Meteors deposit many tons of material into Earth's upper atmosphere each day. The physics and chemistry of meteoric metals in the atmosphere have long been active topics of study, but sophisticated models have emerged just recently of the gas-phase chemical reactions that affect the evolution of the state of these metals. At high latitudes, this portion of the upper atmosphere is also shared by the aurora borealis, or northern lights, which dramatically alter the properties of the background plasma.; This thesis concerns coupled chemical models and one-dimensional dynamical models that were developed to investigate the effects of auroral ionization on the time evolution of meteoric iron and sodium elements and compounds in the upper atmosphere. These models are used to show that aurorae can result in rapid ionization of recently deposited iron and sodium, with time constants on the order of 15 minutes. The models are also used to investigate the influence of aurorae on the background iron and sodium layers. Because of the nominal altitude of the neutral iron layer, aurorae will not normally have a measurable impact on that constituent. For sodium, on the other hand, the impact is more significant but highly dependent on the chemical makeup of the aurorally produced ions. For either case, sporadic neutral atom layers at auroral altitudes are significantly affected.; A case study of radar and lidar measurements from the Sondrestrom Facility in Greenland is used to test the sodium model. Results are presented which are consistent with the model predictions of the effects of the aurorally enhanced ionization. For this specific case, evidence is also presented to support a gas-phase chemical mechanism for the formation of a thin the formation of a thin sporadic sodium layer.
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