The Growth of the Storm-Time Radiation Belt and the Magnetospheric Substorm

Important features of the radiation belt (or the so-called ‘ring current”) which grows in the magnetosphere during geomagnetic storms are summarized. The growth of the belt is studied in relation to a frequent occurrence of intense magnetsospheric substorms (of which manifestations in the polar upper atmosphere are the auroral and polar magnetic substorms). It is concluded that during the magnetospheric substorm, the particles responsible for the storm-time belt are produced locally in the trapping region in the evening sector, but not in the midnight sector.