Mapping of the heavy ion outflows as seen by IMAGE and multifluid global modeling for the 17 April 2002 storm

Pressures in excess of 1 nPa can be supported by the enhanced O+ outflows. The presence of these enhanced outflows appears at about the same time and over a similar region to enhancements seen in the HENA 51-180 keV oxygen data. These results provide a direct tie between heavy ionospheric outflows and their energization in the tail and suggest that during this period the heavy ions provide a substantial amount of the plasma required to support the magnetotail current sheet.

The model results also show that the enhanced O+ outflow leads to the enhanced exclusion of light ions of both solar wind and ionospheric origin in the plasma sheet, albeit with the light ions experiencing enhanced heating in an O+ dominated current sheet. These results indicate that observed heavy ionospheric outflows and their energetization in the tail have global consequences for the magnetosphere including supporting the dynamics of the tail current sheet during active times and in global circulation including the cross-polar cap potential and the region 1 and 2 currents.