Fredagskollokvium: Magnetic field of sunspots in the chromosphere
Jayant Joshi, ITA
The photospheric magnetic field of sunspots has been studied extensively in the last few decades through Zeeman diagnostics of various magnetically sensitive spectral lines. Measurement of the magnetic field in the chromosphere is much more challenging than that in the photosphere. Therefore, the chromospheric magnetic field of sunspots has remained lesser explored. In addition to understanding three-dimensional structure of sunspots, knowledge of the chromospheric magnetic field is essential for understating the small-scale transient events in sunspots, e.g., penumbral micro-jets, transition region penumbral bright dots, and chromospheric oscillations. High spatial resolution spectropolarimetric observations from ground-based telescopes, e.g., Swedish 1-meter Solar Telescope (SST) and 1.5-meter GREGOR telescope, have improved our knowledge about different aspects of the chromospheric magnetic field of sunspots. I will present some recent results on general- and fine-structure of the chromospheric magnetic field of sunspots.