Astoul, A. orcid.org/0000-0002-8561-0769 and Barker, A. J. (2024) Interactions between tidal flows and magnetic fields in stellar/planetary convective envelopes. [Preprint - arXiv]
Abstract
Stars and gaseous planets are magnetised objects but the influence of magnetic fields on their tidal responses and dissipation rates has not been well explored. We present the first exploratory nonlinear magnetohydrodynamic (MHD) simulations of tidally-excited waves in incompressible convective envelopes harbouring an initial dipolar magnetic field. Simulations with weak magnetic fields exhibit tidally-generated differential rotation in the form of zonal flows (like in the purely hydrodynamic case) that can modify tidal dissipation rates from prior linear predictions. Moreover, tidal waves and zonal flows affect the amplitude and structure of the magnetic field, notably through creation of toroidal fields via the Ω-effect. In contrast, simulations with strong magnetic fields feature severely inhibited zonal flows, due to large-scale magnetic stresses, excitation of torsional waves, or magnetic instabilities. We predict that the different regimes observed for weak and strong magnetic fields may be both relevant for low-mass stars when using turbulent values of the magnetic Prandtl number.
Metadata
Item Type: | Preprint |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This is an open access preprint under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | tidal interactions, magneto-hydrodynamics, waves, star-planet interactions, low mass stars, extrasolar gaseous giant planets, close binary stars |
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 Leverhulme Trust ECF-2022-362 |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Jan 2025 15:00 |
Last Modified: | 21 Jan 2025 15:09 |
Published Version: | https://arxiv.org/abs/2411.16534 |
Identification Number: | 10.48550/arXiv.2411.16534 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:222019 |
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