alfvén waves (axisymmetric, non-dispersive) and quasi-geostrophic Magneto-Coriolis (QG-MC) waves (non-axisymmetric, dispersive).

While the authors characterize the propagation and transformation of QG-Alfvén wave packets into QG-MC waves near the core-mantle boundary and revisit the scaling of torsional wave thickness, they explicitly state uncertainty regarding potential dynamical interactions between torsional Alfvén waves and QG-MC waves. This leaves open whether these two wave families couple or remain dynamically independent under the conditions studied.