Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior out into space, where it meets the solar wind, a stream of charged particles emanating from the Sun.
The magnetic field of a current loop could sustain the magnetic dipole type magnetic field of the earth. Large-scale computer models are approaching a realistic simulation of such a geodynamo.
Roughly speaking it is the field of a magnetic dipole currently tilted at an angle of about 10 degrees with respect to Earth's rotational axis, as if there were a bar magnet placed at that angle at the center of the Earth.
Compute Earth's Magnetic Field Values. On-line calculators to estimate current and past values of the magnetic field. If you want only the magnetic declination (variation) for a single day between 1900-present, visit our declination calculator.
The magnetic field of Earth actually changes its polarity over time.
The basic dipole shape of Earth's magnetic field (bottom) and the teardrop shape of the magnetosphere created by the solar wind (top).
She believes Earth's magnetic field could have made the difference in the past when the solar wind was presumably stronger. "People aren't putting all the cards on the table," Luhmann said. "We can't say that magnetic fields are unimportant from the current data."
The Earth's magnetic field can be closely approximated by the field of a magnetic dipole positioned near the centre of the Earth.
Earth's magnetic field, which protects the planet from huge blasts of deadly solar radiation, has been weakening over the past six months, according to data collected by a European Space Agency (ESA) satellite array called Swarm.
Figure 18.1: Earth’s Magnetic Field - Note that each of the 3 elements of the circuit are connected in series. Note the large power supply: large power supply ! large current.