Theoretical incoherent scatter spectra of non-Maxwellian velocity distributions in STEVE

The subauroral Strong Thermal Emission Velocity Enhancement (STEVE) is an optical phenomenon hypothesized to be caused by local emissions from collisions of highly energized electrons with thermospheric neutral particles. Electrons become heated by enhanced parallel electric fields from magnetosphere-ionosphere coupling through field-aligned currents. Some of these electrons reach energies at which excitation collisions with neutrals become an important mechanism that will drive the velocity distribution to become highly non-Maxwellian. In this work, we examine different methods of solving the collisional Boltzmann equation to calculate steady state electron velocity distributions. From these, we use a recently developed method to calculate the theoretical incoherent scattering spectra, which can be compared with data to validate the local emission hypothesis.