 |
| Titel |
On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
| VerfasserIn |
M. Uspensky, P. Eglitis, H. Opgenoorth, G. Starkov, T. Pulkkinen, R. Pellinen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 18, no. 12 ; Nr. 18, no. 12, S.1560-1575 |
| Datensatznummer |
250014101
|
| Publikation (Nr.) |
 copernicus.org/angeo-18-1560-2000.pdf |
|
|
|
|
|
| Zusammenfassung |
Observations and modelling are presented
which illustrate the ability of the Finland CUTLASS HF radar to monitor the
afternoon-evening equatorward auroral boundary during weak geomagnetic activity.
The subsequent substorm growth phase development was also observed in the late
evening sector as a natural continuation of the preceding auroral oval dynamics.
Over an 8 h period the CUTLASS Finland radar observed a narrow (in range) and
persistent region of auroral F- and (later) E-layer echoes which gradually moved
equatorward, consistent with the auroral oval diurnal rotation. This echo region
corresponds to the subvisual equatorward edge of the diffuse luminosity belt (SEEL)
and the ionospheric footprint of the inner boundary of the electron plasma
sheet. The capability of the Finland CUTLASS radar to monitor the E-layer SEEL-echoes
is a consequence of the nearly zero E-layer rectilinear aspect angles in a
region 5–10° poleward of the radar site. The F-layer echoes are probably the
boundary blob echoes. The UHF EISCAT radar was in operation and observed a
similar subvisual auroral arc and an F-layer electron density enhancement when
it appeared in its antenna beam.
Key words: Ionsophere (ionospheric irregularities) ·
Magnetospheric physics (auroral phenomena; magnetosphere–ionosphere
interactions) |
| |
|
| Teil von |
|
|
|
|
|
|
|
|