Doppler temperatures from O(<sup>1</sup>D) airglow in the daytime thermosphere as observed by the Wind Imaging Interferometer (WINDII) on the UARS satellite

oleh: C. Lathuillère, C. Lathuillère, C. Lathuillère, W. A. Gault, B. Lamballais, Y. J. Rochon, B. H. Solheim

Format: Article
Diterbitkan: Copernicus Publications 2002-02-01

Deskripsi

From 1992 to 1997, the WINDII interferometer on board the UARS satellite acquired a large set of thermospheric data from the O(<sup>1</sup>D) and O(<sup>1</sup>S) airglows. We report here for the first time on daytime O(<sup>1</sup>D) Doppler temperatures obtained with version 5.11 of the WINDII data processing software. Using a statistical analysis of the temperatures independently measured by the two WINDII fields of view, we estimate that the temperature variations larger than 40 K can be considered as geophysical. Comparisons of WINDII temperatures measured during magnetically quiet days with temperatures obtained by the MSIS-90 and DTM-94 thermospheric models show a 100 K bias. We demonstrate, however, that the modeled temperature variations represent very well the mean temperature variation observed by WINDII over 4 years. We also show that the observed latitudinal/local time variation is in very good agreement with the two empirical models. Finally, the temperature variations during a magnetically disturbed day are found to be qualitatively well represented in form by the models, but largely underestimated. The presence of non-thermal atoms and instrument related issues are discussed as possible explanations for the 100 K bias between the WINDII Doppler temperatures and the empirical models.<br><br><b>Key words. </b>Atmospheric composition and structure (air-glow and aurora; pressure, density and temperature; instruments and techniques)