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Alfvén waves in simulations of solar photospheric vortices

journal contribution
posted on 2013-10-10, 00:00 authored by Sergiy ShelyagSergiy Shelyag, P S Cally, A Reid, M Mathioudakis
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.

History

Journal

Astrophysical journal letters

Volume

776

Issue

1

Article number

L4

Pagination

1 - 4

Publisher

IOP Publishing

Location

Bristol, Eng.

ISSN

2041-8205

eISSN

2041-8213

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2013, The American Astronomical Society