Meteors and atmospheres

Meteoroid ablation in an atmosphere produces a weak plasma column. The processes important in governing the state of the meteoric species subsequent to column formation are reviewed. The actions of transport and of chemical reactions in controlling the life of the various species in the column are described. It is found that the interaction of meteoric ions with atmospheric gases leads to the dissipation of ionization and is the source of anomalous radio-meteor echo characteristics: recognition of these effects is important in permitting meaningful interpretations of radio-meteor data. Several modes of interaction between meteoric species and an atmosphere can yield enduring emissions. The fate of the various species is discussed.