The sunspot activity is the end result of the cyclic destruction and regeneration of magnetic fields by the dynamo action .
We propose a new method to analyze the daily sunspot areas data recorded since 1874 .
By computing the power spectral density of daily data series using the Mexican hat wavelet , we found a power spectrum with a well-defined shape , characterized by three features .
The first term is the 22 yr solar magnetic cycle , estimated in our work to be of 18.43 yr .
The second term is related to the daily volatility of sunspots .
This term is most likely produced by the turbulent motions linked to the solar granulation .
The last term corresponds to a periodic source associated with the solar magnetic activity , for which the maximum of power spectral density occurs at 22.67 days .
This value is part of the 22–27 day periodicity region that shows an above-average intensity in the power spectra .
The origin of this 22.67 day periodic process is not clearly identified , and there is a possibility that it can be produced by convective flows inside the star .
The study clearly shows a north-south asymmetry .
The 18.43 yr periodical source is correlated between the two hemispheres , but the 22.67 day one is not correlated .
It is shown that towards the large timescales an excess occurs in the northern hemisphere , especially near the previous two periodic sources .
To further investigate the 22.67 day periodicity we made a Lomb-Scargle spectral analysis .
The study suggests that this periodicity is distinct from others found nearby .