TY  - JOUR
AU  - Effenberger, F.
AU  - Thust, K.
AU  - Arnold, L.
AU  - Grauer, R.
AU  - Dreher, J.
TI  - Numerical simulation of current sheet formation in a quasiseparatrix layer using adaptive mesh refinement
JO  - Physics of plasmas
VL  - 18
SN  - 1070-664X
CY  - [S.l.]
PB  - American Institute of Physics
M1  - PreJuSER-15157
SP  - 032902
PY  - 2011
N1  - This work was supported by Deutsche Forschungsgemeinschaft through Forschergruppe FOR 1048 and by the European Commission through the Solaire network (Grant No. MTRN-CT-2006-035484).
AB  - The formation of a thin current sheet in a magnetic quasiseparatrix layer (QSL) is investigated by means of numerical simulation using a simplified ideal, low-beta, MHD model. The initial configuration and driving boundary conditions are relevant to phenomena observed in the solar corona and were studied earlier by Aulanier et al. [Astron. Astrophys. 444, 961 (2005)]. In extension to that work, we use the technique of adaptive mesh refinement (AMR) to significantly enhance the local spatial resolution of the current sheet during its formation, which enables us to follow the evolution into a later stage. Our simulations are in good agreement with the results of Aulanier et al. up to the calculated time in that work. In a later phase, we observe a basically unarrested collapse of the sheet to length scales that are more than one order of magnitude smaller than those reported earlier. The current density attains correspondingly larger maximum values within the sheet. During this thinning process, which is finally limited by lack of resolution even in the AMR studies, the current sheet moves upward, following a global expansion of the magnetic structure during the quasistatic evolution. The sheet is locally one-dimensional and the plasma flow in its vicinity, when transformed into a comoving frame, qualitatively resembles a stagnation point flow. In conclusion, our simulations support the idea that extremely high current densities are generated in the vicinities of QSLs as a response to external perturbations, with no sign of saturation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3565018]
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000289151900055
DO  - DOI:10.1063/1.3565018
UR  - https://juser.fz-juelich.de/record/15157
ER  -