Plasma sheet disruption by interchange-generated flow intrusions



[1] A three-dimensional particle-in-cell simulation is used to examine the interaction of interchange-generated flow intrusions with the near-Earth plasma sheet. The interchange heads narrow in cross-tail extent as they propagate earthward and dawnward, and the maximum Bz in the head increases to be comparable to the lobe field strength. The interaction of the flow heads with the near-Earth plasma sheet leads to a strong disruption involving localized reconnection on east-west scales of a few ion inertia lengths. This mechanism may explain several key signatures of substorm onset associated with pre-breakup auroral streamers and the disruption of the near-Earth plasma sheet.