A significant degree of linear polarization (up to few percent) of some spectral lines is occasionally reported from the observations of solar flares. This polarization is often found at the edges of the flare ribbons and it is usually radial or tangential. The mechanism usually considered as being responsible for this effect is the impact polarization by electron and/or proton beams bombarding the chromosphere. We point out that resonant scattering polarization in a multi-dimensional geometry of the chromosphere has to be considered as an important ingredient of the problem. The significant horizontal inhomogeneities at the boundaries of the flare ribbons causes a considerable change in the radiation field anisotropy which may lead to emission of strongly linearly polarized spectral lines. For more details see ?těpán & Heinzel (2013)
展开▼
