Abstract
Twilight airglow emissions in the wavelength ranges at about 1.3μm, 1.7μm and 2.2μm were observed by a rocket-borne photometer. The heights of the airglow layers and the local times at emission regions were derived taking into account the roll, precession and altitude of the rocket. The volume emission rates in these three bands were peaked at about 73km. The mean lifetime of the O2(1Δg) molecules was obtained to be 33±2 minutes from the time variation of the airglow intensity in the 1.3μm band. This is accounted for in terms of a combination of the spontaneous decay and the collisional deexcitation. The rate constant for the latter is about a half of that obtained in laboratory measurements at room temperature.
