The vibrational distribution of O⁺₂ in the dayside ionosphere

The vibrational distributions of O ₂ ⁺ in the X ² Π _g , A ² Π _u , a ⁴ Π _u , and b ⁴ Σ- _g states in the dayside terrestrial ionosphere are calculated for both low and high solar activity models. The distributions are found to be significantly different from the O ₂ ⁺ vibrational distributions found by Fox (1985) for the Venusian ionosphere. The sources and sinks of vibrational excitation and the implications for the chemistry, dayglow, and hot oxygen coronas are discussed. Finally, intensities of the first negative and second negative band systems of O ₂ ⁺ are presented.