Enhanced ion acoustic fluctuations and ion outflows
A number of observations showing enhanced ion acoustic echoes observed by means of incoherent scatter radars have been reported in the literature. The received power is extremely enhanced by up to 1 or 2 orders of magnitude above usual values, and it is mostly contained in one of the two ion acousti...
Published in: | Annales Geophysicae |
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Springer Verlag
1999
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00037113 2023-05-15T16:04:47+02:00 Enhanced ion acoustic fluctuations and ion outflows Forme, F. R. E. Fontaine, D. 1999-02 electronic https://doi.org/10.1007/s00585-999-0182-6 https://noa.gwlb.de/receive/cop_mods_00037113 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00037067/angeo-17-182-1999.pdf https://angeo.copernicus.org/articles/17/182/1999/angeo-17-182-1999.pdf eng eng Springer Verlag Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.1007/s00585-999-0182-6 https://noa.gwlb.de/receive/cop_mods_00037113 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00037067/angeo-17-182-1999.pdf https://angeo.copernicus.org/articles/17/182/1999/angeo-17-182-1999.pdf https://open-access.net/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 1999 ftnonlinearchiv https://doi.org/10.1007/s00585-999-0182-6 2022-02-08T22:43:40Z A number of observations showing enhanced ion acoustic echoes observed by means of incoherent scatter radars have been reported in the literature. The received power is extremely enhanced by up to 1 or 2 orders of magnitude above usual values, and it is mostly contained in one of the two ion acoustic lines. This spectral asymmetry and the intensity of the received signal cannot be resolved by the standard analysis procedure and often causes its failure. As a result, and in spite of a very clear spectral signature, the analysis is unable to fit the plasma parameters inside the regions of ion acoustic turbulence. We present European Incoherent Scatter radar (EISCAT) observations of large ion outflows associated with the simultaneous occurrence of enhanced ion acoustic echoes. The ion fluxes can reach 1014 m-2 s-1 at 800 km altitude. From the very clear spectral signatures of these echoes, a method is presented to extract estimates of the electron temperature and the ion drift within the turbulent regions. It is shown that the electron gas is strongly heated up to 11 000 K. Also electron temperature gradients of about 0.02 K/m exist. Finally, the estimates of the electron temperature and of the ion drift are used to study the possible implications for the plasma transport inside turbulent regions. It is shown that strong electron temperature gradients cause enhancement of the ambipolar electric field and can account for the observed ion outflows. Key words. Ionosphere (auroral ionosphere; ionosphere · magnetosphere interactions; plasma waves and instabilities). Article in Journal/Newspaper EISCAT Niedersächsisches Online-Archiv NOA Annales Geophysicae 17 2 182 189 |
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article Verlagsveröffentlichung Forme, F. R. E. Fontaine, D. Enhanced ion acoustic fluctuations and ion outflows |
topic_facet |
article Verlagsveröffentlichung |
description |
A number of observations showing enhanced ion acoustic echoes observed by means of incoherent scatter radars have been reported in the literature. The received power is extremely enhanced by up to 1 or 2 orders of magnitude above usual values, and it is mostly contained in one of the two ion acoustic lines. This spectral asymmetry and the intensity of the received signal cannot be resolved by the standard analysis procedure and often causes its failure. As a result, and in spite of a very clear spectral signature, the analysis is unable to fit the plasma parameters inside the regions of ion acoustic turbulence. We present European Incoherent Scatter radar (EISCAT) observations of large ion outflows associated with the simultaneous occurrence of enhanced ion acoustic echoes. The ion fluxes can reach 1014 m-2 s-1 at 800 km altitude. From the very clear spectral signatures of these echoes, a method is presented to extract estimates of the electron temperature and the ion drift within the turbulent regions. It is shown that the electron gas is strongly heated up to 11 000 K. Also electron temperature gradients of about 0.02 K/m exist. Finally, the estimates of the electron temperature and of the ion drift are used to study the possible implications for the plasma transport inside turbulent regions. It is shown that strong electron temperature gradients cause enhancement of the ambipolar electric field and can account for the observed ion outflows. Key words. Ionosphere (auroral ionosphere; ionosphere · magnetosphere interactions; plasma waves and instabilities). |
format |
Article in Journal/Newspaper |
author |
Forme, F. R. E. Fontaine, D. |
author_facet |
Forme, F. R. E. Fontaine, D. |
author_sort |
Forme, F. R. E. |
title |
Enhanced ion acoustic fluctuations and ion outflows |
title_short |
Enhanced ion acoustic fluctuations and ion outflows |
title_full |
Enhanced ion acoustic fluctuations and ion outflows |
title_fullStr |
Enhanced ion acoustic fluctuations and ion outflows |
title_full_unstemmed |
Enhanced ion acoustic fluctuations and ion outflows |
title_sort |
enhanced ion acoustic fluctuations and ion outflows |
publisher |
Springer Verlag |
publishDate |
1999 |
url |
https://doi.org/10.1007/s00585-999-0182-6 https://noa.gwlb.de/receive/cop_mods_00037113 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00037067/angeo-17-182-1999.pdf https://angeo.copernicus.org/articles/17/182/1999/angeo-17-182-1999.pdf |
genre |
EISCAT |
genre_facet |
EISCAT |
op_relation |
Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.1007/s00585-999-0182-6 https://noa.gwlb.de/receive/cop_mods_00037113 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00037067/angeo-17-182-1999.pdf https://angeo.copernicus.org/articles/17/182/1999/angeo-17-182-1999.pdf |
op_rights |
https://open-access.net/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1007/s00585-999-0182-6 |
container_title |
Annales Geophysicae |
container_volume |
17 |
container_issue |
2 |
container_start_page |
182 |
op_container_end_page |
189 |
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1766400409865289728 |