Principles of magnetohydrodynamic simulation in space plasmas.

The aim of this article is to place a special emphasis on the philosophical as well as physical principles which are essential in the establishment of the magnetohydrodynamic (MHD) simulation study in the solar terrestrial plasma research. Taking the limits of the abilities of the present-day computers for granted, the author emphasizes the importance of the "local" MHD simulation. The local MHD simulation is defined as a self-contained MHD simulation in each elementary region. Differences in the roles between the local and present-day global MHD simulations are briefly discussed. The importance and difficulties of the boundary condition are also discussed in some detail. Finally, a couple of notes on the finite-difference method and the importance of the diagnostics are pointed out.