Fang Fang, Ward Manchester IV, William P. Abbett, Bart van der Holst
We simulate the buoyant rise of a magnetic flux rope from the solar
convection zone into the corona to better understand the energetic coupling of
the solar interior to the corona. The magnetohydrodynamic model addresses the
physics of radiative cooling, coronal heating and ionization, which allow us to
produce a more realistic model of the solar atmosphere. The simulation
illustrates the process by which magnetic flux emerges at the photosphere and
coalesces to form two large concentrations of opposite polarities. We find that
the large-scale convective motion in the convection zone is critical to form
and maintain sunspots, while the horizontal converging flows in the near
surface layer prevent the concentrated polarities from separating. The foot
points of the sunspots in the convection zone exhibit a coherent rotation
motion, resulting in the increasing helicity of the coronal field. Here, the
local configuration of the convection causes the convergence of opposite
polarities of magnetic flux with a shearing flow along the polarity inversion
line. During the rising of the flux rope, the magnetic energy is first injected
through the photosphere by the emergence, followed by energy transport by
horizontal flows, after which the energy is subducted back to the convection
zone by the submerging flows.
View original:
http://arxiv.org/abs/1111.1679
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