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www.ann-geophys.net/18/640/2000/
doi:10.1007/s00585-000-0640-7
© European Geosciences Union 2000
CUTLASS HF radar observations of high-latitude azimuthally propagating vortical currents in the nightside ionosphere during magnetospheric substorms
Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, UK7
E-mail: J.Wild@ion.le.ac.uk
Correspondence to: J. A. Wild
Abstract. High-time resolution CUTLASS observations and ground-based magnetometers have been employed to study the occurrence of vortical flow structures propagating through the high-latitude ionosphere during magnetospheric substorms. Fast-moving flow vortices (~800 m s-1) associated with Hall currents flowing around upward directed field-aligned currents are frequently observed propagating at high speed (~1 km s-1) azimuthally away from the region of the ionosphere associated with the location of the substorm expansion phase onset. Furthermore, a statistical analysis drawn from over 1000 h of high-time resolution, nightside radar data has enabled the characterisation of the bulk properties of these vortical flow systems. Their occurrence with respect to substorm phase has been investigated and a possible generation mechanism has been suggested.
Key words: Ionosphere (auroral ionosphere; electric fields and currents) ยท Magnetospheric physics (storms and substorms)
Full Article (PDF, 874 KB)
Citation: Wild, J. A. and Yeoman, T. K.: CUTLASS HF radar observations of high-latitude azimuthally propagating vortical currents in the nightside ionosphere during magnetospheric substorms, Ann. Geophys., 18, 640-652, doi:10.1007/s00585-000-0640-7, 2000. Bibtex EndNote Reference Manager XML
