ROLE OF HELICITY IN THE FORMATION OF INTERMEDIATE FILAMENTS

In the last few years new observations have shown that solar filaments and filament channels have a surprising hemispheric pattern. To expla in this pattern, a new theory for filament channel and filament format ion is put forward. The theory describes the formation of a specific t ype of filament, namely the 'intermediate filament' which forms either between active regions or at the boundary of an active region. It des cribes the formation in terms of the emergence of a sheared activity c omplex. The complex then interacts with remnant flux and, after conver gence and flux cancellation, the filament forms in the channel. A key feature of the model is the net magnetic helicity of the complex. With the correct sign a filament channel can form, but with the opposite s ign no filament channel forms after convergence. It is shown how the h emispheric pattern of helicity in emerging flux regions produces the o bserved hemispheric pattern for filaments.