An interpretation for the bipolar electric field structures parallel to the magnetic field observed in the auroral ionosphere
A physical model for the existence of bipolar structures in the electric field that are parallel to the magnetic field and observed in the auroral ionosphere, is established by deriving the "Sagdeev potential" from the two-fluid equations in a cylindrical coordinate system. The model sh...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2008-06-01
|
| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/26/1431/2008/angeo-26-1431-2008.pdf |
| Summary: | A physical model for the existence of bipolar structures in the electric
field that are parallel to the magnetic field and observed in the auroral
ionosphere, is established by deriving the "Sagdeev potential" from the
two-fluid equations in a cylindrical coordinate system. The model shows that
the bipolar electric field structure can develop not only from an ion
acoustic wave, but also from an ion cyclotron wave, when the Mach number and
the initial electric field satisfy certain conditions. Moreover, in the
auroral region, it shows that the polarity of this electric field structure
can be oriented either negative to positive or the reverse polarity, its
amplitude can be varied from 35 to 330 mV/m, and its duration can be 7 ms to 23 ms.
These results are in agreement with observation. Therefore, our
two-fluid model can interpret the bipolar structures observed in the auroral
ionosphere. |
|---|---|
| ISSN: | 0992-7689 1432-0576 |