Auroral-arc splitting by intrusion of a new convection channel

• Published in: Annales Geophysicae
• Main Authors: H. U. Frey, G. Haerendel, S. Buchert, B. S. Lanchester
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 1996
• Subjects: Science; Q; Physics; QC1-999; Geophysics. Cosmic physics; QC801-809; EISCAT
• Online Access: https://doi.org/10.1007/s00585-996-1257-2; https://doaj.org/article/8b49083a147f485c96ca0d4cff531ebe

During a run of the Common Programme Three of the EISCAT radar the splitting of an auroral arc was observed by high time-resolution, ground-based cameras when the UHF radar beam was close to the arc. The evening eastward electrojet situation with a large-scale northward ionospheric electric field was disturbed by the intrusion of a convection channel with southward electric field from the east. The interaction of the new convection channel with the auroral arc caused changes in arc brightness and arc splitting, i.e. the creation of a new arc parallel to the pre-existing auroral arc. The event is described as one possibility for the creation of parallel arcs during slightly disturbed magnetic conditions far from the Harang discontinuity.