Category Archives: Solar Flux

Predicting Solar Cycle 25. Are We Heading For Another Maunder Minimum?

A study was published in 2012, Sudden transitions and grand variations in the solar dynamo, past and future” by Cornelis DeJager and Silvia Duhan . The authors attempt to predict whether Solar Cycle 25 will transition to a “Grand Minimum” or “Regular “ Episode. They believe the Sun is transitioning from a “Grand Maximum” to one or the other aforementioned Episodes. This study is being used because their prediction was based upon knowing the Solar Cycle 24’s maximum Sunspot number which we now have.

First a look at the “Episodes” that the authors have placed the Solar Cycles from 1620 to the present.

grandcyclesswsc120009-fig4The diagram shows the sunspot numbers plotted against time. The three Grand Episodes are marked by their different colors. They are separated by vertical black lines.

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Cycle 24-November ’14—Sunspot Number Trend

Cycle 24 solar activity looked liked it had peaked somewhere around March of 2011 at about 68. But it hadn’t.   The smoothed International Sunspot (SS) number is currently around 82 around as shown by the dashed blue line on this chart:

cycle24-2More detail can be seen on the following chart where the activity in November is up from October. Both SS and solar flux (F10.7 cm) peaked at about 170 in November.


Solar Cycle 24 is still much less active than Solar Cycle 23 as can be seen in the chart below:

sunspotscycles23_24 nov14

The green line is the predicted path of the smoothed International SS number.  This time the turn down in solar activity  may actually be the “maximum” for Solar Cycle 24.

An El Nino is happening now. It should continue into next year. Early indications were that it would be very weak, but it has picked up some strength. This event is likely to have an effect and may even break the run of more than 18-year pause in global temperatures. Solar Cycle 24’s low solar activity might offset the El Nino with the “pause’ continuing. Nobody knows.

Probably the most comprehensive discussions of the what and where-fore of an El Nino are by Bob Tisdale postings. Clicking here will direct you to his postings.












Early look at Solar Cycle 24 July Activity

Since late last year, Solar Cycle 24 has picked up activity as it goes through a double peak maximum.   I doubt that is an official term but it does describe what has been going on. It was generally though that the peak International Smoothed Sunspot number for Cycle 24 was going to be about 66.   But the recent activity will result in a smoothed peak number of 81 or there about.  (Click on charts for clarity.)


This chart of approximately the last 12 months, shows that F-10.7cm solar flux and Sunspot numbers are closely aligned, both being good proxies for solar activity.

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Solar Cycle24 Mid-November Update

Solar Cycle 24 at November mid-month still is showing relatively high activity. The Sunspots are up and the F10.7cm solar flux is as well.  The Solen Chart below was updated on 15 November.  (Click on Chart to enlarge.)

sunspotsmidnov13solarThe green line is not the official smoothed 6 month lagging number that is used to describe the Cycles.  But it currently is showing that the increase in solar activity in the month of October is still underway in November.  Even so, this activity is well below its recent predecessors.


Solar Cycle 24 October Update

The 30 day smoothed International Sunspot number for October 2013 was 78.9.  The Sun was more active as indicated by Sunspots and F10.7cm radio flux in October than any time since the middle of July this year.  The chart, by Solen, below shows this activity. (Click on chart to enlarge.)


The chart shows that the NOAA Sunspot number and the F10.7 cm flux are trending downward at month-end, indicating the likelihood that the 30-day smoothed Sunspot number will begin dropping.  A bit of prospective is that while the October solar activity was up, Cycle 24 is still much having much lower activity relative to the 3 preceding Solar Cycles.


Solar Cycle 24 October Sunspot Number Rising

It was beginning to look like the Sunspots were in freefall based on last month’s 30 day smoothed number of 36.9.  But the Sun continues to let us know that we don’t know a lot about it for certain.   It looks like the Cycle 24 Sunspot number may reach 70 for the month of October.  A jump in Sunspot activity began in second week of this month and has continued through the third week.  It will be interesting to see how high it will go.  This number is not the official smoothed 6 month lagging number* that will not move up a lot, unless this higher activity continues for several months.  See the Chart below that shows, in Green, the smoothed 30 day number at the last updating on 25 October 2013.   It is nearly 70 at this time. (Click on chart to enlarge.)


This chart is from  This is an excellent site for monitoring solar data.

*The smoothed number is calculated by doing a 13 month average from the numbers that lag 6 months behind the current month.


Penn And Livingston Cycle 25 Sunspot Forecast

Penn and Livingston, in their September 2010 IAU publication “Long-Term Evolution Of Sunspot Magnetic Fields” predicted that Solar Cycle 24 would peak at an International Sunspot number of 66 and Solar Cycle 25 at 7!!


Considering that NASA believes that the peak for Cycle 24 will be 67, their prediction looks pretty good.   So would you bet against their Cycle 25 prediction of 7?

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