Abstract
Using advanced numerical magneto-hydrodynamic simulations of the
magnetized solar photosphere, including non-gray radiative transport and
a non-ideal equation of state, we analyze plasma motions in photospheric
magnetic vortices. We demonstrate that apparent vortex-like motions in
photospheric magnetic field concentrations do not exhibit "tornado"-like
behavior or a "bath-tub" effect. While at each time instance the
velocity field lines in the upper layers of the solar photosphere show
swirls, the test particles moving with the time-dependent velocity field
do not demonstrate such structures. Instead, they move in a wave-like
fashion with rapidly changing and oscillating velocity field, determined
mainly by magnetic tension in the magnetized intergranular downflows.
Using time-distance diagrams, we identify horizontal motions in the
magnetic flux tubes as torsional Alfvén perturbations propagating
along the nearly vertical magnetic field lines with local Alfvén
speed.
Original language | English |
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Journal | The Astrophysical Journal Letters, Volume 776, Issue 1, article id. L4, 4 pp. (2013). |
Volume | 776 |
Publication status | Published - 01 Oct 2013 |
Keywords
- magnetohydrodynamics: MHD
- plasmas
- Sun: magnetic fields
- Sun: photosphere