HR: 0800h
AN: SM41C-1203    [Abstracts]
TI: Comparison between Features of Very Thin Current Sheets Observed From Cluster and 3D Simulations
AU: * Singh, N
EM: singh@eng.uah.edu
AF: The University of Alabama in Huntsville, Electrical and Computer Engineering, Huntsville, AL 35899 United States
AU: * Singh, N
EM: singh@eng.uah.edu
AF: The University of Alabama in Huntsville, Center for Space Plasma and Aeronomy Research, Huntsville, AL 35899 United States
AU: Deverapalli, C
EM: deverapallic@cspar.uah.edu
AF: The University of Alabama in Huntsville, Center for Space Plasma and Aeronomy Research, Huntsville, AL 35899 United States
AB: The features of evolving current sheets (CS) are studied using fully 3D particle-in-cell (3DPIC) simulations. Some of the features are found to be remarkably similar to those revealed by recent observations from Cluster [Wygant et al., 2005]. In a recent paper from Cluster by Wygant et al. [2005] the following features of CSs in the magneto-tail are highlighted: (i) Thin CSs with widths of a few electron skin depth (~3le) are embedded in wider ones of thickness (~10-40le). (ii) Sometimes the very thin CSs are bifurcated with a current disruption in the middle. (iii) The embedded thin CSs are co-located with a deep potential well. (iv)Un-magnetized ions are accelerated into the potential well. Such remarkably similar features of CSs are also seen in our simulations. The simulation shows that a very thin CS develops dynamically in the midst of a wider CS as revealed by Cluster. The thin CS develops under the influence of the J'B force on the electrons. As the electrons move into the center of the CS under the influence of this force, the central region becomes negative and un-magnetized ions are accelerated into the potential well. During the course of the evolution of the CS the depth of the potential well can be as high as ~20 kBTe/e, which could easily range in a few kV range. Instabilities developing in the embedded thin CS disrupts the current in its central part [Singh, 2004], bifurcating it. Wygant et al. [2005] point out that the each part of the bifurcated CS have widths of about ~3le. This is borne out from our simulations.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 6984 Waves in plasma (7867)
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005