Mutual Relations of the Intermediate Periodicities of the Wolf Sunspot Number

First results of an analysis of the temporal variability of the solar activity represented by the relative Wolf sunspot number in the epoch 1850-2002 are presented within range of the intermediate periods from 0.3 up to 4 years. The daily data of the Wolf number has been utilized using the wavelet transform while different ways of estimation of the significance of periods were applied. The performed analysis was focused on a search for possible mutual relations between the appearance of the intermediate periods and their connection to the overall course of the cycle of solar activity. Results have revealed several significant periods but, in general, only of an intermittent character of appearance. Besides some other periods especially that of ~2-year, ~1.3-year, ~0.75-year, and 4-year were found to be significant in several instances of time. Comparison of these results allow to conclude that the quasi-biennial period is not related to any particular phase of the solar cycle and that presence of the 4-year period is independent from the quasi-biennial period. Additionally the well-known 155-day period was confirmed with its particular intermittent appearance both in phase and out of phase of the 1.3-year period in difference time intervals. Possible influence of estimation of the background noise for determination of the significance of periods is discussed as well.

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