Magnetotail dipolarization and associated current systems observed by Cluster and Double Star

Volwerk, M. and Lui, A. T. Y. and Lester, M. and Walsh, A. P. and Alexeev, I. and Cao, X. and Dunlop, M. W. and Fazakerley, A. N. and Grocott, A. and Kistler, L. and Lun, X. and Mouikis, C. and Pu, Z. and Shen, C. and Shi, J. K. and Taylor, M. G. G. T. and Baumjohann, W. and Nakamura, R. and Runov, A. and Vörös, Z. and Zhang, T. L. and Takada, T. and Rème, H. and Klecker, B. and Carr, C. M. (2008) Magnetotail dipolarization and associated current systems observed by Cluster and Double Star. Journal of Geophysical Research, 113 (A8). ISSN 0148-0227

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Abstract

A dipolarization and its associated current systems are studied using Cluster, Double Star TC1, and ground-based observations. The Cluster spacecraft are located approximately 16 RE downtail near 0030 LT. The Double Star TC1 spacecraft is located more earthward at approximately 7 RE just before local midnight. Auroral observations by the Wideband Imaging Camera on the Imager for Magnetopause-to-Aurora Global Exploration spacecraft are used to determine the onset times of substorms. It is shown that the magnetic phenomena at the earthward site of a magnetic reconfiguration region are governed by field-aligned currents, which in their turn generate auroral brightenings near the foot points of the spacecraft. It is also shown that the inward and outward motion of the dipolarization front near Cluster has a direct influence on the parallel plasma flow at TC1, indicating a piston mechanism. Just like a piston, the inward moving dipolarization at Cluster pushes in plasma along with the flux transport, which turns to parallel plasma flow at TC1. When the flow reverses at Cluster, i.e., outgoing flux transport, the plasma gets “sucked out” again, which is directly reflected in the plasma data from TC1.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Geophysical Research
Additional Information:
Copyright 2008 by the American Geophysical Union.
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1912
Subjects:
ID Code:
67141
Deposited By:
Deposited On:
11 Oct 2013 12:36
Refereed?:
Yes
Published?:
Published
Last Modified:
20 Oct 2020 02:41