High-altitude and high-latitude O + and H + outflows: the effect of finite electromagnetic turbulence wavelength

The energization of ions, due to interaction with electromagnetic turbulence (i.e. wave-particle interactions), has an important influence on H + and O + ions outflows in the polar region. The effects of altitude and velocity depen- dent wave-particle interaction on H + and O + ions outflows in the auroral region were investigated by using Monte Carlo method. The Monte Carlo simulation included the effects of altitude and velocity dependent wave-particle interaction, gravity, polarization electrostatic field, and divergence of au- roral geomagnetic field within the simulation tube (1.2-10 earth radii, RE). As the ions are heated due to wave-particle interactions (i.e. ion interactions with electromagnetic turbu- lence) and move to higher altitudes, the ion gyroradius i may become comparable to the electromagnetic turbulence wavelength ? and consequently (k? i ) becomes larger than unity. This turns the heating rate to be negligible and the mo- tion of the ions is described by using Liouville theorem. The main conclusions are as follows: (1) the formation of H + and O + conics at lower altitudes and for all values of ?; (2) O + toroids appear at 3.72 RE, 2.76RE and 2RE, for ?=100, 10, and 1 km, respectively; however, H + toroids appear at 6.6RE, 4.4RE and 3RE, for ?=100, 10, and 1 km, respec- tively; and H + and O + ion toroids did not appear for the case