Fine Scale Radio Studies of the Sun.
Abstract
Major flare eruptions in solar active regions create geophysical disturbances which may seriously disrupt Air Force communication and surveillance systems. This report discusses interferometric observations of solar active regions which show that small-scale, highly circularly polarized sources dominate solar emission at radio wavelengths. The small-scale sources emit intense circularly polarized radiation immediately prior to and during the eruption of solar flares, whereas the circularly polarized emission remains at a lower, constant level whenever the active regions are quiescent and not erupting. The circular polarization of the flare precursors indicates a direct connection with changing magnetic fields in the solar active regions. The precursors reflect changing magnetic fields which may trigger subsequent flare eruptions, and these trigger sources may serve as reliable flare predictors. Studies of the changes in circularly polarized emission during the flare eruptions suggest that the flare eruption process is also the result of changes in magnetic fields. This report further discusses the synthesis mapping technique in which simultaneous solar observations with as many as 55 different interferometer pairs have been used to produce radio wavelength maps of active regions with second of arc angular resolution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1978
- Accession Number
- ADA062243
Entities
People
- Kenneth R. Lang
Organizations
- Tufts University