Wind Profiler Investigations of Low-Frequency Gravity-Inertia Waves Around the Jet Stream
Final technical rept. 1 Aug 88-2 Dec 91,
CLEMSON UNIV SC DEPT OF PHYSICS AND ASTRONOMY
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The structure and dynamics of inertia-gravity waves in the upper troposphere and lower stratosphere have been studies using data from a wind profiler that was temporarily located in Kansas, data from the Arecibo Observatory 430 MHz radar, data from the SOUSY-VHF-Radar located in Germany, and data from the MU radar in Japan. The radar data has shown that low frequency inertia-gravity wave oscillations are a persistent feature of the region near the tropopause and in the lower stratosphere. Some of our analysis indicates that the wave structure is likely generated by the interaction of the surface winds and the orography. However, the frequency in the earth-fixed frame corresponds to a period of 24 hr and is not zero. The latter effect is presumably due to the strong vertical circulation near the tropopause with a reversal in direction at the height of the wind maximum. The observed vertical velocities are larger than expected but otherwise agree with the predictions of earlier theoretical analyses. We have also investigated the relationship between turbulent layers in the upper troposhere and lower stratosphere ad the low- frequency inertia-gravity waves. The turbulent layers are observed to move in the same direction as the phase progression of the background waves, indicating that the turbulent layers occur at a particular wave phase where the wave- perturbed flow becomes unstable.