A Monte Carlo study for ion outflows at high altitude and high latitude: Barghouthi model

A comparison has been made between the results of three different wave-particle interactions models, RCC model, Bouhram model, and Barghouthi model. These models have been used for investigating the H+ and O+ ion outflows at high altitudes equatorward of the cusp, and their simulation results have been compared to the corresponding observations. The comparison showed that the simulation results of O+ ion temperature (202 eV), H+ ion temperature (74 eV), and H+ and O+ ions velocity distributions (toroids) at 4.8 RE, geocentric distance, in the equatorward region of the cusp, obtained by using Barghouthi model, when the characteristic perpendicular wavelength of the electromagnetic turbulence lambda(perpendicular to) = 8 km, are close to the corresponding observations, T(O+) = 200 eV, T(H+) = 78 eV, and H+ and O+ toroids at 4.8 RE. This close agreement between Monte Carlo simulations and observations provides evidence that the diffusion coefficient, D-perpendicular to(r, v(perpendicular to)) described in this paper and consequently, the Barghouthi model are appropriate to be used when modeling the ion's acceleration through wave-particle interactions (i.e., ion interactions with electromagnetic turbulence) in the auroral regions of Earth's magnetosphere. The model includes the effects of velocity-and altitude-dependent wave-particle interactions, gravitational field, polarization electrostatic field, and diverging auroral geomagnetic field lines. Also, we present much evidence, i.e., comparisons between the simulations results of Barghouthi model for H+ and O+ ions outflows with the corresponding observations at different altitudes in the auroral region, that support the choice of Barghouthi model.