Field-aligned currents associated with dipolarization fronts

摘要: [1] Current densities associated with dipolarization fronts (DFs) have been calculated in the geomagnetic tail using curlometer technique applied to high-resolution magnetic field B→ data obtained by four Cluster spacecraft. We then use relation b→·∇×B→ characterize behavior of field-aligned current (FAC) during 25 DF events. Our results show that magnitude FAC density (J//) ranges from 5 20 nA/m2, and they are observed Northern Southern Hemispheres flowing along both directions B→-field. The FACs dimensions characteristic DFs region-1 sense inside region-2 just front (in Bz dips). Most our observations come 15 RE tail, different previous statistical studies based mainly on made around 9–12 RE. suggest can sustain significant appear as “wedgelets” early stage.