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AMATEUR RADIO

New solar cycle could be among

strongest on record

adio amateurs have been studying the behaviour of the ionosphere since they The NOAA/NASA co-chaired,
started experimenting with shortwave radio and provided anecdotal evidence international panel to forecast Solar
Rthat on higher frequencies, one could communicate worldwide. It is thus not Cycle 25 released their forecast for
surprising that they have developed a keen interest in the mechanics driving the Solar Cycle 25 in November 2019. The
ionosphere and the variation in useable frequencies, and that they keenly follow the forecast consensus: a peak in July 2025
work done by solar scientists. (+/- eight months), with a smoothed
The 11 year sunspot cycle that just ended, Cycle 24, was a noticeably weak one. sunspot number (SSN) of 115. The
Around the peak of the cycle in April 2014, there were substantially fewer sunspots – panel agreed that Cycle 25 would be
and fewer accompanying solar flares and coronal mass ejections – than during other average in intensity and similar to Cycle
recent solar cycles. 24. Additionally, the panel concurred
Experts have predicted that Cycle 25, which was announced to have begun in that solar minimum between Cycles
September 2020, will be a weak sunspot cycle as well. But scientists led by the National 24 and 25 would occur in April, 2020
Centre for Atmospheric Research (NCAR) disagree. They announced on 7 December (+/- six months). If the solar minimum
2020 their prediction that Solar Cycle 25 would be one of the strongest on record. This prediction is correct, this would make
is in direct contradiction to the forecast from NOAA’s Space Weather Prediction Centre, Solar Cycle 24 the seventh longest on
the U.S. government’s official source for space weather. record (11.4 years).

This split image shows the difference between an active sun during solar Predictions are predictions
maximum (on the left, captured in April 2014) and a quiet sun during solar Radio amateurs have, over the
minimum (on the right, captured in December 2019). December 2019 marked years, learned that scientists take
the beginning of Solar Cycle 25, and the sun’s activity will once again ramp different approaches in studying
up until solar maximum, predicted for 2025. Image via NASA/ Solar Dynamics and predicting solar cycles. In an
Observatory (SDO). article published November 24, 2020,
in the peer-reviewed journal Solar
Physics, a team of researchers
predicted that Sunspot Cycle 25 would
peak with a maximum sunspot number
somewhere between approximately
210 and 260, which would put the new
cycle in the company of the top few
ever observed. If their predictions come
true, radio amateurs will be smiling
as they will be able to communicate
worldwide on the proverbial wet string
for an antenna.

New ways of looking at solar
cycles
If the new NCAR-led forecast is borne
out, it would lend support to the research
team’s unorthodox theory – detailed in a
series of papers published over the last
decade – that the sun has overlapping
22 year magnetic cycles that interact to
produce the well-known, approximately 11
year sunspot cycle as a by-product. The
22 year cycles repeat like clockwork and
could be a key to finally making accurate
predictions of the timing and nature of
sunspot cycles, as well as many of the

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