Auroral-arc splitting by intrusion of a new convection channel

• Main Authors: Frey, H. U., Haerendel, G., Buchert, S., Lanchester, B. S.
• Other Authors: Max-Planck-Institut für Extraterrestrische Physik (MPE), Institut für Geophysik und Meteorologie Braunschweig, Technische Universität Braunschweig = Technical University of Braunschweig Braunschweig, University of Southampton, Okayama University
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1996
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; EISCAT
• Online Access: https://hal.science/hal-00316246; https://hal.science/hal-00316246/document; https://hal.science/hal-00316246/file/angeo-14-1257-1996.pdf

International audience 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.