Optimal Spectral Lines for Measuring Chromospheric Magnetic Fields Journal Article uri icon



  • Abstract; This paper identifies spectral lines from X-ray to IR wavelengths which are optimally suited to measuring vector magnetic fields as high as possible in the solar atmosphere. Instrumental and Earth's atmospheric properties, as well as solar abundances, atmospheric properties, and elementary atomic physics are considered without bias toward particular wavelengths or diagnostic techniques. While narrowly focused investigations of individual lines have been reported in detail, no assessment of the comparative merits of all lines has ever been published. Although in the UV, on balance the Mg+; h and k lines near 2800 Å are optimally suited to polarimetry of plasma near the base of the solar corona. This result was unanticipated, given that longer-wavelength lines offer greater sensitivity to the Zeeman effect. While these lines sample optical depths photosphere to the coronal base, we argue that cores of multiple spectral lines provide a far more discriminating probe of magnetic structure as a function of optical depth than the core and inner wings of a strong line. Thus, together with many chromospheric lines of Fe+ between 2585 Å and the h line at 2803 Å, this UV region promises new discoveries concerning how the magnetic fields emerge, heat, and accelerate plasma as they battle to dominate the force and energy balance within the poorly understood chromosphere.

publication date

  • December 1, 2022

has restriction

  • gold

Date in CU Experts

  • June 6, 2023 10:37 AM

Full Author List

  • Judge P; Bryans P; Casini R; Kleint L; Lacatus D; Paraschiv A; Schmit D

author count

  • 7

Other Profiles

International Standard Serial Number (ISSN)

  • 0004-637X

Electronic International Standard Serial Number (EISSN)

  • 1538-4357

Additional Document Info

start page

  • 159

end page

  • 159


  • 941


  • 2