NIGHTGLOW EMISSION ALTITUDES FROM ROCKET MEASUREMENTS

Abstract

Four rocket-borne photometers measured nightglow emissions near λ 6300, λ 5893, λ 5577, and λ 5335. The emitting region of the oxygen green line, λ 5577, was entirely between 90 and 118 km, and had a very sharp lower boundary. The sodium D-lines were encountered primarily between 85 and 110 km, with a maximum intensity at 93 km. The upper boundary of D-line emission was not definite, due to tailing off of the distribution and low total intensity, but D-line emission extending into the 130- to 150-km region is indicated. The λ 6300 photometer showed two distinct features: an emitting region from 56 to 100 km, and a large signal still present at the peak of flight, 163 km. We attribute the 56- to 100-km emission to the (9–3) Meinel OH band, and conclude that the region of oxygen red line emission must lie above 163 km. On the basis of relative band intensities for the Meinel OH bands and the dissimilarity of the signal-νs-altitude curves for the λ 5335 and λ 6300 photometers, we conclude that practically all atmospheric emission near λ 5335 is due to an atmospheric “continuum” and not due to OH band emission. This atmospheric “continuum” has a maximum intensity between 100 and 110 km, and is at least as bright as the stellar background. During descent of the rocket through the E-region, the photometers recorded a bright glow in the rocket's wake. Energy for creating the glow had to come from atmospheric gases and not the rocket. Its spectra and other features are discussed.