Peculiarities of Filament Visual Interaction on the Solar Disk

This chapter discusses some possibilities of magnetic-field line reconnection of solar filaments approaching each other, along with photospheric polarity inversion lines changing their positions. The interaction between filaments depends on their internal properties, which are determined by the filament chirality, or the sign of the helicity of the filament magnetic field. In quadrupolar magnetic configurations, filaments with the same chirality can exchange their halves. Filaments with opposite chirality rupture after the reconnection of the polarity inversion lines, since the two fragments of the different filaments cannot be connected continuously. Observations of filaments are presented that cross each other and this pattern exists for more or less long periods of time. They are always associated with quadrupolar magnetic configurations of the photospheric field.