Notably, ionospheric disturbances producing electromagnetic signals precede some major seismic events by a few hours to days.

The Index is a standard index used to measure ionospheric disturbances.

Effects on Schumann resonances have been reported following geomagnetic and ionospheric disturbances.

"This is an ionospheric disturbance of solar origin."

The Dellinger effect, or sometimes Mögel-Dellinger effect, is another name for a sudden ionospheric disturbance.

The ionospheric disturbance enhances long wave (VLF) radio propagation.

Skywave propagation on the sunlit side of the Earth can be entirely disrupted during sudden ionospheric disturbances.

He also monitored Earth's magnetic field and seismic activity with a magnetometer and a seismograph he had built, and observed sudden ionospheric disturbance.

High levels of sunspot activity lead to improved signal propagation on higher frequency bands, although they also increase the levels of solar noise and ionospheric disturbances.