Influence of Atmospheric Solar Radiation Absorption on Photodestruction of Ions at D-Region Altitudes of the Ionosphere

Abstract

The influence of atmospheric solar radiation absorption on the photodetachment, dissociative photodetachment, and photodissociation rate coefficients (photodestruction rate coefficients) of O−, Cl−, O2 −, O3 −, OH−, NO2 −, NO3 −, O4 −, OH−(H2O), CO3 −, CO4 −, ONOO−, HCO3 −, CO3 −(H2O), NO3 −(H2O), O2 +(H2O), O4 +, N4 +, NO+(H2O), NO+(H2O)2, H+(H2O) n for n = 2–4, NO+(N2), and NO+(CO2) at D-region altitudes of the ionosphere is studied. A numerical one-dimensional time-dependent neutral atmospheric composition model has been developed to estimate this influence. The model simulations are carried out for the geomagnetically quiet time period of 15 October 1998 at moderate solar activity over the Boulder ozonesonde. If the solar zenith angle is not more than 90° then the strongest influence of atmospheric solar radiation absorption on photodestruction of ions is found for photodissociation of CO4 − ions when CO3 − ions are formed. It follows from the calculations that decreases in the photodestruction rate coefficients of ions under consideration caused by this influence are less than 2 % at 70 km altitude and above this altitude if the solar zenith angle does not exceed 90°.