Radio Noise Storms and the Connection with the Reorganization of Photospheric Magnetic Fields

This work presents the analysis of a Type-I radio noise storm (RNS) recorded by the CALLISTO spectrometers network. Considering that RNSs are associated with the reorganization of the photospheric magnetic field of active regions, we have analyzed the temporal evolution of the magnetic power spectra and the dissipation spectra of the photospheric magnetic field of two active regions (NOAA 11542 and NOAA 11543). This analysis was used to identify for which wave-numbers and time intervals this reorganization occurs. The Type-I emission is supposedly generated by the fundamental emission of plasma, and the reorganization of the line-of-sight component of the photospheric magnetic field was investigated as a possible mechanism responsible for the maintenance process of the RNS. The analysis of the magnetic power spectra and the dissipation spectra showed that the RNS was probably generated and maintained by the reorganization of the magnetic field of NOAA 11542. The reorganization of the magnetic-energy spectra occurs mainly for wave-numbers smaller than 0.2 Mm−¹ and the dissipation spectrum increases for wave-numbers around 1 Mm−¹.