Rotating waves of various azimuthal wavenumbers appear in magnetised spherical Couette flows in time-dependent states. The criteria for the flow to enter a time-dependent state are determined by the values of Reynolds and Hartmann numbers for a given geometric configuration of the spherical Couette system. These time-dependent states of the flow have been referred to as the radial jet, the return flow and the shear layer instabilities. In the present work, rotating waves in the flow during radial jet and return flow instabilities are observed.
The rotating waves both have an azimuthal wavenumber of 3, but vary in their spatial and temporal properties.Postprint (published version