Ionospheric HF pump wave triggering of local auroral activation
Experimental results from Tromsø HF pumping experiments in the nightside auroral E region 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 inte...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.262.452 2023-05-15T18:34:12+02:00 Ionospheric HF pump wave triggering of local auroral activation The Pennsylvania State University CiteSeerX Archives 2000 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.262.452 http://arxiv.org/pdf/physics/9906057v3.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.262.452 http://arxiv.org/pdf/physics/9906057v3.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://arxiv.org/pdf/physics/9906057v3.pdf text 2000 ftciteseerx 2016-01-07T20:14:28Z Experimental results from Tromsø HF pumping experiments in the nightside auroral E region 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 ground-based observations and observations from the IMP 8 and IMP 9 satellites, 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 Alfvén boundary layer between the base of the ionosphere ( ∼ 100 km) and the level of sharp increase of the Alfvén velocity (at heights up to one Earth radius), 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 Tromsø |
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English |
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Experimental results from Tromsø HF pumping experiments in the nightside auroral E region 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 ground-based observations and observations from the IMP 8 and IMP 9 satellites, 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 Alfvén boundary layer between the base of the ionosphere ( ∼ 100 km) and the level of sharp increase of the Alfvén velocity (at heights up to one Earth radius), 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. |
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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 |
2000 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.262.452 http://arxiv.org/pdf/physics/9906057v3.pdf |
geographic |
Tromsø |
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Tromsø |
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Tromsø |
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Tromsø |
op_source |
http://arxiv.org/pdf/physics/9906057v3.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.262.452 http://arxiv.org/pdf/physics/9906057v3.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766218864127901696 |