What is the geomagnetic field?

What is the geomagnetic field?

There are magnetic fields in the Earth and near-Earth space, and the strength of the geomagnetic field is the largest among terrestrial planets. The geomagnetic field mainly comes from the inside of the earth, and the composition from outer space is less than 1%. The geomagnetic field can be mainly regarded as a dipole magnetic field. It has two magnetic poles connecting north and south, and the axis of the north and south poles is called the geomagnetic axis. The geomagnetic axis does not coincide with the rotation of the earth, and there is an included angle of about 11 degrees. Solar wind, cosmic rays, ionosphere, aurora, etc. all affect the geomagnetic field, and they cause short-term changes in the geomagnetic field. The solar wind also confines the geomagnetic field to a certain range. When the solar activity is strong, the energy of the solar wind will increase greatly, which will cause a strong disturbance of the geomagnetic field.