Observed associations of substorm signatures at South Pole, at the auroral zone, and in the magnetotail

The characteristics and possible conditions which lead to the sudden poleward movement of auroras and associated magnetic and ionospheric disturbances from below the northern horizon are discussed. The abrupt excursions were recorded in terms of 427.8 nm photometry, 30 MHz riometry, and three-component flux gate magnetometry data recorded at South Pole Station. The data were taken at a 1 Hz rate during various occurrences in 1982-83 and compared with ISEE 1 and 2 electron flux data from the magnetotail. The poleward shift occurred from 30-60 min after the onset of a substorm expansive phase and coincided with recoveries of the magnetotail plasma sheet at distances of 15-20 earth radii. It is concluded that the excursions are part of the retreat of the substorm neutral line outward through the magnetotail during a late phase of substorms.