OBSERVATION OF NITRIC-OXIDE ROVIBRATIONAL BAND HEAD EMISSIONS IN THE QUIESCENT AIRGLOW DURING THE CIRRIS-1A SPACE-SHUTTLE EXPERIMENT

Band head emissions from highly rotationally excited NO (v,J) (J almos t-equal-to 90) have been observed in the quiescent atmosphere at tange nt heights between approximately 115 and 190 km for both sunlit and ni ghttime conditions. The data were obtained by the cryogenic CIRRIS-1A interferometer which was operated on-board the space shuttle between 2 8 and 30 April 1991. Up to ten emission features between 2020 and 1744 cm-1 in the earthlimb spectra have been identified as the R-branch ba nd heads of the NO DELTAv = 1 sequence for the vibrational states v' = 1 - 10. The presence of these band heads requires a very high degree of rotational excitation corresponding to rotational energy in excess of 1.4 eV. These are the first observations of emissions from highly r otationally excited NO in the quiescent airglow and they parallel the recent discovery of highly excited pure rotational transitions of OH i n the airglow for both nighttime and daytime quiescent conditions.