Generation of auroral turbulence through the magnetosphere–ionosphere coupling
The shear Alfvén waves coupled with the ionospheric density fluctuations in auroral regions of a planetary magnetosphere are modeled by a set of the reduced magnetohydrodynamic and two-fluid equations. When the drift velocity of the magnetized plasma due to the background electric field exceeds a cr...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2016-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/aa532a |
| _version_ | 1797750987609341952 |
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| author | Tomo-Hiko Watanabe Hiroaki Kurata Shinya Maeyama |
| author_facet | Tomo-Hiko Watanabe Hiroaki Kurata Shinya Maeyama |
| author_sort | Tomo-Hiko Watanabe |
| collection | DOAJ |
| description | The shear Alfvén waves coupled with the ionospheric density fluctuations in auroral regions of a planetary magnetosphere are modeled by a set of the reduced magnetohydrodynamic and two-fluid equations. When the drift velocity of the magnetized plasma due to the background electric field exceeds a critical value, the magnetosphere–ionosphere (M–I) coupling system is unstable to the feedback instability which leads to formation of auroral arc structures with ionospheric density and current enhancements. As the feedback (primary) instability grows, a secondary mode appears and deforms the auroral structures. A perturbative (quasilinear) analysis clarifies the secondary growth of the Kelvin–Helmholtz type instability driven by the primary instability growth in the feedback M–I coupling. In the nonlinear stage of the feedback instability, furthermore, auroral turbulence is spontaneously generated, where the equipartition of kinetic and magnetic energy is confirmed in the quasi-steady turbulence. |
| first_indexed | 2024-03-12T16:40:50Z |
| format | Article |
| id | doaj.art-c91e7e9dd5c748cab510d91d30effaad |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:40:50Z |
| publishDate | 2016-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-c91e7e9dd5c748cab510d91d30effaad2023-08-08T14:31:46ZengIOP PublishingNew Journal of Physics1367-26302016-01-01181212501010.1088/1367-2630/aa532aGeneration of auroral turbulence through the magnetosphere–ionosphere couplingTomo-Hiko Watanabe0Hiroaki Kurata1Shinya Maeyama2Department of Physics, Nagoya University , Nagoya 464-8602, JapanDepartment of Physics, Nagoya University , Nagoya 464-8602, JapanDepartment of Physics, Nagoya University , Nagoya 464-8602, JapanThe shear Alfvén waves coupled with the ionospheric density fluctuations in auroral regions of a planetary magnetosphere are modeled by a set of the reduced magnetohydrodynamic and two-fluid equations. When the drift velocity of the magnetized plasma due to the background electric field exceeds a critical value, the magnetosphere–ionosphere (M–I) coupling system is unstable to the feedback instability which leads to formation of auroral arc structures with ionospheric density and current enhancements. As the feedback (primary) instability grows, a secondary mode appears and deforms the auroral structures. A perturbative (quasilinear) analysis clarifies the secondary growth of the Kelvin–Helmholtz type instability driven by the primary instability growth in the feedback M–I coupling. In the nonlinear stage of the feedback instability, furthermore, auroral turbulence is spontaneously generated, where the equipartition of kinetic and magnetic energy is confirmed in the quasi-steady turbulence.https://doi.org/10.1088/1367-2630/aa532aAlfvén wavesplasma turbulencemagnetosphere–ionosphere interactions52.35.Bj52.35.Ra94.20.wh |
| spellingShingle | Tomo-Hiko Watanabe Hiroaki Kurata Shinya Maeyama Generation of auroral turbulence through the magnetosphere–ionosphere coupling New Journal of Physics Alfvén waves plasma turbulence magnetosphere–ionosphere interactions 52.35.Bj 52.35.Ra 94.20.wh |
| title | Generation of auroral turbulence through the magnetosphere–ionosphere coupling |
| title_full | Generation of auroral turbulence through the magnetosphere–ionosphere coupling |
| title_fullStr | Generation of auroral turbulence through the magnetosphere–ionosphere coupling |
| title_full_unstemmed | Generation of auroral turbulence through the magnetosphere–ionosphere coupling |
| title_short | Generation of auroral turbulence through the magnetosphere–ionosphere coupling |
| title_sort | generation of auroral turbulence through the magnetosphere ionosphere coupling |
| topic | Alfvén waves plasma turbulence magnetosphere–ionosphere interactions 52.35.Bj 52.35.Ra 94.20.wh |
| url | https://doi.org/10.1088/1367-2630/aa532a |
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