Schumann resonance parameter changes during high-energy particle precipitation

A systematic study of Schumann resonance parameters during high-energy part icle precipitation events is presented. Protons and electrons with energies above 1 MeV ionize the upper boundary of the Earth-ionosphere cavity, lead ing to an increase of the resonance frequency and a decrease of the damping of the first Schumann resonance, as derived from measurements at Arrival H eights, Antarctica. The study uses the nine strongest solar proton events o f the past salar cycle 22 and high-energy electrons emitted periodically fr om corotating interaction regions in the solar wind during 1994-1995. The v ariation of the Schumann resonance parameters is in qualitative agreement w ith current theories of Schumann resonances. The study also shows that high -energy particle precipitation is not the only relevant source affecting Sc humann resonance parameters. The reported findings constitute a so far litt le-explored aspect of solar terrestrial relations.