ALFVÉN WAVES IN SIMULATIONS OF SOLAR PHOTOSPHERIC VORTICES
- Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Victoria 3800 (Australia)
- Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom)
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.
- OSTI ID:
- 22215402
- Journal Information:
- Astrophysical Journal Letters, Vol. 776, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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