Dynamics of the Conjugate Post-Noon Regions during an Auroral Enhancement.

Abstract

The morphological development of an event in the conjugate post-noon auroral ovals over a period of an hour is presented. The Viking UV camera imaged the northern dayside oval with a temporal resolution of 60 or 80s while an active auroral form was observed by all-sky and keogram cameras to move through the zenith at South Pole station. Early in the event a general similarity of form and development is observed between the hemispheres but implying that the Northern Hemisphere forms are located of the order of four degrees of latitude higher, and of the order of one hour of MLT later, than IGRF calculated conjugate locations. Later in the event conjugacy is more difficult to establish. Short-lived features in the Southern Hemisphere photographs for which no Northern Hemisphere conjugate can be found imply that local acceleration processes may be important in this time sector.