Nonlinear coupling of low-frequency waves in finite beat magnetoplasma

A set of three nonlinear equations describing the coupling of convective cells, electrostatic, and magnetic drift waves is presented. If the plasma β is smaller than the square of the inverse aspect ratio (a/R)2, the system reduces to the mode-coupling equations for the electrostatic drift wave turbulence. For β >> (a/R)2, the magnetostatic modes and the convective cells are strongly coupled. When β ∼ (a/R)2, then the system describes the drift-tearing modes. Nonlinear destabilization of the drift-tearing mode in the presence of an ensemble of static magnetic turbulence is investigated. (author). 22 refs