Simulation of the current‐driven electrostatic ion cyclotron instability

Abstract

Particle simulations are employed in a self‐consistent investigation of the growth and saturation of current‐driven instabilities along auroral field lines. Ion cyclotron waves are found to grow to levels eϕ/Te ∼ 0.2‐0.4, which are comparable with the levels observed by the S3‐3 satellite. In the present initial‐value calculations, saturation is due to plateau formation on the electron distribution function. Excitation of the ion cyclotron waves leads to moderate (∼ 40%) perpendicular heating of the ions but does not produce a high‐energy tail. The associated anomalous resistivity is relatively small, ν*/ωpe ∼ 1 × 10−4. Implications of these results for observation of ion cyclotron waves on auroral field lines are discussed.