Shear flow driven tripolar vortices in a nonuniform electron-ion magnetoplasma with non-Maxwellian electrons

A set of nonlinear equations governing the dynamics of finite amplitude drift-ion acoustic-waves is derived for sheared ion flows parallel and perpendicular to the ambient magnetic field in the presence of Cairns and Kappa distributed electrons. It is shown that stationary solution of the nonlinear equations can be represented in the form of a tripolar vortex for specific profiles of the equilibrium sheared flows. The tripolar vortices are, however, observed to form on a scale of the order of ion Larmor radius ρ _i which is calculated to be around a Kilometer for the plasma parameters found in the Saturn’s E-ring. The relevance of the present investigation in planetary environments is also pointed out.