Open AccessDiurnal migrating tide as seen by the high‐resolution Doppler imager/UARS: 1. Monthly mean global meridional winds
Author(s) -
Khattatov B. V.,
Yubin V. A.,
Geller M. A.,
Hays P. B.,
Vincent R. A.
Publication year - 1997
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/96jd03655
Subject(s) - thermosphere , zonal and meridional , atmospheric tide , mesosphere , geology , atmosphere (unit) , atmospheric sciences , satellite , meridional flow , amplitude , climatology , geodesy , environmental science , stratosphere , meteorology , geophysics , ionosphere , physics , quantum mechanics , astronomy
The high‐resolution Doppler imager (HRDI) instrument on board the upper atmosphere research satellite measures global winds in the mesosphere and lower thermosphere on a day‐to‐day basis. The horizontal coverage of the HRDI data is excellent and provides a unique opportunity to study global‐scale dynamic phenomena; however, the local time resolution and coverage are limited because of the nature of the satellite sampling. The lack of local time coverage makes conventional methods of data analysis (e.g., Fourier analysis) both difficult and erroneous. An original method of analysis, based on a numerical model of atmospheric thermal tides, is proposed and applied to the HRDI data. The tidal model is solved for the tidal oscillations in the meridional wind component. The simulated diurnal meridional tidal winds are used as a first guess in the analysis. The results of the model are adjusted to give meridional migrating tidal winds that have maximum consistency with HRDI measurements. This technique is used to derive monthly mean tidal oscillations of the meridional velocity. The derived tidal amplitudes show profound seasonal changes that seem to be consistent with gravity wave breaking theory. The results are compared with MF radar data. It is found that in the upper mesosphere and lower thermosphere, the tidal amplitudes obtained by HRDI can be bigger than those from MF radars by a factor of 2.