HR: 0800h
AN: SM51B-0372    [Abstracts]
TI: Electromagnetic Particle Code With Adaptive Mesh Refinement Technique: Application to the Plasma Sheet
AU: * Fujimoto, K
EM: keizo@kugi.kyoto-u.ac.jp
AF: Department of Geophysics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwaketyo, Sakyo-ku, Kyoto, 606-8502 Japan
AU: Machida, S
EM: machida@kugi.kyoto-u.ac.jp
AF: Department of Geophysics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwaketyo, Sakyo-ku, Kyoto, 606-8502 Japan
AB: It is widely believed that magnetic reconnection plays an important role in the magnetospheric substorm and solar flares. However, physical processes around the diffusion region are not well understood. Recently, it has been suggested that multi-scale coupling process should be important in the reconnection triggering and the anomalous plasma heating and acceleration around the diffusion region. It is necessary to conduct a self-consistent large-scale simulation including phenomena with various scales to describe multi-scale coupling. However, a realization of such a simulation with an ordinary PIC technique is still difficult because electron-scale phenomena are very localized and embedded in an ion-scale or MHD-scale system. To overcome this difficulty, we made a new 2-1/2 dimensional electromagnetic particle code with adaptive mesh refinement (AMR) technique. The AMR technique dynamically subdivides the cells that satisfy a refinement criterion and effectively achieves high-resolution simulations. In fact, it is only in the vicinity of the central current sheet where high-resolution simulations are required and we can reduce the number of cells in the lobe region where plasma density is low so that both the electron Debye length and a characteristic scale length are large. Though conventional AMR algorithm has been unsuitable to the parallel computation, our code is improved by adopting the fully threaded tree (FTT) algorithm developed by Khokhlov (1998), which facilitates to modify the cell structure in parallel. The AMR technique is expected to be one of the promising methods to realize self-consistent multi-scale simulations. In this paper, we report the results of some test simulations and discuss the limitations of our code, especially the reflections at the boundaries of the refined regions. We also report the results on the time developing Harris plasma sheet and show that the hierarchical cell structure is automatically reconstructed and fine cells are produced in the central plasma sheet, especially around the X-type neutral line.
DE: 2744 Magnetotail
DE: 2753 Numerical modeling
DE: 2764 Plasma sheet
DE: 2794 Instruments and techniques
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting