Earth behaves like a huge magnet. The English natural physicist and philosopher William Gilbert was the first to point out this similarity in 1600, although the effects of terrestrial magnetism had been used much earlier in primitive compasses.
The magnetism of the Earth is the result of a dynamic, since its iron core of the Earth is not solid.
On the other hand, various electrical currents produced by various causes are generated on the earth's surface and in the atmosphere, in addition to a constant exchange of electricity between the air and the Earth.
Earth's magnetic field
The Earth has a powerful magnetic field, as if the planet had a huge magnet inside whose south pole was near the geographical north pole and vice versa. Although the Earth's magnetic poles are called the magnetic north pole (near the geographic north pole) and the magnetic south pole (near the geographic south pole), their real magnetism is the opposite of what their names indicate.
The positions of the magnetic poles are not constant and show remarkable changes from year to year. Every 960 years, variations in the Earth's magnetic field include the change in the direction of the field caused by the displacement of the poles. The Earth's magnetic field has a tendency to move westward at a rate of 19 to 24 km per year.
Three electrical systems generated by natural processes are known. One is in the atmosphere. another is inside the Earth, flowing parallel to the surface, and the third, which transfers electric charge between the atmosphere and the Earth, flows vertically.
Atmospheric electricity is the result of ionization of the atmosphere by solar radiation and from the movement of ion clouds. These clouds are displaced by atmospheric tides, which are produced by the attraction of the Sun and the Moon over the atmosphere. They go up and down daily, as in the sea. The ionosphere constitutes an almost perfectly conductive spherical layer.
Earth currents constitute a global system of eight closed circuits of electric current distributed in a fairly uniform way on both sides of the equator, in addition to a series of smaller circuits near the poles. The surface of the Earth has a negative electrical charge. The negative charge would be consumed quickly if it were not replenished in any way.
A positive flow of electricity has been observed that moves down from the atmosphere to Earth. The cause is the negative charge of the Earth, which attracts positive ions from the atmosphere. Apparently, the negative charge moves to Earth during storms and the downward flow of positive current during good weather is counteracted by a return flow of positive current from areas of the Earth with storms.
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