Measurements of spectrally integrated atmospheric transmittance in the O2 Schumann‐Runge bands and derived oxygen column densities: 76–102 km

Abstract

Atmospheric transmittances integrated over wavelength intervals corresponding approximately to the (15–0) through (4–0) Schumann‐Runge bands of O2 have been determined from EUV solar spectra (1768 Å <λ <1948 Å) photographed at seven altitudes between 102 and 76 km with a rocket‐borne spectrograph having a resolution of 0.07 Å. The observed transmittances are compared with atmospheric transmittances predicted from three models of the O2 absorption cross section. The predicted transmittances have also been used to derive column densities of atmospheric O2 from the observations. The results are compared with values calculated from the U.S. Standard Atmosphere (1976) and with oxygen column densities determined by Prinz and Brueckner (1977) from EUV solar spectra of the Schumann‐Runge continuum (λ <1750 Å) and of the H‐Lyman alpha line (1216 Å) recorded on the same films used in the present research. The comparisons test the utility of the models for studies of atmospheric photochemistry, suggest which models may be best for this purpose, and indicate how the models can be improved.