Schematic diagram showing distinction between forms of global meridional circulation (red streamlines) and axisymmetric convective rings (blue). Global meridional circulation is driven by Coriolis forces from differential rotation, Reynolds stresses and buoyancy forces arising from thermodynamics, whereas axisymmetric convective rings are driven by buoyancy forces. Orientation of axisymmetric convective rings is influenced by Ω; they will generate Coriolis forces that will modify differential rotation.