Secondary Electrons MI Coupling in the Presence of ECH and Whistler Waves

Abstract:

There are two main theories for the origin of electron precipitation in the diffuse aurora: first, pitch angle scattering by electrostatic electron cyclotron harmonic (ECH) waves, and second, scattering by whistler mode waves. In the diffuse aurora, precipitating electrons initially injected from the plasmasheet to the loss-cone via wave-particle interaction processes degrade in the atmosphere toward lower energies and produce secondary electrons via impact ionization of the neutral atmosphere. These secondary electrons can escape back to the magnetosphere, become trapped on closed magnetic field lines, and deposit their energy back to the inner magnetosphere. ECH and whistler mode waves can also move electrons in the opposite direction, from the loss cone into the trap zone, if the conjugate ionospheric sources of such electrons is located at the same field lines as the trapped magnetospheric electron population. In this talk, we will discuss secondary electron formation in regions of diffuse aurora in the presence of both ECH and whistler mode waves, taking into account multiple reflection of precipitated plasma sheet electrons. We also compare our modeled results for secondary electron fluxes with MMS data.