Coronal magnetic fields from the inversion of linear polarization measurements

Radio Measurements of Coronal Magnetic Fields

The measurement of magnetic field strengths in the solar corona using radio observations is reviewed. This is a well established technique that exploits the fact that the electron gyrofrequency for typical coronal magnetic field strengths (100–2000 Gauss) lies in the radio frequency range. Opacity from the resulting gyroresonance emission from hot plasma above active regions allows the direct m...

Reconstruction of Solar Coronal Linear Force-Free Magnetic Field

Coronal Magnetic Field Measurements

A long-standing solar problem has been to measure the coronal magnetic field. We believe it determines the coronal structure and dynamics from the upper chromosphere out into the heliospheric environment. It is only recently that Zeeman splitting observations of infrared coronal emission lines have been successfully used to deduce the coronal magnetic flux density. Here we extend this technique...

Spectral Lines for Polarization Measurements of the Coronal Magnetic Field. Iv. Stokes Signals in Current-carrying Fields

We present the first theoretical, forward calculations of the Stokes profiles of several magnetic dipole (‘‘M1’’) coronal emission lines produced in current-carrying magnetic structures. An idealized coronal model of Low, Fong, and Fan is used, which describes a spherically symmetric, hydrostatic background atmosphere, isothermal at a coronal temperature of 1:6 ; 10 K. Embedded is a global, axi...

Magnetic Linear Birefringence Measurements Using Pulsed Fields