PHOTOCHEMISTRY OF N+ IONS

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 1.3×10−10cm³s−1. At altitudes below 300 km, N+ is removed by reactions with O2 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 2.2×10−12cm³s−1 for N+ + O → N + O+ and of 3.6×10−12cm³s−1 for N+ + H → N + H+. Copyright 1979 by the American Geophysical Union.