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Advisor(s)
Abstract(s)
The internal gravity waves of low frequency which
are emitted at the base of the solar convection zone are able
to extract angular momentum from the radiative interior. We
evaluate this transport with some simplifying assumptions: we
ignore the Coriolis force, approximate the spectrum of turbulent
convection by the Kolmogorov law, and couple this turbulence
to the internal waves through their pressure fluctuations, following
Press (1981) and Garc´ıa L´opez & Spruit (1991). The
local frequency of an internal wave varies with depth in a differentially
rotating star, and it can vanish at some location, thus
leading to enhanced damping (Goldreich & Nicholson 1989). It
is this dissipation mechanism only that we take into account in
the exchange of momentum between waves and stellar rotation.
The flux of angular momentum is then an implicit function of
depth, involving the local rotation rate and an integral representing
the cumulative effect of radiative dissipation. We find that
the efficiency of this transport process is rather high: it operates
on a timescale of 107 years, and is probably responsible for the
flat rotation profile which has been detected through helioseismology.
Description
Keywords
Hydrodynamics Turbulence Sun: interior: rotation Stars: interiors: rotation
Citation
Zahn, Jean-Paul; Talon, Suzanne; Matias, José (1997). Angular momentum transport by internal waves in the solar interior. Astronomy & Astrophysics. ISSN 0004-6361. 322:1, p. 320-328