---
_id: '11609'
abstract:
- lang: eng
  text: "Context. Stellar interiors are the seat of efficient transport of angular
    momentum all along their evolution. In this context, understanding the dependence
    of the turbulent transport triggered by the instabilities of the vertical and
    horizontal shears of the differential rotation in stellar radiation zones as a
    function of their rotation, stratification, and thermal diffusivity is mandatory.
    Indeed, it constitutes one of the cornerstones of the rotational transport and
    mixing theory, which is implemented in stellar evolution codes to predict the
    rotational and chemical evolutions of stars.\r\n\r\nAims. We investigate horizontal
    shear instabilities in rotating stellar radiation zones by considering the full
    Coriolis acceleration with both the dimensionless horizontal Coriolis component
    f̃ and the vertical component f.\r\n\r\nMethods. We performed a linear stability
    analysis using linearized equations derived from the Navier-Stokes and heat transport
    equations in the rotating nontraditional f-plane. We considered a horizontal shear
    flow with a hyperbolic tangent profile as the base flow. The linear stability
    was analyzed numerically in wide ranges of parameters, and we performed an asymptotic
    analysis for large vertical wavenumbers using the Wentzel-Kramers-Brillouin-Jeffreys
    (WKBJ) approximation for nondiffusive and highly-diffusive fluids.\r\n\r\nResults.
    As in the traditional f-plane approximation, we identify two types of instabilities:
    the inflectional and inertial instabilities. The inflectional instability is destabilized
    as f̃ increases and its maximum growth rate increases significantly, while the
    thermal diffusivity stabilizes the inflectional instability similarly to the traditional
    case. The inertial instability is also strongly affected; for instance, the inertially
    unstable regime is also extended in the nondiffusive limit as 0 < f < 1 + f̃ 2/N2,
    where N is the dimensionless Brunt-Väisälä frequency. More strikingly, in the
    high thermal diffusivity limit, it is always inertially unstable at any colatitude
    θ except at the poles (i.e., 0° < θ <  180°). We also derived the critical Reynolds
    numbers for the inertial instability using the asymptotic dispersion relations
    obtained from the WKBJ analysis. Using the asymptotic and numerical results, we
    propose a prescription for the effective turbulent viscosities induced by the
    inertial and inflectional instabilities that can be possibly used in stellar evolution
    models. The characteristic time of this turbulence is short enough so that it
    is efficient to redistribute angular momentum and to mix chemicals in stellar
    radiation zones."
acknowledgement: The authors acknowledge support from the European Research Council
  through ERC grant SPIRE 647383 and from GOLF and PLATO CNES grants at the Department
  of Astrophysics at CEA Paris-Saclay. We thank the referee, Prof. A. J. Barker, for
  his constructive comments that allow us to improve the article.
article_number: A64
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: J.
  full_name: Park, J.
  last_name: Park
- first_name: V.
  full_name: Prat, V.
  last_name: Prat
- first_name: S.
  full_name: Mathis, S.
  last_name: Mathis
- first_name: Lisa Annabelle
  full_name: Bugnet, Lisa Annabelle
  id: d9edb345-f866-11ec-9b37-d119b5234501
  last_name: Bugnet
  orcid: 0000-0003-0142-4000
citation:
  ama: 'Park J, Prat V, Mathis S, Bugnet LA. Horizontal shear instabilities in rotating
    stellar radiation zones: II. Effects of the full Coriolis acceleration. <i>Astronomy
    &#38; Astrophysics</i>. 2021;646. doi:<a href="https://doi.org/10.1051/0004-6361/202038654">10.1051/0004-6361/202038654</a>'
  apa: 'Park, J., Prat, V., Mathis, S., &#38; Bugnet, L. A. (2021). Horizontal shear
    instabilities in rotating stellar radiation zones: II. Effects of the full Coriolis
    acceleration. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href="https://doi.org/10.1051/0004-6361/202038654">https://doi.org/10.1051/0004-6361/202038654</a>'
  chicago: 'Park, J., V. Prat, S. Mathis, and Lisa Annabelle Bugnet. “Horizontal Shear
    Instabilities in Rotating Stellar Radiation Zones: II. Effects of the Full Coriolis
    Acceleration.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2021. <a href="https://doi.org/10.1051/0004-6361/202038654">https://doi.org/10.1051/0004-6361/202038654</a>.'
  ieee: 'J. Park, V. Prat, S. Mathis, and L. A. Bugnet, “Horizontal shear instabilities
    in rotating stellar radiation zones: II. Effects of the full Coriolis acceleration,”
    <i>Astronomy &#38; Astrophysics</i>, vol. 646. EDP Sciences, 2021.'
  ista: 'Park J, Prat V, Mathis S, Bugnet LA. 2021. Horizontal shear instabilities
    in rotating stellar radiation zones: II. Effects of the full Coriolis acceleration.
    Astronomy &#38; Astrophysics. 646, A64.'
  mla: 'Park, J., et al. “Horizontal Shear Instabilities in Rotating Stellar Radiation
    Zones: II. Effects of the Full Coriolis Acceleration.” <i>Astronomy &#38; Astrophysics</i>,
    vol. 646, A64, EDP Sciences, 2021, doi:<a href="https://doi.org/10.1051/0004-6361/202038654">10.1051/0004-6361/202038654</a>.'
  short: J. Park, V. Prat, S. Mathis, L.A. Bugnet, Astronomy &#38; Astrophysics 646
    (2021).
date_created: 2022-07-18T13:24:32Z
date_published: 2021-02-08T00:00:00Z
date_updated: 2022-08-19T10:18:03Z
day: '08'
doi: 10.1051/0004-6361/202038654
extern: '1'
external_id:
  arxiv:
  - '2006.10660'
intvolume: '       646'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- hydrodynamics / turbulence / stars
- rotation / stars
- evolution
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2006.10660
month: '02'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
  eissn:
  - 1432-0746
  issn:
  - 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Horizontal shear instabilities in rotating stellar radiation zones: II. Effects
  of the full Coriolis acceleration'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 646
year: '2021'
...