A reanalysis of rocket measurements of the ultraviolet dayglow

We have reexamined rocket measurements of O I 989‐, 1304‐, 1356‐Å and N 2 Lyman‐Birge‐Hopfield band emissions in the mid‐latitude dayglow reported by Gentieu et al. (1979) and Eastes et al. (1985). MSIS‐83 atomic oxygen densities, the 1304‐ and 1356‐Å excitation cross sections of Zipf and Erdman (1985), and Solar Mesosphere Explorer solar 1304‐Å irradiance measurements are consistent with the observed O I and N 2 emission intensities. Atmosphere Explorer E measurements of the solar EUV irradiance near solar maximum are consistent with the 1980 rocket airglow data ( F 10.7 = 213). However, the solar EUV irradiance required to explain the 1978 airglow data ( F 10.7 = 106) is a factor of 1.5 larger than indicated by AE‐E. Enhancement of the 1304‐Å excitation cross section due to radiative entrapment of cascade‐feeding photons is much less than the factor of 2 predicted by the cascade model of Julienne and Davis (1976). The 3 s′ ³ D° direct excitation cross section of Vaughan and Doering (1987) is consistent with the 989‐Å airglow data and leads to an inferred total branching ratio of 1–2 × 10 −4 for transitions other than 989 Å from 3 s′ ³ D° , in agreement with the value for the 1173‐Å branch measured in laboratory experiments.