  Wavelet spectral analysis is applied to the daily indices K (SK) registered
in Huancayo geomagnetic observatory from 2000.0 to 2015.0, it has become
possible to identify predominant periodic components with a confidence level of
95%. In particular we have investigated the periodicity of 27.0 days and its
13.5, 9.0 and 6.8 harmonics, related to the fundamental period of solar
rotation effects. A special analysis registered on periods of 59.0 days might
be related to the double period of 29.53 days corresponding to the synodic
month. The manifestation of the periods of 182.6, 365 and 730 days
corresponding to the harmonics of the seasonal variation of the annual cycle is
also observed. An important observation is that the global predominant periods
registered 6.8 and 9.0 days, in the years 2009, 2013 and 2014 its effect is too
small or null, those periods corresponds to the minimum and maximum solar
activity. On the other hand, it is observed that the order of predominance of
the harmonic period solar rotation are different for each solar cycle (Solar
Cycle 23: 9.0, 13.5, 27.0 and 6.8 days; solar cycle 24: 27.0, 13.5, 9.0 and 6.8
days), and it is weaker contribution in the solar cycle 24 with respect to the
solar cycle 23.
