What is a “polar wind”

Hard to catch “polar wind”A phenomenon of vital importance for understanding the Earth’s atmospheric dynamics. The hypothesis of its existence was put forward more than 60 years ago. It described how particles in the Earth’s atmosphere fly into space, especially at the poles. Scientists have long believed that this force, despite its weakness, is as important for our planet as gravity and magnetism.

Glyn Collinson, principal investigator of the Endurance mission at NASA’s Goddard Space Flight Center, said the polar wind is fundamental to how Earth functions.

It’s been there all along, along with gravity and magnetism. And even though it’s weak, it still opposes gravity and actually lifts the sky up.
Collinson said in a NASA video:

Briefly about the discovery of the “polar wind”: watch the video

Ten years of research

The first clues to the existence of polar winds emerged in the late 1960s, when spacecraft detected atmospheric particles flying into space at supersonic speeds. But technology at the time was not advanced enough to directly detect the invisible, weak electric field that causes the phenomenon.

In 2016, Collinson and his team developed: Special sensors for measuring polar windsThese sensors were launched from the Svalbard Mountains in Norway by a suborbital rocket during the Endurance mission in May 2022. This location near the North Pole provided an ideal vantage point to study unique atmospheric phenomena.

Endurance rocket launch / Photo by Andøya Space/Leif Jonny Eilertsen

During the 20-minute flight, the Endurance rocket climbed to an altitude of 767 kilometers, collecting vital data from 518 kilometers of the atmosphere. The sensors recorded a small change of 0.55 volts, which Collinson compared to the power of a watch battery. Although small, it was enough. confirm the existence of polar wind.

The study found that the polar wind begins about 241 kilometers (150 miles) above the Earth’s surface, where atmospheric atoms split into negatively charged electrons and positively charged ions. The resulting electric field counteracts gravity and allows lighter hydrogen ions to fly into space at supersonic speeds along with heavier oxygen ions.

Illustrative image of Earth’s electric field / Visualization by NASA

Scientists believe that similar electric fields may exist on other planets, such as Venus and Mars, and could potentially affect their atmospheres in the same way that polar winds do on Earth.