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| Titel |
IMF BY and the seasonal dependences of the electric field in the inner magnetosphere |
| VerfasserIn |
H. Matsui, J. M. Quinn, R. B. Torbert, V. K. Jordanova, P. A. Puhl-Quinn, G. Paschmann |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 23, no. 7 ; Nr. 23, no. 7 (2005-10-14), S.2671-2678 |
| Datensatznummer |
250015339
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| Publikation (Nr.) |
 copernicus.org/angeo-23-2671-2005.pdf |
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| Zusammenfassung |
It is known that the electric field pattern at high latitudes depends on the
polarity of the Y component of the interplanetary magnetic field (IMF BY)
and season. In this study, we investigate the seasonal and BY dependences in
the inner magnetosphere using the perigee (4<L<10) Cluster data taken from
low magnetic latitudes. The data consist of both components of the electric
field perpendicular to the magnetic field, obtained by the electron drift
instrument (EDI), which is based on a newly developed technique, well suited for
measurement of the electric fields in the inner magnetosphere. These data are
sorted by the polarities of IMF BZ and BY, and by seasons or hemispheres.
It is demonstrated from our statistics that the electric fields in the
inner magnetosphere depend on these quantities. The following three points are
inferred: 1) The electric fields exhibit some differences statistically
between Cluster locations at the Northern and Southern Hemispheres with the same
dipole L and magnetic local time (MLT) values and during the
same IMF conditions. These differences in the electric fields might result from
hemispherical differences in magnetic field geometry and/or those in
field-aligned potential difference.
2) The IMF BY and seasonal dependence of the dawnside and duskside
electric fields at 4<L<10 is consistent with that seen in the polar
convection cell. In addition, it is possible that these dependences are affected
by the ionospheric conductivity and the field-aligned current.
3) The nightside electric field in the inner magnetosphere measured by Cluster
is often similar to that in the magnetotail lobe. In the future, it will be
necessary to incorporate these dependencies on IMF BY and season into
a realistic model of the inner magnetospheric convection electric field.
Keywords. Magnetospheric physics (Electric fields;
Magnetosphere-ionosphere interactions; Solar windmagnetosphere
interactions) |
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