A first-principles model of spectrally resolved 5.3 μm nitric oxide emission from aurorally dosed nighttime high-altitude terrestrial thermosphere

Abstract

The spectrally resolved nighttime 5.3 μm emission from NO observed by the Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS-1A) experiment aboard space shuttle Discovery at 195 km tangent altitude during a strong auroral event is modeled using a first-principles kinetics model. An appropriate SHARC (Strategic High Altitude Radiance Code) Atmospheric Generator (SAG) is dosed with an IBC class III aurora. The spectrally resolved fundamental vibration-rotation band emissions from NO around 5.3 μm resulting from impacts of ambient NO with O as well as reactions of N atoms with O2 are calculated under steady state conditions. The calculated results, using a local translational temperature derived from the observed spectrum, are in excellent agreement with the CIRRIS-1A observations, validating our model. The importance of the accurate nascent vibrational and rotational distribution of chemically produced NO as well as the collisonally induced rotation-to-vibration relaxation of rotationally hot NO is pointed out. Copyright 2005 by the American Geophysical Union.