|
Titel |
Quasi-parallel electron beams and their possible application in inferring the auroral arc's root in the magnetosphere |
VerfasserIn |
J. Liang, F. Jiang, E. Donovan, E. Spanswick, V. Angelopoulos, R. Strangeway |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 31, no. 6 ; Nr. 31, no. 6 (2013-06-20), S.1077-1101 |
Datensatznummer |
250019053
|
Publikation (Nr.) |
copernicus.org/angeo-31-1077-2013.pdf |
|
|
|
Zusammenfassung |
In this study we investigate the upgoing electron beams
at the topside ionosphere and their counterpart feature, the bidirectional
quasi-parallel electron beams (QPEB) in the equatorial magnetosphere, with
highlight on their potential application in estimating the location of the
arc's root (AR) in the magnetotail central plasma sheet (CPS). We infer from
FAST data that the upgoing electron beam is often found in the equatorward
vicinity of the inverted-V arc. On the premise of such a scenario, we
propose a method to estimate the location of the AR from available
magnetospheric measurements by assuming that the tailward boundary of the
QPEB demarcates the earthward boundary of the AR. We report two events with
THEMIS observations of QPEBs in the magnetotail CPS, and demonstrate how to
use the QPEB features, together with the magnetic signatures of the current
circuit constituted by the QPEB and arc, to estimate the earthward boundary
of the AR. We find that the estimated earthward boundary of AR is situated
at the periphery of a quasi-dipolar magnetosphere characterized by a strong
Bz gradient. This finding is consistent with previously existing
proposals on the possible AR location in the tail (e.g., Lui and Burrows,
1978; Sergeev et al., 2012). |
|
|
Teil von |
|
|
|
|
|
|