The Utility of NO 5.3 μm Radiation for Remote Sensing of Thermospheric Atomic Oxygen or Temperature

A major mechanism for vibrational excitation of NO in the thermosphere is collisional energy transfer from atomic oxygen, NO(ν ''=0) + O -> NO(ν '=1) + O. Emission from NO(ν '=1) produces the bright 5.3 μm band. At altitudes where this process dominates vibrational excitation during daylight or aurora, a relationship exists between atomic oxygen and ground state NO densities and temperature (due to the strong temperature dependence of the rate coefficient for vibrational excitation). Simultaneous measurements of ground state NO density, NO 5.3 μm volume emission rate, and either temperature or atomic oxygen density, would enable determination of the remaining quantity. This could provide a powerful remote sensing technique for temperature or atomic oxygen for altitudes where their determination is presently difficult. We will present a sensitivity analysis of this technique and discuss its limitations and range of applicability.