On the Effect of Planetary Rotation on Shear and Density Layers in Stratified Flows

The effect of the Coriolis forces on the dynamicsof shear and density layers instratified flows is investigated, an effectthat has not been taken into account inmost previous studies of turbulence-meanfield or wave-mean field interactions.For instance, recent studies have shownthat shear and density layers can grow inthe presence of turbulence in a stronglystratified fluid but the effect of planetaryrotation was not taken into account. Toaddress this problem, wave-mean flowinteraction in a stratified fluid is hereinvestigated in the presence of rotation usingdirect numerical simulation. The results showthat the wave-mean flow interactionand the formation of layers is less intensewhen rotation is present because thehorizontal mean motions are deviated by theCoriolis forces, which tends to reducethe distortion of the wave field, and thusthe wave-induced fluxes of buoyancy andmomentum. This effect appears even when therotation rate is weak.