The effect of sheared diamagnetic flow on turbulent structures generated by the Charney-Hasegawa-Mima equation

摘要

The generation of electrostatic drift wave turbulence is modeled by the Charney-Hasegawa-Mima equation. The equilibrium density gradient n(0) = n(0)(x) is chosen so that dn(0)/dx is nonzero and spatially variable (i.e., v(*e) is sheared). It is shown that this sheared diamagnetic flow leads to localized turbulence which is concentrated at max(del n(0)), with a large dv(*e)/dx inhibiting the spread of the turbulence in the x direction. Coherent structures form which propagate with the local v(*e) in the y direction. Movement in the x direction is accompanied by a change in their amplitudes. When the numerical code is initialized with a single wave, the plasma behavior is dominated by the initial mode and its harmonics. (C) 1999 American Institute of Physics. [S1070-664X(99)00510-8]. [References: 50]