Infrared solar absorption spectra recorded at 0.002–0.003 cm−1 resolution in the 10 μm region during two recent balloon flights from near 32°N latitude have been analyzed to determine the isotopic ratios of 16O16O18O and 16O18O16O, the two most abundant forms of isotopically substituted ozone, relative to normal ozone, in the stratosphere. The analysis has used recent improvements in the line parameters for 16O3, 16O16O18O, and 16O18O16O. Normalized to the standard isotopic ratios in ozone, the results show column‐averaged isotopic enhancement ratios of 1.20±0.14 and 1.40±0.18 for 16O18O16O/16O16O16O and 16O16O18O/16O16O16O, respectively, above 37 km altitude for flight measurements on November 18, 1987, and corresponding values of 1.16±0.08 and 1.25±0.12 for flight measurements on June 6, 1988. These measurements are the first such results obtained at high altitude using infrared techniques. The values are compared with heavy‐to‐normal O3 ratios reported previously from other techniques.

Long-term trends in the concentrations of SF 6, CHCIF2 (CFC-22), and COF2 in the lower stratosphere have been derived from analysis of ca. 1980 and more recent infrared solar occultation spectra recorded near 32øN latitude at --•0.02-cm -1 resolution. Consistent sets of line parameters and spectral calibration methods have been used in the retrievals to minimize systematic error effects. Quoted error limits are 1 sigma estimated precisions. The SF 6 and CHCIF2 results are based on spectra recorded by balloon-borne interferometers in March 1981 and June 1988 and a comparison of these results with the Atmospheric Trace Molecule Spectroscopy (ATMOS) Experiment/Spacelab 3 measurements obtained in May 1985 near 30øN latitude. In the 13-18 km altitude range the mean measured SF 6 mixing ratio in parts per trillion by volume (pptv) increased from 1.17 +_ 0.21 in March 1981 to 2.02 +_ 0.20 pptv in June 1988, and the CHC1F 2 mixing ratio below 15 km altitude increased from 51 +_ 8 pptv in March 1981 to 102 +_ 10 pptv in June 1988. The CHC1F2 retrievals used new empirical CHCIF2 line parameters derived from 0.03-cm-1 resolution laboratory spectra recorded at six temperatures between 203 and 293 K' the derived mixing ratios are --•30% higher than obtained with earlier sets of line parameters, thereby removing a large discrepancy noted previously between IR and in situ measurements of CHCIF2. Assuming an exponential growth model for fitting the trends, SF 6 and CHC1F2 mean increase rates of 7.4% +_ 1.9% and 9.4% +_ 1.3% year -• are obtained, respectively which correspond to cumulative increases by factors of--• 1.7 and --•2.0 in the concentrations of these gases over the 7.2-year measurement period. Analysis of spectra recorded in October 1979 and April 1989 yields COF2 volume mixing ratios that are respectively 0.44 +_ 0.17 and 1.21 +_ 0.24 times the ATMOS/Spacelab 3 values, from which an average COF2 increase rate of 10.3 +_ 1.8% year -1 over this time period has been estimated. The present results are compared with previously reported observations and trends and with one-dimensional model calculations. The model calculated trends are in reasonably good agreement with the observations.

A new Michelson‐type interferometer system operating in the infrared at very high resolution (0.002–0.003 cm−1 full width at half maximum) has been used to record numerous balloon‐borne solar absorption spectra of the stratosphere, ground‐based solar absorption spectra, and laboratory spectra of molecules of atmospheric interest. In the present work we report results obtained for several important stratospheric trace gases, HNO3, ClONO2, HO2NO2, NO2, and COF2, in the 8‐ to 12‐μm spectral region. Many new features of these gases have been identified in the stratospheric spectra. Comparison of the new spectra with line‐by‐line simulations shows that previous spectral line parameters are often inadequate and that new analysis of high‐resolution laboratory and atmospheric spectra and improved theoretical calculations will be required for many bands. Preliminary versions of several sets of improved line parameters under development are discussed.

Absorption bands of CF2Cl2, CFCl3 and CCl4 have been observed in infrared sunset solar spectra in the 800‐1000 cm−1 region from 30 km altitude during a balloon flight made in September 1975. The infrared absorption bands were used to derive the distribution of these constituents in the upper troposphere and lower stratosphere. The results are compared with 1968 data and with current results of other authors.

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