Luminosity variations in several parallel auroral arcs before auroral breakup

V. Safargaleev (1) , W. Lyatsky (1) , V. Tagirov (1)

1 PGI - Polar Geophysical Institute of Russian Academy of Sciences

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.

Domaines: Océan, Atmosphère; Sciences de la Terre

V. Safargaleev, W. Lyatsky, V. Tagirov. Luminosity variations in several parallel auroral arcs before auroral breakup. Annales Geophysicae, 1997, 15 (8), pp.959-966. ⟨hal-00316299⟩