|
Titel |
Repetitive X-line Hall current structures over the dawnside ionosphere induced by successive exo-magnetosphere pressure pulses |
VerfasserIn |
D. V. Sarafopoulos |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 22, no. 12 ; Nr. 22, no. 12 (2004-12-22), S.4153-4163 |
Datensatznummer |
250015081
|
Publikation (Nr.) |
copernicus.org/angeo-22-4153-2004.pdf |
|
|
|
Zusammenfassung |
This work is a synthesis of observational and magnetosphere model produced
results. In the first place, we observe geographic latitude-dependent delays
in signature arrival times at dawnside ground magnetograms. We use the IMAGE
chain ground station magnetograms associated with in-situ observations obtained
from the Wind, ACE, IMP-8, LANL 97A and Cluster satellites. We demonstrate
that the structures under study of ground signatures are directly dictated
by successive exo-magnetosphere pressure pulses applied along the
magnetopause. In one case, using the Cluster configuration, we determine the
magnetopause surface wave velocity ~210km·s–1, the
wavelength λ≈16 RE and the azimuthal wave number
m≅6. For this case, via Tsyganenko's T96 model, the positions from
the ground stations are traced out along the magnetic field lines, and their
conjugate points over the XYGSM plane are determined. In this way, we
have found that especially the conjugate points corresponding to the highest
latitude stations are systematically dispersed along the X-axis (ranging up
to ~8 RE and consequently, each of these points is associated
with a different amount of magnetopause displacement dictated by the
pressure wave. The local magnetopause compressions produce increments of the
cross tail electric field, which is directly mapped over the ionosphere
plane, where successive X-line Hall current structures are developed.
Key words. Ionosphere (electric fields and currents) –
Magnetospheric physics (Magnetosphere-ionosphere interactions,
Electric fields) |
|
|
Teil von |
|
|
|
|
|
|