Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations
We described the ground signatures of dynamic substorm features as observed by the imaging riometer, magnetometers and all-sky camera (ASC) at Kilpisjärvi, Finland on 5 and 25 October 1999 during the late evening hours. The magnetometer data was consistent with the motion of up-ward field-aligned cu...
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ftcopernicus:oai:publications.copernicus.org:angeo34660 2023-05-15T17:03:43+02:00 Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations Danielides, M. A. Shalimov, S. Kangas, J. 2018-09-27 application/pdf https://doi.org/10.5194/angeo-19-699-2001 https://angeo.copernicus.org/articles/19/699/2001/ eng eng doi:10.5194/angeo-19-699-2001 https://angeo.copernicus.org/articles/19/699/2001/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.5194/angeo-19-699-2001 2020-07-20T16:27:54Z We described the ground signatures of dynamic substorm features as observed by the imaging riometer, magnetometers and all-sky camera (ASC) at Kilpisjärvi, Finland on 5 and 25 October 1999 during the late evening hours. The magnetometer data was consistent with the motion of up-ward field-aligned currents (FACs) associated with absorption patches moving within the field of view of the riometer. We used riometer data in order to estimate the intensity of FACs associated with these local current-carrying filaments. It is shown that during these events, the estimated FAC intensity exceeds a threshold value that corresponds to the excitation of the low-frequency turbulence in the upper ionosphere. As a result, a quasi-oscillating regime of anomalous resistivity on the auroral field lines can give rise to the burst-like electron acceleration responsible for simultaneously observed auroral forms and bursts of Pi1B pulsations. Key words. Ionosphere (active experiments; auroral ionosphere; electric fields and currents) Text Kilpisjärvi Copernicus Publications: E-Journals Kilpisjärvi ENVELOPE(20.767,20.767,69.034,69.034) Annales Geophysicae 19 7 699 706 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We described the ground signatures of dynamic substorm features as observed by the imaging riometer, magnetometers and all-sky camera (ASC) at Kilpisjärvi, Finland on 5 and 25 October 1999 during the late evening hours. The magnetometer data was consistent with the motion of up-ward field-aligned currents (FACs) associated with absorption patches moving within the field of view of the riometer. We used riometer data in order to estimate the intensity of FACs associated with these local current-carrying filaments. It is shown that during these events, the estimated FAC intensity exceeds a threshold value that corresponds to the excitation of the low-frequency turbulence in the upper ionosphere. As a result, a quasi-oscillating regime of anomalous resistivity on the auroral field lines can give rise to the burst-like electron acceleration responsible for simultaneously observed auroral forms and bursts of Pi1B pulsations. Key words. Ionosphere (active experiments; auroral ionosphere; electric fields and currents) |
format |
Text |
author |
Danielides, M. A. Shalimov, S. Kangas, J. |
spellingShingle |
Danielides, M. A. Shalimov, S. Kangas, J. Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
author_facet |
Danielides, M. A. Shalimov, S. Kangas, J. |
author_sort |
Danielides, M. A. |
title |
Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
title_short |
Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
title_full |
Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
title_fullStr |
Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
title_full_unstemmed |
Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
title_sort |
estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations |
publishDate |
2018 |
url |
https://doi.org/10.5194/angeo-19-699-2001 https://angeo.copernicus.org/articles/19/699/2001/ |
long_lat |
ENVELOPE(20.767,20.767,69.034,69.034) |
geographic |
Kilpisjärvi |
geographic_facet |
Kilpisjärvi |
genre |
Kilpisjärvi |
genre_facet |
Kilpisjärvi |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.5194/angeo-19-699-2001 https://angeo.copernicus.org/articles/19/699/2001/ |
op_doi |
https://doi.org/10.5194/angeo-19-699-2001 |
container_title |
Annales Geophysicae |
container_volume |
19 |
container_issue |
7 |
container_start_page |
699 |
op_container_end_page |
706 |
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1766057642243915776 |