Thermospheric and Ionospheric Response to the Solar Flares of April 2002 as Observed by the TIMED Global UltraViolet Imager (GUVI)

We present an analysis of GUVI observations of the thermospheric and ionospheric response to the solar flares and ensuing magnetic storms and solar particle events known collectively as the "April Storm" of 2002. GUVI's scanning spectrometer provides continuous imaging of emissions from atomic oxygen, molecular nitrogen, and atomic hydrogen in the earth's upper atmosphere and geocorona. The absolute and relative intensities of these emissions are diagnostic of flare-driven changes in the composition and thermal structure of the atmosphere, in addition to transient variations in the excitation rates of the transitions that give rise to the observed radiation.