Interpretation of fast magnetic-field changes associated with solar flares

The topological model was applied to explain changes recently revealed in the magnetic field of the active region NOAA 9077 during the July 14, 2000 flare. The following observed effects were explained self-consistently: 1) the magnetic field decreases in outer regions of the sunspot group and intensifies in the inner region near the neutral line; 2) centers of «masses» of the north and south magnetic polarities approach each other; 3) the active region's magnetic flux decreases. These changes were shown to result from the restructuring of the coronal magnetic field due to the reconnection at separators.