Geomagnetic storms contrasted during solar maximum and near solar minimum Original Research Article

Although considerable attention has been focused on CMEs/magnetic clouds and geomagnetic activity during solar maximum, very little effort has been expended towards understanding the effects of proto CIRs (Corotating Interaction Regions) during the descending phase of the solar cycle. We show that the three phases of magnetic storms (initial, main and recovery) associated to proto CIRs are considerably different than those during solar maximum. We also indicate that auroral activity can be significantly higher during the descending phase than during solar maximum.