A magnetic filament connected to sunspot AR3229 erupted on 24 February 2023 producing a chain reaction of events that could lead to a geomagnetic storm on Earth. Dr Tony Phillips of Spaceweather.com reported that the action began at 19.49 UTC when the filament rose up and sliced through the sun's atmosphere.
The violent lift off destabilised sunspot AR3229, sparking a long duration M3-class solar flare (2030 UTC). Radiation from the flare, in turn, ionized the top of Earth's atmosphere, blacking out shortwave radio transmissions around the Pacific Ocean.. Mariners and radio amateurs may have noticed loss of signal at frequencies below 25 MHz for as much as an hour after the explosion.
Next, a CME emerged from the blast site. Coronagraph images from SOHO show a lopsided halo with an Earth-directed component.
Type II solar radio emissions from the leading edge of the CME suggest a departure speed of 1200 km/s. The flank of the fast-moving cloud could reach Earth on 27 February.
Shock waves inside the CME accelerated protons to nearly light speed, and they have already reached Earth. Our planet's magnetic field is funnelling the particles toward the poles where a second type of radio blackout is underway--a polar cap absorption (PCA) event. Airplanes flying over these regions may find that their shortwave radios won't work due to the ionising effect of infalling protons.
