Structure of the Hall current system in the vicinity of the magnetic reconnection site

Abstract

The spacecraft Geotail has observed the Hall current system in the vicinity of the magnetic reconnection site of the near‐Earth magnetotail for substorm onsets. In the outermost region near the plasma sheet/tail lobe boundary, field‐aligned currents flow out of the magnetic reconnection site. In the adjacent region, just inside the outflowing current layer, field‐aligned currents flow into the magnetic reconnection site. Hence, the Hall current circuit forms a thin double‐sheet structure near the separatrix layer.