Scientists Unveil Earth’s Elusive Global Electric Field

Home Scientists Unveil Earth’s Elusive Global Electric Field

Geography

Aug 30, 2024

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An international team of scientists has confirmed the existence of a global electric field on Earth, known as the ambipolar electric field.

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The ambipolar electric field, a weak but fundamental electric field on Earth, is as crucial as gravity and magnetic fields.
The field was measured using NASA’s Endurance suborbital rocket.
- The rocket was launched from Svalbard, Norway, on May 11, 2022, and reached an altitude of 477.23 miles (768.03 kilometres), with data collected over a 322-mile range before landing in the Greenland Sea.

The Ambipolar Electric Field

The field theorised in the 1960s, believed to drive the “polar wind,” a continuous flow of charged particles escaping into space above Earth’s poles.
It begins at an altitude of approximately 150 miles (250 kilometres), where atmospheric atoms ionise into negatively charged electrons and positively charged ions.
It operates in both directions: it helps lift ions to higher altitudes while simultaneously pulling electrons downward.
- This bidirectional effect balances the forces of gravity and electrostatic attraction, effectively extending the atmosphere’s height and facilitating the escape of particles into space.
The field acts like a conveyor belt, lifting the atmosphere upwards and shaping its dynamics.
The successful measurement of this field provides new insights into how our atmosphere evolves and offers clues about atmospheric processes on other planets.

Key Highlights:

The Endurance rocket measured a change in electric potential of 0.55 volts.
This field strength is sufficient to explain the observed polar wind phenomena.
The ambipolar field exerts an outward force on hydrogen ions 10.6 times stronger than gravity, allowing them to escape into space at supersonic speeds.
The ambipolar field increases the “scale height” of the ionosphere by 271%, meaning the ionosphere remains denser at higher altitudes than without this field.

Implications:

The discovery helps us understand Earth’s atmospheric history and could be applied to study other planets and their atmospheres, such as Venus and Mars.
Any planet with an atmosphere is expected to have an ambipolar field, which can shape atmospheric dynamics over time.
The Endurance mission’s findings open new avenues for exploring how such fields influence atmospheric evolution on Earth and other planets.