High-resolution O3(v3) spectral emission data, obtained between 80 and 125 km during an aurora by the rocketborne HIRIS cryogenic interferometer spectrometer, have been analyzed by a spectal simulation least squares technique. Data obtained below 110 km exhibit behavior independent of local auroral strength and thus appear to represent quiescent nightglow. The derived vibrational state population distributions for levels v'3≥1 can be expressed as vibrational ''temperatures'' of 400--600 K. This result is interpreted in terms of formation of O3(v'3) by three-body recombination of O with O2 as well as other radiative and collisional processes. Additional data, obtained near 120 km and sampling intense auroral are, indicate a hither to unexpected auroral enhancement of O3(v3) fluorescence intensity and vibrational state distribution.