Anelastic torsional oscillations in Jupiter's metallic hydrogen region

Hori, K., Teed, R. J. and Jones, C.A. (2019) Anelastic torsional oscillations in Jupiter's metallic hydrogen region. Earth and Planetary Science Letters, 519, pp. 50-60. (doi: 10.1016/j.epsl.2019.04.042)

189167.pdf - Published Version
Available under License Creative Commons Attribution.



We consider torsional Alfvén waves which may be excited in Jupiter's metallic hydrogen region. These axisymmetric zonal flow fluctuations have previously been examined for incompressible fluids in the context of Earth's liquid iron core. Theoretical models of the deep-seated Jovian dynamo, implementing radial changes of density and electrical conductivity in the equilibrium model, have reproduced its strong, dipolar magnetic field. Analysing such models, we find anelastic torsional waves travelling perpendicular to the rotation axis in the metallic region on timescales of at least several years. Being excited by the more vigorous convection in the outer part of the dynamo region, they can propagate both inwards and outwards. When being reflected at a magnetic tangent cylinder at the transition to the molecular region, they can form standing waves. Identifying such reflections in observational data could determine the depth at which the metallic region effectively begins. Also, this may distinguish Jovian torsional waves from those in Earth's core, where observational evidence has suggested waves mainly travelling outwards from the rotation axis. These waves can transport angular momentum and possibly give rise to variations in Jupiter's rotation period of magnitude no greater than tens of milliseconds. In addition these internal disturbances could give rise to a 10% change over time in the zonal flows at a depth of 3000 km below the surface.

Item Type:Articles
Additional Information:We acknowledge support from the Japan Society for the Promotion of Science (JSPS) under Research Activity Start-up No. 17H06859, as well as from the Science and Technology Facilities Council of the UK, STFC grant ST/N000765/1.
Glasgow Author(s) Enlighten ID:Teed, Dr Robert
Authors: Hori, K., Teed, R. J., and Jones, C.A.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Mathematics
Journal Name:Earth and Planetary Science Letters
ISSN (Online):0012-821X
Published Online:20 May 2019
Copyright Holders:Copyright © 2019 Elsevier
First Published:First published in Earth and Planetary Science Letters 519:50-60
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record