|Waves created by lightning flashes – here shown in blue, green, and red – circle around Earth, creating something called Schumann resonance. These waves can be used to study the nature of the atmosphere they travel through. (Credit: NASA/Simoes)|
At any given moment about 2,000 thunderstorms roll over Earth, producing some 50 flashes of lightning every second. Each lightning burst creates electromagnetic waves that begin to circle around Earth captured between Earth's surface and a boundary about 60 miles up. Some of the waves -- if they have just the right wavelength -- combine, increasing in strength, to create a repeating atmospheric heartbeat known as Schumann resonance.
NASA's Vector Electric Field Instrument (VEFI) aboard the U.S. Air Force's Communications/Navigation Outage Forecast System (C/NOFS) satellite has detected Schumann resonance from space. This comes as a surprise.
Fernando Simões, Robert Pfaff, Henry Freudenreich.Satellite observations of Schumann resonances in the Earth's ionosphere. Geophysical Research Letters, 2011; 38 (22) DOI: 10.1029/2011GL049668