On the longitudinal localization of the substorm active region and its changes during the substorm

During the expansive phase of a substorm the active region frequently changes its situation by a jump, both to the evening and morning sectors. The typical interval between successive activizations is often ? 10–20 min. It is emphasized that in such events the definition of a substorm phase for all the magnetosphere is ambiguous, because the conditions characteristic for different phases can be realized in different parts of the magnetosphere simultaneously.