PROPERTIES OF A 2-NONLINEARITY MODEL FOR DRIFT-WAVE TURBULENCE

The physical and mathematical consequences of a two-nonlinearity equation for drift-wave turbulence are discussed. The one-field model contains the linear electron Landau damping, the ion polarization drift nonlinearity, and, due to the E×B convected phase shift between density and potential fluctuations, an additional E×B nonlinearity. The latter changes the behavior of the system significantly. It is proved that for the two-nonlinearity model canonical variables do not exist within a Hamiltonian description. Numerical simulations show that the self-organization into large vortices is suppressed, and for dominating E×B nonlinearity a tendency to a zonal flow-like state is favored. © 1995 American Institute of Physics.