Interpretation of NO and OH Emission from 1976 Airborne Measurements

Abstract : Measured infrared emission enhancements and backgrounds in the 2.83 to 3.04 micron region are analyzed. The measurements used for the analyses were collected from the AFGL NKC-135A flying laboratory during the 1976 DNA/AFGL ICECAP program. Chemiluminescence from hydroxyl fundamental chemistry was found to be the major background emitter in the measurement region, and aurorally excited, nitric oxide first overtone chemistry is believed to account for large observed enhancements. Assuming the enhancements result from NO chemistry, calculations were made to determine the percentage of the total auroral electron energy which is radiated as first overtone nitric oxide photons. The calculated percentage was found to vary from one measurement period to the next. It ranged from .4% to 1.0%, which probably indicates that the excitation is dependent on the auroral penetration depths and characteristics. (Author)