Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere
Temperature anisotropies may be encountered in space plasmas when there is a preferred direction, for instance, a strong magnetic or electric field. In this paper, we study how ion temperature anisotropy can affect the threshold conditions of a shear-modified current driven electrostatic ion-acou...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2013-03-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/31/451/2013/angeo-31-451-2013.pdf |
| _version_ | 1818065320309424128 |
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| author | P. J. G. Perron J.-M. A. Noël K. Kabin J.-P. St-Maurice |
| author_facet | P. J. G. Perron J.-M. A. Noël K. Kabin J.-P. St-Maurice |
| author_sort | P. J. G. Perron |
| collection | DOAJ |
| description | Temperature anisotropies may be encountered in space plasmas when there is a
preferred direction, for instance, a strong magnetic or electric field. In
this paper, we study how ion temperature anisotropy can affect the threshold
conditions of a shear-modified current driven electrostatic ion-acoustic
(CDEIA) instability. In particular, this communication focuses on
instabilities in the context of topside auroral F-region situations and in
the limit where finite Larmor radius corrections are small. We derived a new
fluid-like expression for the critical drift which depends explicitly on ion
anisotropy. More importantly, for ion to electron temperature ratios typical
of F-region, solutions of the kinetic dispersion relation show that ion
temperature anisotropy may significantly lower the drift threshold required
for instability. In some cases, a perpendicular to parallel ion temperature
ratio of 2 and may reduce the relative drift required for the onset of
instability by a factor of approximately 30, assuming the ion-acoustic speed
of the medium remains constant. Therefore, the ion temperature anisotropy
should be considered in future studies of ion-acoustic waves and
instabilities in the high-latitude ionospheric F-region. |
| first_indexed | 2024-12-10T14:50:01Z |
| format | Article |
| id | doaj.art-16954ea16df5493fb12b723b48325444 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-10T14:50:01Z |
| publishDate | 2013-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-16954ea16df5493fb12b723b483254442022-12-22T01:44:28ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762013-03-013145145710.5194/angeo-31-451-2013Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphereP. J. G. Perron0J.-M. A. Noël1K. Kabin2J.-P. St-Maurice3Department of Physics, Royal Military College of Canada, Kingston, Ontario, CanadaDepartment of Physics, Royal Military College of Canada, Kingston, Ontario, CanadaDepartment of Physics, Royal Military College of Canada, Kingston, Ontario, CanadaInstitute of Space and Atmospheric Studies and Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaTemperature anisotropies may be encountered in space plasmas when there is a preferred direction, for instance, a strong magnetic or electric field. In this paper, we study how ion temperature anisotropy can affect the threshold conditions of a shear-modified current driven electrostatic ion-acoustic (CDEIA) instability. In particular, this communication focuses on instabilities in the context of topside auroral F-region situations and in the limit where finite Larmor radius corrections are small. We derived a new fluid-like expression for the critical drift which depends explicitly on ion anisotropy. More importantly, for ion to electron temperature ratios typical of F-region, solutions of the kinetic dispersion relation show that ion temperature anisotropy may significantly lower the drift threshold required for instability. In some cases, a perpendicular to parallel ion temperature ratio of 2 and may reduce the relative drift required for the onset of instability by a factor of approximately 30, assuming the ion-acoustic speed of the medium remains constant. Therefore, the ion temperature anisotropy should be considered in future studies of ion-acoustic waves and instabilities in the high-latitude ionospheric F-region.https://www.ann-geophys.net/31/451/2013/angeo-31-451-2013.pdf |
| spellingShingle | P. J. G. Perron J.-M. A. Noël K. Kabin J.-P. St-Maurice Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere Annales Geophysicae |
| title | Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere |
| title_full | Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere |
| title_fullStr | Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere |
| title_full_unstemmed | Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere |
| title_short | Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere |
| title_sort | ion temperature anisotropy effects on threshold conditions of a shear modified current driven electrostatic ion acoustic instability in the topside auroral ionosphere |
| url | https://www.ann-geophys.net/31/451/2013/angeo-31-451-2013.pdf |
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