MONOPOLAR VORTICES IN ETA-I-MODES

Steadily propagating monopole vortex solutions to the eta(i)-mode equa tions are investigated. A general condition for non-linear vortex solu tions to be steadily propagating is derived by demanding that their ve locity is outside the regime of linear-wave propagation. The velocity of the vortex is determined by the ratio of the pressure perturbation and the electrostatic potential. Numerical studies show that such vort ices generally emerge from localized initial conditions. A new type of vortex interaction is also revealed.