Radar Interferometer Investigations of the Horizontal Winds, Vertical Velocities, Vorticity, and Divergence Around Frontal Zones and in Mesoscale Waves.
Final rept. 15 Sep 91-30 Jun 95,
CLEMSON UNIV SC
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Objectives of the research project included the development and testing of interferometric radar techniques for measuring horizontal winds, unbiased vertical velocities, refractivity layer thicknesses, and small scale flow and reflectivity gradients. The highly flexible MU radar, located near Kyoto, Japan, was to be the primary instrument used for the observational studies. The observational techniques developed in the course of the study were to be used to study the dynamics of gravity and mesoscale waves over Japan. The primary objectives were achieved in a series of experiments using the MU radar with interleaved interferometric and standard multiple beam Doppler measurements. Tests of the techniques that were developed were carried out by intercomparison of the two types of radar measurements, by comparisons between the measurements and numerical modeling calculations of the scattering mediums characteristics, and by comparisons between the radar and rawinsonde measurements. In addition, we found opportunities for two additional technique developments and tests. The first dealt with simultaneous interferometric measurements of precipitation and air motions within the radar beam. The second dealt with frequency domain interferometric measurements of refractivity layer characteristics using a nonaspect sensitive radar operating at 1290 Mhz. Finally, the measured horizontal winds and the vertical velocities corrected for off vertical in beam incidence angles were used to study the dynamics of gravity and mesoscale waves. A major finding of the study was that the wave dynamics are dominated by quasilinear wave breaking instabilities rather than nonlinear diffusive filtering.