On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study
Using EISCAT data, we have studied the behavior of the E region electron temperature and of the lower F region ion temperature during a period that was particularly active geomagnetically. We have found that the E region electron temperatures responded quite predictably to the effective electric fie...
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ftdoajarticles:oai:doaj.org/article:d929ca03bd1849848aa9fdf0d1b9e848 2023-05-15T16:04:50+02:00 On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study J.-P. St.-Maurice C. Cussenot W. Kofman 1999-09-01T00:00:00Z https://doi.org/10.1007/s00585-999-1182-2 https://doaj.org/article/d929ca03bd1849848aa9fdf0d1b9e848 EN eng Copernicus Publications https://www.ann-geophys.net/17/1182/1999/angeo-17-1182-1999.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-999-1182-2 0992-7689 1432-0576 https://doaj.org/article/d929ca03bd1849848aa9fdf0d1b9e848 Annales Geophysicae, Vol 17, Pp 1182-1198 (1999) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 1999 ftdoajarticles https://doi.org/10.1007/s00585-999-1182-2 2022-12-31T02:27:42Z Using EISCAT data, we have studied the behavior of the E region electron temperature and of the lower F region ion temperature during a period that was particularly active geomagnetically. We have found that the E region electron temperatures responded quite predictably to the effective electric field. For this reason, the E region electron temperature correlated well with the lower F region ion temperature. However, there were several instances during the period under study when the magnitude of the E region electron temperature response was much larger than expected from the ion temperature observations at higher altitudes. We discovered that these instances were related to very strong neutral winds in the 110-175 km altitude region. In one instance that was scrutinized in detail using E region ion drift measurement in conjunction with the temperature observations, we uncovered that, as suspected, the wind was moving in a direction closely matching that of the ions, strongly suggesting that ion drag was at work. In this particular instance the wind reached a magnitude of the order of 350 m/s at 115 km and of at least 750 m/s at 160 km altitude. Curiously enough, there was no indication of strong upper F region neutral winds at the time; this might have been because the event was uncovered around noon, at a time when, in the F region, the E × B drift was strongly westward but the pressure gradients strongly northward in the F region. Our study indicates that both the lower F region ion temperatures and the E region electron temperatures can be used to extract useful geophysical parameters such as the neutral density (through a determination of ion-neutral collision frequencies) and Joule heating rates (through the direct connection that we have confirmed exists between temperatures and the effective electric field). Key words. Ionosphere (auroral ionosphere; ionosphere atmosphere interactions; plasma temperature and density) Article in Journal/Newspaper EISCAT Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 17 9 1182 1198 |
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Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
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Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 J.-P. St.-Maurice C. Cussenot W. Kofman On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Using EISCAT data, we have studied the behavior of the E region electron temperature and of the lower F region ion temperature during a period that was particularly active geomagnetically. We have found that the E region electron temperatures responded quite predictably to the effective electric field. For this reason, the E region electron temperature correlated well with the lower F region ion temperature. However, there were several instances during the period under study when the magnitude of the E region electron temperature response was much larger than expected from the ion temperature observations at higher altitudes. We discovered that these instances were related to very strong neutral winds in the 110-175 km altitude region. In one instance that was scrutinized in detail using E region ion drift measurement in conjunction with the temperature observations, we uncovered that, as suspected, the wind was moving in a direction closely matching that of the ions, strongly suggesting that ion drag was at work. In this particular instance the wind reached a magnitude of the order of 350 m/s at 115 km and of at least 750 m/s at 160 km altitude. Curiously enough, there was no indication of strong upper F region neutral winds at the time; this might have been because the event was uncovered around noon, at a time when, in the F region, the E × B drift was strongly westward but the pressure gradients strongly northward in the F region. Our study indicates that both the lower F region ion temperatures and the E region electron temperatures can be used to extract useful geophysical parameters such as the neutral density (through a determination of ion-neutral collision frequencies) and Joule heating rates (through the direct connection that we have confirmed exists between temperatures and the effective electric field). Key words. Ionosphere (auroral ionosphere; ionosphere atmosphere interactions; plasma temperature and density) |
format |
Article in Journal/Newspaper |
author |
J.-P. St.-Maurice C. Cussenot W. Kofman |
author_facet |
J.-P. St.-Maurice C. Cussenot W. Kofman |
author_sort |
J.-P. St.-Maurice |
title |
On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study |
title_short |
On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study |
title_full |
On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study |
title_fullStr |
On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study |
title_full_unstemmed |
On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study |
title_sort |
on the usefulness of e region electron temperatures and lower f region ion temperatures for the extraction of thermospheric parameters: a case study |
publisher |
Copernicus Publications |
publishDate |
1999 |
url |
https://doi.org/10.1007/s00585-999-1182-2 https://doaj.org/article/d929ca03bd1849848aa9fdf0d1b9e848 |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Vol 17, Pp 1182-1198 (1999) |
op_relation |
https://www.ann-geophys.net/17/1182/1999/angeo-17-1182-1999.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-999-1182-2 0992-7689 1432-0576 https://doaj.org/article/d929ca03bd1849848aa9fdf0d1b9e848 |
op_doi |
https://doi.org/10.1007/s00585-999-1182-2 |
container_title |
Annales Geophysicae |
container_volume |
17 |
container_issue |
9 |
container_start_page |
1182 |
op_container_end_page |
1198 |
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1766400482543140864 |