Solar Cycle 24 Ends-Solar Cycle 25 Begins

The government science agencies, NOAA and NASA determined that Solar Cycle 24 ended November 17, 2019 and Solar Cycle 25 began.  Solar Cycle 24 was the least active cycle in 100 years. There are several ways to express solar activity, but sunspot counting is the most frequently used method.  Solar Cycle 24 smoothed maximum count was 116.4 in April 2014.  The highest unsmoothed count was 146.1 in February 2014.  The smoothed count is the official number.  It is smoothed over 13 months. Six months before and six months after.  The smoothed count method is detailed at the end of this posting if you are curious.

The consensus of the experts regarding the predicted count of Cycle 25, at maximum, will be 115.  This prediction came from the Solar Cycle 25 Prediction  Panel made up international experts  according to PhysOrg posting .  In my May 2020 posting of a summary of expert’s predictions, NASA predicted that Cycle 25 would be the least active Cycle for 200 years.  NOAA however, predicted it would be more active than Solar Cycle 24.

The following chart compares Cycles 23, 24 and the predicted Cycle 25:

Some say that you can tell how active a cycle will be by the early formation of sunspots.  Lots of sunspots right away would mean an active cycle.  And conversely, slow development of sunspots would likely be the opposite. If that is true, perhaps you can make a prediction from the following chart courtesy of Solen info solar :


Virtually everything on this chart is Cycle 24.  This chart’s info box is probably very hard to read.  So let me describe the lines to you.  The dashed lines are the smoothed sunspot numbers.  The blue dashed line is the sum of the smoothed sunspots in the Northern and Southern solar polar fields. You can probably see that the blue dashed line crosses the solar max (the vertical red line) where the smoothed sunspots are at about 116.  But to make our predictions, we need to actually unsmoothed monthly sunspot reading.  That is the brown line. Here again this line is the sum of the Northern and Southern solar polar field sunspots.  In February, 2014, the monthly max of 146 was registered. Those numbers, 116 and 146, are the ones noted in the opening of this posting.

Comparing the brown line peak at 9 months after Solar Cycle 24 began, it looks like it is about a monthly 7 sunspots.  Doing the same for Cycle 25, at 9 months it looks like a monthly sunspot count of 7.  That would suggest to me that perhaps those that say 24 and 25 are going to be the same, may be right. But I would not make a bet on that.

As Yogi Berra, the Hall of Fame Baseball player, was alleged to have said, “It’s tough to make predictions, especially about the future.


Smoothed Count Method.

The smoothed count is a 13-month averaged sunspot count using this Belgium’s formula:
Rs= (0.5 Rm-6 + Rm-5 + Rm-4 + Rm-3 + Rm-2 + Rm-1 + Rm + Rm+1 + Rm+2 + Rm+3 + Rm+4 + Rm+5 + 0.5 Rm+6 ) / 12
Rs = smoothed monthly sunspot count
Rm = One month’s actual sunspot count
The “-6” through “+6” appended to each Rm is the number of months before or after the month whose smoothed count is being calculated. The beginning and ending months in the formula are only given half the value of the others.*

2 responses to “Solar Cycle 24 Ends-Solar Cycle 25 Begins


    Chuck –

    Back in 2014, NASA’s TIMED program verified that the upper atmosphere is cooling due to reduced solar activity.

    Another interesting item is that Univ of Delaware’s David Legates has been hired by NOAA and the Warmists are hysterical (again). Here’s the story of the character assassination that the U of D administration visited on Legates. His specific expertise is climatology but now they only allow him to teach geography.


    Sent from my iPhone


    • Dick I am in the process of gathering expert opinions regarding global cooling. Cooling is underway, coming down from a powerful El Nino. But the question is —is this long term?

      I have been following President Trump’s nomination of David. At one time we had a good bit of email exchange. We have not done that lately. I haven’t talked to him going on 3 years. Probably will see him in May next year at a conference I plan to attend.

      cbdakota aka Chuck

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