Generation of zonal flows by drift waves in a dusty plasma

Abstract

It is well known that the spectra of electrostatic drift waves and convective cells are modified by the presence of stationary charged dust grains in a nonuniform dusty magnetoplasma. While modification of the drift wave frequency is caused by the modification of the equilibrium quasineutrality condition, purely damped convective cells of an electron–ion plasma obtain a real frequency due to the finite E×B0 currents in a nonuniform dusty magnetoplasma, where E is the wave electric field and B0 is the external magnetic field. It is shown that the ponderomotive force of electrostatic drift waves in a dusty plasma can generate zonal flows or dust convective cells. Explicit expressions for the growth rates of parametrically excited zonal flows are presented. The growth rates strongly depend on the dust parameters. Linearly unstable zonal flows can self-organize in the form of long-living vortices. Such nonlinear zonal flow structures constitute a dynamical paradigm for intermittency in drift wave driven long wavelength turbulence in a nonuniform dusty magnetoplasma.