Structure of the near-Earth plasma sheet during tailward flows
Balogh, A.; Nakamura, R.; Fujimoto, M.; Takada, T.; Baumjohann, W.; Asano, Y.; Volwerk, M.; Rème, H.; Runov, A.; Fazakerley, A.; Vörös, Z.; Voronkov, I.; Meurant, M.
Austria, United States, Canada, Japan, Germany, Czech Republic, United Kingdom, France
Abstract
A detailed analysis of successive tailward flow bursts in the near-Earth magnetotail (X~-19 RE) plasma sheet is performed on the basis of in-situ multi-point observations by the Cluster spacecraft on 15 September 2001. The tailward flows were detected during a northward IMF interval, 2.5 h after a substorm expansion. Each flow burst (Vx<300 km/s) was associated with local auroral activation. Enhancements of the parallel and anti-parallel ~1 keV electron flux were detected during the flows. The spacecraft configuration enables to monitor the neutral sheet (Bx≈0) and the level of Bx≈10-15 nT simultaneously, giving a possibility to distinguish between closed plasmoid-like structures and open NFTE-like surges. The data analysis shows NFTE-like structures and localized current filaments embedded into the tailward plasma flow. 3-D shapes of the structures were reconstructed using the four-point magnetic filed measurements and the particle data.