SIMULTANEOUS SATELLITE AND GROUND-BASED OBSERVATIONS OF POLAR-CAP PHENOMENA

In order to understand the processes of formation and motion of sun-al igned polar cap arcs as well as patches, we have analyzed simultaneous observations from the Akebono (EXOS-D) satellite and ground based ins truments at Qaanaaq. Results demonstrated the correspondence between t he localized electron precipitation signatures observed from Akebono a nd multiple sun-aligned arcs observed using an all sky camera (ASC) at Qaanaaq and have confirmed that sun-aligned arcs correspond to divE < 0. We also confirmed the time delay of appearance and disappearance o f sun-aligned arcs in response to IMF change. As for patches, most of the patches drifted anti-sunward, but some ceased to drift within fiel d of view of the all sky camera. Results of comparison between patch m ovement and the convection demonstrated a general consistency between them.