Physical properties of chromospheric features, plage, peacock jets, and calibrating it all

The chromosphere is a complex and dynamic layer of the solar atmosphere, largely dominated by the local magnetic field configuration. It acts as an important interface between the photosphere below it and the hot corona above. However, studying this layer is not straightforward, as it is largely transparent in optical wavelengths. On top of that most of its observable radiation is formed in conditions far from thermodynamic equilibrium, and thus only partially sensitive to local plasma conditions. Observations of the active features found in the chromosphere such as plage, fibrils, and jets, are therefore more difficult to interpret than emission from active features in the photosphere. In this seminar I will discuss two types of chromospheric features, namely plage and a peacock jet.