GUVI Observations of the Ionosphere and Thermosphere

The TIMED mission is the first of the Solar Terrestrial Probes line and was much delayed, low cost, and highly productive. The Global Ultraviolet Imager, as one of the four components of TIMED, has been an important contributor to the TIMED mission and to our understanding of the interaction of the Earth with geospace. GUVI, which operates in the far ultraviolet (115 to 180 nm), measures the emissions from O, N2 and H and observes the absorption of the N2 Lyman Birge Hopfield bands by O2. From these emissions we are able to infer dayside neutral composition, nightside ionosphere electron density profiles, and auroral energy deposition. In this talk we review the range of contributions that GUVI has made to the TIMED mission objectives, how GUVI supports SEC objectives, how GUVI fits into the new NASA Science directorate and future TIMED and GUVI activities.