Radio Science

Improved Photoionization Rates of O2(1Δg) in the D Region


  • D. E. Paulsen,

  • R. E. Huffman,

  • J. C. Larrabee


The recent discovery of relatively large concentrations of O2(1Δg) in the upper atmosphere had led to consideration of photoionization of this metastable molecule as a major source of O2+ in the D region. Our initial calculations indicated that this process was less important than previously believed, primarily because of CO2 absorption. In this paper we consider further the effect of various reasonable O2, CO2, and O2(1Δg) density profiles on the ion-production rates by this process. Within the limits described herein the ion-production rate (ion cm−3sec−1) is approximated by the following function of No2, the O2 column density in molecules per square-centimeter column, and n, the O2(1Δg density in molecules per cubic centimeter:

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