SUNSPOT CYCLE ANOMALY
Spectrum analysis shows strong 52 and 105 year peaks Graphic representation of the anomaly: The graph depicts anomalies (with fundamental half-period of 52.5 years) within solar periodic activity with an immediately recognisable minimum between 1650-1700, coinciding with the Maunder Minimum.
Further relevant dates are at or near the equation's zero value:
1809 - Dalton minimum;
1913 - another minimum but not so pronounced;
1860 and 1969 are the years of two cycles with suppressed amplitudes, 30% - 50% lower than in the neighbouring peaks

The anomaly was first described here:Resonance

Possible consequences of the anomaly are also evident in:
More charts can be found here: Graphs and Formulae

© m.a. vukcevic