Zonal Flow as Patter Formation
Authors: Jeffrey B. Parker and John A. Krommes
Abstract:
Zonal flows are well known to arise spontaneously out of turbulence. We show that for statistically averaged equations of the stochastically forced generalized Hasegawa-Mima model, steady-state zonal flows and inhomogeneous turbulence fit into the framework of pattern formation. There are many implications. First, the zonal flow wavelength is not unique. Indeed, in an idealized, infinite system, any wavelength within a certain continuous band corresponds to a solution. Second, of these wavelengths, only those within a smaller subband are linearly stable. Unstable wavelengths must evolve to reach a stable wavelength; this process manifests as merging jets.
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Submitted to: Physics of Plasmas (August 2013)
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Download PPPL-4943 (pdf 1.4 MB 5 pp)
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