Observations and measurements of the highly dynamic chromosphere

The chromosphere is the key atmospheric layer to understand the heating of the Sun’s upper atmosphere, as it isthe conduit for mass and energy transfer from the relatively cold photosphere into the hot corona. However, due to the complex physical conditions governing it, the chromosphere is also the most challenging layer to study.

Thanks to this complexity, the chromospheric landscape is rich of very dynamic and energetic events, which are often driven by not-well understood mechanisms. Their study is then a necessary piece to solve the puzzle of the physics of the chromosphere.

Among the many different dynamic phenomena that can be observed there, jets are indeed some of the most fascinating.

This seminar will focus on the less-studied fan-shaped jets, observed in the most active areas of the Sun. These large-scale jets, which extend to several thousands of kilometers and move at hundreds of km/s, are typical of sunspot light-bridges and sunspot-group penumbrae.

In this presentation, we will show high-spatial resolution observations of such regions, harbouring fan-shaped jets, which were recorded at the Swedish 1-m Solar Telescope by CRisp Imaging SpectroPolarimeter Imaging Spectropolarimeter.

By means of polarimetric data inversion and other techniques that will be discussed, we are able to retrieve some of the main atmospheric parameters, as the magnetic field vector, the temperature and the velocity. The aim is to show how these parameters appear, change with height, and what are the physical consequences of it.