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 Hα 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 disappearance of magnetic flux was always observed when the small fragments of flux encountered other small fragments or concentrations of flux of opposite polarity. This type of disappearance of magnetic flux, called 'cancellation', is shared by both polarities of magnetic field. Cancellation was the only observed means of major loss of flux in the photospheric magnetic fields of the active region. Approaching fragments of opposite polarity flux always collided and, after apparent collision, permanent loss of magnetic flux was subsequently and invariably observed. Thus, cancellation is a highly predictable phenomenon.
- Publication:
-
Australian Journal of Physics
- Pub Date:
- 1985
- DOI:
- 10.1071/PH850929
- Bibcode:
- 1985AuJPh..38..929M
- Keywords:
-
- Magnetic Flux;
- Solar Activity Effects;
- Solar Flares;
- Solar Magnetic Field;
- Cancellation;
- Decay;
- Filtergrams;
- Fragmentation;
- H Alpha Line;
- Magnetic Poles;
- Magnetic Signatures;
- Solar Physics