Luminosity variations in several parallel auroral arcs before auroral breakup

• Main Authors: V. Safargaleev, W. Lyatsky, V. Tagirov
• Format: Article
• Language: English
• Published: Copernicus Publications 1997-08-01
• Series: Annales Geophysicae
• Online Access: https://www.ann-geophys.net/15/959/1997/angeo-15-959-1997.pdf

Variation of the luminosity in two parallel auroral arcs before auroral breakup has been studied by using digitised TV-data with high temporal and spatial resolution. The intervals when a new arc appears near already existing one were chosen for analysis. It is shown, for all cases, that the appearance of a new arc is accompanied by fading or disappearance of another arc. We have named these events out-of-phase events, OP. Another type of luminosity variation is characterised by almost simultaneous enhancement of intensity in the both arcs (in-phase event, IP). The characteristic time of IP events is 10–20 s, whereas OP events last about one minute. Sometimes out-of-phase events begin as IP events. The possible mechanisms for OP and IP events are discussed.