DETERMINATION OF THE SOURCES AND SINKS OF N+ IONS IN THE THERMOSPHERE

Measurements of atmospheric parameters made by the Atmosphere Explorer‐C satellite are used to identify mechanisms for the production and loss of N+ ions in the ionosphere. The main source below 250 km is found to be photo‐dissociative ionization of N2. Above 250 km the reaction (Formula Presented.) is dominant; k1 is found to be 5 −2+7 × 10−11cm³s−1. A possible minor source of N+ is the reaction (Formula Presented.) where k2 = 1 −.5+1 × 10−10cm³s−1. Photoionization of N(4S) and dissociative charge exchange of He+ with N2 constitute detectable sources above 350 km. Charge exchange of N+ with O is identified as a significant sink above 300 km. The rate coefficient for this reaction is 5 −2+7 × 10−13 cm³s−1 Copyright 1979 by the American Geophysical Union.