HR: 0800h
AN: SM31A-1216    [Abstracts]
TI: Cluster Observations of Earthward Flowing Plasmoid in the Tail
AU: * Zong, Q
AF: Boston University, 725 Commonwealth Ave Boston, MA 02215, Boston, MA 02215 United States
AU: Fritz, T
AF: Boston University, 725 Commonwealth Ave Boston, MA 02215, Boston, MA 02215 United States
AU: Fu, S
AF: Peking UniversitY, ISPAT, Peking University, Beijing, China, Beijing, 100871 China
AU: Pu, Z
AF: Peking UniversitY, ISPAT, Peking University, Beijing, China, Beijing, 100871 China
AU: Baker, D
AF: University of Colorado, Lab. for Atmos. and Space Physics, Boulder, 80309 United States
AU: Zhang, H
AF: Boston University, 725 Commonwealth Ave Boston, MA 02215, Boston, MA 02215 United States
AU: Lui, A
AF: Johns Hopkins University, APL, Johns Hopkins University, Laurel, 20723 United States
AU: Glassmeier, K
AF: Technische Universiteat Braunschweig, Institut fuer Geophysik und extraterrestrische Physik, Technische Universiteat Braunschweig, German, Brauscheig, 37156 Germany
AU: Korth, A
AF: Max-Planck-Institut f Solarsystem, D-37191, Katlenburg-Lindau, Germany., Lindau, 37191 Germany
AU: Daly, P
AF: Max-Planck-Institut f Solarsystem, D-37191, Katlenburg-Lindau, Germany., Lindau, 37191 Germany
AU: Balogh, A
AF: Imperial College, Space and Atmospheric Physics Group, London, UK, Landon, 1234 United Kingdom
AU: Reme, H
AF: Centre d_8222;3_8230;4Etude Spatiale des Rayonnements, Toulouse, France, Toulouse, 1234 France
AB: The energetic electrons and ions embedded in Earthward-moving plasmoid structures have been observed. These plasmoids are associated with a rotational local B$_z$ component (bi-polar) signature. Energetic electrons are found to be confined in a smaller spatial region than ions inside the plasmoid. Energetic ions and electrons seem to be a good indicator for the structure boundary. The fleet of Cluster spacecraft cross the plasmoid structure in a "first entry, last out" order (Note: when spacecraft cross a planar discontinuity, e.g. magnetopause, they will be in "first entry, first out" order). This documents the fact that the plasmoid has a non-planar nested structure. The large separation distance (around 1 R$_E$) of the Cluster satellites in October 2002 is an advantage to provide constraints on the size and shape of the plasmoid structure of interest. In addition, the plasmoid (with closed field lines) should preserve the ion composition information where it is formed. The ion composition observed in the plasmoid shows significantly lower O and He than in the ambient plasma. This implies few heavy ions are involved in the reconnection process where the plasmoid is formed. Multiple flux ropes/plasmoids observation presented in this paper can be interpreted as strong evidence for multiple X-lines.
DE: 2720 Energetic particles, trapped
DE: 2744 Magnetotail
DE: 2748 Magnetotail boundary layers
DE: 2764 Plasma sheet
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting