Open Questions and New Challenges in Chromospheric Solar Physics

Abstract:

The heating and mass loading mechanisms of the solar chromosphere remain some of the foremost open questions in solar physics. In particular, the exact role of processes related to magnetic fields remains greatly unconstrained. Our understanding of chromospheric physics has greatly evolved during the past 10 years thanks to a new generation facilities that have allowed observing the chromosphere with unprecedented spatio-temporal resolution including very rich spectral information. The interpretation of such complex data has been possible to a large extent thanks to new 3D magnetohydrodynamic simulation and advanced non-local thermodynamical inversion methods. Despite great progress in our understanding of some observational signatures that are present in the chromosphere such as spicules, bursts and a variety of jets, these new data also have revealed other challenges that we have not been able to properly address. In this review I will present a selection of open questions in chromospheric physics, along with new insights from observations and simulations.