Coronal Magnetic Fields Deduced from Radio Methods

Abstract

AbstractMajor problems of the physics of the solar atmosphere and processes of solar activity are due to the poor knowledge of the magnetic fields outside the photosphere. Unique methods to determine magnetic fields in the corona and chromosphere make use of radio observations in close connection with information obtained in other spectral ranges e.g. the optical and X-ray regions. Based on relevant emission and propagation processes, the basic radio methods providing information on the parent magnetic fields are summarized. Signatures in the microwave and meter wave regions are used to derive magnetic field parameters at different levels in the solar atmosphere of active regions during quiet and flaring conditions. Implications on fine and gross structures are briefly discussed and consequences on acting physical processes mentioned.