Observation and analysis of chromospheric magnetic fields

TL;DR

This paper presents new spectropolarimetric observations of the solar chromosphere in Ca II 8542, analyzing magnetic fields and atmospheric parameters in active regions and sunspots to improve chromospheric diagnostics.

Contribution

It introduces high-resolution full-Stokes measurements of the chromosphere and applies LTE inversion to derive atmospheric parameters in umbral flashes, advancing chromospheric magnetic field analysis.

Findings

Detected Stokes signals in all four parameters near the limb

Observed signals mainly in Stokes I and V near disk center

Derived atmospheric parameters in umbral flashes using LTE inversion

Abstract

The solar chromosphere is a vigorously dynamic region of the sun, where waves and magnetic fields play an important role. To improve chromospheric diagnostics, we present new observations in Ca II 8542 carried out with the SST/CRISP on La Palma, working in full-Stokes mode. We measured Stokes line profiles in active regions. The line profiles observed close to the solar limb show signals in all four Stokes parameters, while profiles observed close to disk center only show signals above the noise level in Stokes I and V. We used the LTE inversion code 'NICOLE' to derive atmospheric parameters in umbral flashes present in a small round sunspot without penumbra.