 |
| Titel |
Statistical and superposed epoch study of dipolarization events using data from Wind perigee passes |
| VerfasserIn |
K. Sigsbee, J. A. Slavin, R. P. Lepping, A. Szabo, Marit Øieroset, M. L. Kaiser, M. J. Reiner, H. J. Singer |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 23, no. 3 ; Nr. 23, no. 3 (2005-03-30), S.831-851 |
| Datensatznummer |
250015185
|
| Publikation (Nr.) |
 copernicus.org/angeo-23-831-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| From 1995 to 2000, the Wind spacecraft spent over 500h in the
magnetotail, much of it within ~2x104km of the
predicted location of the neutral sheet. Wind passed through the near
magnetotail at distances of -15 RE<X GSM<-6 RE on 35
occasions. Another 10 passes took place at distances of -30 RE<X GSM<-15 RE.
We identified 65 dipolarization events in the Wind
magnetic field data set between Y GSM~-16 and +16 RE based
upon our requirements that the magnetic field inclination had to change by
more than 15°, the maximum inclination angle had to be greater than 20°,
and the inclination angle had to increase by a factor of at least 1.5. Most
of the dipolarization events occurred in the pre-midnight region of the
magnetotail and were accompanied by earthward flows with speeds greater than
100km/s. The properties of the dipolarization events did not depend
upon the Y GSM position. However, they did vary with the distance to the
neutral sheet. Isolated dipolarization events, defined as occurring more than
20min apart, were characterized by a decrease in Bx GSM and
BTOTAL, and an increase in Bz GSM and the magnetic field
inclination. Dipolarizations that occurred as part of a series of small
dipolarizations spaced less than 20min apart were characterized by a
transient increase in Bz GSM and the magnetic field inclination, but no
significant change in Bx GSM and BTOTAL. The events consisting of a
series of small dipolarizations occurred predominantly near midnight. We
interpret these results in terms of two different modes of magnetotail
convection: 1) a classical substorm pattern featuring storage of magnetic
energy in the tail lobes which is explosively released at onset, and 2) a
directly driven process. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|