Some characteristics of the development and decay of active region magnetic flux

Mount Wilson synoptic data of both plages and sunspots are examined in an effort to determine in some detail the manner of the appearance and disappearance of the magnetic flux of active regions at the solar surface. Separating regions into leading and following portions by magnetic polarity in the case of the plages and by position in the case of sunspots (for which there is no magnetic information available in this data set), various characteristics of these features are studied, namely their rotation, their relative longitudinal motions, and the east-west inclinations of their magnetic fields. The evidence, taken together, suggests that the magnetic flux loops which comprise a region rise to the surface at the time of its formation, and (at least some of them) sink back below the surface at the time of the decay of the region. It is likely that not all the magnetic flux that arises sinks again below the surface.Operated by the Association of Universities for Research in Astronomy, Inc., under Cooperative Agreement with the National Science Foundation.