Review of Chromospheric Magnetic Field Measurement from SOLIS/VSM Instrument at NSO, Tucson.

Abstract:

SOLIS/VSM instrument makes fulldisk synoptic measurements of the magnetic field at the photospheric and chromospheric layers of the Sun routinely. In my presentation I will briefly review the instrument capabilities and data products. Further, I will give a detailed account of the results obtained in relation to the chromospheric magnetic field in solar active regions. Some of these results pertain to observed longitudinal chromospheric field and its comparison with current free field extrapolations using photospheric longitudinal magnetograms. The inference of field topology in superpenumbral canopy and filament channels using solar rotation will be presented. Also, I will summarize recent upgrades that enabled the full Stokes measurements of the chromospheric Ca Ii 854.2 nm spectral line. These observations will allow inference of vector magnetic field in active region chromosphere routinely. Quick look vector maps derived under weak field approximation will be presented.