Topic/Type: 1.1 Space & astrophysical plasmas, Poster

Comparative study of global MHD simulations of the terrestrial magnetosphere with different modern numerical schemes

Y. Matsumoto1, N. Terada2, T. Miyoshi3, K. Fukazawa4, T. Umeda1, K. Seki1

1 Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, Japan
2 Department of Geophysics, Tohoku University, Sendai, Miyagi, Japan
3 Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
4 Department of Earth and Planetary Sciences, Kyushu University, Fukuoka, Japan

Since 1980\'s the magnetohydrodynamic (MHD) simulation has been a powerful tool for modeling an interaction of the supersonic solar wind plasma with the terrestrial magnetosphere. Increasing computational capability enables us to predict the geospace environment in response to transient solar activities such as the coronal mass ejection (CME), that is, Space Weather forecast. Nowadays, a number of global MHD models have been developed. However, due to restricted CPU time and a memory capacity, even the modern global MHD models of the magnetosphere solve limited area in the magnetosphere and physical processes. Despite the great progresses on the global MHD simulations, some issues are remained to be solved for the future high performance computing.

Recent numerical simulations and in-situ observations have shown that turbulence is of particular importance in discussing plasma transport and acceleration in the magnetosphere. For example, the turbulent transport of the solar wind plasma via Kelvin-Helmholtz instability has been proposed by the local numerical simulations [Matsumoto and Hoshino, 2006]. In-situ observations of the high energy electrons in the plasma sheet can be also related to the turbulent magnetic fields [Imada et al., 2005]. Despite its importance, little has been understood by the global MHD simulations. This is mainly due to the spatial resolution which increases both CPU time and memory consumption. To tackle with this problem, robust and high-resolution schemes have been required. Also, there has been no comprehensive comparative study under a same solar wind condition with different numerical schemes. In this presentation, we compare recent global MHD models based on modern MHD schemes. These include the shock capturing schemes based on HLLD Rieman solver [Miyoshi and Kusano, 2005] and the semi-discrete central scheme [Kurganov and Tadmor, 2000], the semi-Lagrangian scheme based on the CIP algorithm [Matsumoto and Seki, 2008], and the finite difference method based on the modified leapfrog scheme [e.g., Ogino et al., 1992]. Advantages and disadvantages of each scheme are discussed in the context of the interaction of the solar wind with the terrestrial magnetosphere.