Monday, January 16, 2023

Solar Cycle 25 Progression Update - Jan '23

I've been posting solar cycle updates for a very long time - a casual look shows one in 2013 and that one refers to a post six months prior.  I usually try to keep them around six months apart, in attempt to keep them focused on the "big picture" rather than day to day events like minor flares or Coronal Mass Ejections.  The last one was last July, so this is as good a day as any to put one up.  

To begin with, I'll start with today's version of the same plot last July's post did, the Cycle 24/25 plot from the National Oceanographic and Atmospheric Administration, NOAA, and their Space Weather Prediction Center.  This plot shows the sunspot numbers and you can read numbers directly by hovering your mouse over one of the points on the chart - on the website linked there, not this graphic.  The smoothed red curve is the predicted values while the jagged points on the purple curve are measured data. 

I did a screen capture from the NOAA site showing the smoothed sunspot number for December '22 of 113.1  The smoothed Solar Flux Index (SFI - the plot directly below this one on that NOAA site) for December was 148.5.  Remember this is an average over the month; I recall days around Christmas when solar flux was in the 160s.  Furthermore, since the start of the year (notice how that sounds more impressive than "for the last two weeks?"), the SFI has been above 160.  It crossed 200 early in the month and is currently 234; today's sunspot number is 186. These values are well above the NOAA/NASA predictions.

The next plot is an update to the second plot in the July post, the one I jokingly refer to as my "ham radio autobiography" because these are smoothed sunspot plots of every solar cycle since 1976, the year I got my first ham license. 

I think a key takeaway from this graphic is that while cycle 25, the gray line at lower left ending at month 30, is somewhat better than cycle 24 (in pink) it's not what most people would call much better than the 24, and dramatically worse than 21 and 22 (a half to a third of the sunspot numbers).  It bears repeating that cycle 24 was the weakest cycle in 100 years (or more) so saying "better than cycle 24" isn't saying much. This plot is from, linked from Space Weather News, which (I believe) is run by Suspicious0bservers from You Tube.

Finally, an update to another graphic that I posted in February of '22, the progression of this cycle vs the NOAA predictions.  This plot is from and is one that Dr. McIntosh uses.

These are busy plots but the first the key feature to note is the black zigzag line, which is the observed monthly mean sunspot number.  You'll note the peak to peak excursions of the black line don't go above the one in the middle of '22 until the last peak.  That black line is based on the the raw daily sunspot numbers shown as the light green very jiggly line and the same 'little change from last June' comment applies to those, too.  After that, note the light blue band with the dark blue line it; the band is the NOAA/NASA prediction for cycle 25.  The dark blue line is the median of the predictions in that light blue band shifted six months earlier in time.  The red lines/band are McIntosh's predictions.  The dark green line is the mean of every solar cycle since 1750.  It appears the observed cycle 25 sunspot numbers are looking to split the difference between the upper end of the NOAA/NASA predictions and the lower end of McIntosh's.  The last peak variation of the black curve looks like it's quite a bit higher than the blue band.  

Cycle 25 is looking better than the NOAA/NASA prediction but not quite as good as McIntosh's which have been lowered several times.  If you go back to that February post and compare its plot to this, you'll find this revision of McIntosh's prediction is quite a bit lower than a year ago.  Note that the solid green and red lines cross 2023 a bit under 125.  Last February's plot shows the intersection with 2023 closer to 145 for McIntosh's prediction while the average of all cycles seems the same (the scales are different enough to make it hard to tell). 

Scott McIntosh did his (quarterly? semi-annual?) visit to one of the ham radio groups, the Front Range 6 meter Group on (where he's also a member) and hosted a Zoom video talk that went about 45 minutes of new content and 20 minutes of Q&A. Scott said that he thinks signs that he looks for on the sun are pointing to the peak of this cycle coming a bit earlier than previous predictions, perhaps in late '24, and solar activity should be around what it is now for a couple of years.  So far, we've had two or three X-class solar flares out of this cycle, but none were strong or placed to cause harm.  There have been (as you'd expect) more M-class and even more C-class flares, but honestly, most of us could damage the power grid as much as a C-class flare by farting.


  1. I have great fun telling climatistas that anthropogenic sunspot depletion is due to all the solar energy panels we're using. (Yes, I know its nonsense but it sounds sciency and they don't know the difference.)

  2. All of that makes me wonder:
    Why is the government hyping hardening the infrastructure so much?
    Is it not because of a natural event, but because they have reason to fear enemy action?

    1. I haven't seen any talk of that lately, but if they mean hardening it against a solar flare like the Carrington Event, that's prudent simply because the long powerlines are very subject to it and losing the grid would hurt more people than anything else. It would be one day it's the present, the next day it's 1870.

      The conditions that a solar flare like that requires are rare which makes putting odds on rare things with horrendous impacts is harder than it seems. It's the kind of thing that has only been observed once in human history, that we're sure of. There are other lines of evidence that say it seems to happen maybe every few hundred years. It's kind of related to sunspot cycles but we just don't know for sure. People haven't been aware of and tracking sunspots long enough.

      Which would be worse, spending a lot of money and not needing to or not spending it and a flare killing off maybe 90% of humanity?

      My way of looking at it is that since a flare like that is so unpredictable, the industry should spend money to make their product more survivable, but since it's not urgent (like we know it'll be here in X years) there's no reason to spend like crazy. A long term goal is fine.