Alternating zonal jets and energy fluxes in barotropic wind-driven gyres

The barotropic β-plane vorticity equation is considered under steady large scale (double-gyre) and small scale (stochastic) forcing. For both forcings, regimes are found in which alternating zonal jets appear. For steady large scale forcing, this regime is characterized by weak forcing and weak dissipation. Attention is focused on energy cascades due to the nonlinear and β terms and the jets are found to be associated with to a near compensation in these cascades over a range of wavenumbers. Additionally, interaction between flow forced at large scale and flow forced at small scale is examined.