### Abstract

The theory of turbulence regulation by oscillatory zonal flows is presented for passive scalar field models. Zonal flows are assumed to have linear spatial variation of the form U=-xΩ (t) ŷ, where Ω (t) has amplitude Ωm and frequency ωz. The flux and fluctuation levels are found to scale as 1 ∫ ky Um ∫ and τ* ∫ ky Um ∫, respectively, for Ωm > ωz. Here, τ* = τη (ωz Ωm) 2 is the effective decorrelation time, τη = τ* (Ω=0), Um =x Ωm, and ky is the typical poloidal wave number of the turbulence. The effect of stochasticity of oscillatory zonal flows on shear decorrelation is discussed. The results complement the theory of turbulence regulation by low-frequency random zonal flows [E. Kim and P. H. Diamond, Phys. Rev. Lett 91, 075001 (2003)].

Original language | English |
---|---|

Article number | 022308 |

Journal | Physics of Plasmas |

Volume | 13 |

Issue number | 2 |

DOIs | |

Publication status | Published - 10 Feb 2006 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Condensed Matter Physics

### Cite this

*Physics of Plasmas*,

*13*(2), [022308]. https://doi.org/10.1063/1.2168154

**Theory of turbulence regulation by oscillatory zonal flows.** / Kim, Eun Jin.

Research output: Contribution to journal › Article

*Physics of Plasmas*, vol. 13, no. 2, 022308. https://doi.org/10.1063/1.2168154

}

TY - JOUR

T1 - Theory of turbulence regulation by oscillatory zonal flows

AU - Kim, Eun Jin

PY - 2006/2/10

Y1 - 2006/2/10

N2 - The theory of turbulence regulation by oscillatory zonal flows is presented for passive scalar field models. Zonal flows are assumed to have linear spatial variation of the form U=-xΩ (t) ŷ, where Ω (t) has amplitude Ωm and frequency ωz. The flux and fluctuation levels are found to scale as 1 ∫ ky Um ∫ and τ* ∫ ky Um ∫, respectively, for Ωm > ωz. Here, τ* = τη (ωz Ωm) 2 is the effective decorrelation time, τη = τ* (Ω=0), Um =x Ωm, and ky is the typical poloidal wave number of the turbulence. The effect of stochasticity of oscillatory zonal flows on shear decorrelation is discussed. The results complement the theory of turbulence regulation by low-frequency random zonal flows [E. Kim and P. H. Diamond, Phys. Rev. Lett 91, 075001 (2003)].

AB - The theory of turbulence regulation by oscillatory zonal flows is presented for passive scalar field models. Zonal flows are assumed to have linear spatial variation of the form U=-xΩ (t) ŷ, where Ω (t) has amplitude Ωm and frequency ωz. The flux and fluctuation levels are found to scale as 1 ∫ ky Um ∫ and τ* ∫ ky Um ∫, respectively, for Ωm > ωz. Here, τ* = τη (ωz Ωm) 2 is the effective decorrelation time, τη = τ* (Ω=0), Um =x Ωm, and ky is the typical poloidal wave number of the turbulence. The effect of stochasticity of oscillatory zonal flows on shear decorrelation is discussed. The results complement the theory of turbulence regulation by low-frequency random zonal flows [E. Kim and P. H. Diamond, Phys. Rev. Lett 91, 075001 (2003)].

UR - http://www.scopus.com/inward/record.url?scp=33644605941&partnerID=8YFLogxK

U2 - 10.1063/1.2168154

DO - 10.1063/1.2168154

M3 - Article

VL - 13

JO - Physics of Plasmas

JF - Physics of Plasmas

SN - 1070-664X

IS - 2

M1 - 022308

ER -