Impact of Solar Energy Protons and Magnetospheric Energetic Particles on the Upper Atmosphere

In addition to solar irradiance, solar and magnetospheric energetic particles are important sources of ionization of nuetral gases in the upper atmosphere. Energetic particles have a significant impact on thermospheric chemistry, energetics, and dynamics, as well as ionospheric electrodynamics. However, due to the difference in their characteristic energies, there are some distinctive differences among solar energetic protons, the ring current energetic protons and electrons, and auroral precipitating electrons in terms of their relative effects on the ionosphere and thermosphere. This paper will demonstrate the atmospehric effects associated with the various sources of energetic particles based on numeric simulations from the NCAR general circulation models, with an emphesis on the intercomparison amongst the different source particles.