Reflection and Ducting of Gravity Waves Inside the Sun

K. B. MacGregor, Tamara Rogers

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Internal gravity waves excited by overshoot at the bottom of the convection zone can be influenced by rotation and by the strong toroidal magnetic field that is likely to be present in the solar tachocline. Using a simple Cartesian model, we show how waves with a vertical component of propagation can be reflected when traveling through a layer containing a horizontal magnetic field with a strength that varies with depth. This interaction can prevent a portion of the downward traveling wave energy flux from reaching the deep solar interior. If a highly reflecting magnetized layer is located some distance below the convection zone base, a duct or wave guide can be set up, wherein vertical propagation is restricted by successive reflections at the upper and lower boundaries. The presence of both upward and downward traveling disturbances inside the duct leads to the existence of a set of horizontally propagating modes that have significantly enhanced amplitudes. We point out that the helical structure of these waves makes them capable of generating an α-effect, and briefly consider the possibility that propagation in a shear of sufficient strength could lead to instability, the result of wave growth due to over-reflection.

Original languageEnglish (US)
Pages (from-to)417-436
Number of pages20
JournalSolar Physics
Volume270
Issue number2
DOIs
StatePublished - Jun 2011

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gravity waves
gravity wave
sun
ducts
propagation
convection
magnetic field
solar interior
internal wave
wave energy
energy flux
magnetic fields
traveling waves
disturbances
shear
disturbance
interactions
energy

Keywords

  • Internal gravity waves
  • Magnetohydrodynamics
  • Solar interior
  • Solar magnetic field

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Reflection and Ducting of Gravity Waves Inside the Sun. / MacGregor, K. B.; Rogers, Tamara.

In: Solar Physics, Vol. 270, No. 2, 06.2011, p. 417-436.

Research output: Contribution to journalArticle

MacGregor, K. B. ; Rogers, Tamara. / Reflection and Ducting of Gravity Waves Inside the Sun. In: Solar Physics. 2011 ; Vol. 270, No. 2. pp. 417-436.
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