The Cancellation of Magnetic Flux. II. In a Decaying Active Region

Abstract

An active region was studied in detail during its period of decay from 3 to 8 August 1984 using Ha filtergrams and videomagnetograms acquired at the Big Bear Solar Observatory. The decay was initiated by a process of fragmentation in which very small knots of magnetic flux separated from larger concentrations of flux. The fragmentation was observed at discrete locations around the periphery of both the dominant areas of negative and positive field, but possibly occurred more frequently in the main polarity inversion zone. The fragmentation and migration of knots of magnetic flux were common predecessors to the disappearance of flux.