The diffusion of multiple ionic species in meteor trails

• Meteor trail diffusion involves a mixture of different types of ions.
• Multi-ion diffusion depends strongly on the initial distributions of different species.
• Numerical simulation results vary, depending on initial ion distributions.
• Multi-ion diffusion does not cause observed wavelength dependence of D.

Meteor trails are composed of a number of different types of ions that are produced during the meteoroid ablation process. The diffusion of meteoric plasma is usually presented in terms of the diffusion of a single ionic species, but this ignores the possibility of non-linear diffusion due to complex meteor trail composition. This study uses numerical simulations to investigate what effect multi-ion diffusion has on the time-decay of meteor radar echoes, and whether multi-ion diffusion could be responsible for the anomalous diffusion coefficient estimates produced by radars operating at different frequencies. It is found that the diffusion of different species of ions in meteor trails does not produce the same discrepancies seen in estimates of the ambipolar diffusion coefficient made using meteor radar.