“THE RING CURRENT encircling the Earth roughly in the region 2–7 RE from the Earth consists of plasmas originating both from the solar wind and the ionosphere. The ring current typically consists of ions in the energy range from a few tens of keV to several hundred keV, and has a highly variable intensity controlled by the level of geomagnetic activity.”
https://link.springer.com/article/10.12942/lrsp-2007-1