Model of intermittent zonal flow structure formation

Journal Article · Sat Nov 01 04:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3033708· OSTI ID:21251741

Anderson, Johan; Kim, Eun-jin ^[1]

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1. Department of Applied Mathematics, University of Sheffield, S3 7RH Sheffield (United Kingdom)

We present a theory the PDF tails of the zonal flow formation by assuming that a modon (a bipolar vortex) drives a zonal flow through the generalized Reynolds stress. We show that the PDF tails of zonal flow formation have exponential behavior {approx_equal}e{sup -{xi}}{sup {phi}{sub Z}{sub F}{sup 3}}, with the overall amplitude {xi} severely quenched by strong flow shear. It is found that stronger zonal flows are generated in ITG turbulence than Hasegawa-Mima (HM) turbulence as well as further from marginal stability. This suggests that although ITG turbulence has a higher level of heat flux, it also more likely generates stronger zonal flows, leading to a self-regulating system. It is also shown that shear flows can significantly reduce the PDF tails of structure formation.

• OSTI ID: 21251741
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1069; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLITUDES
HEAT FLUX
PLASMA
PLASMA DRIFT
PROBABILITY
REYNOLDS NUMBER
STABILITY
TURBULENCE