Morning and evening behavior of the F region green line emission: Evidence concerning the sources of O(¹S)

Measurements of the green line emission from atomic oxygen by a satellite-borne photometer show consistently larger volume emission rates in the evening than at comparable solar zenith angles in the morning between altitudes of 150 and 200 km. The temporal variation in the airglow is consistent with diurnal model calculations if we assume that the reaction N + O2+ → NO+ + O(¹S) provides a significant source for the green line, O(¹D−1S).