‘Geospace’ represents the near-Earth space where the influence of Earth is noticeable. Human activities in geospace have become important since the 20th century. Exploration and utilization of the near-Earth space started in the 1960s, and the space infrastructure, such as meteorological spacecraft for weather forecasting and GPS satellites for navigation systems, has become a part of our daily life. Our research field, space physics, has developed rapidly since the beginning of the space age, and describing and understanding dynamic variations in the geospace environment has become one of the outstanding problems in space physics. Research into geospace storms, which can cause various natural and artificial phenomena, such as active auroras, satellite communication blackouts, and spacecraft malfunctions, are getting more international focus in preparation for the next solar maximum. RBSP (Radiation Belt Storm Probes) and Orbitals missions are being conducted in the US and Canada, respectively, with the ILWS (International Living With a Star) program aiming at the launch of geospace exploration satellites around 2013. Japan is also planning the ERG (Energization and Radiation in Geospace) project as a mission of the scientific community. One of characteristics of the ERG project is close collaboration between three task teams, namely, the satellite, ground-based observation, and theory/simulation/modeling teams.
Research activities in the GEMSIS project are expected to carry an important part of the ERG theory/simulation/modeling team.