Near‐Earth breakup triggered by the earthward traveling burst flow

Computer modeling is performed in order to explore a hypothesis stating that the near‐Earth breakup can be triggered by a pulse of convection traveling earthward from the more distant magnetotail. The following possible scenario for the interaction of the burst with the near‐Earth edge of the plasma sheet (PS) is revealed. The near‐dipolar magnetic field topology of the inner PS leads to the flow breaking which in turn launches a wide spectrum of dispersive compressional waves propagating further Earthward. Strong topological variations of the magnetic field at the inner edge of the PS, required by the equilibrium conditions, play a role of the resonant cavity for selected compressional modes. Growing resonance modes provide a ponderomotive force pumping up corresponding nonlinear ballooning eigenmodes. The latter extract energy stored in the inner PS and produce vortical structures expanding tailward.