M.D. Burrage, W.R. Skinner, D.A. Gell, P.B. Hays, A. R. Marshall, D.A. Ortland, A.H. Manson, S.J. Franke, D.C. Fritts, P. Hoffman, C. McLandress, R. Niciejewski, F.J. Schmidlin, G.G. Shepherd, W. Singer, T. Tsuda, and R.A. Vincent (1996) Validation of mesosphere and lower thermosphere winds from the High Resolution Doppler Imager on UARS Journal of Geophysical Research, VOL. 101, NO. D6, PAGES 10,365-10,392

Abstract:

Horizontal wind fields in the mesosphere and low thermosphere are obtained with the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) by observing the Doppler shifts of emission lines in the 02 atmospheric band. The validity of the derived winds depends on an accurate knowledge of the positions on the detector of the observed lines in the absence of a wind-induced Doppler shift. Relative changes in these positions are readily identified in the routine measurements of the onboard calibration lines. The determination of the absolute values relies on the comparison of HRDI observations with those obtained by MF radars and rockets. In addition, the degrees of horizontal smoothing of the recovered wind profiles have been optimized by examining the effects of these parameters both on the amplitude of the HRDI-derived diurnal tidal amplitude and on the variance of the wind differences with correlative measurements. This paper describes these validation procedures and presents comparison with correlative data. The main discrepancy appears to be in relative magnitudes measured by HRDI and by the MF radar technique. Specifically, HRDI generally observes larger winds than the MF radars, but the size of the discrepancy varies significantly between different stations. HRDI wind magnitudes are found to be somewhat more consistent with measurements obtained by rockets launched falling sphere technique and are in very good agreement with the wind imaging interferometer (WINDII), also flown on UARS.