CONVECTION-DRIVEN RECONNECTION AND THE STABILITY OF THE NEAR-EARTH PLASMA SHEET

Driven convection in the near-Earth plasma sheet is investigated using 3-D, full particle simulations. The inductive response to an external ly imposed, uniform convection electric field leads to the effective t ailward propagation of magnetic flux, the erosion of the equatorial ma gnetic field, the development of an embedded thin current sheet, and t he eventual formation of a neutral line at the inward edge of the plas ma sheet. In addition to creating a magnetic island, the neutral line permits the growth of a kink-like mode with a characteristic scale of 1-2 R-E in the east-west (y) direction. The combined plasma flows from reconnection and the kink mode are in the range of 200-400 km/s and e xhibit a reversal between earthward and tailward flow as a function of y. These modifications of the plasma sheet resemble the substorm brea kup changes which are observed in the current disruption region.