This paper describes a study of the frequency spectra, the vertical profiles of energy density, and the momentum flux of the motion field observed during a six-day campaign in March 1986 using the MU Radar in Shigaraki, Japan. Our results reveal significant differences between the mean zonal and meridional frequency spectra as well as different profiles of mean energy density with height for different frequency bands and for zonal and meridional components. The vertically averaged momentum flux exhibited considerable temporal variability and good consistency between adjacent beam pairs. A mean vertically averaged flux toward 267° was inferred, suggesting an essentially zonal drag in regions of wave dissipation. A mean frequency spectrum and height profiles of momentum flux in four frequency bands revealed a westward flux at all frequencies. Ratios of the differenced to the mean variance of radial velocity in each vertical plane suggested an ∼20%–30% excess of westward over eastward propagating wave energy as well as a significant contribution to the flux at low observed frequencies due to motions with high intrinsic frequencies. Inferred momentum flux profiles indicated largely zonal accelerations below the tropospheric jet and decelerations above.
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Fritts et al. (1990) studied this question.