Analytical theory of tachocline transport at mid latitudes

N. Leprovost, E. J. Kim

Research output: Contribution to journalArticle

Abstract

We provide a theory of magnetic diffusion, momentum transport, and mixing in the solar tachocline by considering magnetohydrodynamics (MHD) turbulence on a β 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
Pages (from-to)1155-1157
Number of pages3
JournalAstronomische Nachrichten
Volume328
Issue number10
DOIs
Publication statusPublished - 27 Dec 2007
Externally publishedYes

Fingerprint

magnetic field
Rossby wave
magnetohydrodynamics
Rossby regimes
planetary waves
magnetic fields
magnetic diffusion
momentum
magnetohydrodynamic turbulence
angular momentum
diffusivity
shearing
viscosity
turbulence
crossovers
shear
radii
augmentation
parameter

Keywords

  • Sun: interior
  • Sun: rotation
  • Turbulence

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Analytical theory of tachocline transport at mid latitudes. / Leprovost, N.; Kim, E. J.

In: Astronomische Nachrichten, Vol. 328, No. 10, 27.12.2007, p. 1155-1157.

Research output: Contribution to journalArticle

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