Aircraft Observations of the Infrared Emission of the Atmosphere in the 700-2800-cm(-1) Region.

Atmospheric emission spectra in the 700-2800-cm(-1) region have been measured from an aircraft at 9.45-11.89-km altitudes. All measurements were made viewing at the zenith at a spectral resolution of 2 cm(-1). The measurements were obtained using interferometer spectrometers, and the atmospheric radiation was modulated with a liquid nitrogen cooled chopper that eliminated the thermal emission of the spectrometers from the measured spectra. Essentially all the features of the spectra can be identified with known constituents of the atmosphere. The comparison with a theoretical emission calculation using a tropical atmospheric model was satisfactory except for the H(2)O that showed a smaller concentration by a factor of 5 than was assumed in the model at these altitudes.