Variations in the altitude of the F2 peak associated with trough-formation processes
A novel approach is described which can help to determine, from ground-based data, which of the possible production mechanisms for the mid-latitude F-region ionospheric trough is dominant during a particular event. This approach involves numerically modelling the possible causal mechanisms of the mi...
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ftdoajarticles:oai:doaj.org/article:a02c2ae3aef3463cb2d88bec756020c4 2023-05-15T13:52:15+02:00 Variations in the altitude of the F2 peak associated with trough-formation processes R. I. Crickmore B. Jenkins G. J. Bailey 1996-06-01T00:00:00Z https://doi.org/10.1007/s00585-996-0628-z https://doaj.org/article/a02c2ae3aef3463cb2d88bec756020c4 EN eng Copernicus Publications https://www.ann-geophys.net/14/628/1996/angeo-14-628-1996.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-996-0628-z 0992-7689 1432-0576 https://doaj.org/article/a02c2ae3aef3463cb2d88bec756020c4 Annales Geophysicae, Vol 14, Pp 628-636 (1996) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 1996 ftdoajarticles https://doi.org/10.1007/s00585-996-0628-z 2022-12-31T14:23:16Z A novel approach is described which can help to determine, from ground-based data, which of the possible production mechanisms for the mid-latitude F-region ionospheric trough is dominant during a particular event. This approach involves numerically modelling the possible causal mechanisms of the mid-latitude trough to see how each will affect the altitude of the F2-layer electron-concentration peak (hmF2), and then comparing these predictions with the observed variation of hmF2 during trough formation. The modelling work predicts that, if the neutral-wind velocity does not vary, hmF2 will remain almost constant if the trough is formed via stagnation, but will rise if it is formed as a result of high ion velocities or neutral upwelling. Observations made at Halley (76°S, 27°W, L =4.2), Antarctica, show that most frequently the only changes in hmF2 during trough formation are those expected due to variations in the neutral wind, which suggests that stagnation is the most common production mechanism. During the most geomagnetically active night studied, on which Ap varied between 18 and 32, there was a rise in hmF2 that cannot be explained by changes in the neutral wind. On this night the plasma also decayed faster, and the poleward edge of the trough was seen earlier than on other nights. These differences, together with the fact that the ion velocities remained relatively low, suggest the trough was caused by a change in neutral composition, possibly advected into the observing area. Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 14 6 628 636 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 R. I. Crickmore B. Jenkins G. J. Bailey Variations in the altitude of the F2 peak associated with trough-formation processes |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
A novel approach is described which can help to determine, from ground-based data, which of the possible production mechanisms for the mid-latitude F-region ionospheric trough is dominant during a particular event. This approach involves numerically modelling the possible causal mechanisms of the mid-latitude trough to see how each will affect the altitude of the F2-layer electron-concentration peak (hmF2), and then comparing these predictions with the observed variation of hmF2 during trough formation. The modelling work predicts that, if the neutral-wind velocity does not vary, hmF2 will remain almost constant if the trough is formed via stagnation, but will rise if it is formed as a result of high ion velocities or neutral upwelling. Observations made at Halley (76°S, 27°W, L =4.2), Antarctica, show that most frequently the only changes in hmF2 during trough formation are those expected due to variations in the neutral wind, which suggests that stagnation is the most common production mechanism. During the most geomagnetically active night studied, on which Ap varied between 18 and 32, there was a rise in hmF2 that cannot be explained by changes in the neutral wind. On this night the plasma also decayed faster, and the poleward edge of the trough was seen earlier than on other nights. These differences, together with the fact that the ion velocities remained relatively low, suggest the trough was caused by a change in neutral composition, possibly advected into the observing area. |
format |
Article in Journal/Newspaper |
author |
R. I. Crickmore B. Jenkins G. J. Bailey |
author_facet |
R. I. Crickmore B. Jenkins G. J. Bailey |
author_sort |
R. I. Crickmore |
title |
Variations in the altitude of the F2 peak associated with trough-formation processes |
title_short |
Variations in the altitude of the F2 peak associated with trough-formation processes |
title_full |
Variations in the altitude of the F2 peak associated with trough-formation processes |
title_fullStr |
Variations in the altitude of the F2 peak associated with trough-formation processes |
title_full_unstemmed |
Variations in the altitude of the F2 peak associated with trough-formation processes |
title_sort |
variations in the altitude of the f2 peak associated with trough-formation processes |
publisher |
Copernicus Publications |
publishDate |
1996 |
url |
https://doi.org/10.1007/s00585-996-0628-z https://doaj.org/article/a02c2ae3aef3463cb2d88bec756020c4 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Annales Geophysicae, Vol 14, Pp 628-636 (1996) |
op_relation |
https://www.ann-geophys.net/14/628/1996/angeo-14-628-1996.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-996-0628-z 0992-7689 1432-0576 https://doaj.org/article/a02c2ae3aef3463cb2d88bec756020c4 |
op_doi |
https://doi.org/10.1007/s00585-996-0628-z |
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Annales Geophysicae |
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14 |
container_issue |
6 |
container_start_page |
628 |
op_container_end_page |
636 |
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