|
Titel |
Plasma convection in the magnetotail lobes: statistical results from Cluster EDI measurements |
VerfasserIn |
S. Haaland, G. Paschmann, M. Forster, J. Quinn, R. Torbert, H. Vaith, P. Puhl-Quinn, C. Kletzing |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 26, no. 8 ; Nr. 26, no. 8 (2008-08-05), S.2371-2382 |
Datensatznummer |
250016195
|
Publikation (Nr.) |
copernicus.org/angeo-26-2371-2008.pdf |
|
|
|
Zusammenfassung |
A major part of the plasma in the Earth's magnetotail is populated through transport of plasma
from the solar wind via the magnetotail lobes. In this paper, we present a statistical study of plasma
convection in the lobes for different directions of the interplanetary magnetic field and for different
geomagnetic disturbance levels. The data set used in this study consists of roughly
340 000 one-minute vector measurements of the plasma convection from the Cluster Electron
Drift Instrument (EDI) obtained during the period February 2001 to June 2007.
The results show that both convection magnitude and direction are largely controlled by the
interplanetary magnetic field (IMF). For a southward IMF, there is a strong convection towards the
central plasma sheet with convection velocities around 10 km s−1. During periods of northward IMF,
the lobe convection is almost stagnant. A By dominated IMF causes a rotation of the convection
patterns in the tail with an oppositely directed dawn-dusk component of the convection for
the northern and southern lobe.
Our results also show
that there is an overall persistent duskward component, which is most likely a result of conductivity
gradients in the footpoints of the magnetic field lines in the ionosphere. |
|
|
Teil von |
|
|
|
|
|
|