Toward the radiation belt forecast in Japan

We have observed satellite anomalies when the flux of highly energetic electrons is extremely high. Highly energetic electrons in the outer radiation belt disappear during the main phase of a magnetic storm, and rebuilding of highly energetic electrons is made during the recovery phase of the magnetic storm. The increase is caused by the supply of intermediate-energy electrons by substorms and these seed electrons are accelerated internally up to the MeV energy range by the intense plasma waves. The distance of the new peak of highly energetic electron flux from the Earth is inversely proportional to the amplitude of the magnetic storm. Integration of the magnetic activity index is a good proxy for the increase of the flux of MeV electrons, not only at the geostationary orbit altitude, but also in the outer radiation belt, which gives us a clue for the radiation belt forecast.