Chromospheric magnetometry from high-resolution, ground-based observations

Measurements of the magnetic field is key to our understanding of the structure, dynamics and evolution of the solar atmosphere. The most powerful magnetic diagnostics of solar and astrophysical plasmas are based on measurements of polarized states of light (polarimetry). Polarimetry of the Sun's chromosphere and corona are challenging due to the inherently low signal-to-noise ratios. These layers are populated with relatively cool and dense structures, such as spicules, prominences, flare loops and coronal rains. These structures, tracing the magnetic field lines, are visible in optical and near infrared spectral regions and hence can be observed with the large aperture, highest resolution ground-based telescopes giving an unique diagnostic for measuring the otherwise unknown magnetic field. In this seminar I will present results from our recent works were magnetic field has been successfully measured using chromospheric diagnostic. In particular, I will present the ground-based observations obtained with Swedish Solar Telescope and Daniel K. Inouye Solar Telescope that yielded some unique spectropolarimetry and allowed the construction of the maps of the magnetic field of the off-limb flare loops, plage chromosphere and spicules. I will discuss the inconsistencies and contradictions of some magnetic field estimates inferred with different techniques in the chromosphere and corona.