Polar wind

[3] In 1966 Bauer[4] and, separately, Dessler ahd Michel[5] noted that since the Earth's geomagnetic field above the poles forms a long tail away from the Sun out beyond the Moon's orbit, ions should flow from the higher pressure region in the ionosphere out into space.

[6] The term "polar wind" was coined[7]: 1937  in 1968 in a pair of articles by Banks and Holzer[8] and by Ian Axford.

[9] Since the process by which the ionospheric plasma flows away from the Earth along magnetic field lines, is similar to the flow of solar plasma away from the Sun's corona (the solar wind), Axford suggested the term "polar wind."

[10][11] Additional data from the 1981 Dynamics Explorer led to some uncertainty in the theoretical models about the role of cool O+ ions.

[7]: 1966 The idea for the polar wind originated with the desire to solve the paradox of the terrestrial helium budget.

Additional mechanisms include ion acceleration by solar photoelectrons escaping along magnetic field lines.

[13]: 167  Ions following open magnetic field lines are push away from the Sun by forces of the solar wind (anti-solar convection).

Some of the conclusions include:[7] The polarization or ambipolar electric field was directly measured in 2022 by a sounding rocket launched from Svalbard.

The Earth's plasma fountain, showing oxygen, helium, and hydrogen ions which gush into space from regions near the Earth's poles. The faint yellow area shown above the north pole represents gas lost from Earth into space; the green area is the aurora borealis —or plasma energy pouring back into the atmosphere. [ 1 ]
Conceptual diagram of the two main effects of the ambipolar electric field: inflating the ionosphere and generating the polar wind.The sparkling blue haze surrounding Earth represents the plasma in the ionosphere. The sparkling lines represent polar wind flowing up and out. [ 12 ]