Carrington Longitude Research Articles

A series of related active regions during January 14 ? June 1, 1969

The history of a series of active regions is traced for the first half of 1969. At least four active regions successively occupied positions near Carrington longitude 270. In some cases the emergence of new regions in the midst of old regions was observed. All the larger flares observed in the studied region were associated with inverted polarity. In some cases the fields emerged inverted; in other cases the inverted polarity appeared to result from the interaction of emerging flux with fields already present at the surface.

Unusual solar disturbance

The solar flares, the speeds of shocks propagated in the solar-terrestrial space and driven by coronal mass ejections (CMEs), the heliographic longitudes and Carrington longitudes of source regions, and the geomagnetic storms, which are accompanied by the super solar proton events with a peak flux equal to or exceeding 10 000 pfu, have been studied by using the data of ground-based and space observations. The results show that the heliographic longitudes of source regions of super solar proton events distributed in the range from E30̊ to W75°. The Carrington longitudes of source regions of super solar proton events distributed in the two longitudinal belts, 130°∼220° and 260°∼320°, respectively. All super solar proton events were accompanied by major solar flares and fast CMEs. The averaged speeds of shocks propagated from the sun to the Earth were greater than 1 200 km/s. Eight super solar proton events were followed by major geomagnetic storms (Dst≤−100 nT), except that one super solar proton event was followed by a geomagnetic storm with the geomagnetic activity index Dst=−96 nT, a little smaller than that of major geomagnetic storms.