 |
| Titel |
Phenomena in the ionosphere-magnetosphere system induced by injection of powerful HF radio waves into nightside auroral ionosphere |
| VerfasserIn |
N. F. Blagoveshchenskaya, T. D. Borisova, V. A. Kornienko, B. Thidé, M. T. Rietveld, M. J. Kosch, T. Bösinger |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 23, no. 1 ; Nr. 23, no. 1 (2005-01-31), S.87-100 |
| Datensatznummer |
250015123
|
| Publikation (Nr.) |
 copernicus.org/angeo-23-87-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| Experimental results from three ionospheric HF pumping
experiments in overdense E or F regions are summarized. The experiments were
conducted by the use of the EISCAT HF Heating facility located near
Tromsø, Norway, allowing HF pumping the ionosphere in a near geomagnetic
field-aligned direction. Distinctive features related to auroral activations
in the course of the experiments are identified. Typical features observed in
all experiments are the following: generation of scattered components in
dynamic HF radio scatter Doppler spectra; strong increase of ion
temperatures Ti and local ionospheric electric field E0;
modification of the auroral arc and local spiral-like formation. However,
some effects were observed only when the HF pump wave was reflected from the
F2 layer. Among them are the generation of intense field-aligned ion outflows,
and a strong increase in the electron temperature Te with altitude. A
possible scenario for the substorm triggering due to HF pumping into an
auroral ionosphere is discussed. The authors present their interpretation of
the data as follows. It is suggested that two populations of charged
particles are at play. One of them is the runaway population of electrons
and ions from the ionosphere caused by the effects of the powerful HF radio
wave. The other is the population of electrons that precipitate from the
magnetosphere. It is shown that the hydrodynamical equilibrium was disrupted
due to the effects of the HF pumping. We estimate that the parallel electric
field can reach values of the order of 30mV/m during substorm triggering. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|