Angular Momentum Transport by Gravity Waves in the Solar Interior

AbstractThe possible mechanisms of angular momentum transport in convectively stable regions of a star are reviewed, with emphasis on transport by magnetic torques. The strength and configuration of the field in such layers is quite uncertain, because it is not known if the field can reach a dynamically stable configuration. A lower limit to the field strength is obtained by assuming that the field is always dynamically unstable, and decaying at the (rotation modified) dynamical time scale. The present field in the sun would then be of the order 1G, with poloidal and toroidal components of similar strength. The differential rotation in the core, if due only to the solar wind torque, would be very small for this field strength, and instead would more likely be governed by magnetic coulpling to the differential rotation of the convection zone. If small scale hydrodynamic transport mechanisms are present, their properties would also be influenced by a field of this strength.

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Angular Momentum Transport and Magnetic Fields in the Solar Interior

Inside the Sun - Astrophysics and Space Science Library ◽

10.1007/978-94-009-0541-2_34 ◽

1990 ◽

pp. 415-423 ◽

Cited By ~ 6

Author(s):

H. C. Spruit

Keyword(s):

Angular Momentum ◽

Magnetic Fields ◽

Solar Interior ◽

Momentum Transport ◽

Angular Momentum Transport

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Angular momentum transport by internal gravity waves

10.1063/1.1324948 ◽

2000 ◽

Author(s):

Eun-jin Kim

Keyword(s):

Angular Momentum ◽

Gravity Waves ◽

Internal Gravity Waves ◽

Momentum Transport ◽

Angular Momentum Transport

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Corotation resonances for gravity waves and their impact on angular momentum transport in stellar interiors

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313014634 ◽

2013 ◽

Vol 9 (S301) ◽

pp. 377-378

Author(s):

Lucie Alvan ◽

Stéphane Mathis ◽

Thibaut Decressin

Keyword(s):

Angular Momentum ◽

Gravity Waves ◽

Stellar Evolution ◽

Transport Processes ◽

Momentum Transport ◽

Critical Layer ◽

Secondary Source ◽

Angular Momentum Transport ◽

Critical Layers ◽

Stellar Interiors

AbstractGravity waves, which propagate in radiation zones, can extract or deposit angular momentum by radiative and viscous damping. Another process, poorly explored in stellar physics, concerns their direct interaction with the differential rotation and the related turbulence. In this work, we thus study their corotation resonances, also called critical layers, that occur where the Doppler-shifted frequency of the wave approaches zero. First, we study the adiabatic and non-adiabatic propagation of gravity waves near critical layers. Next, we derive the induced transport of angular momentum. Finally, we use the dynamical stellar evolution code STAREVOL to apply the results to the case of a solar-like star. The results depend on the value of the Richardson number at the critical layer. In the first stable case, the wave is damped. In the other unstable and turbulent case, the wave can be reflected and transmitted by the critical layer with a coefficient larger than one: the critical layer acts as a secondary source of excitation for gravity waves. These new results can have a strong impact on our understanding of angular momentum transport processes in stellar interiors along stellar evolution where strong gradients of angular velocity can develop.

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