The last time we took a look at Leif Svalgaard’s SC25 prediction in 2018, he was predicting a peak amplitude of around 140SSN in 2024 according to the plot or (giving himself more latitude) “SC25 will be somewhere between SC24 and SC20, provided the Polar Field Precursor Relationship holds.”

This has been modified in his latest presentation on the subject. The peak amplitude has been revised downwards to 128+/-10SSN.


Our own prediction, made in 2013 by Rick Salvador is still looking good at the moment. Rick’s model doesn’t allow any ‘dwell’ at solar minimum, and runs about a year early. It predicted a cycle 24 peak of around 100SSN, compared to the actual of 116SSN. It’s possible it’ll underestimate cycle 25 too. Within the next few years, we’ll know the facts.

Looking at the latest TSI data from the TSIS-1 NASA mission, it’s hard to tell what will happen next, but after an initial spurt of activity at the end of November last year, solar activity has quietened down again for now. The F10.7 radio flux and SSN data from also show low activity.

The Sun’s changing activity is hard to model. There is a vast range of predictions out there from many researchers using different methods. Leif’s falls in the middle of the range; ours falls at the low end. Scott Mcintosh’s is at the high end.

As they say on BANZAI! – Place bets now!

Source (with additions by TB) :

via Tallbloke’s Talkshop

May 18, 2021