Profound change of the near-Earth radiation environment caused by solar superstorms

The outer radiation belt is often enhanced during storms while the inner belt is usually considered to be unaffected by geomagnetic activity. During the most recent Halloween superstorms, the extreme erosion of the plasmasphere allowed particles to be transported closer to the Earth where they were locally accelerated. Modeling, which now includes transport with resonant acceleration and loss processes and mixed diffusion, shows a rather good correspondence with observations. In this study, we use the same version of the VERB code to model a storm stronger than the Halloween storms, which most likely occurred in the past and may occur in the future. Our simulations indicate that during such a strong event, electrons will be transported into the heart of the inner zone, where they will be accelerated by chorus waves. When the plasmapause extends to larger distances, electrons accelerated by resonant wave-particle interactions in the inner radiation belt will find themselves in a very different plasma environment and strong fluxes may persist for several years after such a storm. Such intensification of the near-Earth plasma environment would substantially decrease satellite lifetimes at LEO. The radiation mitigation strategy for satellites operating in the inner belt should include a consideration of the potential for a dramatic increase in the near-Earth radiation. Such intensification of the near-Earth radiation environment may be truly devastating and would substantially decrease the lifetimes of meteorological, communication, and military satellites.

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