HIRAAS Observations of Daytime Temperature of N2 Lyman-Birge-Hopfield Emission

The High Resolution Airglow and Aurora Spectroscopy (HIRAAS) experiment was successfully launched on the USAF Advanced Research and Global Observation Satellite (ARGOS) and has monitored the thermospheric and ionospheric airglow since May 1999 using three ultraviolet spectrographs. The High-resolution Ionospheric and Thermospheric Spectrograph (HITS) is a far- and extreme-ultraviolet (FUV/EUV) Rowland circle spectrograph sensing the 500-1500 Angstrom passband with 0.5-Angstrom spectral resolution. The Low Resolution Airglow and Auroral Spectrograph (LORAAS) instrument measures the EUV and FUV over the 800-1700 Angstrom passband with 18-Angstrom spectral resolution. Thermospheric temperature can be inferred from the rotational temperature of N2 in far-ultraviolet Lyman-Birge-Hopfied (LBH) emission when the band shapes are measured with sufficient spectral resolution. Dayside observations of molecular nitrogen LBH bands have been acquired by both HITS and LORAAS. Techniques have been developed for retrieving termperature from the LBH (1-1) band in the 1440-1560 Angstrom passband. The HITS spectrograph periodically operates in stare mode at 200km and 120km tangent altitudes in this passband. Calibration of both HITS and LORAAS instruments has continued over this last year. Results will be presented of the day side temperature distribution derived from the LBH emission observed by HITS and LORAAS over the time coverage after June 2000 and global coverage of the low and mid latitudes. Theses results will be discussed with respect to excitation mechanisms, geolocation, and geomagnetic activity effects.