Photodetachment rates for O⁻ and O₂⁻ in the D layer of the ionosphere as function of solar zenith angle and solar activity

Abstract

We present the results of calculation of photodetachment rates for negative ions in the D layer of the ionosphere, using recent photodetachment cross-section measurements. The calculations have been made for the standard atmosphere by means of the TUV (Terrestrial UltraViolet) code. We have obtained dependences of the photodetachment rates on altitude and solar zenith angle. The nonlinear nature of these dependences causes similar variations in the role of the photodetachement processes with altitude and solar zenith angle as compared to other processes in the middle atmosphere and the lower ionosphere, especially under terminator conditions. Calculations with solar spectrum for 2011–2020 for the summer/winter solstice and the spring/autumn equinox have shown no quantitative difference between the photodetachement rates for ions in the D layer of the ionosphere.