Flows through the magnetically structured solar atmosphere

Abstract

The upper solar atmosphere until three solar radii is controlled by the magnetic field. The plasma β (P kin/P magn) is decreasing with increasing altitude in the low corona but is already less than unity in the middle chromosphere. The dynamics of the chromosphere and the transition region are driven by magnetic effects, even in the “quiet” Sun. We will review some promising research programs concerning steady flows and oscillatory phenomena in the small scale structures, mainly based on new two-dimensional spectral diagnostics. The filamentary behaviour of the solar atmosphere may be the key to understanding basic problems like coronal heating. The importance of the chromospheric network, plages and penumbra is emphasized by the fact that they represent footpoints of coronal loops. Largescale coronal structures (streamers, jets, post-flare loops, arcades) are linked to photospheric and chromospheric events and give a three-dimensional view of the atmosphere.