radiation belts
From Glossary of Meteorology
(Also called Van Allen radiation belts.) Belts of energetic electrons, protons, and heavier ions encircling the earth and trapped in the geomagnetic field.
The radiation belts are characterized by intense fluxes of high-energy radiation, creating a dangerous environment for spacecraft. The particle density and energy spectrum, as well as the physical characteristics of the belts, depend on the level of solar activity.
