Recurrent solar cosmic ray events and solarMregions

During the latter stages of cycle 19, a characteristic series of M region magnetic storms were observed from 1962–1964. Energetic particle events were associated with many of these storms. The relation between the corotating particle stream and magnetic disturbances is examined. These particle increases appear to be similar to those that sometimes appear on the next solar rotation after a large flare-associated particle event. Both sets of data strongly suggest that the volume above some active centers is magnetically closed. This provides the trapping region with particles preferentially escaping from the base of the preceding portion of the bipolar region. Many of the statistical studies of M regions, which established that there is a geomagnetic minumum some 3 days after the central meridian passage of an active center, support this view. A simple model for these particle events is proposed.