R. Moll, R. H. Cameron, M. Schüssler
Aims: We study the differences between non-magnetic and magnetic regions in
the flow and thermal structure of the upper solar photosphere. Methods:
Radiative MHD simulations representing a quiet region and a plage region,
respectively, which extend into the layers around the temperature minimum, are
analyzed. Results: The flow structure in the upper photospheric layers of the
two simulations is considerably different: the non-magnetic simulation is
dominated by a pattern of moving shock fronts while the magnetic simulation
shows vertically extended vortices associated with magnetic flux
concentrations. Both kinds of structures induce substantial local heating. The
resulting average temperature profiles are characterized by a steep rise above
the temperature minimum due to shock heating in the non-magnetic case and by a
flat photospheric temperature gradient mainly caused by Ohmic dissipation in
the magnetic run. Conclusions: Shocks in the quiet Sun and vortices in the
strongly magnetized regions represent the dominant flow structures in the
layers around the temperature minimum. They are closely connected with
dissipation processes providing localized heating.
View original:
http://arxiv.org/abs/1201.5981
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