Periodicities in irradiance and in other solar activity indices during cycle 23

Magnetic fields give birth to distinctive features in different solar atmosphere regimes. In this respect time variations of the flare index, the sunspots numbers and the sunspot areas arising from different physical conditions were compared with the solar composite irradiance during the running cycle 23. The Rieger-type periodicities in these time series were calculated using the Fourier and wavelet transforms. The peaks of the wavelet power of these periodicities were appeared between the years 1999-2002. We found that the solar irradiance oscillations compared with the other's, are less significant during this running cycle. The irradiance shows non-periodic fluctuations during this time interval. The peaks of the flare index, the sunspot number and the sunspot total area were seen around 2000.4, 1999.9 and 2001.0, espectively. These periodicities appeared intermittently and were not simultaneous in different solar activity indices between the three years of the maximum phase of the solar cycle 23.