Nonlinear wave structures in collisional plasma of auroral E-region ionosphere
Studies of the auroral plasma with small-scale inhomogenieties producing the VHF-radar reflections (radar aurora) when observed in conditions of the saturated Farley-Buneman instability within the auroral E region, show strong nonlinear interactions and density fluctuations of 5–15%. Such nonlin...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
1997-07-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/15/890/1997/angeo-15-890-1997.pdf |
| _version_ | 1818549361289723904 |
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| author | A. V. Volosevich Y. I. Galperin |
| author_facet | A. V. Volosevich Y. I. Galperin |
| author_sort | A. V. Volosevich |
| collection | DOAJ |
| description | Studies of the auroral plasma with
small-scale inhomogenieties producing the VHF-radar reflections (radar aurora)
when observed in conditions of the saturated Farley-Buneman instability within
the auroral E region, show strong nonlinear interactions and density
fluctuations of 5–15%. Such nonlinearity and high fluctation amplitudes are
inconsistent with the limitations of the weak turbulence theory, and thus a
theory for arbitrary amplitudes is needed. To this end, a nonlinear theory is
described for electrostatic MHD moving plasma structures of arbitrary amplitude
for conditions throughout the altitude range of the collisional auroral E
region. The equations are derived, from electron and ion motion self-consistent
with the electric field, for the general case of the one-dimensional problem.
They take into account nonlinearity, electron and ion inertia, diffusion,
deviation from quasi-neutrality, and dynamical ion viscosity. The importance of
the ion viscosity for dispersion is stressed, while deviation from the
quasi-neutrality can be important only at rather low plasma densities, not
typical for the auroral E region. In a small amplitude limit these equations
have classical nonlinear solutions of the type of "electrostatic shock
wave" or of knoidal waves. In a particular case these knoidal waves degrade
to a dissipative soliton. A two-dimensional case of a quasi-neutral plasma is
considered in the plane perpendicular to the magnetic field by way of the
Poisson brackets, but neglecting the nonlinearity and ion inertia. It is shown
that in these conditions an effective saturation can be achieved at the
stationary turbulence level of order of 10%. |
| first_indexed | 2024-12-12T08:32:21Z |
| format | Article |
| id | doaj.art-648b8de10a6042e7b549a7d272cbfd0b |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-12T08:32:21Z |
| publishDate | 1997-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-648b8de10a6042e7b549a7d272cbfd0b2022-12-22T00:31:03ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05761997-07-011589089810.1007/s00585-997-0890-8Nonlinear wave structures in collisional plasma of auroral E-region ionosphereA. V. Volosevich0Y. I. Galperin1Mogilev Pedagogical Institute, Mogilev, 212026, Belarus RepublicSpace Research Institute of RAN, Moscow, 117810, Russia RepublicStudies of the auroral plasma with small-scale inhomogenieties producing the VHF-radar reflections (radar aurora) when observed in conditions of the saturated Farley-Buneman instability within the auroral E region, show strong nonlinear interactions and density fluctuations of 5–15%. Such nonlinearity and high fluctation amplitudes are inconsistent with the limitations of the weak turbulence theory, and thus a theory for arbitrary amplitudes is needed. To this end, a nonlinear theory is described for electrostatic MHD moving plasma structures of arbitrary amplitude for conditions throughout the altitude range of the collisional auroral E region. The equations are derived, from electron and ion motion self-consistent with the electric field, for the general case of the one-dimensional problem. They take into account nonlinearity, electron and ion inertia, diffusion, deviation from quasi-neutrality, and dynamical ion viscosity. The importance of the ion viscosity for dispersion is stressed, while deviation from the quasi-neutrality can be important only at rather low plasma densities, not typical for the auroral E region. In a small amplitude limit these equations have classical nonlinear solutions of the type of "electrostatic shock wave" or of knoidal waves. In a particular case these knoidal waves degrade to a dissipative soliton. A two-dimensional case of a quasi-neutral plasma is considered in the plane perpendicular to the magnetic field by way of the Poisson brackets, but neglecting the nonlinearity and ion inertia. It is shown that in these conditions an effective saturation can be achieved at the stationary turbulence level of order of 10%.https://www.ann-geophys.net/15/890/1997/angeo-15-890-1997.pdf |
| spellingShingle | A. V. Volosevich Y. I. Galperin Nonlinear wave structures in collisional plasma of auroral E-region ionosphere Annales Geophysicae |
| title | Nonlinear wave structures in collisional plasma of auroral E-region ionosphere |
| title_full | Nonlinear wave structures in collisional plasma of auroral E-region ionosphere |
| title_fullStr | Nonlinear wave structures in collisional plasma of auroral E-region ionosphere |
| title_full_unstemmed | Nonlinear wave structures in collisional plasma of auroral E-region ionosphere |
| title_short | Nonlinear wave structures in collisional plasma of auroral E-region ionosphere |
| title_sort | nonlinear wave structures in collisional plasma of auroral e region ionosphere |
| url | https://www.ann-geophys.net/15/890/1997/angeo-15-890-1997.pdf |
| work_keys_str_mv | AT avvolosevich nonlinearwavestructuresincollisionalplasmaofauroraleregionionosphere AT yigalperin nonlinearwavestructuresincollisionalplasmaofauroraleregionionosphere |