DAYSIDE AURORAL DYNAMICS - SOUTH-POLE - AMPTE CCE OBSERVATIONS/

Coordinated observations were made between the South Pole Station 630- nm all-sky imager and the Active Magnetospheric Particle Tracer Explor er (AMPTE) CCE satellite when it was at 9 R-E apogee in the midday sec tor in an effort to understand the variety of dynamical changes at the magnetopause that map to the dayside aurora. On June 18, 1988, three events were observed. The first, at 1150 MLT, was a local event showin g a rotation of the magnetic field and the sudden appearance of low-en ergy electrons indicating the satellite entering the magnetosheath or low-altitude boundary layer. This event was preceded by a type of pole ward expansion of the aurora which had been previously interpreted as a possible signature/footprint of a flux transfer event (FTE), Althoug h the magnetic field signatures at the satellite are not characteristi c of an FTE, the event could be a magnetic field change produced by an FTE, which after some delay propagated to the vicinity of the satelli te. The foot of the field line containing the satellite was at some di stance from the south pole meridian, The second event, starting at 161 0 UT (1240 MLT), was a clear case of field erosion during which the sa tellite entered the magnetosheath characterized by a reduction in ener getic electrons, an increase in soft electrons, and a decrease in the magnetic field strength accompanied by an equatorward motion of the au rora. The third event, in the afternoon at about 1900 UT (1530 MLT), s howed similar changes in the electron fluxes and similar equatorward m otion of the aurora. However, this event was associated with an increa se in the magnetic field at the satellite. Such a field increase could be characteristic of a pressure pulse. However, there was a correspon ding equatorward motion of the aurora, which suggests that the event w as also a flux erosion event in which the fringing fields of the regio n 1 current system, which normally cause a field depression at the sub solar region, created an increase in the field at the CCE satellite ne ar the late afternoon side. The latitudinal (equatorward) movements of the aurora for all three events were strongly correlated with the glo bal AE index which was dominated by stations in the dawn/dusk sectors.