title: Coherent structure phenomena in drift wave-zonal flow turbulence
abstract: Zonal flows are azimuthally symmetric plasma potential perturbations spontaneously generated from small-scale drift-wave fluctuations via the action of Reynolds stresses. We show that, after initial linear growth, zonal flows can undergo further nonlinear evolution leading to the formation of long-lived coherent structures which consist of self-bound wave packets supporting stationary shear layers. Such coherent zonal flow structures constitute dynamical paradigms for intermittency in drift-wave turbulence that manifests itself by the intermittent distribution of regions with a reduced level of anomalous transport.
authors.affiliation: Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, S7N 5E2 Canada.
authors.initials: AI
authors.lastname: Smolyakov
authors.initials: PH
authors.lastname: Diamond
authors.initials: M
authors.lastname: Malkov