Scientists find a long-sought electric field in Earth’s atmosphere

[Elderberry]

Science News by Lisa Grossman 9/13/2024
The field could be a key component to life on the planet

For the first time, scientists have measured a long-sought global electric field in the Earth’s atmosphere. This field, called the ambipolar electric field, was predicted to exist decades ago but never detected, until now.

“That’s the big whoop,” says atmospheric scientist Glyn Collinson of NASA’s Goddard Space Flight Center in Greenbelt, Md. “It’s a whole frickin’ new planetary energy field that’s never been measured before!”

The field is weak, only 0.55 volts — about as strong as a watch battery, Collinson says. But that’s strong enough to control the shape and evolution of the upper atmosphere, features that could have implications for the suitability of our planet for life.

“It’s fundamental to the DNA of our planet,” says Collinson, who reported the new measurement in Nature August 28.

The existence of the ambipolar electric field was first predicted in the 1960s, at the dawn of the space age. Early spacecraft flying over Earth’s poles detected a supersonic outflow of charged particles from the atmosphere, called the polar wind.

The most reasonable thing to explain that speedy wind would be an electric field in the atmosphere. The idea is that sunlight can kick electrons out of atoms in the upper atmosphere. Those negatively charged electrons are light and energetic enough that they want to float out into space. The positively charged oxygen ions left behind are heavier and want to sink down in Earth’s gravity.

But the atmosphere wants to remain electrically neutral, keeping an equal balance between electrons and ions. The electric field forms to keep the electrons tied to the ions and prevent them from escaping.

Once established, the field can act as a booster for lighter ions like hydrogen, giving them enough energy to break free of Earth’s gravity and zoom away as the polar wind. It can also pull heavier ions higher up in the atmosphere than they would otherwise reach, where other forces can strip them into space as well.

More: https://www.sciencenews.org/article/electric-field-in-earths-atmosphere