MHD simulation of an externally driven magnetic reconnection.

Abstract Using two-dimensional magnetohydrodynamic (MHD) simulations, we investigate the onset and growth of an instability associated with forced magnetic reconnection phenomenon in the well-known equilibrium structure of the Harris current sheet in the presence of a plasma resistivity. To derive externally the magnetic reconnection process, we perturb the plasma velocity close to the boundaries in the form of two localized pulses. The results show that these pulses propagate towards the current sheet, where the magnetic field changes its direction, generate perturbed magnetic field consequently and trigger the magnetic reconnection phenomenon in an X-point in the center of the current sheet. We realized that increasing the amplitude of pulses results in a faster reconnection and symmetric pulses are more efficient in deriving the reconnection process. Furthermore, by imposing a transient (time-dependent) MHD wave normal to the current sheet, we found that an MHD wave with a larger period (lower frequency) affects considerably on the topology of current sheet and excites a faster reconnection. A similar conclusion was also obtained for an MHD wave with a larger wavelength (lower wavenumber). The obtained results are of interest for understanding the interaction of an MHD wave with an equilibrium current sheet in the contexts of confined fusion plasmas and also the solar corona plasmas.