Ionospheric HF pump wave triggering of local auroral activation
Results from ionospheric HF pumping experiments in the nightside auroral E region above Tromsø, Norway, are reported. We found intriguing evidence that a modification of the ionosphere-magnetosphere coupling, due to the effects of powerful HF waves beamed into an auroral sporadic E layer, can lead t...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.261.7808 2023-05-15T18:34:09+02:00 Ionospheric HF pump wave triggering of local auroral activation The Pennsylvania State University CiteSeerX Archives 1999 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.261.7808 http://arxiv.org/pdf/physics/9906057v2.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.261.7808 http://arxiv.org/pdf/physics/9906057v2.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://arxiv.org/pdf/physics/9906057v2.pdf text 1999 ftciteseerx 2016-01-07T20:12:47Z Results from ionospheric HF pumping experiments in the nightside auroral E region above Tromsø, Norway, are reported. We found intriguing evidence that a modification of the ionosphere-magnetosphere coupling, due to the effects of powerful HF waves beamed into an auroral sporadic E layer, can lead to a local intensification of the auroral activity. Summarizing multi-instrument groundbased observations, one can distinguish the following peculiarities related to this auroral activation: modification of the auroral arc and its break-up above Tromsø; local changes of the horizontal currents in the vicinity of Tromsø; increase of the electron temperature and ion velocities at altitudes above the HF pump reflection level; distinctive features in dynamic HF radio scatter Doppler spectra; pump-induced electron precipitation; substorm activation exactly above Tromsø. The mechanisms of the modification of the ionosphere-magnetosphere coupling through the excitation of the turbulent boundary layer between the base of the ionosphere ( ∼ 100 km) and the level of sharp increase of the Alfvén velocity ( ∼> 1000 km), and the formation of a local magnetospheric current system are discussed. The results suggest that a possible triggering of local auroral activation requires specific geophysical conditions. Text Tromsø Unknown Norway Tromsø |
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ftciteseerx |
language |
English |
description |
Results from ionospheric HF pumping experiments in the nightside auroral E region above Tromsø, Norway, are reported. We found intriguing evidence that a modification of the ionosphere-magnetosphere coupling, due to the effects of powerful HF waves beamed into an auroral sporadic E layer, can lead to a local intensification of the auroral activity. Summarizing multi-instrument groundbased observations, one can distinguish the following peculiarities related to this auroral activation: modification of the auroral arc and its break-up above Tromsø; local changes of the horizontal currents in the vicinity of Tromsø; increase of the electron temperature and ion velocities at altitudes above the HF pump reflection level; distinctive features in dynamic HF radio scatter Doppler spectra; pump-induced electron precipitation; substorm activation exactly above Tromsø. The mechanisms of the modification of the ionosphere-magnetosphere coupling through the excitation of the turbulent boundary layer between the base of the ionosphere ( ∼ 100 km) and the level of sharp increase of the Alfvén velocity ( ∼> 1000 km), and the formation of a local magnetospheric current system are discussed. The results suggest that a possible triggering of local auroral activation requires specific geophysical conditions. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
title |
Ionospheric HF pump wave triggering of local auroral activation |
spellingShingle |
Ionospheric HF pump wave triggering of local auroral activation |
title_short |
Ionospheric HF pump wave triggering of local auroral activation |
title_full |
Ionospheric HF pump wave triggering of local auroral activation |
title_fullStr |
Ionospheric HF pump wave triggering of local auroral activation |
title_full_unstemmed |
Ionospheric HF pump wave triggering of local auroral activation |
title_sort |
ionospheric hf pump wave triggering of local auroral activation |
publishDate |
1999 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.261.7808 http://arxiv.org/pdf/physics/9906057v2.pdf |
geographic |
Norway Tromsø |
geographic_facet |
Norway Tromsø |
genre |
Tromsø |
genre_facet |
Tromsø |
op_source |
http://arxiv.org/pdf/physics/9906057v2.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.261.7808 http://arxiv.org/pdf/physics/9906057v2.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766218823447347200 |