Geodynamo Simulation Using Yin-Yang Grids on the Earth Simulator

Since the Earth is composed of spherical layers, computer simulations of the Earth's interior, such as those concerning the geodynamo and mantle convection,need efficient spatial discretization schemes in spherical geometry.
The importance of non-spectral approaches for large scale simulations on massively parallel computers is now increasingly recognized. In order to make the best use of the Earth Simulator, we have developed a new spherical grid system, the Yin-Yang grid, upon which we have based a finite-difference geodynamo simulation code.  The Yin-Yang geodynamo code attains 46% of theoretical peak performance on 4096 processors of the Earth Simulator.
The basic idea of the Yin-Yang grid and its application to the geodynamo simulation will be presented.  Other applications of the Yin-Yang grid, including simulation of mantle convection and visualization in the spherical geometry, will also be mentioned.
Another focus of this talk will be on the application of the virtual reality (VR) technology to the three-dimensional, interactive, and immersive visualization of simulation data.  Our VR visualization program, VFIVE, for the CAVE-type VR system, will be introduced with its applications to Yin-Yang geodynamo simulation.