Article
A Large Eddy Simulation of Turbulent Compressible Convection: Differential Rotation in the Solar Convection Zone
Monthly Notices of the Royal Astronomical Society
(2001)
Abstract
We present results of two simulations of the convection zone, obta
ined by solving the
full hydrodynamic equations in a section of a spherical shell. The firs
t simulation has
cylindrical rotation contours (parallel to the rotation axis) and a s
trong meridional
circulation, which traverses the entire depth. The second simulatio
n has isorotation
contours about mid-way between cylinders and cones, and a weak m
eridional circula-
tion, concentrated in the uppermost part of the shell.
We show that the solar differential rotation is directly related to a lat
itudinal
entropy gradient, which pervades into the deep layers of the conv
ection zone. We also
offer an explanation of the angular velocity shear found at low latitud
es near the
top. A non-zero correlation between radial and zonal velocity fluc
tuations produces a
significant Reynolds stress in that region. This constitutes a net tr
ansport of angular
momentum inwards, which causes a slight modification of the overall s
tructure of
the differential rotation near the top. In essence, the
thermodynamics controls the
dynamics through the Taylor-Proudman momentum balance
. The Reynolds stresses
only become significant in the surface layers, where they generate
a weak meridional
circulation and an angular velocity ‘bump
Disciplines
Publication Date
June 2, 2001
Citation Information
Frank Robinson. "A Large Eddy Simulation of Turbulent Compressible Convection: Differential Rotation in the Solar Convection Zone" Monthly Notices of the Royal Astronomical Society (2001) Available at: http://works.bepress.com/frank-robinson/31/