Guest essay by David Archibald
One of the most accurate ways of predicting the amplitude of the next solar cycle is to derive it from the strength of the solar polar fields at solar minimum. And you don’t have to wait for solar minimum. An accurate assessment can be made four years before minimum, which is where we are at the moment. This graphic shows the last 40 years of solar polar field strength data:
Figure 1: Solar Polar Field Strength 1976 – 2016 (source Wilcox Solar Observatory)
And this graph shows that data averaged and all converted to a positive sign:
Figure 2: Solar Minima relative to Solar Polar Field Strength 1976 – 2016
It is evident from Figure 2 that solar polar field strength has an early peak and then relaxes by an average of 12 units to solar minimum before falling away. The recent peak value was 53 in 2016. Therefore the field strength is likely to be 40 at the 24/25 solar minimum. How that value translates to peak amplitude of Solar Cycle 25 is shown in the following graphic:
Figure 3: Deriving peak amplitude of the following cycle
A monthly smoothed maximum sunspot number of 62 is derived for Solar Cycle 25. This would probably be around 2025. This is almost down to Dalton Minimum levels.
In terms of other interesting aspects of solar behaviour, the F10.7 flux has settled into a narrow range:
Figure 4: F10.7 Flux 2014 – 2016
The F10.7 has been in a narrow range over the last two months and is now only just above the immutable floor of activity of 64, though it may be three years to solar minimum.
Figure 5: Oulu Neutron Count 1964 – 2016
The neutron flux caused by galactic cosmic rays is at a rate equivalent to that three years prior to the 23/24 solar minimum. Skies should be getting cloudier according to Svensmark’s theory which will ameliorate the Earth’s “fever.”.
My prediction for the peak sunspot number of Cycle 25 is a monthly count of 62.
David Archibald’s next book is American Gripen: The Solution To The F-35 Nightmare.