Multiple, discrete arcs on sunward convecting field lines in the 14-15 MLT region

Moen, J., Sandholt, P. E., Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172, Egeland, A. and Fukui, K. (1994) Multiple, discrete arcs on sunward convecting field lines in the 14-15 MLT region. Journal of Geophysical Research, 99 (A4). p. 6113. ISSN 0148-0227 doi: 10.1029/93JA03344

Abstract/Summary

Ionospheric plasma flow measurements and simultaneous observations of thin (∼0.2° invariant latitude (ILAT)), multiple, longitudinally extended auroral arcs of transient nature within 74°-76° ILAT and 1030-1130 UT (∼14-15 MLT) on January 12, 1989, are reported. The auroral structures appeared within the luminous belt of strong 630.0-nm emissions located predominantly on sunward convecting field lines equatorward of the convection reversal boundary as identified by the European Incoherent Scatter UHF radar. The events occurred during a period of several hours quasi-steady solar wind speed (∼ 700 km s−1) and a radially orientated interplanetary magnetic field (IMF) with a weak northward tilt (IMF Bz>0). These typical dayside auroral features are related to previous studies of auroral activity related to the upward region 1 current in the postnoon sector. The discrete auroral events presented here may result from magnetosheath plasma injections into the low-latitude boundary layer (LLBL) and an associated dynamo mechanism. An alternative explanation invokes kinetic Alfvén waves, triggered either by Kelvin-Helmholtz instability at the inner (or outer) edge of the LLBL or by pressure pulse induced magnetopause surface waves.

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URI	https://reading-clone.eprints-hosting.org/id/eprint/38815
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Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
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