The Maunder Minimum was a period of low solar activity characterized by few sunspots. During the roughly 75 years of this Minimum, global temperatures were well below normal.
David Archibald figures that the time between Cycle 23 and Cycle 24 Solar Maximum will be 15 years. The time between Solar Maximums is typically 11 years.
Archibald conclude based on the longer period of time between Maximums that:
“Activity and timing of the current minimum, as well as the timing of the Solar Cycle 24 maximum in 2015, is paralleling the start of the Maunder Minimum. There is no data to date which diverges from the pattern of the start of the Maunder Minimum.”
Dr Lief Svalgaard presented this chart at Solar Analogs II, September 22, 2009. This chart plots sunspot locations across the face of the Sun during cycles 21, 22, 23 and the new cycle 24. Svalgaard overlaid a green arrow on the trail of the sunspots toward the Equator. This movement is called Sporer’s Law and it is chacterized by this statement from Wikipedia:
“At the start of a sunspot cycle, sunspots tend to appear around 30° to 45° latitude on the Sun‘s surface. As the cycle progresses, sunspots appear at lower and lower latitudes, until they average 15° at solar maximum. The average latitude of sunspots then continues to drift lower, down to about 7° and then while the old sunspot cycle fades, sunspots of the new cycle start appearing at high latitudes.”
Archibald overlaid a yellow bar that is a measure of years between the cycle 23 and the developing cycle 24 and gets 15 years. This is technique is consistent with the measured 10 years between the former Cycles 22 and 23. The Solar cycles during the Maunder Minimum period averaged 20 years.
You can read all of David Archibald’s posting by clicking here.
Lief Svalgaard’s presentation at Solar Analogs II can be seen by clicking here.
Svalgaard is a little more reticent than Archibald about predicting solar cycles,as you will see if you read his presentation.
While I am not a big leaguer like Svalgaard and Archibald, it seems to me to be a little early to call a new Maunder Minimum.
Cbdakota
Climate Change Sanity 