Study of the substorm: Part 1: From the observation at Syowa Station to the motivation for simulation

Abstract

I had an opportunity to observe the auroral substorm at Syowa Station through the participation in the 24th JARE, and got a strong motivation to study the substorm. Since then, I have been trying to reproduce the substorm from the numerical simulation. My intention was to start from the reproduction of whole magnetosphereionosphere (M-I) system and then realize the substorm observations as parts in the reproduced whole. For this purpose, I developed the finite volume TVD scheme, magnetohydrodynamic (MHD) equations with potential field subtraction, and a triangular grid system made from a dodecahedron. These studies enabled the reproduction of the field-aligned current (FAC) and M-I coupling convection. Recently, initial intention is achieved from the high-resolution version of simulation that adopts a large-scale mpi-omp hybrid simulation. From these calculations, we can reproduce local substorm perturbations and developments of the whole system, self-consistently. Looking at these results, we can reconsider the magnetospheric physics so far believed. In the traditional magnetospheric physics, the whole is estimated from the analysis of parts. The simulation results show that many misleadings are included in the whole structure estimated from parts.