On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt
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 nat...
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ftcopernicus:oai:publications.copernicus.org:angeo34623 2023-05-15T16:04:44+02:00 On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt Uspensky, M. Eglitis, P. Opgenoorth, H. Starkov, G. Pulkkinen, T. Pellinen, R. 2018-09-27 application/pdf https://doi.org/10.1007/s00585-001-1560-x https://angeo.copernicus.org/articles/18/1560/2000/ eng eng doi:10.1007/s00585-001-1560-x https://angeo.copernicus.org/articles/18/1560/2000/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.1007/s00585-001-1560-x 2020-07-20T16:27:56Z 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) Text EISCAT Copernicus Publications: E-Journals Annales Geophysicae 18 12 1560 1575 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
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) |
format |
Text |
author |
Uspensky, M. Eglitis, P. Opgenoorth, H. Starkov, G. Pulkkinen, T. Pellinen, R. |
spellingShingle |
Uspensky, M. Eglitis, P. Opgenoorth, H. Starkov, G. Pulkkinen, T. Pellinen, R. On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
author_facet |
Uspensky, M. Eglitis, P. Opgenoorth, H. Starkov, G. Pulkkinen, T. Pellinen, R. |
author_sort |
Uspensky, M. |
title |
On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
title_short |
On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
title_full |
On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
title_fullStr |
On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
title_full_unstemmed |
On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt |
title_sort |
on auroral dynamics observed by hf radar: 1. equatorward edge of the afternoon-evening diffuse luminosity belt |
publishDate |
2018 |
url |
https://doi.org/10.1007/s00585-001-1560-x https://angeo.copernicus.org/articles/18/1560/2000/ |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.1007/s00585-001-1560-x https://angeo.copernicus.org/articles/18/1560/2000/ |
op_doi |
https://doi.org/10.1007/s00585-001-1560-x |
container_title |
Annales Geophysicae |
container_volume |
18 |
container_issue |
12 |
container_start_page |
1560 |
op_container_end_page |
1575 |
_version_ |
1766400363584290816 |