A model of odd nitrogen in the aurorally dosed nighttime terrestrial thermosphere

[1] A model of the production and loss of odd nitrogen species (mainly, N(S-4), N(D-2), NO, and NO+) and the enhanced vibration-rotation band emission from NO in the infrared from the aurorally dosed terrestrial nighttime thermosphere is described. This model is assessed by analyzing the observations of the fundamental (Deltav = -1, similar to5.3 mum) and overtone (Deltav = -2, similar to2.7 mum) NO vibration-rotation band limb emissions made by a Michelson interferometer and radiometer, respectively, aboard the Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS-1A) experiment on the space shuttle Discovery during an auroral event. The auroral dosing along the line of sight is inferred from the 2.7-mum radiance profiles using a self-consistent procedure. The dosing obtained is then used in the model to predict the spectrally resolved emission in the 5.3-mum region. The calculated overtone radiance profiles agree with the measured ones at lower tangent altitudes, where the signal-to-noise ratio is large. The calculation, however, underpredicts the observed radiance, both fundamental and overtone, at higher tangent altitudes by a factor of similar to3 and gives a colder rotational temperature for the rotationally hot component of the spectrally resolved emission from nascent NO. The causes of this discrepancy and its impact on the densities of the odd N species are discussed.