Dynamic Magnetic Reconnection Events Triggered by Density-Temperature Non-uniformity

Magnetic reconnection plays an important role on energy transfer in space plasma. In this study, we use two-dimensional magnetohydrodynamic (MHD) simulation with finite resistivity to study magnetic reconnections triggered by density-temperature nonuniformity. In addition to the primary ejected plasmoid and a steady Sweet-Park-type current sheet, we also found continuous eruption of secondary plasmoids along the reconnecting current sheet. Our results show that the flow speed increases after the formation of the secondary plasmoids. This increase leads to the formation of slow-mode Mach-cone-like nonlinear waves at the trailing edge of the plasmoid. The newly formed secondary plasmoids may be related to the continuous ejection of plasma blob during transient solar eruption events as shown in recent observations [e.g. Liu et al., 2010]. The relation between the increasing of the flow speed and the formation of the slow-mode Mach-cone-like nonlinear waves will also be discussed.