Linear asymptotic stability of geophysical channeled flows in the presence of arbitrary longitude-shaped perturbations

Sufficient conditions for the linear asymptotic stability of large scale wind-driven oceanic flows are derived in the presence of arbitrary longitude-shaped perturbations. Criteria work when both bottom dissipation and lateral diffusion of relative vorticity are simultaneously present. The stability is controlled by the maximum of the shear of the basic flow and by the maximum of its meridional derivative and involves the dissipation-diffusion coefficients.