Presentation #202.02 in the session Observing and Inferring Solar Chromospheric and Coronal Magnetic Fields I.
Magnetism is paramount to most, if not all, solar and stellar physics phenomena and how stars interact with planetary environments, particularly those residing in the habitable zone. Solar magnetic fields are generated by dynamo processes in the convection zone and rise through the photosphere to dominate the corona and solar wind. It structures the atmosphere and causes eruptive activity that drives space weather. Most importantly, the magnetic field controls the transfer of the mechanical energy abundant in the solar interior to heat and accelerate the plasma in the corona and the solar wind. Knowing the magnetic field and its evolution is essential for understanding how the Sun works. Despite the significant advances in observing solar magnetic fields, particularly in the photosphere, we still face major hurdles to routinely measuring the field in the chromosphere and the corona, where most of the action occurs. I will review the techniques used to observe magnetic fields in the chromosphere and the corona, including the theoretical, computational, and instrumental aspects, and what it entails to make significant strides toward determining the magnetic field reliably and routinely in the upper layers of the solar atmosphere.