Physics

Dr. Jayant Joshi
University of Oslo, Norway

Abstract: Sunspots are the most readily identifiable manifestation of magnetic field concentrations on the solar surface. Interaction of the sunspot magnetic field with the plasma makes them one of the most interesting objects for research in solar physics. The photospheric structure of the magnetic field of sunspots has been studied extensively in the last few decades through Zeeman diagnostics of various magnetically sensitive spectral lines. On the other hand, observation of the magnetic field in the solar 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 the three-dimensional structure of sunspots, knowledge of the chromospheric magnetic field is essential for understating the small-scale transient events in sunspots, which might have an important role in the chromospheric and coronal heating. 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. Speaker will present some recent results on general and small-scale properties of the chromospheric magnetic field of sunspots.