Turbulent drift-wave dynamics and coherent structures

The dynamics of decaying 2D drift-wave turbulence are investigated numerically in the absence of assumptions in the relation between the electrostatic potential and the density response, with the result that nonlinear coupling dominates this in the hydrodynamic region about the resonant surface. Outside this region, an adiabatic relation prevails. Thus, the nonadiabatic density response is small away from the resonant surface but can be as large as the potential fluctuation near it. This response is much more self-coherent than either the density or potential fluctuations and decays more slowly as well, becoming dominant