Characterize SEP access through the early Earth–Moon magnetosphere

Characterize the fraction of solar energetic particles from young-Sun CME-driven shocks that precipitated into the early Earth's atmosphere after interaction with the evolving terrestrial and lunar magnetospheres.

Background

The atmospheric energy budget initially treats the intercepted SEP energy as the energy available for deposition, using an access factor near unity. The actual precipitating fraction depends on the early geomagnetic field, its rigidity cutoff, the size of the open polar cap, polarity reversals, field multipolarity, and possible shielding or restructuring by the contemporaneous lunar dynamo.

Because this access factor directly affects atmospheric nitrogen fixation and climate estimates, a self-consistent palaeomagnetospheric model incorporating the coupled Earth–Moon system remains necessary.