Short and long-term variability of solar cycle and
fluctuations of dynamo drivers
Dmitry Sokoloff1,2
1
Department of Physics, Moscow State University, Moscow, Russia
2
IZMIRAN, Moscow, Russia
Cyclic solar activity is far to be just a sinusoidal oscillations. Shape of activity wave
underlying by a wave of quasistationary magnetic field varies from one cycle to the
other. Moreover, from time to time catastrophyc events like Maunder minimum and
other Grand minima occur. A short presentation of available observations for this
variability is given.
The cycle is supported by solar dynamo based on a joint action of mirror-asymmetric
convection and differential rotation. The dynamo drivers being spatial averaging of
noisy quantities contain some random contributions. Contemporary ideas concerning
possible amplitude of such noisy contributions are considered.
We argue that these noisy contributions can be sufficient to explain the observed
variability of solar cycle.