Quasi-Periodicity in global solar radio flux at metric wavelengths   during Noise Storms
  We present observational results from studying the quasi-periodicities in global solar radio flux during periods of enhanced noise storm activity, over durations of ~4 hrs a day ("intra-day" variations), observed at 77.5 MHz with the newly commissioned log-periodic array tracking system at the Gauribidanur radio observatory. Positional information on the storm centers were obtained with the radio imaging data from the Nancay (sic.) Radioheliograph (NRH), while their active region (AR) counterparts on the photosphere (and the overlying chromosphere) were located from the H-alpha images of the Big Bear Solar Observatory (BBSO). The quasi-periodicity in flux was found to be 110 minutes, with the fluctuation in flux being 3(+/- 1.5) solar flux units (sfu). The results of such pulsations are interpreted qualitatively as evidence for coronal seismology. 
G. A. Shanmugha Sundaram & K. R. Subramanian