Spectral features of large type IV bursts and interrelation to solar-terrestrial phenomena

The type IV burst phenomenon consists of at least five physically distinct components or phases. Concerning the spectral and polarization characteristics of the radio emission, the X-ray emission and the association of energetic particle emission, two main classes of type IV burst components can be distinguished. The first class associated with energetic particle events comprises the (especially hard) X-ray burst, the type IV and mA₁ components. With respect to the dynamics of the burst source a quasistationary mA₁-phase can be distinguished from a moving mA₂-phase. The general tendencies of the development of large type IV events have been discussed with regard to the possibility of the occurrence of neutral points of the magnetic field in greater coronal heights.