Understanding Earth’s ambipolar electric field

News | August 29, 2024

By Wisse Hettinga

earth NASA ambipolar

Using observations from a NASA suborbital rocket, an international team of scientists has, for the first time, successfully measured a planet-wide electric field thought to be as fundamental to Earth as its gravity and magnetic fields

Known as the ambipolar electric field, scientists first hypothesized over 60 years ago that it drove how our planet’s atmosphere can escape above Earth’s North and South Poles. Measurements from the rocket, NASA’s Endurance mission, have confirmed the existence of the ambipolar field and quantified its strength, revealing its role in driving atmospheric escape and shaping our ionosphere — a layer of the upper atmosphere — more broadly.

Key Points

A rocket team reports the first successful detection of Earth’s ambipolar electric field: a weak, planet-wide electric field as fundamental as Earth’s gravity and magnetic fields.
First hypothesized more than 60 years ago, the ambipolar electric field is a key driver of the “polar wind,” a steady outflow of charged particles into space that occurs above Earth’s poles.
This electric field lifts charged particles in our upper atmosphere to greater heights than they would otherwise reach and may have shaped our planet’s evolution in ways yet to be explored.