Sferics
Under Sferics (short for English atmospheric ; sometimes atmospheric pulse radiation or AIS ) is defined as the pulse-like occurrence of electromagnetic waves of natural origin within the earth's atmosphere .
The sferics were discovered at the beginning of the 20th century when the cause of interference - crackling and crackling - in radio receivers was investigated. However, it was not until the beginning of the 1980s that Hans Baumer, Josef Eichmeier and Walter Sönning undertook a targeted study of sferics and their effects.
Ferrite rod antennas are used to receive and analyze the sferics .
properties
Sferics are very brief wave packets, often consisting of only a few oscillations, which are caused by charge shifts / migrations in the troposphere . These are so-called damped vibrations . The frequencies are between 3 and 100 kHz, the amplitudes up to 1000 times normal radio radiation, whereby a distinction must still be made between vertically and horizontally polarized radiation. The pulse repetition frequency is a maximum of 150 Hz, the typical pulse duration between 35 and 250 μs.
The main sources of sferics are thunderstorms , the lightning activities of which generate electromagnetic fields, and air-electrical fluctuations that are triggered by the movement and friction of large air masses. Since the causing lightning is often invisible dark field discharges , the sferics are often incorrectly referred to as dark lightning .
Even tornadoes are known as producers of Sferics.
Subdivision
Weather ferics
As Wettersferics the stationary near occurrence is referred to electromagnetic waves, in which a direct connection with the current weather conditions exist. The range of the pulses of visible lightning - so-called lightning ferics - is a few hundred kilometers at most. The sferics of the dark field discharges can spread over more than 1000 km. They arise z. B. by friction of air masses.
Geophysical Sferics
The geophysical sferics are natural electromagnetic waves that travel a very long distance to the point of reception and are called Whistler . Most of the time, the origin lies in lightning, even if they cannot be assigned to any special weather events due to the distance covered. Characteristic of these spherical phenomena is a diversification of the various frequency components through different signal transit times. This effect is called dispersion .
Schumann resonances
The space between the earth and the ionosphere can act as a cavity resonator . Schumann resonances are those frequencies at which the wavelength of an electromagnetic oscillation in the waveguide between the earth's surface and the ionosphere is an integral part U / n of the earth's circumference U. When excited with electromagnetic oscillations of such frequencies, standing waves , the so-called Schumann waves, are created . The energy for the low-frequency excitation comes from the worldwide thunderstorm activity. The fundamental wave of the Schumann resonance is 7.8 Hz, plus various harmonics between 14 and 45 Hz. Due to atmospheric turbulence, these values fluctuate. The Schumann resonances were proven in 1955 by the physicist Winfried Otto Schumann at the Technical University of Munich .
Effects
Meteorological importance
The activities of Sferics are used in meteorology for weather forecasting . In Bavaria alone there are now more than 100 measuring stations for Sferics. With the help of their data, the weather forecasts could be refined significantly.
Biological effects
The effect of sferics on biological systems, which has so far been little researched by science, creates a broad field for speculation. To what extent the occurrence of sferics correlates significantly with the frequency of occurrence of sensitivity to the weather , symptoms of illness, the number of accidents and the souring of milk, has not yet been conclusively scientifically clarified. Only a connection between sferics activity and the accumulation of epileptic seizures was found in one study.
Chemical and physical effects
In his book, Hans Baumer describes private research for the publishing house and graphic art institute F. Bruckmann KG in Munich on the influence of sferics at 28 kHz and 10 kHz on the diffusion processes in photo gelatine during the twelve-color printing process that was common at the time (→ chrome gelatine process , gravure printing process - Conventional etching and heliogravure ). He was able to convert his findings into a control of the printing process which, according to his statements, can reduce the sferic-related error rate in this printing process to a tenth. Furthermore, he claims to have cleared up the functionality of the historical FitzRoy 's storm glass through his research .
Baumer's main statement is that the printer's guild had long suspected that gelatine was sensitive to weather, but that a clear correlation to local weather could never be established. In numerous experiments and measurements (partly with the support of the Technical University of Munich), he examined both the "trivial" parameters of meteorology (pressure, temperature, relative humidity) as well as many other parameters such as ion content, etc. that these are not the cause of the observed changes in the gelatin processes, e.g. B. by air-conditioned, pressure-stabilized process rooms made of reinforced concrete. The extremely long-wave sferics would come into question, since such long-wave electromagnetic waves cannot be shielded by a normal reinforced concrete wall.
He saw the connection to other chemical and biological processes in a changed ion diffusion rate, which z. B. plays a role in a certain form of epilepsy .
Web links
- Radio in Space and Time - Whistler, Sferics and Tweeks, G. Wiessala in RadioUser 1/2013 (PDF; 8.7 MB)
- Astrosurf sound samples of different sferics
Individual evidence
- ↑ Joseph Eichmeier, Hans Baumer: Atmospherics and the weather . In: Natural Sciences . tape 77 , no. 4 , April 1990, pp. 164-169 , doi : 10.1007 / BF01131158 .
- ↑ Example of a ferrite antenna for receiving Sferics ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (JPEG).
- ↑ a b Hans Baumer: Sferics, the discovery of weather radiation . Rowohlt, 1987
- ↑ G. Ruhenstroth-Bauer, S. Vogel, Hans Baumer, C. Moritz, H.-M. Weinmann: Natural atmospherics and occurrence of seizures in six adolescents with epilepsy: a cross correlation study . In: Seizure . tape 4 , no. 4 , 1995, p. 303-306 , doi : 10.1016 / S1059-1311 (95) 80008-5 .
