Macro-Micro Multiplier Simulator

Tetsuya Sato
The Earth Simulator Center
Japan Agency for Marine-Earth Science and Technology

Simulation Science is now standing on a turning point. After the appearance of the Earth Simulator, HEC is struggling with several severe difficulties due to the physical limit of LSI technologies and the so-called latency problem. In this paper I would like to propose one clever way to overcome these difficulties from the simulation algorithm viewpoint. Nature and artificial products are usually organized with several nearly autonomously acting internal systems. The Earth Simulator has gifted us with a scientific tool that can deal with the evolution of one such internal system with a sufficient soundness. In order to make a leap jump of Simulation Science, therefore, it is desired to design an innovative simulator that enables us to deal with simultaneously and as consistently as possible a real system that evolves cooperatively with several internal autonomous systems.

In this paper, I propose one clever simulation algorithm, which I would like to call “Algorithm for multiple interlocking systems”, or “Macro-Micro Multiplier algorithm”, and present a couple of such examples to validate the proposed algorithm. The first example is an aurora-arc formation as a result of the combination between the Magnetosphere-Ionosphere macroscopic coupling and the microscopic field-aligned electron and ion coupling. The second example is the local heavy rain fall resulting from the interaction between the global climate environment and the local raindrop growth process. I came up with this novel algorithm as a natural idea emerging from the three years productive experience of the Earth Simulator Project.