Schumann resonance

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The Schumann Resonance is a set of spectrum peaks in the extremely low frequency (ELF) portion of the Earth's electromagnetic field spectrum.

1 Description
- 1.1 Lightning in tropics is dominant component
- 1.2 Diurnal variations
2 Popular culture
3 See also
4 External articles and references

[edit] Description

The terrestrial stationary waves phenomenon is named after physicist Winfried Otto Schumann who predicted it mathematically in 1952.

Schumann resonance is due to the space between the surface of the Earth and the conductive ionosphere acting as a waveguide. The limited dimensions of the Earth cause this waveguide to act as a resonant cavity for electromagnetic waves in the ELF band. The cavity is naturally excited by energy from lightning strikes. The lowest-frequency (and highest-intensity) mode of the Schumann resonance is at a frequency of approximately 7.83 Hz.The fundamental mode of the Schumann Resonance is a standing wave in the earth-ionosphere cavity with a wavelength equal to the circumference of the earth. Additional resonant peaks are found at 14, 20, 26, 33, 39 and 45 Hz.

[edit] Lightning in tropics is dominant component

E. R. Williams ^[1] remarks that the convection is deeper in the tropics than at higher latitudes and that lightning activity increases with the depth of convection. Approximately two of every three lightning flashes occur in the latitude interval ±23°. Observations from space reveal that tropical land areas exhibit substantially more lightning than do the central oceans.

[edit] Diurnal variations

D.D. Setman ^[2], who succeeded by 1991 to measure the Schumann Resonance intensities simultaneously in two distant locations, in California and Western Australia proved, that there are diurnal variations. The magnetic power of the Schumann Resonance augments after Sunrise and decreases in the afternoon of the local time. So called horizontal magnetic component of the Schumann resonance intensities exhibit also seasonal intensity variations and depend on the local height of the ionosphere.