CUTLASS HF radar observations of high-latitude azimuthally propagating vortical currents in the nightside ionosphere during magnetospheric substorms
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<sup>-1</sup>) associat...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2000-06-01
|
| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/18/640/2000/angeo-18-640-2000.pdf |
| Summary: | 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<sup>-1</sup>)
associated with Hall currents flowing around upward directed field-aligned
currents are frequently observed propagating at high speed (~1 km s<sup>-1</sup>)
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.<br><br><b>Key words:</b> Ionosphere (auroral ionosphere; electric
fields and currents) · Magnetospheric physics (storms and substorms) |
|---|---|
| ISSN: | 0992-7689 1432-0576 |