Pontin, CM, Barker, AJ orcid.org/0000-0003-4397-7332, Hollerbach, R et al. (2 more authors) (2020) Wave propagation in semiconvective regions of giant planets. Monthly Notices of the Royal Astronomical Society, 493 (4). pp. 5788-5806. ISSN 0035-8711
Abstract
Recent observations of Jupiter and Saturn suggest that heavy elements may be diluted in the gaseous envelope, providing a compositional gradient that could stabilise ordinary convection and produce a stably-stratified layer near the core of these planets. This region could consist of semi-convective layers with a staircase-like density profile, which have multiple convective zones separated by thin stably-stratified interfaces, as a result of double-diffusive convection. These layers could have important effects on wave propagation and tidal dissipation that have not been fully explored. We analyse the effects of these layers on the propagation and transmission of internal waves within giant planets, extending prior work in a local Cartesian model. We adopt a simplified global Boussinesq planetary model in which we explore the internal waves in a non-rotating spherical body. We begin by studying the free modes of a region containing semi-convective layers. We then analyse the transmission of internal waves through such a region. The free modes depend strongly on the staircase properties, and consist of modes with both internal and interfacial gravity wave-like behaviour. We determine the frequency shifts of these waves as a function of the number of steps to explore their potential to probe planetary internal structures. We also find that wave transmission is strongly affected by the presence of a staircase. Very large-wavelength waves are transmitted efficiently, but small-scale waves are only transmitted if they are resonant with one of the free modes. The effective size of the core is therefore larger for non-resonant modes.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. This is an author produced version of an article published in Monthly Notices of the Royal Astronomical Society. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | planets and satellites; gaseous planets ; hydrodynamics ; waves ; planets and satellites; physical evolution ; asteroseismology ; methods; analytical |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Funding Information: | Funder Grant number STFC (Science and Technology Facilities Council) ST/R00059X/1 STFC (Science and Technology Facilities Council) ST/S000275/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Mar 2020 16:34 |
Last Modified: | 23 Apr 2020 12:31 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/mnras/staa664 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:158086 |