HIGHLY ROTATIONALLY EXCITED NO(NU,J) IN THE THERMOSPHERE FROM CIRRIS 1A LIMB RADIANCE MEASUREMENTS

Earthlimb spectra of thermospheric NO fundamental band emissions, obta ined in the CIRRIS 1A Space Shuttle experiment, have been analyzed usi ng nonlinear least-squares spectral fitting. Absolute NO(upsilongreate r-than-or-equal-to1,J) column densities have been determined in the 10 0 to 260-km tangent height region and inverted to yield altitude-depen dent number densities for both a rotationally thermalized and a highly rotationally excited population component. Emissions from high-J leve ls are predicted to dominate the DELTAupsilon=2 overtone bands during the daytime. The rotationally excited population is found to decrease more at night than the rotationally thermalized component. In addition , radiance from the CO upsilon=1-->0 fundamental band is observed in t he NO R-branch band head region, with greater relative importance at n ight. The derived CO rotational temperatures are significantly greater than modeled local kinetic temperatures. These results provide import ant inputs to models of NO(upsilon,J) formation mechanisms, and of the chemistry, radiative processes, and energy budget of the thermosphere .