Oscillations Excited by Plasmoids Formed During Magnetic Reconnection in a Vertical Gravitationally Stratified Current Sheet

0482622 - ASÚ 2018 RIV US eng J - Journal Article
Jelínek, P. - Karlický, Marian - Van Doorsselaere, T. - Bárta, Miroslav
Oscillations Excited by Plasmoids Formed During Magnetic Reconnection in a Vertical Gravitationally Stratified Current Sheet.
Astrophysical Journal. Roč. 2, č. 847 (2017), 98/1-98/15. ISSN 0004-637X. E-ISSN 1538-4357
R&D Projects: GA ČR(CZ) GA16-13277S; GA ČR(CZ) GA17-16447S
Institutional support: RVO:67985815
Keywords : magnetohydrodynamics * numerical methdos * Sun corona
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.551, year: 2017

Using the FLASH code, which solves the full set of the 2D non-ideal (resistive) time-dependent magnetohydrodynamic (MHD) equations, we study processes during the magnetic reconnection in a vertical gravitationally stratified current sheet. We show that during these processes, which correspond to processes in solar flares, plasmoids are formed due to the tearing mode instability of the current sheet. These plasmoids move upward or downward along the vertical current sheet and some of them merge into larger plasmoids. We study the density and temperature structure of these plasmoids and their time evolution in detail. We found that during the merging of two plasmoids, the resulting larger plasmoid starts to oscillate with a period largely determined by L/c(A), where L is the size of the plasmoid and c(A) is the Alfven speed in the lateral parts of the plasmoid. In our model, L/c(A) evaluates to similar to 25 s.
Permanent Link: http://hdl.handle.net/11104/0278036