Solar Minimum: Deep, Deeper…and even Deeper?

Solar Minimum is DEEP and appears to be continuing.  Observer Franky Dubois from Belgium – who posts for the Solar Section of A.L.P.O. – Assoc. of Lunar & Planetary Observers ( has fully observed three complete Solar Cycles over the past 38-years and he’s graphed the Sunsport R Number – defined as R = K (10g + s), where g is the number of sunspot groups and s is the total number of distinct spots. 

This is what he posted yesterday on the A.L.P.O. Solar Message Group:

Minimum cycle 21: 11.4 April 19[8]6

Minimum cycle 22: 10.4 May 1996

Minimum cycle 23: 2.88 November 2008

Status of cycle 24 thus far: 1.6

Many experts in December (2019) speculated we had reached “Solar Minimum” (error factor of +/- 6-months).  Well, it’s 5-months later and we’ve only seen a couple of next cycle [reversed polarized areas] sunspots/small groups – most of which died-out very quickly and did not sustain a full transit across the observable disc of the sun.  We’ve seen no real evidence – yet – that we’re on the other side or up-side of Minimum.  As an amateur/hobbyist astronomer & Solar Observer myself, I’ve seldom taken the time to set-up my gear & observe (even in wavelengths other than visible).

It’s been discussed here and elsewhere before, but looking at the last 53-years of data there has been a very, very sharp decline in Solar Maximums [and Minimums] sunspot numbers.

Guest Post by Troy Riedel

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4 thoughts on “Solar Minimum: Deep, Deeper…and even Deeper?

  1. Donald J Glocka

    Is Shortwave dead? No, but it certainly is in ICU and the nurses’ station is looking up the number for the local florist.

    1. Mike

      Not by a long shot. Hams, including new hams like me, are adapting to conditions in the solar minimum There is a huge surge of interest right now in solar minimum-friendly modes like CW (Morse Code), FT-8, etc. These modes enable good propagation despite band conditions in the solar minimum. Additionally, interest in portable operating like SOTA (Summits on the Air) and POTA (Parks on the Air) continues to grow year after year. If anything, there’s a shift from the traditional “ham shack” op to a more rugged ultra-portable, mobile, and emcomm-style ops.


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