Gravity wave-driven flows in the solar tachocline

Eun Jin Kim, K. B. MacGregor

Research output: Contribution to journalArticle

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1 Downloads (Pure)

Abstract

We present results from time-dependent hydrodynamic calculations of the interaction between internal gravity waves and the mean radial differential rotation in the solar tachocline. Such waves are thought to be generated by turbulent fluid motions at the base of the convection zone. Our simplified model treats the effects of wave forcing, produced by radiative damping of downward propagating disturbances, on the rotational shear flow in the region immediately below the convection zone. We have used the model to investigate the dependence of the computed flow properties on the values assumed for the wave frequency, the horizontal component of the wavevector, the initial wave velocity amplitude, and the viscosity of the background medium. Our results indicate that if the first three of these quantities are held fixed, stationary shear flow solutions are obtained for viscosities larger than a parameter-dependent critical value. If the viscosity is continuously decreased from this value, the flow undergoes a succession of dramatic transformations, first becoming periodic, then quasi-periodic, and ultimately chaotic when the viscosity is made sufficiently small. We discuss the implications of these results for the recently reported time variability of the angular velocity of rotation within the solar tachocline.

Original languageEnglish
Pages (from-to)L117–L120
Number of pages4
JournalAstrophysical Journal
Volume556
DOIs
Publication statusPublished - 13 Jul 2001
Externally publishedYes

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gravity waves
gravity wave
viscosity
shear flow
convection
internal wave
angular velocity
damping
wave velocity
disturbances
hydrodynamics
disturbance
fluid
fluids
interactions

Bibliographical note

Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders.

Keywords

  • Hydrodynamics
  • MHD
  • Sun: interior
  • Sun: magnetic fields
  • Sun: rotation
  • Waves

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Gravity wave-driven flows in the solar tachocline. / Kim, Eun Jin; MacGregor, K. B.

In: Astrophysical Journal, Vol. 556, 13.07.2001, p. L117–L120.

Research output: Contribution to journalArticle

Kim, Eun Jin ; MacGregor, K. B. / Gravity wave-driven flows in the solar tachocline. In: Astrophysical Journal. 2001 ; Vol. 556. pp. L117–L120.
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