Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM17] Space Plasma Physics: Theory and Simulation

Wed. May 23, 2018 9:00 AM - 10:30 AM 304 (3F International Conference Hall, Makuhari Messe)

convener:Takayuki Umeda(Institute for Space-Earth Environmental Research, Nagoya University), Yohei Miyake(Education Center on Computational Science and Engineering, Kobe University), Yasuhiro Nariyuki(富山大学人間発達科学部, 共同), Tadas Nakamura(Fukui Prefectural University), Chairperson:Umeda Takayuki(Institute for Space-Earth Environmental Research, Nagoya University), Miyake Yohei(Education Center on Computational Science and Engineering, Kobe University)

9:45 AM - 10:00 AM

[PEM17-04] Formation Mechanism of Petschek-type Reconnection Region in Uniform Resistivity Plasma

*Takuya Shibayama1, Kanya Kusano1, Takahiro Miyoshi2 (1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Department of Science, Hiroshima University)

Keywords:Magnetic reconnection, MHD, Solar flare

Magnetic reconnection is the explosive energy conversion mechanism of solar flare and magnetospheric substorm. It is, however, still not clear how to explain the fast and explosive energy conversion in the highly conductive plasma of the solar corona or magnetotail. Petschek model is a steady state reconnection model, which can explain fast reconnection. But Kulsrud 2001 argues that Petschek model cannot maintain the diffusion region structure in plasma with uniform resistivity.
We conducted numerical experiment of magnetic reconnection in high Lundquist number (low resistivity) regime and discovered Petschek-type diffusion region appear in a time dependent manner even with uniform resistivity (Shibayama et al. 2015). Furthermore, we developed local model with plasmoid, which allows a formation of quasi-steady Petschek-type fast reconnection in uniform resistivity. In this model, asymmetry of diffusion region between plasmoids restrict the motion of X-point and flow stagnation point. As a result, diffusion region is localized nearby a plasmoid. Reconnection rate is determined by the Petschek-type diffusion region, not by the Sweet-Parker scaling. We can develop a new reconnection regime with Petschek-type model.