TY - JOUR
T1 - Alfvén waves in simulations of solar photospheric vortices
AU - Shelyag, S.
AU - Cally, P. S.
AU - Reid, A.
AU - Mathioudakis, M.
PY - 2013/10/10
Y1 - 2013/10/10
N2 - 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.
AB - 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.
KW - magnetohydrodynamics (MHD)
KW - plasmas
KW - Sun: magnetic fields
KW - Sun: photosphere
UR - http://www.scopus.com/inward/record.url?scp=84884883133&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/776/1/L4
DO - 10.1088/2041-8205/776/1/L4
M3 - Article
AN - SCOPUS:84884883133
SN - 2041-8205
VL - 776
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L4
ER -