Energetic particles in the magnetosphere can precipitate into the atmosphere due to wave-particle interactions, Coulomb scattering, and field line curvature scattering. The collisions between the precipitated energetic particles and neutral particles in the atmosphere release photons and form auroras. Precipitated energetic electrons contribute to the presence of nitric oxide (NOx) in the upper atmosphere, influencing ozone levels, temperatures, and wind patterns. Geomagnetic activity has been incorporated into climate models for the first time, reflecting its role in atmospheric dynamics. However, uncertainties remain regarding the accuracy of data on atmospheric ionization rates derived from precipitated electron fluxes, which could affect model predictions. A recent study revealed that there is or are missing precipitation mechanism(s) of energetic electrons. It can be due to the waves or other mechanisms not taken into account. On the other hand, the role of electromagnetic ion cyclotron waves in causing the loss of energetic electrons is still under debate, especially about which energies of electrons are affected significantly by these waves.
In this project, using methods of satellite observation, theoretical analysis and modelling, our team will unveil the mysterious missing precipitation mechanism(s) and shed light on the question under debate. We will also quantify the consequent effects on the atmosphere and carefully validate the simulation results against satellite observations.