|
|
 |
|
 |
Ann. Geophys., 22, 2535-2540, 2004 www.ann-geophys.net/22/2535/2004/ © European Geosciences Union 2004
Properties of a bifurcated current sheet observed on 29 August 2001
A. Runov1, V. Sergeev2, R. Nakamura1, W. Baumjohann1, Z. Vörös1, M. Volwerk1,3, Y. Asano1, B. Klecker3, H. Rème5, and A. Balogh6 1Institut für Weltraumforschung der ÖAW, Graz, Austria 2St. Petersburg University, Russia 3MPE Garching, Germany 5CESR, Toulouse, France 6Imperial College, London, UK
Abstract. Ion density, velocity and temperature, measured by Cluster
spacecraft in the plasma sheet during an isolated substorm
at 10:20-11:15 UT, 29 August 2001 are discussed.
The Custer/CODIF data for subinterval 10:55-11:03 UT,
during which a bifurcation of the
current sheet was detected, are studied in particular.
It is shown that ion density and temperature have a
plateau-like profile in the central part of the bifurcated
current sheet. An enhanced proton flow directed in positive
YGSM was detected during the selected subinterval. Other
components of proton bulk velocity are found to be negligibly
small, i.e. the structure is likely not directly associated
with magnetic reconnection. Alternative models, including ion
anisotropy and localized magnetic turbulence, which result in
a two-peak profile of the current density, are discussed briefly.
Full Article in PDF (925 KB) |
|
|