Measured profiles of the vertical distributions of the volume emission rates of the O H infrared airglow are presented. These measurements by various investigators constitute a total of 34 rocket flights and were obtained at both mid and high latitudes, at various solar depression angles, and at various times of the year using rockets which flew into the middle atmosphere. Some 55 profiles are summarized. Quantitative altitude comparisons are made at various locations. Included in the comparisons are volume emission rate profiles at IR as well as at visible wavelengths. From all of the profiles reported, the value of the mean altitude of the peak OH volume emission rate is 87.4 km, and the mean half-power thickness is 12.4 km. However, we recommend as working numbers to be used: 86.8 2.6 km for the altitude of the peak and 8.6 i 3.1 for the thickness of the O H emission layer [taken from the selected profiles of Table 1111.* This paper was contributed to the 6th International Symposium on Solar Terrestrial Physics, held in Toulouse, France, June 30-July 5 , 1986, and will be included in part I1 of the Conference proceedings (editor: B. Hultqvist).

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A recursive algorithm was developed to invert spectrally resolved earth limb radiance profiles representing the non‐local thermodynamic equilibrium altitude regime and species/tangent heights that are optically thin. It was used to infer vertical distributions of temperature and excited NO density from data measured by the Spectral Infrared Rocket Experiment in the NO fundamental band near 5.3 µm. The solution for excited NO density was used to compute atmospheric cooling rates for the 5.3‐µm band and the de‐excitation rate constant ko for the reaction NO* + O → NO + O.

A Spectral Infrared Rocket Experiment was launched from Poker Flat, Alaska, on September 28, 1977, to measure infrared emission spectra from the earth limb atmosphere. Spectrometers measured emission spectra from 1.40 to 16.5 µm during 12 vertical scans of the limb region (tangent heights 0 to 250 km) traversing the night, terminator, and day sectors of the limb atmosphere. The spectrometers were cryogenically cooled and telescoped for out‐of‐field rejection of the more intense radiation from lower altitudes. High‐quality spectra were obtained with clearly identifiable features of CO2, O3, NO, OH, H2O, NO2, HNO3, and O2, as well as Rayleigh scattering. Spectra and tangent height emission profiles of selected species are presented and compared with theoretical emission models including those of Degges and Smith (Limb Model) and LOWTRAN 4. The salient findings are as follows: At a height of 80 km, CO2 daytime emission from fluorescence around 4.3 µm was almost 2 orders of magnitude greater than the nighttime emission. At 15 µm the CO2 radiance profiles showed little day‐night differences but exhibited an unexpected radiance plateau between 95 and 110 km. The ozone peak radiance at 9.6 µm (ν3) showed order of magnitude day‐night differences above 70 km tangent height showing a decrease in concentration of O3 during daytime due to photodissociation. The observed radiance in the 9‐ to 12‐µm wavelength region exhibited evidence of chemiluminescent emission from hot bands of O3. NO (Δυ = 1) peak radiance at 5.3 µm, due to O atom excitation, is a broad maximum at 120 km tangent height. The nighttime OH fundamental (Δυ = 1) and overtone (Δυ = 2) emissions showed extensive radiation from higher vibrational levels. The daytime 2.7‐µm fluorescent radiation was composed of emission from both H2O and CO2. Emission from NO2 at 6.15 µm (ν3) was observed at night only but was clearly identifiable amid the H2O (ν2) spectrum. Measured radiation in the 6.3‐µm vibrational band of water vapor at 60 and 70 km agrees with the Air Force Geophysics Laboratory non‐local thermodynamic equilibrium Limb Model using mixing ratios of 5 and 1.5 parts per million by volume, respectively. The radiance from O2 (a¹Δg) at 1.58 µm was observable from tangent heights of 30 to 80 km in the daytime only and shows a critical dependence upon the solar elevation angle. As expected, Rayleigh scattering was the dominant daytime source of radiation between 1 and 3 µm in the limb atmosphere for tangent heights of up to 40 km.

High‐resolution NO (X²Π, Δυ=1) emission data, obtained in an aurora between 100 and 125 km by the rocket‐borne HIRIS cryogenic interferometer spectrometer, have been analyzed by a spectral simulation/least squares technique. The vibrational state population distributions determined by this method exhibit significant population of up to six vibrational states of NO and a multimodal behavior with vibrational quantum number that is not predicted by present models. This result is interpreted in terms of direct auroral formation of NO(υ) by the chemiluminescent reaction of N(²D) with O2, coupled with excitation of NO(υ=1) by collisions between thermal atomic oxygen and aurorally enhanced NO(υ=0). The distribution shapes and their apparent invariance between 100 and 125 km suggest that collisional relaxation of NO(υ), probably by atomic oxygen, prevails over radiative cascade at these altitudes; this result is not in keeping with the present understanding of the kinetics and component densities in this region. The apparent auroral photoefficiency for NO(Δυ = 1) radiation deduced from these measurements is 1.1±0.4% over the range 100–125 km, with a calibration uncertainty of a factor of 2.5; approximately 70–90% of the observed radiation is directly excited via the N(²D) precursor.