A model of meteoric iron in the upper atmosphere

Abstract

A one-dimensional steady state model of meteoric iron in the Earth's upper atmosphere has been developed. The model covers the altitude range 70 to 110 km at latitude 40°N and allows for seasonal variations in the chemical composition, total density and temperature of the upper atmosphere. It addresses the three processes thought to be most influential in affecting the layer of free Fe atoms at approximately 85 km altitude, that is, the deposition of iron via meteor ablation, the vertical distribution of the ablated material, and the partitioning of the metal among 10 constituent species as a result of neutral and ion gas phase reactions in dynamical steady state. A comparison between calculated and observed average monthly Fe profiles reveals that many features displayed by the meteoric iron layer (such as the peak height and width, the small scale heights at the topside and underside, and the seasonal changes in these parameters) can be successfully reproduced by the model. Copyright 1998 by the American Geophysical Union.