Teams and Members

The acceleration and loss mechanisms of outer belt particles as well as dynamic evolution of space storms have not been well understood yet in the context of cross-energy and cross-regional coupling. Comprehensive observations of plasma/particles in a wide energy range and electric and magnetic fields in a wide frequency range are essential for the understanding of cross-energy coupling. Complementing satellite observations with ground-based network observations are necessary for the understanding of cross-regional coupling.
The ERG  project has been designed to closely collaborate satellite observations with ground-based observations and simulations and resolve the issues. Namely, the ERG  project is organized into the following teams: the satellite observation team, the ground-based network observation team, and the integrated data analysis/simulation team (Figure 1). The science coordination team and the science center also work with project management. About 100 researchers from about 30 Japanese and overseas institutes/universities participate in the ERG project.

Figure 1: Close collaborations between the three teams.

ERG  Satellite Observation Team

ERG  Satellite Observation Team

  • Project Manager: Iku Shinohara (JAXA)
  • Mission Manager: Takeshi Takashima (JAXA)
  • Mission Submanager: Kazushi Asamura (JAXA)
  • Project Scientist: Yoshizumi Miyoshi (ISEE, Nagoya University)


  • Yosuke Nakamura (JAXA): Project Submanager
  • Seisuke Fukuda (JAXA): Function Manager
  • Kumi Nitta (JAXA): Function Submanager
  • Emiko Ogawa (JAXA)
  • Satoshi Kasahara (JAXA)
  • Takefumi Mitani (JAXA)
  • Ayako Matsuoka (Kyoto University)
  • Kenichiro Maki (JAXA)
  • Makoto Mita (JAXA)

Plasma Particle Experiment Suite (PPE)

  • Lead: Masafumi Hirahara (ISEE, Nagoya University)
  • LEP-e PI: Shiang-Yu Wang, Project Engineer: Yoichi Kazama (Academia Sinica, Taiwan)
  • LEP-i PI: Kazushi Asamura(JAXA)
  • MEP-e PI: Satoshi Kasahara (The University of Tokyo)
  • MEP-i PI: Shoichiro Yokota (Osaka University)
  • HEP PI: Takefumi Mitani (JAXA)
  • XEP PI: Nana Higashio (JAXA)

Magnetic Field Experiment (MGF)

  • PI: Ayako Matsuoka (Kyoto University)

Plasma Wave Experiment (PWE)

  • PI: Yoshiya Kasahara (Kanazawa University), Co-PI: Yasumasa Kasaba (Tohoku University), Satoshi Yagitani (Kanazawa University), Hirotsugu Kojima (RISH, Kyoto University)

Software-type Wave Particle Interaction Analyzer (S-WPIA)

  • PI: Hirotsugu Kojima (RISH, Kyoto University), Co-PI: Yuto Katoh (Tohoku University)

Related Ground-Based Network Observation Team

Multipoint ground-based network observations act as complement to in situ satellite observations. Several networks of SuperDARN HF radars, fluxgate and induction magnetometers, airglow/aurora imagers, riometers, VLF/ELF receivers, and standard LF wave receivers take part in the ERG  project. These ground-based observations can provide the global state of the electric potential, the magnetic field, the current system, particle precipitation, and ULF/ELF/VLF wave activities during space storms. For example, single spacecraft observations cannot determine the spatial distribution of the electric field, but HF radar observations help to resolve the global evolution of the electric fields of both convection and MHD waves.

Integrated Data Analysis/Simulation Team

Integrated analyses of many types of data from both satellite and ground-based observations are crucial for the quantitative understanding of the physical processes affecting particle acceleration and complex dynamics of space storms. Macroprocess and microprocess simulations, which can be compared with observations, are also important for the quantitative understanding of the causal relationships. Several physical models of the inner magnetosphere, such as the GEMSIS ring current model [Amano et al., 2011], the GEMSIS radiation belt model [S. Saito et al., 2010], and a PIC simulation for chorus waves [Hikishima et al., 2009], have been newly developed in Japan and will be compared with observation data from the ERG  project.

Science Coordination Team

The science coordination team promotes close collaborations between the satellite observation team, the ground-based network observation team, and the integrated data analysis/simulation team as well as collaborations with other related satellite missions and international programs.

ERG Science Center

The ERG  Science Center is developing integrated analysis tools for all kinds of project data in cooperation with the THEMIS project [Angelopoulos, 2008] and the Inter-university Upper Atmosphere Global Observation NETwork (IUGONET) project in Japan.