Schumann Resonance (Schumann resonance)

The simplest model of a spherical cavity resonator

Consider a volume resonator consisting of two concentric conducting spheres ^[1] . The inner sphere is the surface of the Earth, and the outer is the ionized gas of the ionosphere, located at an altitude of about 80 km above the ground.

Suppose that an electromagnetic wave, n times reflected alternately from the surface of the Earth and the ionosphere, bends around the globe. If a whole number of reflections fit on the circumference of the Earth, then a resonance occurs, and such a wave can exist for a long time. Considering that the wave propagates at the speed of light c = 300 000 km / s, and the circumference of the Earth is L = 40 000 km, we obtain the oscillation frequency equal to

For the first five harmonics, this formula gives a range of frequencies 7.5 - 15.0 - 22.5 - 30.0 - 37.5 ... Hz. Comparing the theoretical frequencies with the frequencies obtained experimentally (7.83 - 14.1 - 20.3 - 26.4 - 32.4 ... Hz), we note that with a good match of the frequency of the first harmonic, the error increases with increasing n .

In his original work ^[2], Winfried Otto Schumann analyzed oscillations arising in a spherical volume resonator. At the same time, he took into account that the surface of the earth has a constant conductivity of about σ = 10 ⁻³ S / m, and the conductivity of the ionosphere at altitudes of 70–90 km varies within σ = 10 ⁻⁵ —10 ⁻³ S / m. Because of this, the average propagation velocity of an electromagnetic wave V (σ) is approximately 20% less than when reflected from a sphere with infinite conductivity. For the frequency of the nth harmonic, Schumann received

that for the first five harmonics gives 8.5 - 14.7 - 20.8 - 26.8 - 32.9 Hz.

Causes of waves

There are several hypotheses about the occurrence of electromagnetic waves in the Earth-ionosphere cavity.

Thunderstorm Hypothesis

Lightning strikes are believed to be the primary natural source of excitement for Schumann’s resonance. Lightning behaves like huge transmitters that emit electromagnetic energy at frequencies below 100 kHz. ^[3] They are the cause of the excitation of electromagnetic oscillations in a wide frequency range. This phenomenon explains, in the opinion of most experts, the presence of stable ultra-low-frequency oscillations, which practically do not attenuate and have fixed frequencies.

Specifications

After numerous studies and rechecks, the Schumann resonance frequency was accurately determined - 7.83 Hz. Due to the wave processes of the plasma inside the Earth, peaks are most clearly observed at frequencies of about 8, 14, 20, 26, 32 Hz. For the main, lowest frequency, variations within 7–11 Hz are possible, but for the most part during the day the variation of the resonant frequencies usually lies within ± (0.1–0.2) Hz. The spectral density of oscillations is 0.1 mV / m.

The intensity of the resonant oscillations and their frequencies depend on:

• From the time of day. At night, the amplitude of resonant waves is 5–10 times smaller, due to a decrease in the rate of flow of water in the ocean conveyor (C), a decrease in the mutual speeds of the C loop
• From the time of year. In the summer months (from May to August in the northern hemisphere), the resonance frequency increases ^[4] . In the southern hemisphere, resonant frequencies increase from November to February;
• From the location on the globe. Waves of Schumann are most clearly pronounced near the world centers of thunderstorms: Africa, South America, Indonesia, India (in places of unidirectional loops of water flow in OK). In the circumpolar regions, the amplitude peaks at these frequencies are no longer so pronounced (the minimum current component of the electric field strength vector E). At the poles of the maximum vector of magnetic field strength H, the vector E is minimal, on the equator, on the contrary;
• From solar activity. During magnetic storms, their intensity increases by 15%. There are cases of excitation of frequencies of 12,500 Hz, which corresponds to the movement in the core of the Earth at a depth of 3.6 km from the center of the core of the Earth;
• From the rate of water flow in OK;
• Moon phases;
• Periods of solar activity.

Research history

For the first time, the presence of standing electromagnetic waves and their frequencies in the "Earth-ionosphere" system was predicted by the Irish physicist JF Fitzgerald in 1893 ^{[5] [6]} . In 1900, apparently independently, Nikola Tesla came to a similar conclusion, who patented his discovery in 1905 ^[7] . N. Tesla, however, apparently did not know about the existence of the ionospheric layer and the atmospheric conductivity in general, therefore the resonance frequencies calculated by him turned out to be incorrect ^[8] .

However, a systematic study of the effect, later known as the “Schumann Resonance,” began only after almost 50 years. The assumption of the existence of a resonance of electromagnetic waves in the Earth-ionosphere space was expressed by the professor at the University of Munich VO Schumann in 1952 ^[9] . The main results of his research were published in three papers ^{[10] [11] [12]} .

The first undisputed experimental confirmation of the presence of Schumann resonances was made in 1960 ^[13] .

He continued his study of Wolfgang Ludwig, who conducted experiments in the open sea and underground mines. V. Ludwig published a book about Schumann's Resonance Informative Medicine.

Difficulties in the study of Schumann waves are due to the fact that their reception requires special very sensitive equipment ^[14] and the appropriate environment: even the movement of trees, animals or people near the receiver can affect its readings ^[15] .

In September 2011 ^[16], Schumann resonance waves were recorded at an altitude of up to 850 km by the C / NOFS satellite. Previously, the limitation of the height of such waves was considered to be 100 km. ^[17]

Stations for continuous monitoring of the Schumann resonance are located:

• Russia, Tomsk, Tomsk State University. Data on the site is updated every two hours;
• Slovakia, Modra, geophysical observatory.