Upwelling Ion Observation from the Earth's Upper Atmosphere During EISCAT Svalbard Radar and FAST Satellite Conjunctions

The loss of planetary atmospheres is due to the process of heavy ions depletion from the upper atmosphere. It is a significant source of magnetospheric plasma and plays an important role in altering global magnetospheric dynamics. A number of mechanisms are responsible for these outflows, which include electron precipitation, joule heating and other suprathermal energization. Seven events are considered at a time that the Fast Auroral SnapshoT (FAST) satellite and EISCAT Svalbard radar (ESR) simultaneously detected ion upflow, and this is validated by ground-based radars called, the Cooperative UK Twin Located Auroral Sounding System (CUTLASS). ESR and CUTLASS observations around the time of conjunctions are analyzed. The results show that ESR observed upwelling ion flux to be ~ 1013 m-2 s-1. Enhanced electron and ion temperatures are also observed at the time of these events. The dominant mechanism identified is the electron precipitation that results in an ambipolar electric field. The two striking events are the 2006-03-18 event that shows a distinct cusp signature indicated by CUTLASS and the 2002-01-20 event, which indicats a disturbed ionosphere due to data loss at ESR magnetic latitude.