Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Experimental results from ionospheric HF pumping experiments in the nightside auroral E region above Tromsø 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 observations during two consecutive nights, one can distinguish the following peculiarities related to this auroral activation: a modification of the auroral arc and its breakup above Tromsø, local changes in the horizontal currents above Tromsø, a burst-like increase of the electron density and temperature, a large increase in the ion temperature in a wide altitude range and in the north-south component of the electric field, distinctive features in dynamic HF radio scatter Doppler spectra, pump-induced electron precipitation, and substorm activation exactly above Tromsø. We discuss the modification of the ionosphere-magnetosphere coupling in terms of the excitation of a 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. The results suggest that a possible triggering of local auroral activation requires specific geophysical conditions.
Язык оригинала | английский |
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Номер статьи | 2001JA900002 |
Страницы (с-по) | 29071-29089 |
Число страниц | 19 |
Журнал | Journal of Geophysical Research: Space Physics |
Том | 106 |
Номер выпуска | A12 |
Состояние | Опубликовано - 1 дек 2001 |
Опубликовано для внешнего пользования | Да |
ID: 36802230