Morphology of the Venus ultraviolet night airglow

Images of the nightside of Venus in the (0,1)8 band of nitric oxide have been obtained by the Pioneer Venus orbiter ultraviolet spectrometer (OUVS). The emission, which is produced by radiative association of N and 0, shows a bright spot reaching similar to 5 kR and located at 2 a.m. local solar time just south of the equator. The emitting layer is at 11 +/- 7-km altitude. A one dimensional vertical transport model shows that the hemispheric average brightness of 0.8 kR is consistent with the orbiter neutral mass spectrometer (ONMS) measurements of N and 0 near 167 km, and that the altitude of the emitting layer is consistent with the eddy mixing model proposed to explain the dayside helium profile measured by the bus neutral mass spectrometer. In the model, N reaches a peak of 7 x 10(8) cm(-3) at 114 km, and O reaches a peak of 2.6 x 10(11) cm(-3) at 106 km. There is a fair degree of consistency between the ONMS, OUVS, and other airglow measurements, except as regards the local time dependence.