Plasma sheet response to the ionosphere's demand for field-aligned current

The response of the near-Earth plasma sheet to the extraction of a longitudinally-limited field-aligned current is investigated using three-dimensional particle-in-cell simulations. Polarization electric fields produce localized ( in y), thin ( in z), enhanced electron Hall currents, thus augmenting the cross-tail current. The current diversion forces reconnection to occur locally and leads to the formation of a complex magnetic field pattern of adjacent regions of negative and positive B-z.