The photochemistry of N⁺ ions

Abstract

The photochemistry of N + ions in the daytime thermosphere is studied using the data base of the Atmosphere Explorer C Satellite and it is argued that the reaction O + + N(²D) → O + N + is a major source of N + ions at altitudes between 250 and 500 km. Close agreement with measurements is obtained by postulating a rate coefficient of 1.3×10 −10 cm³s −1 . At altitudes below 300 km, N + is removed by reactions with O 2 but at higher altitudes the reactions of N + with O and with H are the most important chemical loss mechanisms. We derive empirical rate coefficients of 2.2×10 −12 cm³s −1 for N + + O → N + O + and of 3.6×10 −12 cm³s −1 for N + + H → N + H + .