[SFDXA] Sun produces strong M1-class solar flare, causing a shortwave radio blackout over the Pacific Ocean, By

[Bill]

  Sun produces strong M1-class solar flare, causing a shortwave radio
  blackout over the Pacific Ocean

By
Strange Sounds <https://strangesounds.org/author/admin>

Apr 20, 2021

Sunspot AR2816 erupted during the late hours of April 19th (2342 UT),

<https://www.spaceweather.com/images2021/20apr21/m1_anim.gif>

This is one of the strongest flares of young Solar Cycle 25. A pulse of 
X-rays and ultraviolet radiation from the flare ionized the top of 
Earth’s atmosphere, causing a shortwave radio blackout over the Pacific 
Ocean. Mariners and ham radio operators in the area might have noticed 
unusual propagation conditions at frequencies below 10 MHz.

blackout map m1 solar flare april 19 2021 
<https://strangesounds.org/wp-content/uploads/2021/04/blackout-map-m1-solar-flare-april-19-2021.png>blackout 
map m1 solar flare april 19 2021

There is a chance that the explosion also hurled a coronal mass ejection 
(CME) toward Earth. If so, it would probably arrive on *April 22-23*. 
The jury’s still out, though. We need to wait for more data from SOHO 
coronagraphs to confirm the CME.


    Solar cycle 25

You probably think Solar Cycle 25 is a dud. Think again. Despite long 
stretches of spotless quiet, the new solar cycle is actually running 
ahead of schedule. In this plot, the red curve shows NOAA’s predicted 
sunspot counts for Solar Cycle 25; the orange curve shows the new best fit:

*Above:* Observed and predicted sunspot numbers: more 
<https://www.swpc.noaa.gov/products/solar-cycle-progression>

“/*The sun is performing as we expected–maybe even a little better*/,” 
says Lisa Upton of Space Systems Research Corporation. She’s a co-chair 
of the NOAA/NASA Solar Cycle 25 Prediction Panel. “/*In 2019, the panel 
predicted that Solar Cycle 25 would peak in July 2025 (± 8 months) with 
a maximum sunspot count of 115 ± 10. The current behavior of the sun is 
consistent with an early onset near the beginning of our predicted range.*/”

If current trends hold, Solar Cycle 25 could peak as early as 2024, 
similar in strength to the relatively weak cycle (SC24) that preceded 
it. *Don’t be fooled by the adjective, however. It’s like hurricane 
season. Even a “weak” season produces hurricanes–and all it takes is one 
good storm to do a lot of damage.*

*Above:* 10.7cm radio flux, another indicator of solar activity, is also 
exceeding predictions: more 
<https://www.swpc.noaa.gov/products/solar-cycle-progression>.

“/I’m not surprised that people are grumbling about SC25 being a dud,/” 
says Upton. “/*Weak cycles are typically preceded by long stretches of 
spotless days, and they are slow to ramp up. All of this is consistent 
with our prediction.*/”

Now the waiting begins. As sunspot counts increase over the next year, 
forecasters will be able to tell if Solar Cycle 25 is *really* following 
the official prediction or doing something completely different. 
Predicting the solar cycle is still an infant science, and much 
uncertainty remains. [Space Weather Archive 
<https://spaceweatherarchive.com/2021/04/17/solar-cycle-update-2/>]

producing a strong M1-class 
<https://www.spaceweather.com/glossary/flareclasses.html> solar flare. 
NASA’s Solar Dynamics Observatory recorded the extreme ultraviolet flash:

https://strangesounds.org/2021/04/m-class-solar-flare-blackout-pacific-ocean.html

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