 |
| Titel |
The ionospheric response to flux transfer events: the first few minutes |
| VerfasserIn |
A. S. Rodger, M. Pinnock |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 15, no. 6 ; Nr. 15, no. 6, S.685-691 |
| Datensatznummer |
250012828
|
| Publikation (Nr.) |
 copernicus.org/angeo-15-685-1997.pdf |
|
|
|
|
|
| Zusammenfassung |
| We utilise high-time resolution measurements
from the PACE HF radar at Halley, Antarctica to explore the evolution of the
ionospheric response during the first few minutes after enhanced reconnection
occurs at the magnetopause. We show that the plasma velocity increases
associated with flux transfer events (FTEs) occur first ~100–200 km
equatorward of the region to which magnetosheath (cusp) precipitation maps to
the ionosphere. We suggest that these velocity variations start near the
ionospheric footprint of the boundary between open and closed magnetic field
lines. We show that these velocity variations have rise times ~100 s and fall
times of ~10 s. When these velocity transients reach the latitude of the cusp
precipitation, sometimes the equatorward boundary of the precipitation begins to
move equatorward, the expected and previously reported ionospheric signature of
enhanced reconnection. A hypothesis is proposed to explain the velocity
variations. It involves the rapid outflow of magnetospheric electrons into the
magnetosheath along the most recently reconnected field lines. Several
predictions are made arising from the proposed explanation which could be tested
with ground-based and space-based observations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|