This is known as the sunspot cycle.

这是被称为太阳黑子周期。

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Many Numbers were based on the sunspot cycle, which they had discovered.

很多号码在太阳黑子周期，这是他们发现的。

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He then correlated the reams of data he'd gathered with the 11-year sunspot cycle.

然后他关联他已收集的大量数据，与11年的太阳黑子活动周期。

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They also argue about the effect of changes in the sunspot cycle on temperatures.

ECONOMIST: A heated controversy

That output is known to vary during the course of the 11-year sunspot cycle, as well as over the longer term, and although such changes have not been matched to temperature changes in the way that rises in the level of greenhouse gases have been, they may still be making a contribution.

ECONOMIST: Changing science

But in the current cycle, sunspot activity has collapsed.

FORBES: To The Horror Of Global Warming Alarmists, Global Cooling Is Here