Recent solar radio astronomy at centimeter wavelengths: The temporal variability of the 10.7‐cm flux

Abstract

Studies made by means of high‐resolution radio telescopes indicate that solar centimetric emission contains contributions from many different sources and involves more than one radiation mechanism. Two emission components have been identified: bright, compact sources and weaker, diffuse emission which is distributed over the plage and surrounding areas of enhanced magnetic field. There is evidence for the occurrence of weaker but widely distributed radiation from elements of the active network. The good correlation between the 10.7‐cm flux and shorter‐wavelength indicators of solar activity, such as Ca II emission, suggests that gyromagnetic processes contribute little to the total centimetric flux. If the 10.7‐cm flux is predominantly thermal (free‐free) emission, its intensity will be a measure of the total amount of magnetic flux emerging through the photosphere and supporting density enhancements in the lower solar atmosphere.