In 10 Years of SOHO and Beyond
(Proceedings of the 17th SOHO Workshop)
(eds. D. Spadaro, B. Fleck and J.B. Gurman)
ESA SP-617: Noordwijk (2006).
Numerical simulations of rotating sunspots
A numerical model of idealized, axisymmetric, rotating sunspots is presented.
The model contains a compressible plasma described by the nonlinear MHD
equations, with density and temperature gradients simulating the upper layer of
the sun's convection zone. The solution forms a central flux tube in the
cylindrical numerical domain, with convection cells pushing the magnetic field
to the axis. When the numerical domain is rotated with a constant angular
velocity, the umbra rotates as a rigid body while the surrounding convection
cells show a swirling, vortical flow. As a result, the azimuthal velocity and
magnetic field have their maximum values close to the flux tube, inside the
innermost convection cell.
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