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.