TRANSIENT FLUX ENHANCEMENTS IN THE MAGNETOSHEATH

This study presents INTERBALL-1, and MAGION-4 observations of transien t ion flux variations in the magnetosheath which cannot be related to similar changes in the solar wind observed by WIND and GEOTAIL. The du ration of the transient events varies from tens of seconds to a few mi nutes and their amplitude can exceed background levels by a factor of 2 or more. We use the closely-spaced INTERBALL and MAGION-4 satellites to estimate that the spatial dimensions of the events are on the orde r of similar to 1R(E). The interaction of foreshock discontinuities wi th the bow shock is identified as a possible source of these events.