Articles | Volume 15, issue 9
Ann. Geophys., 15, 1205–1220, 1997

Special issue: Wind Measurements

Ann. Geophys., 15, 1205–1220, 1997

  30 Sep 1997

30 Sep 1997

Thermal tides and studies to tune the mechanistic tidal model using UARS observations

V. A. Yudin1, B. V. Khattatov2, M. A. Geller1, D. A. Ortland3, C. McLandress4, and G. G. Shepherd5 V. A. Yudin et al.
  • 1Institute for Terrestrial and Planetary Atmospheres, State University of New York at Stony Brook, Stony Brook, NY 11794-5000, USA
  • 2National Center for Atmospheric Research, Boulder, Colorado, P.O. Box 300, USA
  • 3Space Physics Research Laboratory, University of Michigan, Ann Arbor, MI 48109, USA
  • 4Institute for Space and Terrestrial Science, York University, Ontario, M3J 1P3, Canada
  • 5Centre for Research in Earth and Space Science, York University, Ontario, M3J 1P3, Canada

Abstract. Monthly simulations of the thermal diurnal and semidiurnal tides are compared to High-Resolution Doppler Imager (HRDI) and Wind Imaging Interferometer (WINDII) wind and temperature measurements on the Upper-Atmosphere Research Satellite (UARS). There is encouraging agreement between the observations and the linear global mechanistic tidal model results both for the diurnal and semidiurnal components in the equatorial and mid-latitude regions. This gives us the confidence to outline the first steps of an assimilative analysis/interpretation for tides, dissipation, and mean flow using a combination of model results and the global measurements from HRDI and WINDII. The sensitivity of the proposed technique to the initial guess employed to obtain a best fit to the data by tuning model parameters is discussed for the January and March 1993 cases, when the WINDII day and night measurements of the meridional winds between 90 and 110 km are used along with the daytime HRDI measurements. Several examples for the derivation of the tidal variables and decomposition of the measured winds into tidal and mean flow components using this approach are compared with previous tidal estimates and modeling results for the migrating tides. The seasonal cycle of the derived diurnal tidal amplitudes are discussed and compared with radar observation between 80 and 100 km and 40°S and 40°N.

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