MHD turbulence on a β-plane

Nicolas Leprovost, Eun Jin Kim

Research output: Chapter in Book/Report/Conference proceedingConference proceeding

Abstract

We provide a consistent theory of magnetic diffusion, momentum transport, and mixing in the interior of the sun by considering an idealised model of the tachocline, namely magnetohydrodynamics (MHD) turbulence on a beta; plane subject to a large scale shear (provided by the latitudinal differential rotation). In the strong magnetic field regime, we find that the turbulent viscosity and diffusivity are reduced by magnetic fields only, similarly to the two-dimensional MHD case (without Rossby waves). In the weak magnetic field regime, we find a crossover scale (LR) from a Alfvén dominated regime (on small scales) to a Rossby dominated regime (on large scales). For parameter values typical of the tachocline, LR is larger than the solar radius so that Rossby waves are unlikely to play an important role in the transport of magnetic field and angular momentum. This is mainly due to the enhancement of magnetic back-reaction by shearing which efficiently generates small scales, thus strong currents.

Original languageEnglish
Title of host publicationSOHO 18/GONG 2006/HELAS I Beyond the spherical Sun
Publication statusPublished - 1 Oct 2006
Externally publishedYes
EventSOHO 18/GONG 2006/HELAS I Beyond the spherical Sun - Sheffield, United Kingdom
Duration: 7 Aug 200611 Aug 2006

Publication series

NameEuropean Space Agency, (Special Publication) ESA SP
Volume624 SP
ISSN (Print)0379-6566

Conference

ConferenceSOHO 18/GONG 2006/HELAS I Beyond the spherical Sun
CountryUnited Kingdom
CitySheffield
Period7/08/0611/08/06

ASJC Scopus subject areas

  • Aerospace Engineering
  • Space and Planetary Science

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  • Cite this

    Leprovost, N., & Kim, E. J. (2006). MHD turbulence on a β-plane. In SOHO 18/GONG 2006/HELAS I Beyond the spherical Sun (European Space Agency, (Special Publication) ESA SP; Vol. 624 SP).