Schumann

Schumann resonances are natural electromagnetic waves that occur in the Earth's atmosphere, specifically between the Earth's surface and the ionosphere. They are generated by lightning strikes worldwide, creating a background hum of extremely low-frequency signals. These resonances occur at specific frequencies, around 7.8, 14, 20, 26, and 33 Hz, and are influenced by atmospheric and solar conditions. They are used in scientific research to study the Earth's atmospheric processes, monitor global lightning activity, and better understand the Earth's electromagnetic environment.