Solar Radio Emission of Spectral Type IV and its Association with Geomagnetic Storms

Abstract

A new type of solar radio event, the type IV storm, first described by Boischot, has been identified on Dapto radio.spectrographic records. It has been shown to be distinguishable from type I storms by (i) its smooth spectrum, (ii) its close association with type II bursts, and (iii) its remarkably close association with geomagnetic storms. In common with some type I storms, all type IV storms are found to be associated with very large solar flares.