Unusual 10 metre propagation.
29/4/25:
For the past two weeks, 10 metre propagation has been most peculiar. You can see from the map below (1345 GMT) that I’m only being heard in Antarctica, Brazil, Russia, The Canary Islands, Turkey and Namibia. There’s nothing west or east, which is most unusual. I believe there has been geomagnetic storm activity recently so I’m assuming that’s the reason.
Geomagnetic Storms:
A geomagnetic storm is a short-term disturbance in Earth’s magnetic field, usually caused by solar activity. It happens when a strong burst of solar wind, either from a coronal mass ejection (an eruption of charged particles from the Sun) or a high-speed solar wind stream from a coronal hole hits Earth’s magnetosphere, disrupting the planet’s magnetic environment.
Solar flares and geomagnetic storms can disrupt communication in the medium and high frequency bands (300 kHz to 30 MHz). Solar flares trigger radio blackouts by intensifying ionization in the D-region of the ionosphere, leading to increased collisional absorption, particularly at lower frequencies. Meanwhile, geomagnetic storms can cause widespread reductions in ionospheric electron densities, which in turn lower the maximum usable frequency (MUF) for high-frequency communication worldwide.