Nondiffusive convective angular momentum transport ($⟨u_{\varphi }^{\prime }{\mathbf{u}}_m^{\prime }⟩$)

Rotating anisotropic convection can produce an azimuthal-meridional velocity correlation even without a gradient of the mean rotation rate. Its Reynolds stress transports angular momentum and can drive differential rotation, whereas a purely viscous closure only erases shear. Energy comes from the thermally driven convection; the Coriolis force changes the correlations but does no work on a parcel.