On Zonal Flow Formation in Plasmas and Fluids: Probing the Drift-Rossby Analogy

A well-recognized isomorphism exists between the equations describing drift waves within magnetized plasmas and Rossby waves on rotating planets. Both systems also exhibit large-scale zonal flows that arise due to nonlinear energy~transfer from smaller, turbulent motions. While such energy transfer has been recently characterized in plasmas (via Reynolds' stresses), similar data from geophysically relevant flows has been lacking. We report on a new experimental effort to characterize large-scale flow generation within a laboratory fluid. Results are discussed with the aim of better quantifying the analogy.