Plasma fountain

The polar wind, also known as a plasma fountain, is a permanent outflow of plasma from the polar regions of Earth's magnetosphere into space, working on the same underlying principle as the solar wind. The outflow is driven by an ambipolar electric field, a polarization field created as expanding ionospheric plasma at the poles undergoes gravitational charge separation; the field becomes strong enough to overcome gravity's pull on lighter ions, accelerating them upward and outward along Earth's open magnetic field lines and out of the atmosphere. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/