Sudden disruption of the cross-tail current in the magnetotail

A Hall magnetohydrodynamic simulation is used to study current dynamic processes with realistic magnetotail geometry. The simulation results indicate that sudden disruption of cross-tail current at the near Earth region inside 15RE is triggered by fast magnetic reconnection with the reconnection rate ∼0.15. The cross-tail current density exhibits an impulsive intensification in the late growth phase. The magnitude of the current increases more than one order within a few minutes. After the reconnection onset, the cross-tail current is suddenly disrupted in a few Alfven times, which is in good agreement with that from the satellite observations. Associated with the current disruption, the tail-like geometry becomes a dipolarlike structure with an impulsive enhancement of the magnetic field Bz. Large increases of the electric field and Earthward bulk flow in this simulation are observed immediately after the reconnection onset