Scientists call this phenomenon a "pulsation continuous" or "Pc" for short.
SpaceWeather describes as... "Imagine blowing across a piece of paper, making it flutter with your breath. Solar wind can have a similar effect on magnetic fields. Pc waves are essentially flutters propagating down the flanks of Earth's magnetosphere excited by the breath of the sun. During more active phases of the solar cycle, these flutters are easily lost in the noise of rambunctious geomagnetic activity. But during the extreme quiet of Solar Minimum, such waves can make themselves "heard" like a pin dropping in an silent room."
Image from Stuart Green |
Pc waves are classified into 5 types depending on their period. The 10-minute wave on June 23rd falls into category Pc5. Slow Pc5 waves have been linked to a loss of particles from the van Allen radiation belts. Energetic electrons surf these waves down into Earth’s atmosphere, where they dissipate harmlessly.
I looked back at my WSPR reports for 28 MHz but didn't see anything unusual. Perhaps it might have had more of an impact on the lower bands.
Links...
1) Magnetic Pulsations