Leif Svalgaard reveals his Solar Cycle 25 prediction “at last”

Solar scientist and part-time NSA operative Leif Svalgaard has produced a prediction for solar cycle 25, four and a half years after Rick Salvador published his 86 year prediction in the swiftly censored “Pattern Recognition in Physics”.

It appears at the end of a 30 page pdf document he has just published on his website. This is an interesting document, with a wealth of gayly coloured butterfly diagrams, polar field reconstructions and more. Leif self deprecatingly follows his Prediction title with (At last) not only because it comes at the end of 30 pages of preamble, but because he’s acutely aware of his method’s limitations.

The reason this prediction has arrived so late in SC24 is that the method it relies on can’t be applied until shortly before the minimum of the preceding cycle, and it only gives the ability to estimate the peak amplitude of the approaching cycle. It has nothing to say about the cycle length, or what comes after. It predicts that Solar cycle 25 will be higher than SC24 but lower than SC20.

This is in sharp contrast to our orbital resonance theory, developed here at the talkshop, and distilled into a predictive model by Rick Salvador. In his 2013 PRP paper ‘A mathematical model of the sunspot cycle for the past 1000 years’, he gives a 100 year outlook prediction, which he recently re-scaled to match the new Clette et al numbering system when we discussed its progress recently.

The model is performing well, and has alreading closely predicted the average amplitude and descent to minimum of SC24, currently occurring, with 90+ spotless days in the first half of 2018. If the late start to SC24 is repeated, we might estimate that SC25 will get under way in a couple of years. It may run through to the early 2030s, subsuming the five year blip the model predicts between 2028 and 2037. Solar cycle 25 may be long and low.

If the longer term outlook predicted by Rick’s model comes to pass, we are in for a prolonged solar ‘grand minimum’, which is already starting to have effects on Earth’s weather, with late and large hailstones falling across northern Europe and June snow in Scandinavia.