Auroral Omega Bands are a Significant Cause of Large Geomagnetically Induced Currents. Issue 6 (10th March 2020)

• Record Type: Journal Article
• Authors: Apatenkov, S. V.; Pilipenko, V. A.; Gordeev, E. I.; Viljanen, A.; Juusola, L.; Belakhovsky, V. B.; Sakharov, Ya. A.; Selivanov, V. N.
• Is Part Of: Geophysical research letters. Volume 47:Issue 6(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-10
• Subjects: geomagnetically induces currents -- omega bands -- ionosphere -- magnetosphere; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2019GL086677
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The strongest event of geomagnetically induced currents (GIC) detected by the North‐West Russian GIC network occurred during the main phase of the magnetic storm on 28 and 29 June 2013. Extremely high value, 120 A, was recorded in the 330 kV transformers on Kola Peninsula in the 04–07 magnetic local time (MLT) sector. The Defense Meteorological Satellite Program (DMSP) spacecraft took a sequence of ultraviolet (UV) auroral images in the southern hemisphere and observed multiple omega bands. The ionospheric equivalent electric currents based on the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network reveal a sequence of current vortex pairs moving eastward with the speed of 0.5–2.5 km/s that fits to the electrodynamics scheme of omega bands. Although the temporal variations of the associated current system are slow, the omega bands can be responsible for strong magnetic variations and GIC due to fast propagations of currents in the azimuthal direction. Key Points: Auroral omega bands related to large GIC Eastward drifting ionospheric current structures produce large GIC Ionospheric current motion is as important as its intensity variation