skip to main content

Title: Zonal flow formation in the presence of ambient mean shear

The effect of mean shear flows on zonal flow formation is considered in the contexts of plasma drift wave turbulence and quasi-geostrophic turbulence models. The generation of zonal flows by modulational instability in the presence of large-scale mean shear flows is studied using the method of characteristics as applied to the wave kinetic equation. It is shown that mean shear flows reduce the modulational instability growth rate by shortening the coherency time of the wave spectrum with the zonal shear. The scalings of zonal flow growth rate and turbulent vorticity flux with mean shear are determined in the strong shear limit.
Authors:
;  [1]
  1. Center for Astrophysics and Space Sciences and Department of Physics, University of California San Diego, La Jolla, California 92093-0424 (United States)
Publication Date:
OSTI Identifier:
22408089
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; INSTABILITY GROWTH RATES; KINETIC EQUATIONS; PLASMA DRIFT; PLASMA INSTABILITY; SHEAR; TURBULENCE