Solar Cycle 25 is shaping up to be stronger than expected.

Jan 27, 2020
New sunspot counts confirm that the young solar cycle is outperforming official forecasts.

Earth is in a void between solar wind streams. Quiet conditions are expected to prevail until the next stream arrives on Jan. 16th. This forecast could be upended by a solar flare. The sun is dotted with 3 numbered sunspot groups (and a 4th unnumbered region now emerging); unexpected explosions could occur at any time.

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Sunspot counts have exceeded predictions for 15 straight months. The monthly value at the end of December 2021 was more than twice the forecast, and the highest in more than 5 years.

The "official forecast" comes from the Solar Cycle Prediction Panel representing NOAA, NASA and International Space Environmental Services (ISES). Using a variety of leading indicators, the Panel predicted that Solar Cycle 25 would peak in July 2025 as a relatively weak cycle, similar in magnitude to its predecessor Solar Cycle 24. Instead, Solar Cycle 25 is shaping up to be stronger.

Sky watchers have already noticed the change. "We are definitely seeing the effects on the ground in the Arctic!" reports Chad Blakley of the Swedish tour guide service Lights over Lapland. "Auroras now are the best in years."

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(A) The first X-flare of Solar Cycle 25 on July 3, 2021; (B) A radio blackout caused by an X-flare on Oct. 28, 2021; (C) Auroras over Wisconsin photographed by Marybeth Kiczenski on Nov. 4, 2021.

Indeed, geomagnetic activity has nearly tripled since the new solar cycle began. In 2020, the first full year of Solar Cycle 25, there were 9 days with at least minor (G1-class) geomagnetic storms. That number skyrocketed to 25 days in 2021. One of those "storm days" (Nov. 4, 2021) was a borderline G4-class (severe) event with auroras sighted as far south as California and New Mexico.

Another sign of increasing solar activity is the X-flare. X-flares are the most powerful type of solar flare. They can cause strong radio blackouts, pepper Earth's atmosphere with energetic particles, and herald intense geomagnetic storms. The sun produced zero of these flares from late 2017 until mid-2021. Solar Cycle 25 busted the drought on July 3, 2021, with an X1.6 category explosion, followed by an X1-flare on Oct. 28, 2021.

Two down, 98 to go? Typical 11-year solar cycles produce more than 100 X-flares during the years around Solar Max. Stay tuned for updates as Solar Cycle 25 intensifies.


To quote the indomitable Douglas Spencer, from Howard Hawks 1951 film 'The Thing From Another World', "Watch the skies, watch the skies!" Indeed.

The increasing solar activity promises to create spectacular Northern Lights and can wreak havoc on our electrical grids because the upper layers of our atmosphere can induce currents in the long line conductors on the Earth's surface. These additional currents can then overload the electric grid system to trigger voltage collapses, or worse, damage a significant number of expensive extra-high voltage transformers needed to step down the high voltage along the way.

Solar storms interrupt radio communications by altering the properties of the ionosphere, which happens in two basic ways. The first is simply due to the high-energy radiation from the flare. X-rays bombard Earth, knocking electrons off atoms in the ionosphere. This creates an abnormally high density of free electrons in the lower ionosphere and is referred to as a Sudden Ionospheric Disturbance. High frequency (HF) radio waves are absorbed by this increased density, which blocks their “skipping” property and results in a complete blackout of HF communications for minutes to hours. They can also cause waves of noise to roll through the Shortwave (SW) communications bands as well.

Solar storms can also impact radio communications due to the plasma that’s blasted out into interplanetary space. Solar particles, most importantly protons, are accelerated to a significant fraction of light speed and reach Earth within less than an hour. Most are deflected by Earth’s protective magnetic field, but some enter the atmosphere at the poles and collide with and ionize air particles. As with the X-rays, this increases the density of the ionosphere at low heights, causing absorption of HF radio communications. These “Polar Cap Absorption” events can last for days and are particularly disruptive to airline communications needed when they commonly fly near the poles to reduce travel times. Finally, lesser degrees of HF radio interference are experienced for similar reasons during aurora-producing geomagnetic storms caused by Coronal Mass Ejections, which are massive releases of slower plasma that generally takes 2-3 days to reach Earth.