Low Frequency Weak Signals Detected in Storm Sudden Commencements: Is There a Correlation With the Solar Magnetic Cycle?

A series of storm sudden commencements (SSCs) is analyzed during the period from 11 to 22 solar cycles using a Dynamical Spectrum technique combined with the Maximum Entropy Method. Our main interest is to study the low frequencies range. Several periodicities were identified at 22y, 18.6y and 30y approximately. Not all the signals are present in the whole period. We believe that they could be associated to the magnetic solar and Gleissberg cycles and possibly with another intermittent solar phenomena. Additionally and comparing with sunspot numbers a sunspot series for the same period has been analyzed with the same methods. Results between SSCs and sunspot numbers show similarities as expected as well as some marked differences also. They will be discussed in the context of their possible origins.