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Numerical simulations of global solar convection
Mark S. Miesch
In the outer approximately 30 percent by radius of the
solar interior, convective fluid motions are responsible
for transporting the energy generated in the core
out to the photosphere, where it is subsequently radiated
into space. Modelling this convection zone is computationally
difficult due to the highly turbulent nature of the fluid
motions, the rotating spherical-shell geometry, the large
density stratification, and coupling to the relatively
quiescent interior though convective overshoot.
Direct numerical simulations have become possible
only recently, with the advent of sufficiently
powerful supercomputers. The need for improved
dynamical models of the solar convection zone
has been further emphasised by recent advances in
helioseismology which have provided unprecedented
information on the differential rotation profile of the
solar interior. These helioseismological results are
inconsistent with many earlier theoretical models.
In this talk, I will describe a new model of
global-scale turbulent solar convection based on
nonlinear, high-resolution, three-dimensional numerical
simulations. Particular emphasis will be given to the
coupling of convection and rotation, and the implications
of turbulent and laminar angular momentum transport
with regard to the solar differential rotation.
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