The approximate periodicity of a sunspot cycle is 11 years.

Further research is likely in this area during the present sunspot cycle.

He discovered a correlation between tree rings and the sunspot cycle.

A sunspot cycle of eleven years has been found, with changes in activity.

The number of particles rises and falls with the Sun's sunspot cycle.

Wall Street followed the sunspot cycle, he had said.

And we do need your input on the sunspot cycle.

Individual sunspot cycles are partitioned from one minimum to the next.

However there does seem to be some linkage between the 11-year sunspot cycle and the Earth's climate.

The ice will thicken up again with the next sunspot cycle.