Abstract
Thermospheric infrared radiance at 4.3 μm is susceptible to the influence of solar-geomagnetic disturbances. Ionization processes followed by ion-neutral chemical reactions lead to vibrationally excited NO + (i.e., NO +(v)) and subsequent 4.3 μm emission in the ionospheric E-region. Large enhancements of nighttime 4.3 μm emission were observed by the TIMED/SABER instrument during the April 2002 and October–November 2003 solar storms. Global measurements of infrared 4.3 μm emission provide an excellent proxy to observe the nighttime E-region response to auroral dosing and to conduct a detailed study of E-region ion-neutral chemistry and energy transfer mechanisms. Furthermore, we find that photoionization processes followed by ion-neutral reactions during quiescent, daytime conditions increase the NO + concentration enough to introduce biases in the TIMED/SABER operational processing of kinetic temperature and CO 2 data, with the largest effect at summer solstice. In this paper, we discuss solar storm enhancements of 4.3 μm emission observed from SABER and assess the impact of NO +(v) 4.3 μm emission on quiescent, daytime retrievals of Tk/CO 2 from the SABER instrument.
Published Version
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