The eclipse of 20 July 1963 spectrophotometry of atmospheric emissions

Abstract

Abstract Observations of atmospheric emissions from a high-flying aircraft were made near Great Slave Lake, N.W.T., Canada during the eclipse of 20 July 1963. Emissions detected in the day airglow were: λ 5577 [OI], λ 6300 [OI] and λλ 5890–5896 (Na). Extrapolation to a fully illuminated atmosphere leads to an estimated intensity of 21 to 33 kR for the NaD lines, with an estimated altitude of 77 ± 5 km. The photon flux of the OI green line was observed to be 780 R at mid-totality while the OI red line measured 630 R near third contact. In the case of λ6300, u.v. dissociation of O2 is estimated to be responsible for less than 0.7 kR of the red line dayglow in the fully illuminated atmosphere. The brightness and spectral distribution of zenith total radiant flux, measured during totality, is comparable to that measured in the zenith during twilight at a solar depression angle of 7°48'. The observed asymmetry of the total light curve about midtotality is attributed to the shape of the Moon.