Atomic hydrogen and solar Lyman α flux deduced from STP 78‐1 UV observations

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Abstract
Simultaneous observations of the Lyman α and 1026 Å airglow by a spectrometer on the STP 78‐1 satellite have been analyzed. A spherical model of the multiple scattering of solar Lyman α and Lyman β radiation was utilized which includes the effect of pure absorption by O2 and a nonisothermal temperature profile. Analysis of data near 0° latitude yields an exobase temperature Tc = 1300 ± 200 K, exobase density Nc = 2.6 ± 0.2 × 104 cm−3, and escape flux Fc = 2 ± 0.5 × 108 cm−2 s−1. The solar Lyman α line center flux determined from analysis of the Lyman α airglow was 6.0 ± 1.2 × 1011 photons cm−2 s−1 Å‐1. Analysis of the 1026 Å airglow showed that this emission is dominated by multiple scattering of solar Lyman β photons by atomic oxygen and that the Lyman β airglow contributes less than 20% to the observed emission.