Sunspot Cycle in 100 Year Dip

The Royal Observatory of Belgium published July’s official sunspot number on August 1st. It is 57.0. That’s a slight uptick from last month’s 52.5. The uptick came on the strength of a couple exceptionally active sunspot groups early in July.

Activity has tapered off again. We are at solar max of an exceptionally weak Solar Cycle 24. A normal sunspot number would be about 119. The forecast high for this cycle was only 90, but It is even 1/3rd below that right now.

So what’s the deal? Why so pathetically puny?

The 100-year Sunspot Cycle

One possibility is a 100-year centenarian periodicity superimposed on top of the well-known 11-year sunspot cycle.

This makes four centuries in a row that we have started out with weak solar maximums.

We may be near the minimum of the 100-year cycle.

There were feeble sunspot maximums at the beginning of each of the previous three centuries.

Early indicators are that Solar Cycle 25 will be even weaker than the current cycle.

Admittedly, this evidence is anemic, circumstantial at best. There is no known physical mechanism to explain it.

Sunspot activity has been monitored since the invention of the telescope in the early 1600s. Sunspots were so rare and spotty in the first century that the 11-year cycle wasn’t discovered until the mid-1700s.

Conclusions

The July monthly sunspot number from the Royal Observatory of Belgium is consistent with several sunspot activity forecasts.

A few years ago there was a schism between members of the blue-ribbon NASA Solar Cycle Prediction Panel. One faction, led by James Hathaway, thought there would be a high solar maximum. The other, led by Leif Svalgaard, thought it would be low. Low wins big!!

On March 1st 2013, the panel’s project scientist, Dean Pesnell, predicted a double peak for cycle 24 in 2013. That has come and gone as he predicted.

The biggest news in solar physics is a prediction of the near total disappearance of sunspots in the next solar cycle. The first forecast has Solar Cycle 25 peak at only 7 spots!

The prediction was made some years ago. This month’s exceptionally low sunspot number makes the cycle 25 prediction look more and more plausible.