Measurement of stratospheric composition, using far infrared emission spectroscopy

The paper reports on measurements of total quantities and, in some cases, vertical distributions of a number of minor stratospheric constituents, where the method employed was to record the submillimeter wave emission spectrum at the long wavelength end by Fourier spectroradiometry, viewing the stratosphere horizontally with a Michelson-type interferometer through an aircraft window at about 15 km altitude. High-resolution laboratory measurements of all known minor constituents were made with a phase-modulated Michelson interferometer and helium-cooled indium antimonide detector, and these spectra were used to improve the quantitative accuracy of the stratospheric spectra. Measurements presented here include the variation of nitrous oxide with latitude over a wide geographical area, similar results for ozone, the vertical distribution of nitrous oxide, and some profile estimates on a number of gases.