HR: 0800h
AN: SA21A-0264    [Abstracts]
TI: Evolution of the Detached Westward Flow Channel as Observed by the Unwin HF Radar
AU: * Makarevich, R A
EM: r.makarevich@latrobe.edu.au
AF: Department of Physics, La Trobe University, Bundoora, VIC 3086 Australia
AU: Dyson, P L
EM: p.dyson@latrobe.edu.au
AF: Department of Physics, La Trobe University, Bundoora, VIC 3086 Australia
AB: We examine the spatial and temporal evolution of latitudinally narrow regions with enhanced Doppler velocity observed by the Unwin TIGER HF radar equatorward of Auroral Westward Flow Channels. AWFCs were detected by both the Bruny Island and New Zealand (Unwin) TIGER radars as regions with enhanced westward convection, at about -62 deg MLAT. A second, more equatorward (~ -60 deg MLAT) channel with enhanced westward convection was detected only by the Unwin radar. The spatio-temporal behaviour of the second channel and its characteristics were found to be significantly different from those of AWFCs, e.g. both the channel and flow directions were significantly non-L-shell-aligned. We also investigate the relationship between the flow speeds within the two types of flow channels. In all cases, the second channel appeared to originate within or close to the AWFC, with the flow deviation from the magnetic L-shell direction and latitudinal separation between channels increasing with time. In sharp contrast to the AWFC that persisted for 2-3 hours, the second channel was recognizable only for 30-50 min. A relation between multiple flow channels and other subauroral phenomena such as subauroral ion drifts (SAID) and subauroral polarization streams (SAPS), and the implications of observations for models of SAID and SAPS formation are discussed.
DE: 2411 Electric fields (2712)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2463 Plasma convection (2760)
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005