dipolar field

geodesy

Also known as: dipole field

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June 25, 2026

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The dipolar hypothesis suggests that the Earth's magnetic field can be best represented by a magnetic dipole, similar to a bar magnet. This field is the primary component of Earth's magnetism, though a weaker, non-dipolar field also exists, thought to originate in the outer core.1

Geodesy, the science of measuring Earth's shape and size, utilizes magnetic field measurements. Instruments like magnetometers, borne by aircraft, ships, or spacecraft, map these fields. These magnetic surveys help in understanding Earth's internal structure and can indirectly aid in locating mineral and oil deposits, as magnetic properties of rocks vary. The dipolar field's strength is strongest near the magnetic poles and weakest at the magnetic equator.234

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Jupiter
The magnetic field and magnetosphere
The axis of the magnetic dipole is offset by a tenth of Jupiter’s equatorial radius of 71,500 km (44,400 miles) from the planet’s rotational axis, to which it is indeed inclined by 10°. The orientation of the Jovian magnetic field is opposite to the present orientation of Earth’s field,…
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The axis of the magnetic dipole is offset by a tenth of Jupiter’s equatorial radius of 71,500 km (44,400 miles) from the planet’s rotational axis, to which it is indeed inclined by 10°. The orientation of the Jovian magnetic field is opposite to the present orientation of Earth’s field,…
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geomagnetic field
Dipolar field
The magnetic field lines shown in the bar-magnet figure are not real entities, although they are frequently treated as such. A magnetic field is a continuous function that exists at every point in space. A field line is simply a means for visualizing…
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The magnetic field lines shown in the bar-magnet figure are not real entities, although they are frequently treated as such. A magnetic field is a continuous function that exists at every point in space. A field line is simply a means for visualizing…
Read More

Saturn
The magnetic field and magnetosphere
… resembles that of a simple dipole, or bar magnet, its north-south axis aligned to within 1° of Saturn’s rotation axis with the centre of the magnetic dipole at the centre of the planet. The polarity of the field, like Jupiter’s, is opposite that of Earth’s present field—i.e., the field lines…
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… resembles that of a simple dipole, or bar magnet, its north-south axis aligned to within 1° of Saturn’s rotation axis with the centre of the magnetic dipole at the centre of the planet. The polarity of the field, like Jupiter’s, is opposite that of Earth’s present field—i.e., the field lines…
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