Wavelet analysis of photospheric magnetic flux

We link 342 NSO/Kitt Peak synoptic charts during 1978 to 2003 one by one in time order and reconstruct a daily sequence of photospheric magnetic flux (PMF). By using wavelet transform (WT) some typical mid-term periodicities of PMF are identified, such as 1.38-year, 332-, 275- and 158-day periods. We discuss briefly their temporal evolutions and mutual relations in this paper. For a comparison with another solar general index, we also analyze the periodicities of total solar irradiance (TSI) with the same method. We find the wavelet power spectra of such two sequences are very similar. Therefore, we think PMF and TSI may have some common physical origins.