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arXiv · 1411.3559

Gravito-inertial modes in a differentially rotating spherical shell

Giovanni M. Mirouh·Clément Baruteau·Michel Rieutord·Jérôme Ballot
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Abstract

While many intermediate- and high-mass main sequence stars are rapidly and differentially rotating, the effects of rotation on oscillation modes are poorly known. In this communication we present a first study of axisymmetric gravito-inertial modes in the radiative zone of a differentially rotating star. We consider a simplified model where the radiative zone of the star is a linearly stratified rotating fluid within a spherical shell, with differential rotation due to baroclinic effects. We solve the eigenvalue problem with high-resolution spectral computations and determine the propagation domain of the waves through the theory of characteristics. We explore the propagation properties of two kinds of modes: those that can propagate in the entire shell and those that are restricted to a subdomain. Some of the modes that we find concentrate kinetic energy around short-period shear layers known as attractors. We describe various geometries for the propagation domains, conditioning the surface visibility of the corresponding modes.

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Giovanni M. Mirouh, Clément Baruteau, Michel Rieutord, Jérôme Ballot. 2014-11-13. Gravito-inertial modes in a differentially rotating spherical shell. https://arxiv.org/abs/1411.3559

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