TY - JOUR
T1 - Heating by transverse waves in simulated coronal loops
AU - Karampelas, Konstantinos
AU - Van Doorsselaere, Tom
AU - Antolin, Patrick
N1 - Funding information: We would like to thank the referee, whose comments led to
a great improvement of the manuscript. We also thank the editor, for his suggestions. K.K. was funded by GOA-2015-014 (KU Leuven). T.V.D. was supported
by the IAP P7/08 CHARM (Belspo) and the GOA-2015-014 (KU Leuven). P.A.
acknowledges funding from the UK Science and Technology Facilities Council and the European Union Horizon 2020 research and innovation programme
(grant agreement No. 647214). The results were inspired by discussions at the
ISSI-Bern and at ISSI-Beijing meetings.
PY - 2017/8
Y1 - 2017/8
N2 - Context. Recent numerical studies of oscillating flux tubes have established the significance of resonant absorption in the damping of propagating transverse oscillations in coronal loops. The nonlinear nature of the mechanism has been examined alongside the Kelvin-Helmholtz instability,which is expected to manifest in the resonant layers at the edges of the flux tubes. While these two processes have been hypothesized to heat coronal loops through the dissipation of wave energy into smaller scales, the occurring mixing with the hotter surroundings can potentially hide this effect.Aims. We aim to study the effects of wave heating from driven and standing kink waves in a coronal loop.Methods. Using the MPI-AMRVAC code, we perform ideal, three dimensional magnetohydrodynamic (MHD) simulations of both (a) footpoint driven and (b) free standing oscillations in a straight coronal flux tube, in the presence of numerical resistivity.Results. We have observed the development of Kelvin-Helmholtz eddies at the loop boundary layer of all three models considered here, as well as an increase of the volume averaged temperature inside the loop. The main heating mechanism in our setups was Ohmic dissipation, as indicated by the higher values for the temperatures and current densities located near the footpoints. The introduction of a temperature gradient between the inner tube and the surrounding plasma, suggests that the mixing of the two regions, in the case of hotter environment, greatly increases the temperature of the tube at the site of the strongest turbulence, beyond the contribution of the aforementioned wave heating mechanism.
AB - Context. Recent numerical studies of oscillating flux tubes have established the significance of resonant absorption in the damping of propagating transverse oscillations in coronal loops. The nonlinear nature of the mechanism has been examined alongside the Kelvin-Helmholtz instability,which is expected to manifest in the resonant layers at the edges of the flux tubes. While these two processes have been hypothesized to heat coronal loops through the dissipation of wave energy into smaller scales, the occurring mixing with the hotter surroundings can potentially hide this effect.Aims. We aim to study the effects of wave heating from driven and standing kink waves in a coronal loop.Methods. Using the MPI-AMRVAC code, we perform ideal, three dimensional magnetohydrodynamic (MHD) simulations of both (a) footpoint driven and (b) free standing oscillations in a straight coronal flux tube, in the presence of numerical resistivity.Results. We have observed the development of Kelvin-Helmholtz eddies at the loop boundary layer of all three models considered here, as well as an increase of the volume averaged temperature inside the loop. The main heating mechanism in our setups was Ohmic dissipation, as indicated by the higher values for the temperatures and current densities located near the footpoints. The introduction of a temperature gradient between the inner tube and the surrounding plasma, suggests that the mixing of the two regions, in the case of hotter environment, greatly increases the temperature of the tube at the site of the strongest turbulence, beyond the contribution of the aforementioned wave heating mechanism.
KW - Magnetohydrodynamics (MHD)
KW - Sun: corona
KW - Sun: oscillations
U2 - 10.1051/0004-6361/201730598
DO - 10.1051/0004-6361/201730598
M3 - Article
SN - 0004-6361
VL - 604
SP - 1
EP - 10
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A130
ER -