Hindman, B.W. orcid.org/0000-0001-7612-6628 and Jain, R. orcid.org/0000-0002-0080-5445 (2023) Overstable convective modes in a polytropic stellar atmosphere. The Astrophysical Journal, 943. 127. ISSN 0004-637X
Abstract
Within the convection zone of a rotating star, the presence of the Coriolis force stabilizes long-wavelength convective modes. These modes, which would have been unstable if the star lacked rotation, are called overstable convective modes or thermal Rossby waves. We demonstrate that the Sun's rotation rate is sufficiently rapid that the lower half of its convection zone could possess overstable modes. Further, we present an analytic solution for atmospheric waves that reside within a polytropic stratification. We explore in detail the properties of the overstable and unstable wave modes that exist when the polytrope is weakly unstable to convective overturning. Finally, we discuss how the thermal Rossby waves that reside within the convection zone of a star might couple with the prograde branch of the g modes that are trapped within the star's radiative zone. We suggest that such coupling might enhance the photospheric visibility of a subset of the Sun's g modes.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 07 Feb 2023 15:24 |
Last Modified: | 19 Oct 2023 16:01 |
Published Version: | http://dx.doi.org/10.3847/1538-4357/acaec4 |
Status: | Published |
Publisher: | American Astronomical Society |
Refereed: | Yes |
Identification Number: | 10.3847/1538-4357/acaec4 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:196112 |